Hello Geo, and welcome to the aerodrome
,
well it's an interesting what-if .. surely our ancestors had a notion for megalomanic and at the same time militarily pointless machinery
(but at least those giant railway guns were also produced and utilized by the french
).
The airships ..
As a means for breaking the blockade, like it was done with the trade U-boat "Deutschland", it would have been perfect, but their had to be some material, bases and infrastructure at the american continent. And then even with a payload of 60 tons like in the late war airships, most of this load would have consisted of ballast (vital!), and fuel, and then there would have been a maximum of 20 tons of real cargo - and this is already a bit too much, say 7-12 tons would be more believable.
Then there was a second problem - long voyages with Zeppelins, as the L59 performed, were very complicated in war times. Maybe it is not so easy to explain, but the Zeppelins of WW1 had to climb high to evade being shot down by aircraft, or ground fire.
Throughout the war the Zeppelins were a bit ahead of their adversaries, they were mostly shot down because the commander miscalculated the situation (thinking of no enemies present) and flying lower than it would have been necessary, or they just thought they were already above german ground (those 4 low-flying airships lost over France). This was done because of navigation errors and other problems, and also to find targets at the ground during bombing raids. Naval airships did not carry cloud cars for reconnaissance beneath the clouds, too much unnecessary weight (as well as parachutes ahem).
The after-war airships did not have to deal with high altitudes, they would rise to say 800 meters (appx. 2400 feet) and stay there for the rest of their voyage - so they did not have to drop too much ballast, but also they would not lose precious hydrogen gas that would vent off from the inner gasbags at higher altitudes. Smaller altitude corrections would be made dynamically by lifting or lowering the bow, and the engines.
But let's say a Zepp. in 1915 - 17 would head for the US, it would have first to cross France, or maybe take a more southern course, but still. If it would fly at at least 4000 meters or 12000 feet, it would be well above it's "burst height", meaning the pressure in the gasbags would rise to a point where they would blow off gas via emergency valves, for not ripping up the gas cells.
When going down again over the atlantic (for a bit more warmth, and oxygen), and again venting gas for this purpose they would have to drop ballast further down, because now there's this lack of hydrogen (which was ok at 4000 meters, but now ..), just to maintain a certain altitude at say 1000 meters. Navigation would be a problem, no gyrocompass on war airships (weight), but maybe via a sextant on cloudless days, or nights ...
Then there's the US coast, so up with the airship, drop even more ballast, go to 4000 or more meters and evade the US planes, again unwanted venting of precious gas - and maybe down again for looking for targets, or plain navigation, and the final landing somewhere.
The airship would be by now in dire need of replenishment of fuel, and ballast, let alone repairs and spare parts. Mind you, parts of metal and duraluminium alloys, along with special parts for the High-altitude engines from Maybach, gas cell material (very complicated to produce this "Goldschlaegerhaut"). So the problem would have been the repeated up and down - with maintaining a certain height all the time it would have been much less dangerous.
I guess it would be possible, one way - but then a base on the american continent would have been necessary
Thanks and geetings,
Catfish