Today’s ships are expeditionary craft, can go almost anywhere, stay as long as they want. They are no longer land-bound, can be refueled and reserviced at sea. They are much safer, rank high in this respect among all carriers whether on land, sea or in the air.
Three independent lines of study contributed to these results, those of the Army, Navy and Goodyear, each free to follow its own ideas, to observe results found by the others, adopt them, use them as starting points for further developments, or discard them.
The improvements were achieved in a relatively short period. The army started in after the war and carried on a continuing program till 1932. The Navy, absorbed in its rigid airships, did not get into non-rigids till the early 1930’s. Goodyear built the Pilgrim in 1925 but its development program really began with the blimp fleet in 1929.
Noteworthy improvement was found during this period in materials, structure, design, engines and radio communication, with outstanding advances along three major lines.
First was increased safety, permitted by helium gas. Wartime airships used hydrogen because it was all they had, had to develop what protection they could against fire through construction devices and operating technique. Hydrogen was not only inflammable, but under certain conditions explosive. World War pilots had to fly their hydrogen ships through thunder and lightning storms, dodge inflammatory bullets if they could. Zeppelin sailors wore felt shoes, with no nails to create a spark, used frogs for buttons, had to guard against static.
It was a fortunate thing for the airship world when a gas was found in 1907 in Dexter, Kansas, which would not burn. Curious scientists, asking why, found it was helium, a gas previously identified (in 1869) only in the rays of the sun. Helium gas is inert, refusing to combine with any other element, does not deteriorate metal or fabric. It was not much heavier than hydrogen, the lightest of all gases, so proved a welcome gift to lighter-than-air.
For some reason, not explained except on the theory that Providence takes special interest in America, helium has been found in quantity only in this country. It is a component, present to the extent of two or three percent in certain natural gas, though ranging as high as eight or ten percent in favored areas. It can be separated by compression and liquefaction from the natural gas,—which is that much improved by the removal of the non-inflammable content.
The world’s chief known supply of helium lies in certain sections of Texas, Kansas, Colorado and Utah. More important, United States is the only country having great pipe lines, can distribute natural gas from Texas to cities as far away as Kansas City, St. Louis and Chicago. Without such a market operators would have to separate and release the 95% of natural gas to get the 5% of helium, and costs would be still higher.
Helium is perhaps the most useful of the few natural monopolies given to this country.
It was only toward the end of the World War, however, that Army engineers worked out a process of separating helium from natural gas. A plant was built at Fort Worth and the first cylinders of helium had reached New Orleans ready for shipment to France to inflate observation balloons when the Armistice was signed.