Massive airships flying 90/km an hours are LESS susceptible to blockades than cargo ships? I think I'll need a little more explanation than that. Seems like a shoulder-mounted rocket launcher would be more than enough to bring one down.
Airships were routinely used and shot at in WWI, but very few were lost due to being hit.
If you think about it, it makes sense: they are massive, so the loss of pressure from a bullet hole isn't a real concern. And while the right hydrogen-oxygen mix is explosive, hydrogen needs oxygen to even burn. But there isn't any oxygen in the tank bladder. The escaping hydrogen can burn as it mixes with air if it finds an ignition source, but as long as your hull is from fire resistant material the flame can't do much, and is probably extinguished by the next wind gust.
Of course the "make your hull from fire resistant material" is where the Hindenburg went wrong. Her hull material could have been used at rocket fuel, the engineers just didn't realize that.
A quick scan of the Zeppelin list on wikipedia shows that significant proportion were lost after being hit by enemy fire. For example: LZ 20, 21, 22, 23, 28, 29, 32, 33, 34...
Surely you could design some redundancy into the hull? It's not like the ship needs to be one giant gas bubble. It can be a mesh of a few hundred bubbles that could each pop without bringing the whole thing down.
So several hundred times the weight of the pressure envelope? Tracer bullets was only an example. Airships would be spectacularly vulnerable to all sorts of modes of attack.
Standard tracer ammo, yes. As was the case with most weapon systems in WWI, innovation ran rampant and the various armed forces tried out any number of solutions such as explosive-filled bullets[1]
