Posted 09 June 2012 - 10:58 PM
Thought I'd join in on this one. Time for some facts I think.
Goldbeaters' skin was very much a standard material used for the gas cells of British and some non-rigids. In fact its use in lighter-than-air craft goes back as far as the 1780s in France.
According to the Naval Air Service Manual (1915)... "Gold-beater's skin is very gas tight in proportion to its weight and thickness. To give, however, sufficient strength it requires to be thick and heavy. Unless varnished, it absorbs a great deal of moisture from the air in humid weather and this increases its weight. It is extremely durable and lasting and withstands the sun's rays very much better than rubber fabrics. Beta's envelope and most of the small spherical balloons are made of gold-beater's skin."
As far as I can see pretty much every British rigid airship and some non-rigids used gas cells made of goldbeater's skin. Nulli Secundus was made entirely from skin. It seems the gas cells of the many of Germany's Zeppelins were made of, or used, goldbeater's skin (among other materials). The Germans only really started using goldbeater's skin for the construction of Zeppelin gas cells after the start of the war - but as a result of the war and blockades they had to rely on domestic production rather than imports. This is a fascinating piece from Capt. L Chollets 1922 report "Balloon Fabrics made of Goldbeater's Skin"...
"The collection of goldbeater's skins was very systematic in Germany during the war. Each butcher was required to deliver the ones from the animals he killed. Agents exercised strict control in Austria, Poland and Northern France, where it was forbidden to make sausages"
Much later, however, the Hindenberg's gas bags were made of a gelatinised latex developed by Goodyear.
Right up to the 30s goldbeater's skins continued to be used for the gas cells of airships of all nations. R101 was 777ft long, a volume of 5,509,753 cubic ft and 17 gas cells all made from goldbeater's skins glued to fabric. Graf Zeppelin's gas cells were made of goldbeater's skin bonded to linen. The USS Shenandoah used 750,000 sheets of goldbeater's skin. That's a lot of cow's intestines.
A bit of googling brought this up from the Danish Post and Tele Museum of all places...
"Goldbeaters skin is made from part of a cows intestine, the outer layer of the caecum to be precise, which is also called blind gut or even the appendix. The outer layers of the blind-gut are carefully stripped off into sheets of around 60 cm in length by 25 cm in width. They are then cleaned of fat by dipping the gut in a mild alkaline solution and scraped with a blunt knife. The cleaned gut is then stretched over a frame. One quite remarkably quality of this material is that separate sheets can be joined or welded when wet by carefully rubbing the overlap of the two sheets. Several layers can be made this way as well, for example, airship gasbags usually consisted of up to seven layers of skin.
The living tissues in the sheets grew together making a seamless and Hydrogen proof join. As well as being impermeable to Hydrogen it was also light and very strong, making it the perfect gasbag material. However it was very labour intensive and time consuming to produce. Supply of goldbeaters skin ran out during the First World War, forcing the Zeppelin Company to recycle the material from older airships as well as use an inferior artificial substitute for the construction of the gasbags. The poor quality of these wartime gasbags were considered responsible for the loss of many war-time airships and their crew."
My specialisation is really British naval non-rigids (specifically NS-class) but I find this subject fascinating. Just think of the poor people who had to prepare the skins.