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The paper entitled "The Engineering Development of Rigid Airships" by Sir Alfred Pugsley OBE FRS, is published in the Transactions of the Newcomen Society, 1981-82 Vol 53.
It is not often that the author of a paper on engineering history "discusses the history of a subject that started and ended within the span of his own lifetime", but in Sir Alfred's lifetime the first successful rigid airship (the LZ2) flew in 1906, and the last and greatest, the Hindenburg, from 1930 to 1936, the year of its last fateful flight.The author remembers seeing rigid airships in flight, and being "caught emotionally by the beauty and grandeur of such a sight".
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| R101 on the mast at Cardington © copyright |
"The difficulties of moving a rigid airship in and out of its shed, especially in cross winds, have played a large part in airship design as well as airship operation. The fact that it was cheaper to build a long shed rather than one of large cross section has not only tended to cramp airships in the matter of side clearance, but has also pushed designers to adopt longer ships with larger fineness ratios than they would otherwise have wished.
So far as the sheds themselves are concerned, two lines of action to minimise cross wind difficulties have been tried. The first was to build the shed on a floating raft that could be rotated into the direction of the wind; this was tried both by the Zeppelin Company on Lake Constance and by the British for their R1. The second was to provide large windscreens near the entrance to the shed to reduce any cross winds there. Both proved expensive and not very effective. Thus it came about that until 1925 most rigid airships were handled in and out of their sheds by ground crews in the manner used with the earlier non-rigid airships; and then only in quiet periods of light winds with small cross components. For such periods the airship was expected to postpone arrival or departure (often until late evening or dawn) rather like an ocean liner waiting for the tides or a calm sea to enter or leave harbour or dock.
This proved too much of an operational restriction, particularly in war time, and a number of rigid airships were damaged on leaving or entering sheds. Airship designers therefore turned to the use of mooring masts to which a ship could be "tethered" in any normal wind for long or short periods, leaving entry to its building shed an occasional operation only for maintenance and repair.
The English pioneered in this matter and developed the tall stiff mast of the type that became familiar at Cardington for the use of the R100. The airship would slowly approach the mast at an altitude of 500 to 1000 feet and drop a cable from its nose to the ground, where it would be attached to another leading to a winch at the top of the mast. The winch would then wind in the cable, kept taut by the wind or reversal of the airship propellers, until the ship's nose fitting coupled into one at the mast head, some 250 feet above ground. The airship was then left to swing into the wind as and when it changed the direction. To keep the ship in horizontal trim and lessen any tendency to pitch, a series of weights was hung from the after end of the ship. These were picked up from the ground as the tail lifted and lowered to the ground as the tail fell.
The Germans, originally for ease of transport and for economy, developed a system using much lower masts. The nose of the ship was tethered as before to the mast head, which was only a little higher than the semi-diameter of the ship's hull. The lower fin at the stern was then fixed to a heavy carriage running on a circular railway track around the mast, and this carriage was powered so as to be able to move around the track to keep the ship head on to the wind. In the most sophisticated form, used by the Hindenburg, the rail system was linked to rails running from the mast straight into the airship shed, and the mast was powered so that the ship could be moved mechanically into the shed, complete with mast and stern carriage."
The Hindenburg at stub mast © copyright
Biographical Note: Sir Alfred Pugsley OBE FRS (1903-98) worked at the Royal Airships Works at Cardington and was head of Structural and Mechanical Engineering at the Royal Aircraft Establishment, Farnborough 1941-45. He was Professor of Civil Engineering at Bristol University from 1945 until retirement, and was Pro Vice-Chancellor there from 1961-64.
The complete text of this paper can be purchased on line from our archive.
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