Sussex auction: personal effects of Dam Busters bouncing bomb inventor

Sir Barnes Neville Wallis (1887-1979) is considered one of Britain’s most influential engineers and innovators. The sale comes with the consent of the surviving members of the Wallis family.

Managing director of Denhams Auctioneers, Leo Denham said: “This rare and deeply personal archive provides an intimate insight into the life and work of the visionary engineer whose ideas helped shape modern aviation and wartime engineering.

“Sir Barnes Wallis enjoyed a career spanning more than seven decades of aviation and innovation and is best remembered as the inventor of the bouncing bomb used by the RAF during Operation Chastise, the famous Dam Buster raid. Educated at Christ’s Hospital School, Horsham, he later completed a degree in engineering and joined Vickers, where he worked on the company’s pioneering airship programme.

“Following the outbreak of the Second World War, Wallis recognised the strategic importance of precision bombing and turned his attention to experimental weapons design. Operation Chastise took place on the night of May 16 1943, targeting the three major dams in Western Germany, Möhne, Sorpe and Eder. The successful breaching of the Möhne and Eder dams caused extensive flooding, temporarily disrupting German industrial production.

“Although the raid was judged a military success, Wallis was deeply affected by the loss of life. Wallis’ post-war work extended into supersonic aerodynamics, his aversion to risking aircrew in future projects manifests itself in the use of remote-controlled models (with the Swallow and Wild Goose) to trial his high speed, variable geometry designs.”

Leo added: “We are honoured to be offering for auction the effects of one of the greatest engineers in British history, it is an outstanding auction that spans an incredible career from his foundations in airships to aircraft and munitions and finally the development of supersonic flight”.

“The highlight lot offered in the auction is a set of marbles belonging to Sir Barnes Wallis’ daughter, Elisabeth Gaunt (now aged 93). These marbles were famously used by Wallis during his early garden experiments whilst developing the conceptual principles behind the Dam Busters bouncing bomb. Estimate £20,000-£30,000.”

Of the day Elisabeth recalls “I remember the Easter bank holiday weekend when Daddy came home with a strange device and placed it in front of a metal wash tub that he had filled with water in the garden. He then asked if he could borrow my marbles for an experiment. I was fiercely protective of my marbles but reluctantly agreed, I was very worried in case any of my precious marbles were lost, sadly some of them did get chipped.”

Elisabeth’s late sister Mary Stopes-Roe, also reflected on these formative experiments, recalling: “We had this wonderful experiment at our family home, where my father set up the washtub and got a catapult made by his department. He altered the angle of the slant at which the ball was delivered and the distance from the water, and then he bounced my sister’s marbles, which she has never forgotten, the fact that they were her marbles.”

Leo added: “These are an incredible piece of history. That such a simple collection of a child's marbles was foundational in an experiment leading to the Dam Buster raid is remarkable".

Lots also offered within the auction of particular significance are:

Two aerial photographs documenting the effects of the Dam Busters raid on the Möhne Dam. One of the photographs is a post-raid image signed by Wing Commander Guy Gibson VC, DSO, DFC (1918-1944) along with other members of 617 Squadron, ground crew and admin staff. Estimate £15,000-£20,000.

A 2-inch aluminium sphere of the type used in the Teddington ship tanks during the development of the Golf Mine bouncing bomb. The sphere, which was discovered in an unmarked box of Sir Barnes Wallis’ lectures slides on the Dam Busters raid. The spheres were the next evolutionary step after the garden marbles leading eventually to the development of the Highball and Upkeep bombs. Estimate £10,000-£15,000.

A pair of briefing plans from the Operation Chastise showing two crayon coloured cross sections of the Möhne dam and where the Upkeep mine ‘bouncing bomb’ must land and the depth to detonate. Estimate £15,000-£20,000.

The auction also includes the contents of Sir Barnes Wallis’ personal office offering a rare glimpse into his working environment. Items include his tweed jacket, spectacles, original draughtsman’s desk, period office furniture, his personal library (including many volumes with handwritten notes and formulae), paintings and a wide range of other personal effects and models accumulated over a lifetime of innovation.

The auction will take place at Denhams Auctioneers, Dorking Road, Warnham, near Horsham, West Sussex, RH12 3RZ on March 25 at 10am. The auction is available to view by the public. The auction is available to view online at www.denhams.com. Live bidding via

www.the-saleroom.com