By Andy Cooke
In the last article, I looked at how airships could gain traction by earlier development, making them harder to dislodge from an economic niche. This week, we look at the 'What If...' for 'What If World War I didn't disrupt airship development and turbocharge aeroplane development?'
There are three things to consider:
- What actually happened
- Why that disrupted airship development
- What could have happened instead
Just as airship development was becoming competitive, and with no consideration at all for the lighter-than-air aviation world, World War One broke out.
Up until this point, the start of the Twentieth Century (and the close of the Nineteenth Century) had been very exciting for aviation. Very exciting for potential aviators, as well, even if said excitement was often brief and occasionally rather final.
Observation balloons became more popular
Work on rigid dirigibles leapt forwards, with Otto von Zeppelin piloting his first experimental airship in July 1900 and developing his series of Zeppelins
Other dirigibles entered the public eye; Alberto Santos-Dumont winning a 100,000FF prize by piloting his dirigible "Number Six" from the Aero-Club de France to the Eiffel Tower, around it, and back in under thirty minutes around the Eiffel Tower
The Wright Brother flew a heavier-than-air aircraft under control, during a worldwide outbreak of competition to try to do such a thing
Americans, British, Spanish, German, French inventors, companies, and militaries joined in what was starting to appear as an air race, with polar attempts in 1907 and 1909, and transatlantic attempts in 1910 and 1912 (all unsuccessful)
Air Arms were formed by militaries around the world
Then Gavrilo Princip shot Archduke Franz Ferdinand, and an escalating and seeming inevitable series of events plunged the world into war.
Why that disrupted airship development
It's axiomatic that war is the Mother of Invention, so maybe we'd think that it would help airship development. That invention, though, is specifically for the purposes of the machinery of war. Sometimes the output enhances the general capability of an entire swathe of technology - such as it did with aeroplanes in World War I, with engine technology, aerodynamic knowledge, and support technology leaping forwards in great bounds.
Aeroplanes, being small and (at the time) simple, could be constructed quickly and experimented upon easily, iterating them rapidly. Resources that could turn out a handful of airships could produce dozens of aeroplanes - which could be deployed rapidly and flexibly.
Attempts to use airships as scouts and as tactical bombers ran into the problem that they were slow, not very manouevrable, and very vulnerable to ground fire and other aircraft. These attempts were largely curtailed by 1917, although use of Zeppelins for long range strategic bombing by the German military were more successful, diverting considerable British resources to defend against them. The British defenders found out to their unhappy surprise that shooting holes in the envelopes tended to have little effect, until they hit upon the use of incendiaries and explosive bullets.
A further successful role was in anti-submarine and convoy protection roles, mainly by the British military.
A third role was in long-range resupply - the L59, nicknamed The Africa Ship, carrying out a 4,200 mile, 95 hour round trip deep into Africa, before aborting their mission when told the army it was to resupply had been forced into jagged mountains, providing nowhere to land. It still had more than 60 hours of fuel left on board at the time of its landing bat at base.
The two main roles (bombing and convoy escort), though, drove development in a direction unhelpful for civilian airship travel: long range bombing Zeppelins were pushed to strive for very high altitudes in order to provide greater safety from the more nimble aeroplanes, usually by the simple expedient of reducing their weight. Wood and fabric replaced aluminium and steel, and were then in their turn made as light as possible.
The resultant airships could indeed reach up to 20,000 feet in altitude and more (the wartime record being over 24,000 feet), and the Zeppelin raids on London and the English coast struck fear into the civilians (and reputedly contributed to the death of the famous W G Grace, from a heart attack. The great cricketer was known to shake his fist at Zeppelins floating high above South London, and when a contemporary, trying to lighten the mood, said that he hadn't let fast bowlers unsettle him, replied "I could see those beggars; I can't see these").
This development, unlike the wartime aeroplane development, was positively harmful for later civilian life. Airships with their structures reduced in weight to that extent became fragile in lower air, and their service life was measured in months rather than years. An example is the British R-38, which broke up in calm air at low-level, during trials before selling to the US Navy (who unsurprisingly pulled out of the deal). Designed to be capable of patrolling for six days at ranges of up to 300 miles from home base and altitudes of up to 22,000 ft, the structure was so lightweight that sudden manouevres in the thicker air low down caused it to break apart, killing 45 of the 49 on board.
The convoy protection role focused development on small, non-rigid, rapidly produced blimps - a direction of minimal use in civilian capacities.
Meanwhile, the huge numbers of aeroplanes employed in the fighting meant that there was a glut of trained aeroplane pilots, and large numbers of surplus aeroplanes, available for any entrepreneur or daredevil.
One such surplus machine, and two recently redundant aviators, were used for the first non-stop crossing of the Atlantic, in 1919. To the occasional surprise of Americans who cite Lindbergh as the first to do this, it was, in fact, the duo of Alcock and Brown in a Vickers Vimy biplane.
As it happens, the second crossing occurred a few weeks later; the R-34 airship carrying 31 people (including a stowaway) and a cat (brought on board by the stowaway). On their arrival, memorably, as the local Americans had no experience in handling large airships, one of the aircrew (Major Pritchard, who would later die in the wreck of the R-38), jumped out and descended by parachute in order to co-ordinate the ground crew.
No-one ever remembers who came second, though. And, in addition, wartime surplus airships were usually unsuitable to be pressed into long-range transport, their fragility and short service life weighing against them.
What could have happened instead
As well as galvanizing aeroplane development, providing huge numbers of leftover aeroplanes and pilots, and taking airship development down a dangerous side path, World War I derailled the early moves of airships towards long-range transport.
For long range transport of people and/or cargo, an airship needed to lift as much weight as possible - both as payload, and as fuel. It also needs to retain its lifting gas as long as possible.
Given the way air reduces in density with altitude, the lifting power of any lighter-than-air gas reduces as well (deriving its lift from the difference in density from the outside air; less-dense air obviously providing less of a difference). This means that the same quantity of lifting gas lifts a lesser weight, the higher you go.
In addition, as the pressure outside reduces, the gasbag comes under more strain from within, necessitating a release in pressure. Valves therefore release some of the lifting gas until the differential pressure within and without is minimal (further reducing the lifting power, and driving the weight reduction needed for high altitude dirigibles).
Accordingly, the pressure to which an airship's gasbags are inflated gives a "pressure height" - a most efficient flight altitude. The altitude at which the lifting gas pressure balances the lifting power with minimal stress on the envelope. For the reasons specified above, this points towards staying low. For air transport, this tended to be about 1500 feet (compared to the 20,000 feet-plus targets of the wartime Zeppelins). That height was clear of most low hills and structures on the ground, stayed out of the most turbulent air from obstacles, and gave some time to recover if anything went wrong, while giving a high level of lift for the quantity of lifting gas provided.
The issue was well expressed by A. H. Ashbolt, Agent-General for Tasmania, The Journal of the Royal Society of Arts, 23/12/21:
"When at Cardington the R.38 was in shed undergoing some slight repairs necessitated by the previous flight. Mr Campbell showed me the principle structural differences between that ship and R.36 and the German Zeppelin L71. Subsequently, on thinking matters over, I felt uneasy on the subject of building commercial vessels on the lines of R.38, and had a further interview with Mr Campbell at my office in London. I expressed my doubt on this point and asked him whether in the event of an Imperial Service being established he would design on the lines of R.38.
Before I could express myself further, Mr Campbell exclaimed ‘Good God, man, no! R.38 was specially designed in accordance with Admiralty instructions for purely war purposes to over-fly and out-fly all existing Zeppelins. We have, therefore, built her as light as possible to attain maximum heights, and she has very considerable engine power. When we build for commercial work maximum height and maximum speeds are not essential. With a war craft, if she serves her purpose during hostilities for, say, six months, she has achieved all that one can ask from her, but for commercial purposes you want strength and stability instead of lightness and height."
Without World War One - or if it had been significantly delayed (David Flin looks at the prospects of this), airship development would have continued without the drive to high altitude/high performance/short lifespan airships. Given the original advantage that airships had for long-range transport, it is reasonable to conclude that such development would have been focused here - while aeroplane development would have been far less increased, with the apparent prospects and roles being significantly less.
By 1915, we would have expected to see transatlantic transport successfully carried out by airship. Successful designs would be built upon. There would be well-publicised disasters, of course, as designers and pilots pushed the envelope of possibility. These would, as in OTL, have probably resulted in multiple deaths, as the temptation to provide "joyrides" in experimental airships was frighteningly high (as seen in the R100 and R101 in OTL); that was one advantage that early aeroplanes had over airships - in an experimental aeroplane, most crashes merely killed the pilot.
In contrast to the development of airships, aeroplanes would be significantly - even dramatically - behind their level in OTL. Less incentive to develop them, fewer useful roles, far less lightweight engine and airframe development, far fewer trained pilots (especially by the end of the War in OTL), and far fewer surplus airframes. The advantage held by airships would only increase.
By 1920, early airlines could be providing regular transport by airship within Europe and around the Americas. Some intercontinental passenger flights might be possible. Considerable work on air safety would have been undertaken - possibly seeing an early push towards the use of helium (much to the delight of the USA, who held an early monopoly on helium production). Unlike in OTL, the USA would not have banned export of helium to certain countries (including Germany) for fear of wartime use.
Then again, hydrogen airships could be used safely - or, at least, as (or more) safely than early airliners in OTL. Air crashes and air disasters would doubtless occur, but would they be more frequent and with higher fatality rates as air crashes in aeroplanes through OTL?
As to what airship travel would have been like - I'll leave you with some quotes from the 1920s in OTL:
Flight 19/5/1921: “There is little doubt that for long-distance non-stop journeys the airship scores over the heavier-than-air type of craft, and while to organise an ‘all-red’ route to India and Australia or South Africa would be a difficult undertaking with aeroplane and/or seaplanes, a few mooring masts and one or two more permanent bases would be practically all that would be required to start an airship service to these Dominions overseas.”
Flight correspondent, following a flight in R.36, 14/6/1921: “During my short span of years I have journeyed fairly long distances by boat, train, motor-car, and aeroplane but have never experienced such travel-comfort as in an airship – no dust, no smoke, no sway, no draught, very little noise and practically no vibration. We could sit in our arm-chairs – or stroll about – and talk without the slightest difficulty.”
"The passenger accommodation on both airships was internally suspended within the girder framework structure, situated roughly amidships to reduce the effect of personnel movement on the centre of gravity. The style was intended to replicate the comfort of the main competition, the ocean liner, though the ambience was often cosmetic with thin fabric walls and balsa wood features. Those who travelled reported the experience as ‘serene’ with little noise or vibration; indeed, the lightweight cane furniture was not even bolted down. The weight of this accommodation was a critical factor as the deck sizes were set from the beginning when capacity was demanded for 100 persons. Promenades and side windows were provided for ‘watching the world go by’ seen as a pleasurable pastime for passengers on long journeys at low level to exotic places.
Andy Cooke has written the sci-fi Endeavour trilogy (The End and Afterwards, Diamond in the Dark, Beyond the Sunset) and the political alternate history Lectern books (The Fourth Lectern, The Fifth Lectern), published by SLP