The 1950s were wonderful years for science and engineering, where anything was possible. Sputnik 1 was launched into space, the first passenger jets entered service, and people apparently flew around on their own personal helicopters:
Alex Moulton was also very busy in these years. He might be best known for his work on the Mini (the suspension he designed for the Mini owed its roots to his work on ‘Flexitor’ suspension for the Austin Gipsy in the 1950s), but he was a prolific inventor who was interested in almost all areas of engineering design, from steam-powered cars to wheelchair suspension.
Moulton enjoyed novel or interesting engineering challenges, and the “Heli-Vector” personal helicopter above certainly caught his eye as he made a cutting of the article and filed it away for future reference. But Alex Moulton was as much a sportsman who enjoyed physical challenges as he was an engineer, and so when he read an article in a 1955 edition of The Aeroplane which talked of a pre-war German experiment with human-powered flight, the seeds of an idea took root.
Moulton’s personal papers contain a small file of material on human-powered flight. The material mainly consists of correspondence with scientists and engineers working in the field, and Moulton’s letters show his passionate enthusiasm for the concept. In fact, he joined the Low Speed Aerodynamics Research Association in 1956, and wrote to its Director of Research to say “I would like to support, in any way possible, activity in the direction of studying and achieving Man Power Flight”. The papers also include numerous studies and reports which aimed to prove that, theoretically at least, human-powered flight was possible.
A 1955 article in The Aeroplane set out the calculations: “a pre-war German design, the Haessler-Villinger, had an empty weight of 77lb and required only 0.82 bhp to fly at 30mph” whereas a new, more lightweight and aerodynamic, design could be flown at 30mph using only 0.68 horsepower. It was theorized that two people could produce just under 1 horsepower if power was generated by the pilot using their legs only (presumably their arms were being used to fly the plane!) and the co-pilot using both their legs and their arms. If you think that generating power using your legs sounds suspiciously like a bicycle, then you’d be right:
Early ideas for human-powered aircraft seem to have been based around creating what was effectively a tandem bike inside the cockpit, with the addition of a linked handcycle arrangement for the (presumably very fit) co-pilot. Perhaps it was the centrality of the bicycle that attracted Moulton’s interest. He began corresponding with several people involved in the Royal Aircraft Establishment’s Man Powered Aircraft Committee (MAPAC), principally a member of MAPAC called David Rendel. MAPAC considered two main designs for the aircraft: a fixed wing design, and an ornithopter (an aircraft with flapping wings, similar to those of a bird). Both were to be pedal-powered.
I am often guided by those twin pillars of research: serendipity and curiosity. It was these two trusty old friends that led me Henry Charles “inky” Stephens (1841 – 1918). While tidying my desk as part of my New Year resolution I was left with just a few paper clips and two rulers on the work surface, which reminded me of a patent I had spotted in our indexes for “the parallel ruler” (yes, sadly someone had invented this before me). The patent seems to enable …er…two parallel lines to be drawn, more seriously it was used by navigators to draw parallel lines on charts and originally invented by Fabrizio Mordente in 1584 and others sought to improve it. But there was more, with the documents were further patents for inkstands and an adjustable pencil, plus specifications for various ink manufacture and the chemistry behind them. Of course, what I had started to look at was part of an archive relating to the Cholderton estate, once owned by the family and an individual whose single small invention arguably helped change the course of writing.