“Sechs Männer nach vorne…”

 

During the Hindenburg’s final landing approach, with the ship tail heavy and in need of additional weight in the bow to help compensate, first officer Captain Albert Sammt sent an order via telephone to the crew’s mess: “Six men forward.”  Six off-watch crew members, three mechanics and three cooks, responded to the order and made their way along the keel to the ship’s bow to join six of their comrades who were already there manning their landing stations and operating the forward mooring tackle. Of these 12 men, only three of them would end up surviving the fire that broke out several minutes later.

A diagram of the forward part of the Hindenburg, showing the locations of the crew members stationed there at the time of the fire. Alfred Grözinger, Josef Leibrecht, Walter Banholzer, Richard Müller, Fritz Flackus and Alfred Stöckle were the off-watch men called forward from the crew’s mess to join Alfred Bernhardt, Ludwig Felber, Erich Spehl, Ernst Huchel, Ludwig Knorr and Kurt Bauer. Their combined weight would help to bring the tail-heavy Hindenburg into trim for its landing maneuver. Only three,  Grözinger, Bauer and Leibrecht, would survive the  crash.
(Diagram courtesy of David Fowler)

Most people familiar with the events of the Hindenburg disaster are aware of this, however when they try to picture exactly where these crew members were bound, even seasoned airship historians tend to draw a bit of a blank. What did the bow mooring area look like? As thoroughly photographed and documented the Hindenburg is, it turns out that this is one of the few parts of the ship of which virtually no photos survive, even in the extensive Zeppelin Archive in Friedrichshafen. Even written documentation on this section of the Hindenburg is scarce.

Several years back, I was fortunate enough to take part in a fascinating round-table email discussion with several very knowledgeable airship scholars (Rick Zitarosa, Dan Grossman, Dennis Kromm and Andreas Horn) and a gifted drafting engineer named David Fowler in which we attempted to reconstruct the Hindenburg’s bow mooring station. David had already drawn up brilliant, finely detailed structural diagrams of the LZ 129 Hindenburg and her sister ship, the LZ 130 Graf Zeppelin. The idea was to assist him in adding the mooring platforms to his work while satisfying our own curiosity as historians.

Via a particularly extensive piece of detective work, involving close examination of Hindenburg wreckage photos, perusal of a few contemporary written descriptions, some educated guesses and just a wee bit of luck, we were able to approximate the internal layout of the Hindenburg’s bow. Here, then, is what we know about what this integral yet virtually forgotten part of the Hindenburg looked like.

Forward of the control car, the Hindenburg’s keel walkway began to slope upward toward the bow. Alongside the keel here were officers’ cabins, freight storage areas and observation windows. As the angle of the keel increased, the wooden catwalk gave way to duralumin stairs, which began at Ring 233. There were also small platforms alongside the keel for the crewmen called forward to help trim the ship. Known as “galloping kilos”, these men would stand in these areas off of the forward keel so that their body weight would help to bring the bow down when the ship was tail heavy and needed to be brought quickly back to equilibrium. Most of the men called forward during the Hindenburg’s final landing took these positions to either side of the keel catwalk. There were similar areas situated alongside the keel in the aft portion of the ship to be used in the event that the ship became heavy by the bow.

The crewmen who were already at their forward landing stations, however, were even further forward than this. After climbing the keel stairway for eight meters or so, one would reach the mooring area proper, where crew members would handle the various ropes and cables used to bring the Hindenburg toward and secure her to her mooring mast. The mooring stations were on divided into two levels, a broad set of platforms running laterally from the keel below, and the main mooring platform above, where the Hindenburg’s axial catwalk ended and attached to the bow cone.

The following diagrams were created by David Fowler based on our group’s research, and are used here with his kind permission. I have taken the liberty of shading key features of the mooring area to make them more immediately visible.

Hindenburg’s bow mooring area (view from starboard.)
(Diagram courtesy of David Fowler)

  Hindenburg’s bow mooring area (view from aft) showing
Intermediate Ring 241 (outer circle) and Main Ring 244.5 (inner circle)
(Diagram courtesy of David Fowler)

 

 
Hindenburg’s bow mooring area (top view.)
(Diagram courtesy of David Fowler)

The lower platforms flanked the stairs at Ring 241, and were where the bow landing ropes were stored in large barrel-shaped coils during flight. These rope coils would be dropped during the landing maneuver through hatches situated just forward of these platforms.

 Aft view of the lower rope platforms showing the approximate storage positions of the landing rope coils.
(Diagram courtesy of David Fowler)

There were four of these hatches at the Hindenburg’s bow, arranged in pairs on each side of the keel. The yaw lines (also known as yaw guys or  guy ropes) were dropped through the inboard hatches, and were braided manila ropes 400 feet long and 2 inches wide that would be attached to winches on the ground and used to keep the ship’s bow oriented toward the mooring mast. The spider lines were dropped through the outboard hatches, and were manila ropes that each ended in a cluster of 20 shorter manila ropes with hand toggles that the ground crew would hold onto as they physically pulled the ship into mooring position.

Ground crew at Friedrichshafen manning a spider line as the Hindenburg is undocked from its hangar.

Both the yaw lines and the spider lines at the bow were attached to the ship via an external anchor point at Ring 244.5. After landing, crewmen would pull the ropes back into the bow via a short haul-up line that connected each rope to its respective hatch. Though the process of re-coiling each landing line does not seem to have been recorded, it is assumed that this was probably done using a hand-cranked winch, in all likelihood the one situated on the main mooring platform.

In this view from the base of Lakehurst’s Wellman mast during a 1936 landing, the starboard attachment point for the yaw lines and spider lines can be seen in the upper right quadrant of the photo. The landing ropes themselves are the black V-shaped arrangement, while the hauling-up lines for each can be seen as a slightly slack, light-colored line curving from the bow hatches to the landing ropes.

Just forward of the landing rope platforms and the hatches began a series of windows that ran almost all the way up the curve of the bow to just below the mooring cone. When the Hindenburg was first brought out of her hangar for her test flights in March of 1936, there were but four windows in her bow: two just forward of the rope hatches at Ring 241, and two at the forward end of the main mooring platform at Ring 244.5. However, when the ship was returned to the hangar at Löwenthal to have some finishing touches put on her during the second week of June, several additional windows were added, including a large four-paned one between the two rope platform windows and two long, vertical double-paned ones situated just below the main mooring platform windows. The new windows provided additional illumination for the bow work stations as well as creating a unique new observation area for the crew. 

The Hindenburg’s initial bow window arrangement, as seen at the beginning
of her 3-day propaganda flight with the LZ 127 Graf Zeppelin (flying
overhead) on March 26, 1936, less than a month after her first trial flight.

The Hindenburg’s final bow window arrangement, in a photo taken at Rhein-Main
Flughafen in Frankfurt,  following the ship’s refitting at Löwenthal, June 5-16, 1936. Note the
addition of the large four-paned window and the two vertical double-paned windows.

At the very top of the keel walkway stairs, situated forward of the landing rope platforms, below and outboard of the main mooring platform, was a seating area featuring two benches and two tables, one on each side. The benches appear to have been of similar construction to the benches in the crew’s mess and the banquettes next to the observation windows in the passenger area. Though no record has yet been discovered showing when the benches and tables were installed in the Hindenburg’s bow, it is likely that they were added along with the new bow windows at Löwenthal during the second week of June in 1936.

Starboard view of the lower rope platforms, showing the approximate location of the observation benches.
(Diagram courtesy of David Fowler)

This quickly became a favorite spot for off-watch crew members to spend their time. Each bench and table faced out one of the pair of long vertical windows, which provided an amazing view directly out the front of the ship. According to cabin boy Werner Franz, the engines were so far aft that one could sit there in almost completely silence, watching the world fly past the window. Unfortunately, no photos of this seating area are known to exist. The benches can be seen, however, in photos of the wreckage of the Hindenburg’s bow area.

The bow observation benches – or rather, what’s left of them – can
be seen here in this photo of the wreckage of the Hindenburg’s bow
section. The structure is distorted from the impact with the ground,
and the entire hull has rolled about 15 degrees to port. However,
the general location of the benches can be seen (arrows).

 
Above this observation area was the main mooring platform. The crew would reach it via a ladder on the port side that was just aft of the portside observation bench. It was from here that the crew would lower the steel mooring cable that would be used to winch the Hindenburg up to the mooring mast. There were also connecting hoses stored here for topping off the Hindenburg’s gas cells with hydrogen when she was in port. The ship’s emergency radio transceiver was also located here, along with a pedal-powered generator so that it could be operated without having to rely on the onboard electrical systems.

This, cropped from a wreckage photo, appears to be the tripod
and seat for the emergency transceiver’s pedal power system.

The Hindenburg’s axial catwalk ended at the main mooring platform, tapering from a triangular walkway approximately seven feet tall to a point that was connected to the bow frame at Ring 244.5. Here it attached to the frame by a jacking screw that allowed the crew to adjust the tension on the axial girder when they needed to remove portions of the catwalk for installation of the ship’s gas cells.

Aft view of the Hindenburg’s main mooring platform, the axial
catwalk and the “crow’s nest” observation platform.
(Diagram courtesy of David Fowler)

There was also a large winch drum built into the aft end of the main mooring platform, oriented with its axis along the center line of the airship. Given the fact that the only connections to the ship’s electrical system in the ship’s bow were the two running lights situated above and below the nose cone, this winch drum was almost certainly operated manually. There was a double-handled hand crank attached to the forward end of the axial girder as it sloped upward toward its forward attachment point, and in all likelihood this was used to operate the winch drum. As mentioned above, this, presumably, was how the landing ropes were hoisted back into the ship after landing and wound into coils to be stored on the lower rope platforms.

In this rare color photo taken during construction of the Hindenburg’s virtually
identical sister ship, the LZ 130 Graf Zeppelin, we get some sense of how the
main mooring platform was arranged. With the view facing aft from approximately
Ring 244.5, the front end of the axial catwalk can be seen along with the attached
hand crank. The aft end of the mooring platform and the winch drum are at lower center,
with the aft upright of the access ladder visible along the lower right edge of the photo.

This same hand crank may also have been used to lower the Hindenburg’s main mooring cable, although there appear to be no records to confirm this. The mooring cable was a steel 20mm wire that ran out through the nose cone and was lowered by hand during the landing maneuver. Once it reached the ground, the mooring cable would be connected up to a motorized winch on the mooring mast that would pull the ship to the mast and draw the mooring pendant directly into the “flower pot” socket atop the mast where it would then be secured.

Two trapezoidal observation windows were cut into the bow right directly forward of the main mooring platform. In flight, these windows were closed with panes of the same clear celluloid that formed the rest of the ship’s windows. During landings, however, these panes could be removed and stowed against the bow girders beside the windows, allowing the crew members stationed there to communicate with the landing crew atop the mooring mast. If need be, a crew member could (and on at least one occasion actually did) step across to the mooring mast from one of these windows to assist in securing the ship.

During the Hindenburg’s second landing at Lakehurst, NJ on May 20, 1936,
with gusty winds complicating the mooring maneuver, a crew member drops
down to the top of the mooring mast to assist the American landing crew in
connecting the ship’s mooring pendant to the mast’s “flower pot” connection.

Forward of the main mooring platform, a ladder led up to a smaller observation platform that served as the Hindenburg’s “crow’s nest”. This observation platform was used by the ship’s navigators to take star sights through a round hatch in the top of the bow. It was said that Captain Ernst Lehmann, during his off hours, would often sit up on this “crow’s nest” platform, one of the highest and most remote vantage points in the Hindenburg’s structure, and play his accordion.

As mentioned before, very little photographic evidence exists to show what the Hindenburg’s bow mooring area looked like. However, within the past few years, a home movie has surfaced, taken by a passenger on a tour of the ship (likely conducted by one of the stewards) during a flight to America in September of 1936. Two shots in this movie footage appear to show the mooring area, albeit for a few fleeting moments and in fairly tight quarters. A collage of screen captures opens these shots up somewhat, allowing us to see what may be the only existing images of the mooring area as it appeared prior to the disaster.

The following image is clearly identifiable as a view looking down from the port side of the main mooring platform. The main platform’s access ladder can be seen at lower right, with a coiled landing rope visible at bottom center:

                                                                           (Film footage courtesy of the US Holocaust Memorial Museum)

The curving pipe that rises from the ladder’s upright appears to be holding the bottom of the gas cell up and away from the mooring area. However, it is unmistakable how closely the hydrogen gas bag surrounded the crew on the mooring platforms.

The other image is something of a puzzle. It appears in the home movie immediately prior to the previous image, which makes it likely that it is another view of the mooring area. The V-shape of the keel walkway frame can also be seen, along with the aluminum steps that led to the ship’s bow. The same netting seen aft of the rope coil in the first image is also visible here.

 
                                                                         (Film footage courtesy of the US Holocaust Memorial Museum)

However, it’s difficult to get a sense of where precisely the person was standing when they took this footage. The two light-colored curved objects at the top of the image appear to be a gas cell. Given the fact that the forward-most cells draped over the axial catwalk, it would seem that we are somewhere below the axial (which would be tucked up above the fold of the gas cell) and looking down on the keel walkway, panning up forward to look toward one of the bow windows (the light square in upper center.)

The question is, where is the passenger standing? It has to be somewhere above the keel walkway, but below the axial catwalk. Since the stairs and the fold of the gas cell seem to indicate a perspective vanishing point toward the upper right corner of the image, and since we can see light through a window or hatch at upper center, it would seem that the footage cannot have been taken from the main mooring shelf looking aft. Otherwise we would not see any of the windows or hatches in the position that we do here. Presumably, this would place the camera somewhere in the area of Ring 233 or the next intermediate ring forward.

The problem being, of course, that there do not seem to have been any elevated platforms or other installations near Ring 233 that the passenger could have stood upon in order to take this shot. And it is difficult to imagine that the crew member who served as the tour guide would have allowed a passenger to simply start climbing girders in order to take movie footage

To add to the mystery, however, there is the spool shaped object at lower left. It appears to be a pulley or capstan of some sort, evidently quite close to the camera. If we are indeed looking forward from a vantage point aft of the mooring platforms near Ring 233, then what could this object be? Any pulleys or capstans for the mooring tackle would be at least several meters forward of this position. Furthermore, the angle of this spool shaped object doesn’t line up with the apparent perspective indicated by the stairs, the gas cell crease or the net just below the cell. Without further visual context as to location, the appearance of this object doesn’t make much sense.

With luck, more documentation or photos will eventually turn up that will give us a more detailed view of how this area of the ship was set up.

Finally, let us take a look at some of the wreckage photos that our group often referred to during our research. First, two photographs of the Hindenburg’s wreckage that show the internal structure of the bow – or, at least, what was left of it after the crash.

First, a view from the port side, taken from approximately the first intermediate frame aft of Ring 233:

In this view, we can see one of the ship’s fuel oil tanks at lower right, laying alongside the remains of the keel catwalk and the axial catwalk. Forward, just below the reinforced bow structure, the black underside of the main mooring platform can be seen with its aft end tilted up approximately 20 degrees by the force of the bow’s impact with the ground. Additional detail may be seen in the cropped close-ups that follow:

This close up of the main mooring platform shows some of the mooring area’s key features, including the portside observation bench and the mooring platform’s access ladder. Note the pulley attached to the aft upright of the ladder. This was likely used in hauling up the landing lines via the winch drum, which can be seen in the cut-out section on the mooring platform’s aft end.

 

The light-colored winch drum can be seen more clearly here, mounted into the mooring platform. It does not have anything wound around it, indicating that the crew probably did not use it for lowering the steel mooring cable, only about 40 feet of which had been paid out through the mooring cone at the time of the fire.

This detailed close-up shows the “crow’s nest” area. The ladder leads from just forward of the mooring platform to the small observation platform, which can be seen just above the “hub” of the wagon wheel shaped girder reinforcement at Ring 244.5. At the very upper right corner of the photo is the circular frame for the hatch through which the navigators would take their star sights. The small dark rectangle just below the hatch frame may be a writing surface that the navigators could use while making sight notations.

Here, across the lower part of the photo, can be seen the aft edge of the portside rope platform. The two-level stair step design shown in David Fowler’s diagrams is evident here. The spider line rope coil would probably have been stowed on the higher, outboard part of the platform. Since it was not dropped during the landing maneuver, it very likely fell aft as the ship’s bow tilted upward during the crash.

 
This heavy manila rope, tangled in the framework just forward of the fuel tank, may be the port spider line.


A second internal wreckage photo, taken from just about the same location on the starboard side, provides some additional context and detail:

 

Here we see the internal bow wreckage from the starboard side. Many of the same installations from the port side are mirrored here, some in greater clarity. However a number of additional features can be seen as well.

In this view of the main mooring platform, we see one of the celluloid window panes for the observation windows, removed from the window frame and stowed amongst the girders at right. Just in from this are two hoses, which were likely used to reinflate the gas cells with additional hydrogen after landing. In the upper center of the photo can be seen the pedal power tripod shown earlier in the article. It appears to be permanently affixed to the main mooring platform, rather than being something that would have been set up only when the emergency transceiver was needed.

This cropped image shows the starboard rope platform in the lower quadrant of the photo. The starboard spider line coil can be seen at lower center, and unlike what we saw in the port side wreck photo, netting can be seen attached across the entire aft edge of the platform. The starboard observation bench is just above the rope coil, and from this angle the table can also be seen. Another pulley can be seen against the back of the bench, but since there isn’t an access ladder on this side of the mooring platform, the pulley is attached to a boom of some sort. Just beyond the lower arm of the boom are the top three steps of the keel stairway.

This reverse angle of the crow’s nest shows the platform a bit more clearly. The one corner of the platform’s flooring, right at the head of the ladder, was apparently popped from its frame by the force of the impact. The small table surface for the navigators is slightly easier to see here, just below the circular hatch frame above.

 

This image, taken the day after the disaster, shows an external view of the bow wreckage. The US Navy officer at lower left provides some sense of scale. Various features of the mooring area, including the winch drum and the starboard observation bench, can be seen here. This is also an excellent view of the steel mooring cable, which descends from the mooring pendant attached to the nose cone. The white box sitting on the ground at lower center is the ship’s emergency radio transceiver, which somebody apparently removed from its spot on the main mooring platform sometime after the fire.

One last Hindenburg wreckage photo, taken during salvage operations in July of 1937, shows the section from Ring 244.5 forward to the nose cone after being cut from the remainder of the wreckage.

The “wagon wheel” design of the bow reinforcement structure is seen clearly in this photo. We can also see the very forward end of the main mooring platform is still attached to the lower side of Ring 244.5, as well as the ladder to the crow’s nest platform just forward and to the left of the central hub of the support structure. Two additional details are visible here that we did not see in the other wreck photos.

 

Here we see a detailed close up of forward connection for the axial catwalk. The girder has narrowed down to a point, and the jacking screw that was used to adjust tension on the axial catwalk can be seen at approximately the 8:00 position. Presumably, the crew would tighten or loosen the jacking screw tensioner using a large wrench. Loosening it would create just enough “play” in the axial catwalk to allow individual sections  to be removed when a gas cell needed to be replaced. Except for a few at the extreme bow and stern that merely draped over the axial, the Hindenburg’s gas cells were donut-shaped and completely surrounded the axial catwalk. Therefore, a newly installed cell had to be carefully pulled over its corresponding axial catwalk section like a sleeve. The only way to do this was to lower each individual axial section down to the keel, thread the new cell around it, and raise the whole thing back into place so that the cell could then be inflated:

(photo courtesy of the Luftschiffbau Zeppelin GmBH Archive)

Another detail visible in this last photo is what may have been the location of the Hindenburg’s emergency radio transceiver:

Here we see a laterally attached box girder on top of which is mounted a small white board. This could have simply been a work surface for the crew in the event that they needed to quickly splice a landing line, but it is also just about the right size for the ship’s emergency transceiver, shown below (lower left corner of photo) after being removed from its position in the bow following the disaster:

Just to the left of this small counter, attached to the vertical upright of the bow reinforcement structure, is a white spool. It looks too shallow to run a rope through, but it could conceivably have held the 20 meters of antenna wire that the Hindenburg’s emergency transceiver used:

 

Dennis, Dan, Rick, Andreas, David and I spent a month or two back in late 2009 poring over this material, trying to make sense of small details in black-and-white photos of burned-out duralumin wreckage from almost 3/4 of a century before. Gradually, a general image of what the mooring area looked like began to take shape. David drew up some preliminary diagrams, which we all continued to discuss (and sometimes debate) at length. We were slowly making progress, but it still felt like we were feeling our way along in the dark.

Then I got an email from Art Paulson, another very learned scholar of Zeppelin history. Art has always had a knack of turning up at just the right time with the perfect photo or obscure bit of information to help solve one Zep-related mystery or another. This time was no different. I had told him about our research and he had sent us the port and starboard internal bow wreckage photos shown here (the latter of which none of us had ever seen.)

And then one day, after our group had seemingly exhausted every available avenue of investigation and arrived at what we felt was a reasonably accurate approximation of what these internal bow structures looked like, Art sent us something that we were all convinced no longer existed.

An original blueprint/engineering drawing of the Hindenburg’s bow installations:

 

Art had chanced upon this drawing while going through the Lockheed Martin Collection at the University of Akron Archives. It was almost certainly from among the materials that Luftschiffbau Zeppelin had provided to Goodyear-Zeppelin during the 1930s (see the previous article on the LZ 128 for additional background on the LZ/GZ collaboration.) Art managed to get a good digital photograph of the drawing, which he then further cleaned up in Photoshop and sent along to us. As far as our little group and our research was concerned, this was the holy grail, a map of Atlantis and the long-lost cocktail recipe for the “Maybach 12” all rolled into one.

Though the drawing was later stamped “valid for LZ 130”, this is an early layout for the LZ 129. The position of the main mooring platform’s access ladder is different, and the rope platforms aren’t quite the same as how they would ultimately appear in the finished airship, but the overall design is very similar indeed to what our group had settled on. There were some differences in elevation and attachment points, which helped us to further refine the new diagrams that David had drawn up. And there were a lot of features that did not appear in this engineering drawing, though some of them were listed on this engineering drawing and referred to as being present on a different drawing in the series (A6708, which I hope will turn up eventually.)

It was a fantastic way to pull all of our research together and refine David’s diagram of the bow mooring station into a “final” version – for now.

The search continues, however, for additional documents and photos that reveal further details about this part of the Hindenburg’s bow mooring area. Though we now seem to have a fairly strong basic idea of the layout, all we really have to base this on is a comparatively small body of documentation, a few post-wreck photos and the art of the educated guess. For such an important part of the ship, it is odd that so little would be recorded about it. With luck, there may be additional information and photos out there that will eventually be discovered and which will help to clear up lingering questions as to the precise design of this vital yet practically unknown area of the Hindenburg’s structure.

 

This article would not have been possible without the cooperative efforts of Dennis Kromm, Rick Zitarosa, Dan Grossman, Andreas Horn and David Fowler. The information contained in this article is the result of a months-long joint email correspondence and endless microscopic examination of  Hindenburg wreckage photos as the six of us chased down every conceivable detail that was there to be uncovered.

Special thanks to David Fowler for creating the detailed structural diagrams of the Hindenburg used throughout this article. Short of  tracking down heretofore undiscovered photos of the mooring area, David’s diagrams are about as close to the real thing as we’re likely to get.

Another key contributor was Art Paulson, who not only provided our group with the two photos taken inside the Hindenburg wreck, but who also managed to find an early engineering drawing of the Hindenburg's bow structure in an archive of Goodyear-Zeppelin documents. This helped to confirm some of our group’s conclusions, to clarify others, and to provide additional information that helped to greatly advance our research.

Before the Beginning…

by Patrick Russell and Dennis Kromm

 

 

The LZ 129 Hindenburg as we know it wasn’t even a gleam in Hugo Eckener’s eye when Major H. R. Harmon, the military attaché at the United States Embassy in London, wrote a report, dated January 31, 1929 and enclosed an article from The Observer newspaper of January 20th describing the new airship that was being designed by Luftschiffbau Zeppelin in Friedrichshafen, Germany. At that point, the LZ 127 Graf Zeppelin was only five months into its illustrious career, but was already pointing the way to a bright future for the passenger Zeppelin.

Not a great deal of information exists about this airship, known only by its works number, LZ 128. Some contemporary press reports mentioned that it would boast a passenger capacity of 120 and showed artist’s conceptions that included a wildly speculative hull design with a topside lounge. None of this, however, is borne out in the information that currently exists about the LZ 128.

In fact, the LZ 128 was to have essentially been  a refined version of her sister ship. Lifted by hydrogen and powered by ten Maybach VL-2 engines in five tandem gondolas for a total of approximately 5600 HP, it was slated to be about the same length as the Graf Zeppelin (236.6 meters, or 776 ft), only fatter. Whereas the volume of the Graf Zeppelin (105,000 cubic meters, or 3.7 million cubic feet) was dictated by the dimensions of the shed in which it was built, the LZ 128 would be assembled in Luftschiffbau Zeppelin’s brand new construction shed, which would measure 250 meters long (820 feet), 50 meters (164 feet) wide and 46 meters (151 feet) high. This would allow for the construction of much larger airships, and the LZ 128 was to have had a volume of 155,000 cubic meters, or 5.5 million cubic feet – a third again the volume of the Graf Zeppelin. It was also projected to carry 10 tons of freight.

(diagram courtesy of the Luftschiffbau Zeppelin GmBH Archive)

 

Crowds gather to watch the landing of the LZ 127 Graf Zeppelin in 1930



Early reports indicated that the LZ 128 would have accommodations for 25 passengers contained in an external combination control/passenger gondola much like that of the Graf Zeppelin. However, it is unclear whether this was ever part of the actual design, or whether the plans changed later in the process. Available information suggests that the LZ 128 was probably intended to have a passenger deck (or decks) contained up inside the ship’s hull, as would later be found on the LZ 129 Hindenburg.

One of the very few visual resources we have to go on is a paper model of the LZ 128 which was produced by the Otto Maier Verlag in Ravensburg, circa 1933. Given the date, it is reasonable to assume that the model was based on the most recent designs for the LZ 128 prior to the halting of its construction.

 

The tandem engine gondolas are in evidence, with both tractor and pusher propellers mounted on each. A row of observation windows can be seen aft of the control car, in a very similar arrangement to that which would later grace the hull of the LZ 129 Hindenburg.  Though it is possible that the model could be a combination of the final version of the LZ 128 design and early elements of the LZ 129, it is probably safe to assume that what we are seeing here is the furthest point of development which the LZ 128 reached before the project was scrapped.

Another key piece of visual evidence is a diagram of what appears to be a preliminary design for the passenger rooms of the LZ 128, taken from a 1929 book on German architect Fritz August Breuhaus, who would later design the passenger accommodations for the Hindenburg.

Similar in layout to Breuhaus’ eventual design for the Hindenburg, the central area contains 12 double-occupancy cabins, with a dining hall on one side and a lounge area on the other. Each side has a promenade deck with a row of large observation windows. The lounge is divided into three areas: a central lounge flanked by a reading and writing room (“Schreib u. Lese Z.”) and a game room (“Spielzimmer”). The dining room has seating for 26 (allowing perhaps for the ship’s commander to join the guests at dinner.) Just inboard of the dining room (“Speiseraum”) is a row of lavatories (W.C.) on one side of the lateral hallway, with a serving pantry (“Anrichte”), steward’s room and shower bath (“Brause Bad”) on the other side of the the hall. There is also a small onboard store (“Laden”) in the center of the lateral hallway.

Just forward of the serving pantry appears to be a staircase down (“Treppe”). Given early reports of external passenger accommodations, this raises the question of whether the idea was to build a control/passenger gondola with two levels, with the passenger area on an upper deck above the rest of the gondola, or whether the Breuhaus design was for an interior passenger area.

To  consider this more closely, let’s look at a diagram of the gondola on the LZ 127 Graf Zeppelin:

 (diagram courtesy of the Luftschiffbau Zeppelin GmBH Archive)
 

As you can see, the Graf Zeppelin had a gondola that was considerably narrower than what we see in the LZ 128 passenger deck diagram – just wide enough for the passenger cabins and a combination dining room/lounge. The Graf also had an access door to the forward areas of the gondola, including the radio room (“Funkraum”), the navigation room (“Navig.- Raum”), the bridge (“Steuerraum”) and the kitchen (“Kuche”).

Not only is the proposed passenger area for the LZ 128 considerably wider than the Graf Zeppelin’s gondola, but it also contains no other apparent access to the rest of the ship, and there is no kitchen shown. The staircase appears to be the only way in or out of the LZ 128’s passenger deck.

This would seem to suggest one of two things. One possibility is, as previously noted, that the LZ 128 may have originally been intended to have a larger gondola with a broad upper deck for the passengers. This, however, would seem to have created some aerodynamic issues unless the outer part of the upper deck were to be considerably more streamlined than what the available diagram indicates.

One piece of evidence which may provide some degree of support for this idea is a photo of a model of the LZ 128 that was designed for wind-tunnel tests.

(photo courtesy of the Luftschiffbau Zeppelin GmBH Archive)

The gondola in this model is extended aft, and has what appears to be a two-level section at the forward end. It does appear to be a variation on the Graf Zeppelin’s control car, though it is difficult to tell from a wind-tunnel model exactly what the intended design was.

 

 

 

 

 

 

 

 

 

 

The elongated gondola of the LZ 127 Graf Zeppelin

The more likely possibility is that the Breuhaus passenger deck diagram was drawn up sometime later in the design process, and that Luftschiffbau Zeppelin was considering the possibility of moving the passenger decks up into the LZ 128’s hull rather than containing it within the gondola. It is entirely possible that this might have been the case, given advances that the British had been making in rigid airship design.

In late 1929, England launched two new rigid airships. The R-100 made her first flight on December 16, 1929, and the R-101 had flown for the first time two months earlier, on October 14, 1929. Both airships used hydrogen as their lifting gas, but each incorporated new design features – including passenger decks built up into their hulls, rather than in an external gondola.

The R-100 at the mast in Montreal in August of 1930. The double row of windows for the passenger decks can be seen as a half-circle arrangement just below the lettering on the side of the hull. Note also the tandem engine cars, similar to those intended for the LZ 128.

 

The R-101 at the mast in Cardington. The observation windows for her passenger deck can be seen as two black stripes on her lower hull, just above the control car.


In April of 1930, Dr. Eckener traveled to Cardington, Bedfordshire to meet with Lord Thomson, the head of the British Air Ministry, and to inspect the two new British airships. Eckener was to have taken a flight on the R-100, however the ship’s starboard was damaged in a handling accident shortly beforehand and the flight was canceled. The other new British airship, the R-101, was currently undergoing major renovations and was hung up in its shed at the time. However, Eckener did get a good look at the new ships while he was in Cardington, and innovations such as the internal passenger decks would not have gone unnoticed, assuming that Eckener and Luftschiffbau Zeppelin were not already privy to the new British airships’ design features.

Regardless of when or how the decision to incorporate an internal passenger area into the LZ 128 was made, it seems that as the LZ 128 project progressed throughout 1930 the ship that was beginning to take shape on the drawing board began to look less like its sister ship, the Graf Zeppelin, and more like the airship that would ultimately replace it on the drawing board, the LZ 129 Hindenburg.

By mid-summer of 1930, Luftshiffbau Zeppelin began preparations for construction, and by the end of September production of rings for the LZ 128’s framework had begun. Meanwhile, Dr. Eckener was paving the way for a new international airship service in anticipation of the LZ 128’s completion. A meeting was scheduled for early October between Eckener and Dr. Jerome Hunsaker of the International Zeppelin Transport Company. Hunsaker had been responsible for the design of the US Navy’s nonrigid airships in WWI, and had then gone on to take a position as the head of the Design Division of the Navy’s Bureau of Aeronautics. Airship historian Prof. Henry Cord Meyer once called Hunsaker “America’s first and oldest airship expert.”

The International Zeppelin Transport Company had been founded on March 25, 1930 with the express purpose of facilitating regular transatlantic airship service. The organizations that had initially signed on included Luftschiffbau Zeppelin, Goodyear-Zeppelin in Akron, OH; National City Bank; the United Aircraft and Transportation Corporation; the Union Carbide Company; and the Aluminum Company of America. The plan was for airships to be built both by Luftschiffbau Zeppelin and Goodyear-Zeppelin, in their respective countries, for use on a passenger airship line to be run between Europe and the northeastern United States. The IZT was looking at the possibility of building the European airship port in Seville, Spain and the American port somewhere south of Baltimore (as Dr. Eckener felt that weather conditions would rule out operating out of a terminal anywhere north of Baltimore.)

As Luftschiffbau Zeppelin was the only IZT company with an actual passenger airship in production – Goodyear-Zeppelin was in the midst of building the ZRS-4 for the US Navy, and its passenger airship concepts were still on the drawing boards – much depended upon the LZ 128 and its ability to prove itself as a regular and reliable form of transit across the North Atlantic. Dr. Eckener and Dr. Hunsaker, therefore would meet so that Hunsaker could update the other IZT principles on the progress made on the LZ 128 thus far.

Then, on October 4, 1930, came the terrible news that Britain’s R-101, on its maiden overseas flight to India, had crashed and burned with heavy loss of life in northern France. The ship had been forced down in bad weather and caught fire shortly after impact. The resulting hydrogen fire completely destroyed the R-101, and 48 of the 54 people aboard were killed, including Air Minister Lord Thomson. Suddenly, the prospect of inaugurating transatlantic passenger airship service with a hydrogen airship seemed far less appealing.

The wreckage of the R-101, near Beauvais, France, October 1930

Work continued, however, on the LZ 128, and the meeting between Dr. Eckener and Dr. Hunsaker took place as planned. It turned out that Hunsaker was far from impressed by the LZ 128 and the planning that had gone into her.

In his report to the International Zeppelin Transport Company, dated October 13, 1930, Dr. Hunsaker wrote in deeply critical terms about the LZ 128 project:

”As regards the performance, size, etc. of the airships for trans-Atlantic work, Luftschiffbau Zeppelin had evidently given the matter little or no consideration (…). (This) hydrogen ship (…) was designed for trans-Atlantic service either to North or South America without regard to traffic or other considerations. It was frankly a tramp airship good “anywhere” which Dr. Eckener thought should be our first Atlantic ship to be run experimentally to train crews, establish operating schedules, etc. He would run it, perhaps, on mail and express only, both to North and South America.”

“It developed that Dr. Eckener’s idea was to have International Zeppelin Transport Corporation build an American terminal at once (in 1930) and then he would operate his hydrogen ship between this terminal and Germany (Friedrichshafen) in 1931 for the information and benefit of IZT and a German company that would later provide a German terminal (not at Friedrichshafen) and further German helium airships. Then the hydrogen airship could be diverted to another service. I explained that such a program might not be consistent with the purpose and programme of IZT, i.e. to report upon and make a decision as to inaugurating a North Atlantic service using helium airships.”

“I was sure our group would never agree to build a terminal for the use of a hydrogen airship. I also pointed out that Goodyear-Zeppelin could not afford to wait a couple of years while his hydrogen airship operated as a tramp on special voyages with the danger of disaster always present.”

As quoted in John Duggan’s “LZ 129 Hindenburg: The Complete Story”,
Zeppelin Study Group, Ickenham, 2002

Clearly, the LZ 128 project was at odds with what had previously been discussed and apparently agreed upon by Dr. Eckener and the IZT stakeholders. The Americans had been using helium exclusively for their airships since the fiery crash of the US Army’s Italian-built semi-rigid ship Roma in 1922, and IZT wasn’t about to kick off its transatlantic passenger service using a hydrogen airship, let alone one that wasn’t specifically designed for the rough weather conditions common to the the North Atlantic.

Dr. Hunsaker also wrote of Eckener probing the possibility of buying American helium. Foreign sales of the gas being banned by law at the time, Hunsaker volunteered IZT aid with this. On November 4, Dr. Eckener publicly announced that LZ 128 would be redesigned to fly on helium, and made the first references to hydrogen “anti-ballast” cells contained within larger cells of helium to provide for economical valving. No mention, however, was made of any formal attempts to secure American helium.

On December 29, just short of three months after Eckener’s meeting with Hunsaker, an internal Luftschiffbau Zeppelin memo, entitled “Projekt LZ 129," mentioned the new works number LZ 129 for the first time and solicited technical opinions for the project. Clearly, it had been determined that LZ 128 could not effectively be reworked for helium and that a fresh start was necessary. The LZ 128 was officially announced at annual board meeting of DELAG (the company that handled flight operations for the Graf Zeppelin) on June 15, 1931, but it was a mere formality. LZ 128 would not be completed and its construction never progressed beyond the first few rings.

Interestingly, “Projekt LZ 129” would incorporate two things from the ill-fated R-101. Like the British ship, LZ 129’s passenger rooms which, like those for LZ 128, would be designed by Fritz Breuhaus, would be contained entirely within the ship’s hull. More chillingly, at the end of 1930 Luftschiffbau Zeppelin purchased 5,000 kg of duralumin from the wreck of the R-101 and reprocessed it into girders for its new Zeppelin.

For those seeking omens, no worse one could be imagined for the airship that would one day take the name Hindenburg.

 

 

 

Special thanks to Art Paulson for generously providing copies of the Breuhaus diagram of the LZ 128’s passenger decks as well as a copy of Wolfgang Meighörner’s  2002 article, “LZ 128 - Eine Sackgasse auf dem Weg vom Versuchsschiff zum Luxusliner der Lüfte,” (LZ 128 – A Dead End on the Road from Experimental Ship to Luxury Liner of the Skies)

Dr. Meighörner’s article was published as part of a more extensive publication that accompanied the Zeppelin Museum Friedrichshafen’s 2002 exhibition, “Luftschiffe Die Nie Gebaut Wurden” (Airships That Were Never Built) and provided invaluable information for this article.

Also of great help was the late John Duggan’s exceptional reference book, “LZ 129 Hindenburg, The Complete Story,” published also in 2002 by the Zeppelin Study Group in Ickenham, Middlesex, England.

“Das verstehe ich nicht…”

 

 

We may as well begin with the big question and get it out of the way right off the bat. Why did the Hindenburg burn?

(Brace yourselves, folks. This could be a bit of a long haul…)

As he stumbled away from the blazing wreck of what had, moments before, been the newest and most technologically advanced airship in the world, Captain Ernst Lehmann, Director of Flight Operations for the Zeppelin Company (the Deutsche Zeppelin-Reederei, or DZR) and the former commander of the Hindenburg, muttered the same puzzled statement to himself, over and over in German: “Das verstehe ich nicht…”

“I don’t understand it.”

Lehmann, with over 25 years experience as an airship captain, couldn’t fathom how the Hindenburg could have possibly burned while hovering nearly motionless in the air. Yes, it had been filled with inflammable hydrogen gas, but the Germans had been flying passenger airships lifted by hydrogen since before WWI, and had never had a single passenger injury, let alone a sudden fire like this during a routine landing. Hydrogen, after all, was only flammable once mixed with a sufficient amount of oxygen, and the German airship operators had perfected the art of maintaining hydrogen purity to the point where they simply did not consider a hydrogen fire to be a realistic danger.

In fact, the previous year Lehmann had had a conversation with the Deutsche Zeppelin-Reederei’s U.S. representative, Willy von Meister, in which they had discussed the possibility of a deal under which the DZR might allow U.S. Navy officers to train aboard the Hindenburg during each of her North American flights in exchange for helium being made available for German airships (which, under U.S. Congressional legislation, was not currently possible.) Lehmann’s response was indicative of the Germans’ staunch belief in their ability to safely manage their hydrogen: "That is really no inducement; we have been operating our commercial service with hydrogen very successfully for years."

"My dear Lehmann,” von Meister responded, “I sincerely hope you will not have cause to regret your opinion."

And, less than a year later, here they were with the Hindenburg lying in ruins on the Lakehurst Naval Air Station’s landing field and a large number of its passengers and crew either dead or badly injured. Ernst Lehmann himself would die of his burns the day following the disaster.

So, what did happen?

Numerous theories were advanced both in the press and amongst the airshipmen themselves even before the Hindenburg’s wreckage had cooled: perhaps lightning had struck the ship; a broken propeller may have been flung into the hull; sparks from a backfiring engine could have started the fire; there could have been a short circuit in the ship’s electrical system, electrostatic discharge from St. Elmo’s fire could have been the culprit…and, of course, there were those who suspected a far more dramatic cause – sabotage.

A Question of Sabotage

The possibility of deliberate destruction of the Hindenburg by a saboteur was something that had been considered by practically everyone connected with the Zeppelin enterprise since before the ship had even made her maiden flight. The international political climate had steadily deteriorated ever since Germany’s Nazi government had begun to remilitarize their nation, and it had been a matter of increasing concern among German and American officials alike that the Hindenburg and her sister ship, the Graf Zeppelin, their tails painted with huge swastikas, might become targets for a sabotage attempt by somebody seeking to strike a blow at the Nazis. The DZR had received numerous bomb threats via mail throughout the previous year, warning that the Hindenburg would be destroyed. In fact, when Captain Lehmann boarded the airship for her last flight, he carried one of these letters in the pocket of his leather aviator coat. When the Hindenburg burned over the Lakehurst airfield three days later, many people’s thoughts turned instinctively to the question of sabotage.

Even Dr. Hugo Eckener, head of the Luftshiffbau Zeppelin and one of the most well-respected airship commanders in the world, made a brief initial public statement a few hours after the disaster that he considered sabotage to be a highly likely cause. This, however, was based on the initial telephone call that Eckener had received informing him of the disaster in which it was stated that the Hindenburg had “exploded” in mid-air during its landing approach. Eckener knew that there was no way for the Hindenburg to have literally exploded unless foul play were involved.

However, as more details were relayed to him throughout the day, it quickly became obvious to Eckener that the Hindenburg had burned and not exploded. He revised his statements to the press to reflect this, attempting to steer reporters away from the sabotage theory. Nevertheless, the newspapers, anxious to continue to inject as much drama as possible into the story, continued to focus on sabotage even as the official investigation pursued other possibilities.

Commander Charles E. Rosendahl, base commander at Lakehurst, was also of the strong opinion that the Hindenburg had been sabotaged. Though he was later forced to admit the questionable nature of the sabotage theory since officials hadn’t found a single shred of evidence in the wreckage to indicate the presence of an incendiary device, Rosendahl was nevertheless a staunch advocate of the notion that the Hindenburg had been brought down deliberately. The day after the fire, he had sat beside the hospital bed of his old friend Ernst Lehmann and together the veteran airshipmen went through every imaginable possibility as to what may have caused the disaster, eliminating them one by one. At last, Lehmann wearily told Rosendahl, “It must have been an infernal machine.”

Commander Rosendahl seems to have taken Lehmann’s statement to heart, and though he kept his official statements measured, both to the press and to the official investigation board, privately he became more and more convinced that the Hindenburg had been sabotaged. He even had a suspect in mind, a passenger whom several surviving crew members insisted had made multiple unaccompanied trips into the ship’s interior to feed his dog, which happened to be kenneled in a freight room near the tail of the ship. “The man with the dog”, Joseph Spah, was subsequently investigated by the FBI, who turned up absolutely no evidence to support these suspicions. Spah, an international vaudeville performer, was found by the Bureau to be a good family man with no suspicious ties, and the FBI concluded that he had nothing to do with the Hindenburg fire. In fact, no evidence, suspect or motive for sabotage was ever uncovered by any of the official investigators.

But the sabotage theory refused to die. 25 years later, an American author named A. A. Hoehling published a book entitled, “Who Destroyed The Hindenburg?” in which he indicated that a member of the Hindenburg’s crew, a rigger named Erich Spehl, may have planted a time bomb in one of the ship’s aft gas cells at the behest of his girlfriend, whom Hoehling claimed to have been a member of the anti-Nazi resistance in Germany. It was a slick story, and one which was perhaps convincing enough to those who had only a passing knowledge of Zeppelin history. Hoehling cherry-picked evidence that appeared to support his theory and, perhaps concerned about possible libel accusations (though Erich Spehl himself was unable to speak out, as he had died in the disaster) he stopped just short of stating conclusively that Spehl had indeed destroyed the ship.

In fact, there was absolutely no evidence to suggest that Erich Spehl had anything to do with the destruction of the Hindenburg. Even the circumstantial evidence with which Hoehling attempted to support his theory was paper thin, and in many cases involved interpretations of statements made by interview subjects who later strongly disputed those interpretations. Furthermore, subsequent research conducted by a relative of Erich Spehl indicated that much of Hoehling’s sabotage theory came not from Hoehling’s own research, but from the imagination of the son of one of the Hindenburg’s officers.

Nonetheless, the name Erich Spehl had now been tied to the sabotage theory. Ten years later, author Michael M. Mooney, fulfilling the terms of a deal he had made with Universal Pictures to write a book upon which they would base a major motion picture, expanded on Hoehling’s characterization of Erich Spehl in his book, “The Hindenburg”. Whereas Hoehling’s book had primarily consisted of factual reportage with the sabotage theory more or less tacked on during the concluding chapters, Mooney’s book took a great many artistic liberties, to the point where Erich Spehl and numerous others were practically rewritten as fictional characters. Both Hoehling and Mooney’s books have been roundly dismissed by airship historians as opportunistic nonsense (to put it charitably), although the Spehl theory does continue to be referenced from time to time in articles and documentaries on the subject. To this day, however, no reputable evidence has come to light to indicate that the Hindenburg was sabotaged by Erich Spehl, Joseph Spah or anyone else.

 

Painted With Rocket Fuel?

In 1996, retired NASA scientist Dr. Addison Bain put forth a new theory, in which he stated that the doping compound applied to the Hindenburg’s outer cover was highly flammable and, in fact, the initial source of ignition for the Hindenburg fire as well as being the cause of the rapid spread of the fire. According to Bain's theory, known also as the Incendiary Paint Theory, electrostatic discharge across the ship's upper starboard hull, triggered by the release of negatively-charged carbon particles in the exhaust of a backfiring engine, ignited the ship's fabric outer covering. The outer cover then, rather than the hydrogen contained within the ship was, under this thaory, allegedly the driving force behind the sudden and rapid burning of the Hindenburg.

The Hindenburg’s outer cover was treated with a cellulose-acetate butyrate varnish, applied in multiple coats, in order to keep the cover taut and to strengthen it against the elements. There was aluminum powder mixed into this compound in order to reflect the sun’s heat, the effects of which would cause the ship’s hydrogen to expand and eventually be released through the ship’s automatic over-pressure valves. Thus, the Hindenburg’s silver coloration was primarily intended to control expenditure of hydrogen lifting gas.

That coloration was also, according to Bain, the reason for the Hindenburg fire. He proposed that the addition of the aluminum powder to the cellulose-acetate butyrate doping compound, particularly when combined with iron oxide (with which the underside of the outer cover was coated above the ship’s equator to prevent damage to the gas cells from direct exposure to UV radiation) created a mixture that was highly flammable and similar to the fuel used in the Space Shuttle’s solid rocket boosters.

Similar, but not identical. Herein lies one of the problems with this particular theory.

Solid rocket fuel does contain both aluminum powder and iron oxide (16% and 0.2% of the total mixture, respectively) but just a fraction under 70% of the mixture is ammonium perchlorate, the oxidizer which allows the fuel to burn.

The Hindenburg's doping compound, on the other hand, did contain aluminum powder and iron oxide, but in separate coats and suspended in cellulose-acetate butyrate - which was itself used because of its low flammability. There was no ammonium perchlorate or comparable compound on the Hindenburg's outer cover varnish. While the doping compound had some of the ingredients used in solid rocket fuel, it was not the same thing. The Hindenburg was not, therefore "painted with rocket fuel" as Dr. Bain has claimed.

Subsequent burn tests performed by researchers on fabric samples coated with the identical doping compound showed that it burns far too slowly to have destroyed the Hindenburg in the 34 seconds that it took for the entire ship to be consumed. And, in fact, it the doped fabric will self-extinguish if the heat source is removed. For a full analysis of this, I highly recommend reading the report by Dr. Alex Dessler, Donald Overs and William Appleby in which they describe their tests and the results:

http://spot.colorado.edu/~dziadeck/zf/LZ129fire2005jan12.pdf.

Dr. Dessler also published a preliminary paper prior to his collaboration with Overs and Appleby, in which he outlined the areas in which he felt that the Incendiary Paint Theory was fatally flawed. It is also recommended reading:

http://spot.colorado.edu/~dziadeck/zf/LZ129fire.pdf

In addition to the problems with the science behind the Incendiary Paint Theory, there is also the fact that it tends to contradict some very basic facts as described by eyewitnesses and apparent in the film footage of the blaze. First and foremost, the Hindenburg can be seen very clearly burning from the inside out, as opposed to burning from the outer cover into the gas cells as Bain's Incendiary Paint Theory holds. This is supported by the testimony of numerous eyewitnesses, including surviving crew members who witnessed the spread of the fire from their landing stations within the airship.

I find the statements of two of the crew members in particular to be of vital importance in illustrating this. Helmut Lau was a 25 year-old helmsman whose landing station was in the Hindenburg's lower tail fin. He was assisting Hans Freund, one of the ship's riggers, as Freund was hoisting a coil of mooring cable into position on the keel above the fin. Lau, as he later testified, "was looking up and was facing the port side of the fin," when he heard what he later described as a "frwump" sound, similar to the burner on a gas stove being lit.

His official testimony proceeds as follows:

"I heard over me a muffled detonation and looked up and saw from the starboard side down inside the gas cell a bright reflection on the front bulkhead of cell No. 4. The gas cell was approximately at the line that I have indicated on Exhibit 10. I therefore could see from there to the point that I am indicating. I could see from my position at this point to approximately the position indicated. Here and here I saw no fire at first. I saw it on the front side of cell 4. The bright reflection in the cell was inside. I saw it through the cell. It was at first red and yellow and there was smoke in it. The cell did not burst on the lower side. The cell suddenly disappeared by the heat."

"The fire proceeded further down and then it got air. The flame became very bright and the fire rose up to the side, more to the starboard side, as I remember seeing it, and I saw that with the flame aluminum parts and fabric parts were thrown up. In that same moment the forward cell and the back cell of cell 4 also caught fire, cell 3 and cell 5. At that time parts of girders, molten aluminum and fabric parts started to tumble down from the top. The whole thing only lasted a fraction of a second."

"I turned around and pulled in my head - I had no hat on - and jumped back underneath the girder to which the telephone is attached. Whilst I was jumping back, I noticed that the ship was dropping rapidly. The ship at the moment that the explosion went up had an acceleration down."

In other words, Lau heard something very much like gas being ignited, which drew his attention up and forward to a fiery glow which he very clearly placed as having been on the front of gas cell #4, just ahead of the tail fins at Ring 62 (the main structural ring located 62 meters forward of the aft-most point of the hull.) The witness diagram (shown below) which Lau filled out during his testimony further places the fire at approximately at the level of the axial catwalk that tunneled through the center of the gas cells. This fire, as Lau later clarified in his testimony, appeared to be burning its way downward along the front side of cell 4, and almost immediately consumed cell 4. The fire then burned upward and out through the top of the ship as the surrounding gas cells ignited, at which point the entire structure shook violently.

Thus, we have a witness who saw the fire burning inside the ship prior to the second detonation that was captured by still photo and newsreel photographers. Furthermore, the fire spread AFTER cell 4 had been breached, flooding that part of the ship's interior with hydrogen.

The diagram filled out by Helmut Lau during his testimony, showing his position, his line of sight, and the area where he first saw the fire. The stern view shows the path he saw the fire take once it rose back up and burst through the top of the hull.
 

A second witness whose testimony is notable for its detail about the spread of the fire is Kurt Bauer, one of the ship's elevatormen. Bauer was standing along the ship's keel, between the control car and the tip of the bow. He was one of only three men of the twelve crew stationed in the bow section who survived the disaster. He was looking through a hatchway, one of the pair of triangular air vents that flanked the keel walkway beneath gas cell 15, and was watching the ground crew taking up the landing ropes. Bauer later described to the Board of Inquiry what happened. From his official testimony:

"I noticed a cracking shock which originated from the rear. Before I could mention what could have happened, I saw a yellow flame over me in the axial walkway. Then the ship took on an inclination so steeply that I had to take hold of myself. Everything all around me burned, especially over me. The flames were quite close to me, on top of me."

This is important, because it indicates that the fire shot forward along the axial catwalk immediately after fire burst out of the aft hull of the ship, before the ship had even begun to lose buoyancy in its tail section.

 
Kurt Bauer’s position at the time of the fire, with the approximate progress of the fire along the axial catwalk when Bauer first observed it, while the Hindenburg was still on an even keel. (Diagram courtesy of David Fowler)

Later in Bauer's testimony, investigator South Trimble asked Bauer to clarify the sequence of events.

Trimble: "Did you see fire in the axial corridor before any inclination took place?

Bauer: "Yes, sir. It must have been a fraction of a second later, after the explosion."

Trimble: "Which came first, the vibration, the shock or the fire?"

Bauer: "The shock came first, and about half a second later I saw the fire."

Trimble: "Then when did the inclination of the ship take place?"

Bauer: "Shortly after that."

Clearly then, the Hindenburg fire spread internally much faster than it spread along the outer cover.

 

First Thought, Best Thought

For over 75 years, the cause of the Hindenburg fire has been considered a mystery, particularly by those with an interest in putting forth a bold new attention-grabbing theory. The sabotage theory has been used repeatedly over the years in order to sell books and movie tickets. The Incendiary Paint Theory was the result of Addison Bain's desire to improve public opinion of hydrogen as an alternative fuel source by exonerating hydrogen as the cause of the Hindenburg disaster as a way of dealing with the so-called "Hindenburg problem" – the tendency for the Hindenburg disaster to be brought up as an argument against developing hydrogen as an environmentally friendly fuel. While I do not agree with Dr. Bain's conclusions about the cause of the Hindenburg fire, I certainly share his firm support for the development of renewable fuel sources.

As for the authors who attempted to cash in on baseless sabotage theories involving a man who was not alive to defend himself against potentially libelous charges, I have little use for their motives or their means of fulfilling those motives. I think it should go without saying that when one purports to present a non-fictional account of an historical event, indulging in a tendency to favor drama over accuracy undermines the value of the entire project. In my examination of much of the same primary source material used by A. A. Hoehling during the writing of his book, I notice that he did get a great deal of his facts correct, up to the point at which he began delving into his sabotage theory. Had he avoided the subject of sabotage altogether and focused purely on factual reportage and more in-depth interviews with survivors and eyewitnesses, I cannot help but think that he may well have ended up publishing a solid, well-regarded reference book on the Hindenburg disaster. As it is, airship historians have rightly dismissed  “Who Destroyed The Hindenburg?” as frivolous nonsense since it was published in 1962.

So, it wasn’t sabotage, and it wasn’t the outer cover. Where does that leave us? In my opinion, having studied the matter for over 35 years, it leaves us right where investigators settled  back in the summer of 1937. It is my belief that those who ran the Hindenburg investigation, particularly Dr. Eckener, got it right from almost the very beginning.

U.S. Commerce Department’s Board of Inquiry into the Hindenburg disaster. First day of proceedings - May 10th, 1937.

The US Commerce Department's Board of Inquiry into the Hindenburg disaster lasted less than three weeks, from May 10, 1937 (the Monday following the crash) through May 29th. Given the deteriorating political environment where Germany was concerned, coupled with the fact that a German airship had been destroyed on a United States military reservation, investigators from both the American and German commissions seem to have felt the need to balance the need for a thorough investigation with the need to quickly reach a mutually acceptable conclusion as to the cause of the disaster.

Numerous ideas were floated at the time as to possible sources for the Hindenburg fire. Lightning was a prime candidate, due to the stormy weather conditions that had existed over Lakehurst shortly before the ship was cleared to land. However, nobody on the ship or on the ground witnessed any lightning at any point throughout the landing maneuver, and meteorological data from Lakehurst’s aerology station did not show there to have been suitable conditions for a lightning strike at the time of the disaster.

Another theory was that there may have been some sort of engine malfunction, either a broken propeller that had been hurled into the ship’s hull or perhaps an engine backfire that had produced sparks that penetrated the hull and ignited the hydrogen. Investigation of the remains of the engine gondolas indicated that although there was some splintering of some of the propeller blades, this was due to the props having still been rotating when they hit the ground.

The engine exhaust theory was rejected by the Board of Inquiry due to two factors. First, engine exhaust sparks from the Hindenburg’s diesel engines were relatively cool (200-250 degrees centigrade, or 392-482 degrees Fahrenheit) while the ignition temperature of hydrogen was much higher (600-700 degrees centigrade, or 1112-1292 degrees Fahrenheit.) Secondly, the first indication of fire was much too far up the ship’s hull for engine sparks all the way at the bottom of the hull to have been able to start the fire.

The possibility of a short circuit somewhere in the Hindenburg’s electrical systems was also taken into consideration. However, Chief Electrician Philipp Lenz had been in the electrical center at the time of the fire standing next to the electrical system’s switch board. He testified that no fuses blew and no circuit breakers tripped at any time prior to the fire. In addition, the only electrical circuits that ran at the level of the axial catwalk were the running lights at the extreme bow and stern of the ship, and neither of these were anywhere near the area where the fire had apparently begun. This theory, therefore, was also rejected as a possibility.

With most of the prevailing theories falling by the wayside as the investigation progressed, what was left?

Dr. Hugo Eckener, who headed up the German commission, was considered to be one of the foremost experts in the world in the operation of Zeppelin airships. He had been an airship pilot since 1911, had trained German Zeppelin crews during the First World War, and had commanded every post-war airship that the Luftschiffbau Zeppelin had produced, including the Graf Zeppelin on its flights around the globe and to the Arctic. His reputation as an airship commander was impeccable, and his understanding of the design and operation of Zeppelins made him perhaps the single investigation official whom people assumed would be most likely to come up with "the" definitive answer as to what had caused the Hindenburg fire.

Eckener spent two hours addressing the Board on May 22nd, 1937. Several key witnesses, including First Officer Albert Sammt, had not yet been heard. However, Eckener had formed some very definite impressions from the witnesses heard thus far, and presented them in his official testimony, along with his summation of what he believed to be the most likely theory.

Dr. Eckener, at right, during his testimony before the Board of Inquiry. Willy von Meister, at left, translated his statement into English.

He noted that the Hindenburg was significantly tail-heavy and "badly out of trim" as it approached the mooring mast. He estimated that the command crew had generated between 70,000 and 80,000 kilogram-meters (approximately 505,000 to 580,000 foot-pounds) of trimming effect, between ballast dropped from the aft portion of the ship, hydrogen valved from the forward section, and the six crewmen sent forward to the bow to compensate for the tail-heaviness.

In addition, he described the meteorological conditions at the time of the fire, with a thunderstorm front having just moved out of the area and a likely secondary, smaller storm front arriving  behind the first one. This, he noted, would have created a significant difference in electrical potential between the ship and the ground. This would have slowly equalized once the landing ropes were dropped and became damp and conductive in the light rain that was falling. At this point, he says, the electrical potential gradient would have increased between the ship and the air mass above it, thus providing the conditions for electrostatic discharge atop the ship's hull.

All that was needed at this point was something for the static discharge to ignite. Eckener explained his theory this way:

”The ship proceeded in a sharp turn to approach for its landing. That generates extremely high tension in the after part of the ship, and especially in the center sections close to the stabilizing fins which are braced by shear wires. I can imagine that one of these shear wires parted  and caused a rent in a gas cell. If we will assume this further, then what happened subsequently can be fitted in to what observers have testified to here: Gas escaped from the torn cell upwards and filled up the space between the outer cover and the cells in the rear part of the ship, and then this quantity of gas which we have assumed in the hypothesis was ignited by a static spark.”

”Under these conditions, naturally, the gas accumulated between the gas cells and the outer cover must have been a very rich gas. That means it was not an explosive mixture of hydrogen, but more of a pure hydrogen. The loss of gas must have been appreciable.”

“I would like to insert here, because the necessary trimming moments to keep the ship on an even keel were appreciable, and everything apparently happened in the last five or six minutes, that is, during the sharp turn preceding the landing maneuver, that therefore there must have been a rich gas mixture up there, or possibly pure gas, and such gas does not burn in the form of an explosion. It burns off slowly, particularly because it was in an enclosed space between outer cover and gas cells, and only in the moment when gas cells are burned by the burning off of this gas, then the gas escapes in greater volume, and then the explosions can occur, which have been reported to us at a later stage of the accident by so many witnesses.”

”The rest it is not necessary for me to explain, and in conclusion, I would like to state this appears to me to be a possible explanation, based on weighing all of the testimony that I have heard so far.”

Personally, I believe that this is probably very close to what actually occurred. I do differ with Dr. Eckener on one or two points of detail, however overall I think that he got it more or less right – and this was less than two weeks following the disaster. In my opinion, this was a confluence of very specific factors and events, the absence of any one of which might have prevented the disaster:

1.) The Hindenburg experienced a significant loss of hydrogen from one of its aft gas cells (most likely Cell 4) during its landing approach. The two most likely causes for this would be a.) a broken bracing wire on the front of the cell causing a tear in the gas cell, or b.) a gas valve that failed to close firmly after hydrogen was valved to reduce the ship’s altitude.

2.) The free hydrogen combined with the surrounding air and produced a flammable oxyhydrogen mixture. This mixture began to fill either the space between the gas cells, or the vertical gas ventilation shaft.

  An illustration of oxyhydrogen from a stuck gas valve rising up the ventilation shaft and out the vent hood atop the Hindenburg’s hull. (Diagram courtesy of David Fowler)


3.) The stormy weather through which the Hindenburg had flown had created a significant electrostatic charge throughout the ship’s structure.

4.) The Hindenburg was brought up to the mooring mast for a “high landing” at a height of between 150 and 200 feet in preparation for dropping its landing ropes. This created a significant difference in electrostatic potential between the ship and the ground – far moreso than would have been the case during the “low landing” that the Germans traditionally made in which the landing lines were dropped when the ship was less than 50 feet above the ground.

5.) The ship’s manila landing ropes were dropped. Though the ropes were dry and not particularly conductive at first, as they became wet in the light rain they gradually began to ground the airship.

6.) The Hindenburg’s metal framework became grounded faster than its outer cover, which was less conductive and also isolated from the longitudinal girders by wooden dowels as an anti-chafing measure. This created electrostatic discharge between the outer cover and the framework.

7.) The fact that the outer cover was wet with rainwater further increased the likelihood of electrostatic discharge, particularly atop the Hindenburg’s hull. 

Electrostatic discharge begins along the top of the Hindenburg’s hull as oxyhydrogen continues to rise upward from the gas leak. (Diagram courtesy of David Fowler)

8.) Eventually this electrostatic discharge occurred in the vicinity of the oxyhydrogen mixture that was still present in the tail section, igniting the oxyhydrogen. The fire then burned back to the source of the leak (again, either moving down between the gas cells on the forward side of Cell 4 to a rip in the gas cell material, or else down the vertical ventilation shaft between Cells 4 and 5 to a leaking gas valve.)

Escaping oxyhydrogen is ignited by electrostatic discharge atop the ship, and the fire burns straight down to the spot from which the hydrogen is leaking. (Diagram courtesy of David Fowler)


9.) Once the fire had burned back to the source of the leak, it ignited the gas cell material.

At this point, nothing could stop the fire. The gas cell material itself burned fairly quickly, and Cell 4 basically melted – “disappeared by the heat”, as Helmut Lau phrased it. With tens of thousands of cubic feet of hydrogen suddenly released into the open hull and the surrounding gas cells now burning, the fire blazed upward and outward, bursting through the top and sides of the hull and igniting the other gas cells in the aft half of the ship, which were also quickly breached, adding even more oxyhydrogen to the conflagration.

In other words, what actually happened to the Hindenburg was probably not all that different from the answer at which Dr. Eckener and the other Board of Inquiry investigators originally arrived in 1937.

 

“Recommend Landing Now…”

Lets take a look at the Hindenburg’s final landing approach and  I’ll walk through the sequence of events as I see it.

Annotated map of the Hindenburg’s landing approach, with information compiled by the Board of Inquiry from eyewitness testimony, particularly that of Captains Heinrich Bauer and Walter Ziegler.

7:00 PM - The Hindenburg is making her approach to the landing field at Lakehurst, more than 12 hours behind schedule due to persistent headwinds over the North Atlantic. Captain Max Pruss is in command of the ship, with Ernst Lehmann, the DZR’s Director of Flight Operations and Pruss' former commander aboard the flight as an observer. This is the first North American flight of the 1937 season, and there is a full load of 72 passengers waiting at their hotel in New York City for the return flight. Many of them are on their way to England for the coronation of King George VI on May 12th, and will be cutting it rather closely as it is. It can be safely assumed that Captain Pruss is under at least some pressure to make the landing as soon as possible.

7:05 PM – Captain Pruss observes the wind conditions and the position of the ground crew and prepares for landing by ordering the helmsman to make a wide turn to the west, far beyond the air station's boundary, intending to bring the ship in to moor in an easterly direction.

7:10 PM - Navigator Eduard Boetius sounds the signal for the Hindenburg's crew to take their landing stations.

7:11 PM -  First Officer Captain Albert Sammt, issuing orders involving trim and altitude while Captain Pruss issues orders related to direction and engine speed, orders Captain Walter Ziegler to open the master control wheel on the gas valving board for 15 seconds. Known by airshipmen as “valving on the wheel,” this vents hydrogen from cells 3 through 11, plus cells 13 and 14 in order to bring the ship's altitude down for its final landing approach.

The Hindenburg’s gas board is shown at left. The large wheel at upper left would release hydrogen from 12 of the ship’s 16 gas cells simultaneously. The line of small individual toggles to the right of the wheel controlled each gas cell individually. The gauges below the valving controls monitored the fullness of each gas cell. Photo is from a flight in 1936.

7:10-7:11 PM - Captain Sammt orders Eduard Boetius to relieve elevatorman trainee Ludwig Felber at the elevator wheel due to Boetius being more experienced. Felber is sent to the mooring shelf at the bow in order to assist with the lowering of the forward landing lines. Navigator Christian Nielsen sounds the landing stations signal for the second and final time.

Eduard Boetius at the Hindenburg’s elevator wheel, facing the port side of the control car. This photo was taken sometime during autumn of 1936.

7:13 PM - Captain Pruss orders all four engines reduced to "idle ahead" in order to reduce the ship's forward speed. Meanwhile, the command crew has noticed that the ship is out of trim and heavy astern. Captain Sammt orders Captain Ziegler to pull the manual release valves for gas cells 11 through 16 for 15 seconds in an attempt to bring the ship into trim.

** At this point in the landing approach, it is reasonable to assume that whatever damage to cell 4 has occurred, whether a tear in the front of the cell or a valve cover that didn’t completely close after the valving 2-3 minutes before, is allowing enough hydrogen to escape that it is beginning to effect the Hindenburg’s ability to remain in trim. Meanwhile, an oxyhydrogen mixture is beginning to form in the Hindenburg’s stern, either as a vertical plume rising up the ventilation shaft between cells 4 and 5 if the leak is from a gas valve, or throughout the narrow gap between gas cells 4 and 5, eventually moving laterally along the space between the gas cells and the ship’s outer cover.

7:14 PM - The Hindenburg crosses the Lakehurst Naval Air Station's western boundary. Captain Pruss notices that the wind has shifted and the ground crew is now lined up directly north of the mooring mast. The ship will now need to make its approach due south rather than in the easterly direction Pruss had anticipated. Perhaps because of concerns over the already-delayed landing, Pruss (possibly with Lehmann's counsel, we don't know for sure) opts against the standard operating procedure of making another full-speed pass around the airfield in order to line up with the new wind direction and to allow the slipstream to fully vent the hydrogen that Ziegler has just valved from the forward cells. Instead, Pruss decides to bring the Hindenburg up to the mooring mast in a tight S-curve, which will end with the ship facing due south.

 

The Hindenburg, still far to the west, approaches the landing field after making its wide, sweeping turn to the northwest. She appears to be slightly nose-down, which would make sense as she was descending in preparation for mooring. Eduard Boetius, at the elevator wheel, is also attempting to counter the ship’s tail-heaviness, and the apparent nose-down attitude may also be partly due to this.

 

7:15 PM - The ship is still out of trim and tail-heavy. Captain Sammt orders Captain Ziegler to valve hydrogen from the same gas cells, 11 through 16, for another 15 seconds. The ship is turning to port in anticipation of a hard turn to starboard to line up with the wind.

7:17-7:18 PM - The ship begins its turn to starboard. This is the beginning of the "sharp turn" that Dr. Eckener would later blame for the damage to cell 4. Note that the command crew began valving gas from the forward cells several minutes prior to this in order to correct the ship's "badly out of trim" condition. If we assume that the persistent tail-heaviness is connected with the hydrogen leak that will doom the ship a few minutes later, then we must also assume that Dr. Eckener was in error in his belief that the final sharp turn to starboard was to blame for the damage to cell 4 and the hydrogen leak.

 

Now appearing to be slightly up by the nose, the Hindenburg begins its final turn up to the mooring area. The mooring mast in the foreground is not the one to which the ship will dock, although it was the mast the Hindenburg had used throughout the previous year.

7:18 PM - With the ship still tail heavy, Captain Sammt orders Captain Heinrich Bauer (no relation to Kurt Bauer), who is manning the ballast release board, to drop 300 kg of water ballast from Ring 77 (the main framework ring located 77 meters forward of the aft-most point of the ship) near the ship's stern. According to Sammt's autobiography written years later, he experiences a few moments of anxiety as he watches the plume of water falling between the ship and the ground, concerned that perhaps it might create some type of electrostatic discharge. It does not appear to do so, however, and shortly after this Sammt orders another 300 kg of water dropped from Ring 77.

 

As the Hindenburg’s turn to starboard becomes sharper, water ballast is dropped from the aft section.

7:19 PM – Captain Sammt orders one more ballast drop from Ring 77, this time of 500 kg, and simultaneously orders Ziegler to valve cells 11 through 16 once more, this time for 5 seconds. Sammt also rings the telephone extension in the crew's mess to order six men to go forward to the bow in order to use their body weight to help bring the bow down. At the elevator wheel, Eduard Boetius is holding the elevators hard down, attempting to coax as much trimming effect out of them as possible as the ship slows its forward speed to 8 meters per second. The ship is obviously still very much out of trim and down by the tail.

 

The Hindenburg makes its third and final ballast drop as it approaches the fenced-in visitors’ area in front of Hangar One, in which the ship had been docked twice the previous year. The line of people visible in front of the fence include those onhand to greet various passengers and crew members as well as locals who are just there to witness the landing.

7:20 PM - With the Hindenburg now only a few ship's lengths away from the mooring mast, Captain Pruss orders all engines full astern in order to check her speed. Then he orders the forward engines to idle ahead and the aft engines to idle astern, so that they can be ready for a quick burst forward or aft, as needed to position the ship for mooring. Pruss orders full ahead briefly, and then back to idle ahead. The six men from the crew's mess have now reached their positions along the keel walkway leading up to the bow.

The Hindenburg approaches her final position over the landing field, held almost directly into the wind. Note that the elevators at the aft edge of the horizontal tail fins are still in the “hard down” position. Clearly, Boetius is trying to coax the last bit of dynamic lift from both the ship’s remaining forward motion and the wind itself.

7:21 PM - The Hindenburg has now come to a complete stop and is hovering just outside of the outer mooring circle rail. Captain Pruss orders the bow landing ropes dropped. Witnesses note a puff of dust from the landing rope coils as they hit the ground, despite the fact that the ground itself is rain-soaked. This indicates that the landing ropes are completely dry when they are dropped.

In this photo, also taken from the visitors’ area, the Hindenburg hovers just beyond the mooring circle, with its mooring mast visible at extreme left. The port landing rope coil has just been released and is visible below the ship as it drops to the ground. Note that the ship’s elevators are still hard down, even at this late stage of the landing maneuver.

7:22-7:24 PM - A light rain has begun, and the landing ropes are gradually becoming damp, thus increasing their conductivity. The ship's framework begins to ground itself electrostatically, with the outer cover doing so at a much slower rate due to its own lack of conductivity. A gust of wind strikes the Hindenburg's port side and pushes it off to starboard as the ground crew struggle to check its drift. In the ship's tail section, helmsman Helmut Lau climbs up a ladder on the forward port side of the lower fin, helping rigger Hans Freund to free a jammed rope as he hoists the stern mooring cable up from its storage space in the lower fin.

One of the last photographs taken of the Hindenburg prior to the fire. Her bow landing ropes have been dropped and the ground crew has pulled them off to port and starboard and begun to connect them up.

7:24 PM – Electrostatic discharge is now occurring at various points along the Hindenburg’s hull. Near the entrance to the air station, with a view of the starboard side of the ship against the darkening skies to the southwest, Professor Mark Heald and his wife and son watch the landing. Professor Heald suddenly notices a "dim blue flame" flickering along the Hindenburg's backbone girder from a point approximately 1/4 the length abaft the bow to the tail. He exclaims, "The thing's afire!" His son asks, "Where?" Heald replies, "Up there along the top ridge!"

7:25 PM - Helmut Lau, still standing on a small catwalk halfway up the portside of the lower tail fin and facing to port, hears a dull "frwump!" sound and his attention is drawn forward and upward to a sudden glow of fire on the front side of cell 4, toward the center line of the airship. The fire appears to be moving downward, and within a moment the entire gas cell melts and the fire grows very large and bright and rises toward the top starboard side of the ship.

 

Helmut Lau’s field of vision at the moment he first saw the fire, adapted from his official Board of Inquiry testimony. Lau is looking up (field of vision in green) at the bottom of Cell 4 (blue). The red line shows approximately the area on the bottom of cell 4 through which he saw the glow of the fire. The location of the actual fire on the front of Cell 4, although Lau could not pinpoint exactly where it began before it burned its way downward, is estimated by the orange line. (Diagram courtesy of David Fowler) 

 

 An aft view looking forward showing a different angle of Helmut Lau’s field of vision at the moment he first saw the fire. The blue line indicates the bottom of Gas Cell 4, and the green again represents Lau’s approximate field of vision from his position in the lower tail fin. The red line represents the area on the bottom of the gas cell where he saw the glow of the fire through the cell material, and the orange area indicates the general area where the fire itself could have been located on the forward side of the gas cell as it burned its way down. It was, as Lau said in his official testimony, above him and “slightly to starboard and definitely forward.” (Diagram courtesy of David Fowler)

 

Down on the ground, with a view of the port side of the ship, Boatswain's Mate Reginald H. Ward notices a distinct fluttering of the Hindenburg's outer cover up toward the top of the ship between Rings 62 and 77 (in the general location of cell 5, just forward of cell 4.) Within 2 to 3 seconds, Ward sees a ball of fire approximately 10 feet in diameter bursting through the outer cover, followed by a much larger detonation.

Witness diagram filled out by Boatswain’s Mate R.H. Ward, USN during his official testimony, showing the spot at which he first saw fire appear (orange circle), along with the ripples in the outer cover (small horizontal lines beneath orange circle) that he observed a few seconds prior to the fire.

Closer to the mooring mast, Willy von Meister, the American DZR representative to whom Captain Lehmann had expressed his disinclination to try to obtain helium the previous year, is looking toward the Hindenburg's tail when he notices an orange/yellow light atop the ship. The light appears to be just forward of the upper fin, upon which he can see the light reflected. As he would later recall to airship historian Henry Cord Meyer, "The flare plunged downward, apparently along the vertical gas shaft to about the center of the hull. For the tiniest moment it gave off a glow like a lantern being lit. Immediately there followed an upward, outward explosion and billowing of flame. All this occurred in fractions of a second."

Murray Becker, AP news photographer, is standing to the east of the mooring mast and snaps the following still photo with his Speed Graphic camera just as the entire aft half of the Hindenburg is engulfed by a rising ball of flame:

What we are seeing here in Becker’s photo is gas cells 1 through 9 erupting in flame almost simultaneously, as far forward as Ring 140. They didn’t necessarily all ignite at the exact same moment. Cell 4 just forward of the tail fins, we know from Helmut Lau’s testimony, breached and vented its hydrogen a split second before the cells on either side of it caught fire. The first outburst of fire visible to those on the ground seems to have been a fairly small bloom of fire atop the ship, forward of the upper fin (as described in R.H. Ward’s testimony, and repeated in very similar ways in the official testimonies of multiple other eyewitnesses on the ground.)

However, once the fire had taken hold inside the ship, it seems to have almost immediately produced the result we see in Becker’s photo above. The outer edge of the fireball above the hull is uniformly well-defined and level, indicating that one portion of the fireball did not begin rising prior to the rest of it as it would have if the photograph showed the fire progressively burning from one gas cell to the next or along the outer hull. The outer cover is still mostly intact from the forward engine car all the way aft to the tail fins, however the framework in that section is imploding, further indicating that the gas cells are being breached. Fire can also be seen within the ship through a jagged tear in the outer cover just below the front of the forward engine car.

When one also takes into consideration Lau’s statement (repeated later in his testimony) “The ship at the moment that the explosion went up had an acceleration down," it becomes clear that a very short amount of time passed between the moment Lau saw cell 4 “disappear by the heat” and the moment that Murray Becker took the above photograph.

 
The Hindenburg, the hydrogen in its aft cells consumed, very quickly drops to earth. However, the fire does not continue to progress forward along the ship’s outer cover. Instead, the fire is racing toward the bow along the axial catwalk and through the gas cells. At the moment captured in the above photo, the fire is already nearing the bow (per Kurt Bauer’s testimony) and cell 10 amidships has begun to burn, as evinced by the small plume of flame atop the hull just forward of the main fire. This is flame rising up from the ventilation shaft on the forward side of cell 10. A similar puff of fire had been observed above the ventilation shaft forward of cell 4 just before fire first engulfed the stern section.

A split second later, just as the tail section hits the ground, fire bursts from the bow as cell 16 is consumed. Fire will now burn its way back from the bow toward the tail as the aft fire begins to move forward. However, the fire continues to rage within the ship’s hull while the outer cover remains intact.

 
The Hindenburg’s forward section begins to fall as the gas cells within begin to burn. Flames begin to rise along the top of the hull and the fire from the aft section now moves forward as the bow fire moves aft.

With the Hindenburg’s forward section is now almost completely ablaze, passengers begin leaping from observation windows now that the ship has neared the ground. The ship rebounds slightly on the hydraulic landing wheel under the control car touches the ground and the last intact gas cell (cell 14, behind the one remaining vertical strip of outer cover fabric) is finally consumed.

With all of its hydrogen burned off and the fire already subsiding, the Hindenburg finally collapses to earth for the last time. The bright flames generated by hydrogen burning through the mantle of fabric outer cover and gas cell material have now been replaced by dense black clouds of smoke from the tanks of diesel fuel oil that lined the ship’s keel walkway. Though quite a few spectators have retreated from the fire out of fear of the more violent hydrogen explosion that never came, the Navy and civilian ground crew are already running back to the wreckage in an attempt to rescue as many survivors as possible. The entire incident has taken just over half a minute.

There is, of course, no way to know exactly how the Hindenburg fire began, nor the precise location where the initial ignition took place. However, close examination of available photographic and eyewitness evidence combined with an understanding of the Hindenburg’s design and the conditions that were present at the time of her final landing approach indicate that although the disaster itself was incredibly dramatic, the so-called “mystery” behind the fire’s cause was far less so. It was a combination of events that had to occur all at the same time in order to start a fire – something which the Hindenburg’s operators could not have been expected to foresee.

As Dr. Eckener would later describe it to Harold Dick, a Goodyear representative who had worked in cooperation with the Luftschiffbau Zeppelin for a number of years:

“It was like being dealt four aces in a cold hand of poker – it might never happen again, and then it might happen the next day.”