...
Still in all, we have to admit that for sheer size alone, not to mention the times, they were impressive. ...
Indeed! I once lived near a country airport, which at the time hosted the occasional blimp in its peripheral grass fields, and had an opportunity to approach a Goodyear Blimp on foot. Now the Goodyear craft of today are about the same size as the USN class L ships of the WWII era--and the L ships were the smallest class the Navy had in commission, meant for training though they also did wartime coastal patrol. A "little" blimp then (today other blimps are smaller still though).
That thing was huge! I couldn't get as close as I'd have liked but while I was still pretty far away, it loomed.
I could only try to imagine what a sight a ship like Hindenburg or the Naval ZRS would have looked like. Sky ships indeed.
I realize that the airframes were of light construction, but I wonder about the ability to build an ATL design, that could be built to land on sheltered waters, rather than hover next to a tower?
This has been proposed. It has been a long time since I read about it and names elude me now, but there was an airship advocate in the Royal Navy who sought to promote a British Empire serving airship line immediately after WWI, and he had this notion too, of mooring with a sea anchor at various ports.
The tricky thing is that you don't want any airship to have to stand up to cross-winds; the idea is to let it swing around to put its nose to the wind. Then again Zeppelins, being handled by ground crews of hundreds of men, were generally brought into hangars rather than left moored swinging in the breeze. (Mooring towers were more a British and then American development than German). So when being marched into the hangars the Zeps were necessarily exposed to winds not along their axes at some point or other; hangars were laid out to parallel the average wind direction but winds do not stay average!

I took footage of another blimp moored at the airport I used to live at--within the course of less than a minute it veered back and forth through about 40 or 50 degrees--and the winds felt rather gentle that day. Winds shift, and they can shift quite rapidly.
So I'm not sure what this seaman's notion was, whether he'd have had the ship held rigid at a convenient dock, or would have anchored only the nose and let the tail swing around--but I'd design to do the latter, perhaps with a tail mooring designed to hold the tail within a narrow range of pitch angles while it could yaw around freely or nearly so on a float.
Graf Zeppelin, on one of its polar expeditions (perhaps there was only one, I forget) in the Soviet Arctic met with a Soviet research ship off Novaya Zemlya--I believe Umberto Nobile was by coincidence aboard the Russian ship at the time, and wrote about how the Germans snubbed him. The meeting did involve the Germans attempting a sort of temporary sea anchoring--one that Captain Eckener was keen to cast off from as soon as possible!

Still some transferring of cargo and mail was accomplished.
I forget if it was Shenandoah, or probably more likely Los Angeles, that tried landing on a USN aircraft carrier sometime in the 1920s. This did not work well, as the two ships were floating in different mediums and so were constantly in relative jostling motion. After WWII the Navy again tried to operate blimps off a carrier; they made it work but it was problematic and not followed up on further.
The best opportunity for an ATL to develop big transport airships would be to arrange for the politics and economics of a period technologically comparable to the OTL 1920s to allow for ambitious liner schemes. By the 1930s OTL airplanes had pretty much overcome their temporary drawbacks relative to the airships' potentials for long flight endurance and hence range and closed the window. But operations during and just after WWI demonstrated that for that decade, airships could indeed have enabled transoceanic and transcontinental operations. Over land, airships would be competing with established railroad lines which could maintain comparable speed. But this was an era of colonialism and many colonial empires spanned continental expanses over terrain that was poorly developed, in Africa particularly. Airships do better over ocean expanses since the thermal environment is more stable. Ocean storms can be severe of course but Eckener's Zeppelin operations developed the habit of judging developing weather conditions, sometimes even taking advantage of storm systems to sweep along the edges of cyclones to speed their transit--over land, the geography shapes the storm systems into less predictable forms and confronts the navigator with varying altitudes, rising to heights an airship would be ill advised to attempt, only to be caught in the chaotic winds above mountain range peaks. (At sea, the Zeppeliners preferred to fly very low, at lower altitudes than their own ship's length in many cases).
So, routes over land are not particularly desirable to be sure. But unlike a seaborne ship, an airship can certainly cut over short land obstacles that a sea ship must steam around. Over undeveloped land, enduring the challenges of varying terrain, daytime turbulent thermals, and generally wilder weather is harder but could give access to places as yet not served well by roads or railroads. Airships with post-WWI era engines could maintain speeds two or three times faster than surface ships (though not railroads on high-speed stretches--to be sure many lengths of RR lines can hardly maintain full speed). Thus I think that if designs comparable to what the Germans or British could build in 1919 enjoyed a modest degree of extra development, that could be accomplished in just a couple of years, the 1920s might have enjoyed the prospect of dozens or perhaps hundreds of airships running on commercial lines meant to link Europe to the various colonial holdings. The most obvious, given the political geography that emerged post-WWI OTL, would be a British Empire service, the main line going over friendly France to the Mediterranean, thence to Egypt, over Arab land to Baghdad then along the Persian Gulf and past Iran to India, across India to Burma and Australia by way of Singapore, perhaps even reaching to New Zealand. A branch line out of Egypt would run down to Cape Town, and another might close that loop running along the African west coast. Another spur out of Britain would run to Canada.
In an ATL, the span of the British Empire might have some gaps in it--say the Ottoman state survives for instance. It might be the French or the Germans who enjoy the open routes, or perhaps no one does without negotiating passage rights over some country that they have indifferent to poor relations with.
OTOH, OTL the Soviet Union permitted the Graf Zeppelin to cross on its world-circling flight.
One of the niche markets that is promoted perennially today for airship transport is serving the Canadian Arctic--in winter, roads and sledges serve well enough in frozen conditions but in summer the ground gets soggy and building roads good all year round is a dauntingly expensive proposition I gather. The same considerations would hold in much Russian territory. OTL the Soviet Aeroflot operation, formed in the late 20s (or even early 30s) to promote Soviet air transport, hired the Italian airship designer Umberto Nobile to come and develop some airship designs for their operations. I happen to know from other sources than my studies on Nobile that Stalin became hostile to air transport for his underlings when he lost one of them in an airplane crash--the high level Soviet apparatchiks one would have expected to be the "market" for the more advanced Soviet passenger aircraft were forbidden to travel by plane--apparently Stalin felt that he wanted any of his minions dead he'd have them killed himself; he didn't want them dying by accident when they were still useful to him!

Also, Nobile observed that Soviet ground controllers were slow to learn the different operational drawbacks and advantages airships had versus airplanes, and kept giving inappropriate orders. He was also skeptical of the ability of Soviet industry to successfully construct the sorts of semirigid airships he liked to make and considered the most advanced forms--he felt Zeppelin type designs were more primitive--and the right sort for the Soviets to make too!
I do feel that the world would be more interesting if the Soviets had indeed persisted in developing their own airships, for service in the tundra and other places poorly served by roads and railroads in their vast expanses. They might even have considered equipping their Navy with light aircraft carrier airships. And during WWII, I think the Americans also would have found large airships useful logistically as well as for light strike carriers and antisubmarine warfare (which latter role we did exploit with a fleet of a hundred blimps). Once the Grand Alliance against the Axis formed airships could have served to enable long-range air transport; the airplanes of the era OTL were still not quite up to the task of transport across the Atlantic let alone the Pacific, but with the experience of a Golden Age of commercial airships well known from the '20s I'd think airships could have proven most useful. Besides having the range to do the job they'd also be pretty safe from U-boats or even the German surface raiders--indeed German U-boat commanders were very leery of being spotted by blimps OTL and would be very concerned to hide from passing airship transports rather than risk exposing themselves by trying to attack, even if they had missiles that might do some damage. In addition to crossing the Atlantic, transport airships could also master transPolar routes, assisting in delivering Lend-Lease to Soviet territory while avoiding the gauntlet of U-boats and the Luftwaffe based in Norway that was so devastating to the convoys of OTL.
And back in the post-war USSR, I'd think established airship operations would have come in handy for the Soviet rocket projects too. One constraint on the larger rocket designs they wanted in the later 50s and 60s was transporting the large lower stages; the designs of OTL are limited by what can move over rail networks. But custom-designed airships could haul quite enormous stages to the launch sites. I even would suggest in all seriousness that with such airships in operation, they could recover spent lower stages from the land downrange they fall on--and thus perhaps develop a very cost-effective approach to reusable first stages, if they could design them to soft-land, which is far less challenging then trying to enable them to fly back to the launch site themselves.
One reason Soviet airship ops is so interesting to me is that it turns out Siberia is one of the handful of regions in the world where helium can be refined out of natural gas wells. OTL for a very long time only the USA was known to have such wells; nowadays we know that helium can also be found in Algeria as well as Siberia. I don't believe either of these alternates was known as late as WWII and there are good reasons the discoveries were delayed. (I'm quite frustrated not to know just when or why the Russian and African finds were finally made).

Still we have interesting ATL prospects--I expect the Soviet sites were just plain remote and hard to find and would not think they would be found until the 50s or 60s, but perhaps the Algerian sites could have been stumbled upon far earlier; if France were a player in the airship game, or that game was still going on and France suddenly finds itself a helium supplier and thus joins it, it is an interesting shift from the OTL American monopoly. And if the Soviets are still using airships when the Siberian sources are discovered at last, surely the helium will encourage them to continue.
I should make a note of caution--helium is inherently expensive and it tends to escape. It is harder to operate with it than with hydrogen, which is also a superior lift gas (though only modestly so--the advantage is less that pure hydrogen lifts a lot more than pure helium, as that it is easier (and to be sure, also more necessary) to maintain hydrogen in a near-perfectly pure state). And the ability to exploit natural sources effectively is a matter of technology; the Americans could only manage a trickle of useful production in the 1920s. On the other hand we operated that large fleet of blimps during WWII. The point being that there is a technological window that has to open to allow sufficient refining capability; it would do little good to have the American fields discovered in the 1880s for instance.
In general, airships require rather higher technology than people tend to assume; a steampunk airship of the nineteenth century probably belongs in the pages of pure fantasy. You need good materials to hold the lift gas--goldbeater's skin is something of a Gothic nightmare, yet even it was not available in the 19th century. I would say that synthetic gas bag materials are needed and these weren't developed until the late 1920s at the earliest. You need light, strong, corrosion resistant metals, or materials still more advanced such as composites, for the frame; Duralumin was developed in Germany just as the Great War was starting, and better alternatives came later still. You need powerful and reliable engines--weight is less of a paramount concern than with airplanes, but still they have to have reasonably good power to weight ratios, and these two are a 20th century development.
By the time the materials and engines to make a really good airship are on the shelf, the same inputs can rival it with a good airplane.
There are reasons the airship does not prevail over the airplane or helicopter generally. I still think OTL is sadly poor in not taking advantage of airships more often when they are, for some particular reason, more advantageous.
