Always great to hear from Dr. Prentice. Hopefully, remote operating and autonomous capabilities will prove essential in reducing risks and costs, which will lower the high barrier to entry for transport airship prototyping and experimentation.
Additionally, the lack of a crew and their various systems will mean more payload, which makes smaller airships more viable.
Many excellent points raised were raised here. Of particular importance is Cloudline CEO Spencer Horne’s emphasis on the importance of specific productivity on operating economics, and the wider consensus among the panel on the potential for autonomy to improve weight, profitability, regulatory compliance, and throughput.
Over the decades, there have been several examinations of steam as a potential lift gas, ranging from the Germans’ experimental HeiDAS and HeiDAS UH balloons in the 2000s, to the USA Department of Commerce’s seminal 1970s Feasibility Study of Modern Airships, to NASA’s 1980s examinations of LTA vehicle concepts. Only a few snippets of these efforts are shown here.
Presently, there exists a severe gap between extremely slow but incredibly inexpensive hot air airships, and helium airships which are far more capable but about 10 times as expensive to buy, and even more expensive to operate. For most applications that would demand only a few hundred flight hours per year, which is to say the vast majority of general aviation applications, the functional inability of helium airships to be deflated and packed away when not in use makes them prohibitive due to ground crew, masting, and hangaring costs. Even switching to hydrogen wouldn’t change this dynamic, since hydrogen airships were seldom deflated either, as every inflation and deflation event carries fire risks and still costs quite a bit of money.
Current thermal airships do have easy storage capability, and are able to be packed away into a trailer after every flight in just an hour or two, but their dependence on hot air cripples their performance and renders them incapable of accomplishing the vast majority of uses that a helium airship of similar mass might be put to. Some thermal airships have gone for decades with only a few dozen hours of total flight time, which makes them very inexpensive relative to helium airship storage costs, but extremely expensive when it comes to effective lifetime costs per flight-hour.
The use of steam might be the key to unlocking similar speed, payload, and endurance to helium airships, but at a fraction of the cost—only marginally more than using hot air. But since greater speed, endurance, and payload could yield much higher utilization and greater productivity, that implies a steam airship has the potential to vastly outperform a hot air airship in terms of generating profits, and likewise outperform a helium airship on costs by a huge margin. If a steam airship could command the same revenues of a helium airship but at a tenth to a fifth the capital and operating cost, that would be a great boon to advertisers, recreational flyers, scientists, border patrols, and airship companies that don’t want to rely on aging helium blimps like American Blimp Corporation A-60R for flight training their pilots—such as the ones LTA Research and Flying Whales are forced to use, for lack of viable alternatives.
Since the HeiDAS team, Festo, and UltraMagic have already come up with suitable insulation materials to contain steam, and since steam balloons’ excellent performance relative to hot air balloons has already been confirmed by empirical data (~2.5x greater lift at 150°C than a normal hot air balloon of similar volume) collected from experimental subscale models, the remaining issues to resolve are to come up with a full-scale flying prototype to suss out any unforeseen problems, discover the best commercial or bespoke generator to use to produce steam onsite for safe and rapid inflation, design an easily-deflated hull with fully pneumatic or collapsible nose cones and tail fins that are capable of withstanding helium airship speeds, develop procedures for the safe venting of steam at the end of flight, and then proceed to certification and commercialization.
That all sounds like a lot, and it is, but the potential upside of breaking helium’s monopoly on long-endurance airship operations would make such a venture far more likely to result in wider proliferation of airships and trained airship pilots than merely designing the next generation of conventional helium blimp, such as China’s recently-certified Xiangyun-class AS700 and AS700D—since no matter how commendably advanced the propulsion, thrust vectoring, and avionics gets for these new airships relative to the older, smaller A-60R, they still have the same storage problems as all other helium blimps.
A thermal airship even capable of the modest feat of matching but not exceeding the performance of the A-60R would be immensely impactful for the airship industry. 600 mile range, 15-hour endurance, 30 knot cruise, and 50 knot top speed doesn’t sound like much on paper, but if it can come from an airship that costs as much as a Cessna and can be stored in a trailer or garage instead of chased around by a full-time cross-country ground crew? That would be very consequential indeed.
This is a welcome bit of promising news for Flying Whales. Considering the ship lacks landing gear, I am interested to see how a military logistics application for “challenging terrain” and “minimal ground infrastructure” might be accomplished.
Perhaps a military version of the ship might trade off some of its payload to carry extra fuel tanks so that it doesn’t need to land at its destination? Likewise, water ballast would likely be needed to conduct on-site hovering load exchange operations, so a water truck or water tanks might be what counts as the “minimal ground infrastructure.” Large, off-road mining trucks like the Ground Force 15W can carry 60 tonnes of water, so even a single truck (and a relatively cleared area) would be sufficient to conduct load exchange with the airship’s 60-tonne payload.
This particular design was more conservative than the higher aspect ratio “delta” hybrid airship concepts, which had a wide degree of variance in modeling due to uncertainty as to their structural weight. Hence the low aspect ratio hybrid—a design that’s like the airship equivalent of a mullet. Business in the front, party in the back. The front half of the ship is a conventional Zeppelin with a circular cross-section, but then the back half flares out into an efficient wing structure.
A single flight hour for manned military aircraft can cost well into the tens of thousands of dollars, so unmanned surveillance and interception may be the best means of countering the rise of cheap drones and loitering munitions.
Case in point: the United States spends more on its military than the next half-dozen countries combined, but as of a few months ago, it only had 16 E-3 Sentry radar and communications aircraft, of which two have been damaged or destroyed by Iran. The E-3s cost over half a billion dollars each, and were destroyed by drones and missiles costing a tiny fraction as much.
If the United States has difficulty economically sustaining such asymmetric, costly losses, what hope is there for middle powers and regional powers to afford to do the same? That is why it is so vital to have a distributed, persistent, highly attritable network of units with economics of scale and mass production lowering costs even further. The capabilities of these individual units aren’t as advanced as that of a billion-dollar unit, but the cheap drones and loitering munitions they’d be tasked to track aren’t very sophisticated either.
What a delightful video. Highly accurate and touches on many historical and modern aspects.
Hello r/CitiesSkylines!
As Reddit’s resident airship aficionado, I couldn’t help but notice through the Urbanist grapevine that this game has blimps as a transport option! Unfortunately, their specs (35 passengers, ~20 knot speeds) seem based on advertising blimps rather than actual transit-oriented airship designs, which is rather akin to using a Wienermobile to run a bus network.
In real life, airships have only briefly been used in intercity transit with early Zeppelins, but Goodyear Aerospace did do a study on an “airport feeder” short-range transport airship back in the 1970s.
Despite being slightly shorter than Goodyear’s current advertising blimps, which only hold 14 people at most, these transit airships featured durable all-metal construction and thousands of horsepower, permitting for a passenger capacity of 80 and a cruising speed of 130 knots—as fast or faster than most helicopters! Their seat-mile costs were calculated to be $0.06 ($0.35, adjusted for inflation), about half as much as a helicopter’s, and their noise levels were lower, too. Typical stage length was 15-150 nautical miles, and maximum range was 400 nm.
However, given that almost all the intercity helicopter airlines trialed during the 1970s spectacularly failed when their subsidies dried up, forcing a retreat to the private and charter flight sector, there was no established scheduled-service VTOL air transit niche for the high-capacity airport feeder concept to compete in, and thus no funding or investment for the concept eventuated.
Just thought I’d add a touch of realism for those interested in the game’s blimps, who have been wondering how they might be improved!
Hello r/CitiesSkylines!
As Reddit’s resident airship aficionado, I couldn’t help but notice through the Urbanist grapevine that this game has blimps as a transport option! Unfortunately, their specs (35 passengers, ~20 knot speeds) seem based on advertising blimps rather than actual transit-oriented airship designs, which is rather akin to using a Wienermobile to run a bus network.
In real life, airships have only briefly been used in intercity transit with early Zeppelins, but Goodyear Aerospace did do a study on an “airport feeder” short-range transport airship back in the 1970s.
Despite being slightly shorter than Goodyear’s current advertising blimps, which only hold 14 people at most, these transit airships featured durable all-metal construction and thousands of horsepower, permitting for a passenger capacity of 80 and a cruising speed of 130 knots—as fast or faster than most helicopters! Their seat-mile costs were calculated to be $0.06 ($0.35, adjusted for inflation), about half as much as a helicopter’s, and their noise levels were lower, too. Typical stage length was 15-150 nautical miles, and maximum range was 400 nm.
However, given that almost all the intercity helicopter airlines trialed during the 1970s spectacularly failed when their subsidies dried up, forcing a retreat to the private and charter flight sector, there was no established scheduled-service VTOL air transit niche for the high-capacity airport feeder concept to compete in, and thus no funding or investment for the concept eventuated.
Just thought I’d add a touch of realism for those interested in the game’s blimps, who have been wondering how they might be improved!
“Hydrogen-electric propulsion systems delivering continuous power of between 350 and 500 kilowatts could be in production by 2030, according to Josef Kallo, co-founder and chief technology officer of H2Fly.”
Such systems would be perfectly-sized for a wide range of airship applications. This is significant, as hydrogen is just about the perfect fuel for an airship, increasing efficiency, payload, range, and optimal cruising speeds when compared to fossil fuels.
Funding problems: the perennial issue for aviation startups everywhere. While I do hope that HAV secures the hundreds of millions of pounds it needs to complete its Doncaster production facility, I am unsure of where they might possibly raise such a sum from.
The UK government seems like the likeliest prospect, but they have their own issues at the moment. As the world has collectively been given a kick in the pants as to the urgency of moving away from fossil fuels, though, that may lend new urgency and a new avenue of argument for HAV to press their case.
Running simulations on beyond-edge-case conditions seems like an excellent resource for refining airship designs and training crews at the same time.
What a marvelously aesthetic shape this Bolle airship has! It’s like a sleeker version of the R101.
For a small airship like Atlas’s “Atlant,” I am a big fan of the H-shaped internal deck layout. When square footage is limited on such a small ship, this configuration allows the ship to effectively combine the advantages of an external gondola providing good window angles and high natural light exposure to the interior, while also retaining the safety, spaciousness, and low-drag advantages of keeping the passenger spaces internal.
One particularly interesting tidbit of news here is Kelluu’s intent to investigate using their airships to carry interceptor drones as a means to both detect and counter one-way suicide drones. Similar interceptor drone launch platforms have already been successfully employed in the Russo-Ukrainian War, but require a plane or helicopter, which is much more expensive and dangerous as it involves a human crew.
One year ago, I took the limited public info on the Pathfinder 3 to try to extrapolate details of the ship’s gondola. Using new sources of information, we now have many more details about the upcoming Pathfinder 3’s configuration. The Tyréns study posted in October 2025 gives us a closer look at the design-level configuration of the ship, and what seems to be a render of the gondola with a placeholder interior, though details are still yet to be fully finalized. Notable changes and updated details from the 2022-2023 interviews and articles include:
-The ship’s length has increased from 185 to 200 meters, implying the addition of another 15-meter gas cell bay (not shown in the above blueprints I’ve annotated with gondola layout for scale, which instead depict the Pathfinder 1. Imagine another full-diameter cylindrical hull segment aft of the gondola, it improves the overall symmetry as well). Diameter remains 30 meters, so fineness ratio thus increases from about 6 to about 6.7.
-Volume is set at 100,000 cubic meters. Gas volume or total hull volume not specified.
-Passenger capacity is said to be 130.
-Payload is approximately 17 tonnes, useful lift 20.5 tonnes. This highly unusual, payload-heavy ratio is enabled by the ship intending to use liquid hydrogen fuel, which is represented mostly in the structural weight from the fuel tanks, not the variable weight of the fuel itself.
-The gondola design has been updated from the initial render years ago. Instead of having a rectangular structure, it is a more aerodynamic capsule shape thanks to the half-circular viewing galleries in the front and back.
-Rather than spanning three cell bays and being 45 meters long as I theorized in my initial post a year ago, it would appear based on the accommodations for the main structural rings (as shown by the locations of structural bulkheads and the absence of windows) that the gondola instead spans two cell bays, but the front and rear viewing galleries both extend half a cell bay each. Dimensions for the gondola are given as 46 meters long, 12 meters wide, and 3.9 meters tall.
-The gondola is said to be two decks tall, which implies some of the structure extends up into the hull and keel section of the ship. This is similar to some past airship configurations, such as the R102, which kept part of the passenger accommodations (sleeping quarters) in the main hull, while putting the public accommodations in an external gondola. This hybrid approach has the advantage of providing easier access for passengers and cargo, while also maximizing space without intruding too far into the gas cell volume. The ceiling of the upper deck is likely higher than 3.9 meters from the bottom of the gondola, as dividing that evenly in two with allowance for a floor between them would leave too little room for tall people to stand upright, so it seems likely 3.9 meters is the height from top to bottom of the structural gondola portion, i.e. the parts visible from the exterior consisting of the gondola, its two banks of windows, and the faring to remain flush with the hull, not any internal hull structures.
-Due to the interruption in the upper bank of windows and the deep ring structure, it is likely there is a short, 3-meter passage between the two sections of the upper deck located in the cell bays, rather than having one contiguous upper deck space. This would divide the upper deck into two square sections, approximately 12 by 12 meters, for a total floor area of ~144 square meters.
-The lower deck walls have some downward taper, so the floor is likely about 10 meters wide. Assuming the viewing galleries are roughly circular, that amounts to a floor area of ~379 square meters, or a total of 523 square meters, or 5,630 square feet. That is roughly analogous to the post-refit Hindenburg’s passenger compartment, for context. At 130 passengers, that is 43 square feet per passenger, about 40% more individual space than the average first class airline cabin.
-The seating shown in the render is likely a generic filler interior, as the lower deck lacks many of the features and details noted in the weight breakdown.