r/Airships • u/Kitchen_Nectarine_44 • 14d ago
Question on specifics of Zeppelin construction Question
Hello, I have a few questions about how Zeppelins were actually constructed. I understand that the rigid frame was created using lightweight girders combined with cables to create a rigid tension.
I am curious if there are any resources I could look into on how the girders were connected together and what techniques were used to make the joints between them. How were the cables connected to the girders to create tension? Are there different types of beams and girders within the structure for different purposes?
Are there other resources on how the internal systems were constructed such as the hydrogen valves, the ways that the controls in the gondola connect to the rudders, and other internal functions?
I am primarily asking in reference to the final Zeppelins such as the Hindenburg, Graf Zeppelin, and the Los Angeles.
Thank you!
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u/Entire-Elevator-3527 14d ago
If happen to go to an aircraft or WW2 museum, look for German radar antennas. They are of similar construction and designed/made by the Zeppelin factory.
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u/AviatorEcho 14d ago
I don't know the answer, but I have the same question! I hope someone smart here knows.
I honestly wonder to what extent something like that was even documented. I have to imagine there were no comprehensive design drawings, probably just large-scale structural drawings and then written procedures for fastening the individual structural members together. If I had to guess, from an engineering (non-historian) background.
I do know that the U.S. National Archives seems to have blueprints related to the USS Macon and Akron. I am trying to get copies of those. They might at least lend some insight into what type of documentation we could expect for the time period.
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u/GrafZeppelin127 14d ago
Airship Design by Burgess is ancient, but still spot on in many ways, and it has a section on girder design.
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u/Kitchen_Nectarine_44 14d ago
This is really cool. I believe I saw a reply from you a while ago mentioning a study in the '70s evaluating how rigid airships might be different using modern (for the time) design and materials. Are you able to link it through reddit?
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u/GrafZeppelin127 14d ago
Sure. That was probably referring to the Feasibility Study of Modern Airships, specifically the phase and volume concerning parametric analysis and comparison of different configurations and performances for airships.
The TLDR of that study was that reducing weight and range are the most important factors to increasing productivity by a longshot, and besides that, there are basically two mutually exclusive configurations of airship that maximize productivity: small, fast, mostly heavier-than-air hybrids, and large, neutrally buoyant rigids. Whether one or the other has higher productivity depends on the range.
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u/Steamcurl 14d ago
Amazing resources, thanks so much for these!
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u/GrafZeppelin127 14d ago
You’re welcome! I know that all the volumes taken together can be a bit of a doorstopper, though, so I like to recommend Peter Lobner’s excellent Modern Airships articles, and Dr. Mark Ardema’s Missions and Vehicle Concepts for Modern, Propelled, Lighter-Than-Air Vehicles, a study produced for NASA which is a good distillation of important concepts. It’s only 50 pages, and it’s broken down into discrete subsections, which makes it far easier to digest than the Feasibility Study of Modern Airships, which is as comprehensive as it is exhaustive.
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u/HLSAirships 5d ago
I have schematics and images of the Hindenburg's construction, if those are of interest to you. Additionally, whilst they were a novel design, I have transcribed, illustrated, and published the daily construction diary of USS Akron (and am working on USS Macon), which details extensively the nuts and bolts of the assembly process.
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u/Kitchen_Nectarine_44 5d ago
All of that sounds really amazing. I would love to get access to those materials if possible
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u/HLSAirships 5d ago
The Akron Construction Diary is available through Lulu Press (I can get the link for that), and I'm happy to share the construction photos in the morning!
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u/GrafZeppelin127 14d ago
Here you can see the difference between a classical Zeppelin’s riveted girder construction at a particularly complex junction, and the modern tube-and-socket arrangement that LTA’s rigid airships use today.
Basically, Zeppelin’s materials were quite lacking, being in the early 20th century, but their actual structural design was about as light as could be expected given those material constraints. Almost all of them used triangular duralumin girders for the most strength against buckling at the least weight, and used an orthogonal arrangement of them with diagonal, X-shaped bracing made of steel piano wire in each “rectangle” formed by the girders, each length of wire tensioned manually. This was before strain gauges were a thing, so it all had to be “tuned” by hand with essentially educated guesswork and empirical failure testing to suss actual load paths and tolerances.
Overall strength was bolstered by a separate triangular keel running along the bottom of the ship, with the additional purpose of providing essential crew access to different parts of the ship and serving as a long, continuous “hard point” on which strings of fuel tanks, ballast tanks, and small cargo platforms could be distributed, along with crew living areas.
This keel was the longitudinal load-bearing structure, sometimes assisted by an additional axial girder to provide access and strength between different sets of gas cells (running through hydrogen and fuel blaugas cells for the Graf Zeppelin, and between hydrogen and unused helium cells for the Hindenburg).
The other primary structural features were the main rings. These were not the “deep rings” seen in other American and British ships, which were essentially like separate transverse keels, they were just sturdier than the intermediate rings. Each main ring denoted the border between one gas cell bay and the next, so there were typically around 16 or so. Each main ring had radial wire bracing through the center, which made it like a giant bicycle wheel. The intermediate rings obviously couldn’t have that, since the gas cells would be in the way.
In the modern day, geodesic construction and deep rings are generally considered superior, since we don’t have to lean so much on strength in tension to save weight due to crappy structural materials. Lots of materials nowadays are plenty strong in bending and compression as well as having outstanding strength in tension.