Find Spot record MWX4506 - Fleet: Bouncing Bomb

Remains of World War II bouncing bomb designed by Barnes Wallis in 1941 and first tested on Chesil Beach. Used in the famous 'Dambusters Raid' in 1943. Recovered from the Fleet and now on display at Nothe Fort.

A Second World War Bouncing Bomb was recovered from in the Fleet, and is now on display in the Nothe Fort. It is in a very poor condition. (1)
Cylindrical in shape, the bouncing bomb, also known as Highball, designed by Barnes Wallis in 1941. He was aware that in the 19th century the British Navy had bounced cannon balls on water to increase their range. He began by carrying out experiments with marbles and a catapult on a tub of water in his garden. Later he tested his prototype at the National Physics Laboratory in Teddington. These tests were successful and the first bouncing bomb was dropped on Chesil Beach in December, 1942.
Barnes Wallis’ bouncing bomb was 60 inches long and 50 inches in diameter. It contained 3 hydrostatic pistols, which measured the hydrostatic pressure of the water as the bomb sank, until it was equal to the pressure corresponding to 30 feet depth. The bomb was also fitted with a 90 second time fuse so that if the hydrostatic mechanism failed, the bomb would still detonate. The bomb weighed a total 9,250lb, 6000lb of this weight being explosive charge of TNT and RDX and possibly other materials to improve the efficiency of the explosion.
Before being released from specially modified aircraft, the bombs were held by v-shaped arms in the plane and rotated to the speed of 500 rpm by a hydraulic motor and belt drive. The planes had to fly at the low height of 60 feet and to be travelling between 240-250 mph. To help the aircrews obtain these specifications, two spotlights were fitted to the undercarriage of the plane and positioned so that they converged into one at exactly 60 feet.
The speed and height the bombs were dropped at was critical in order for the bomb to reach its target. The bomb hit the water with some backspin and this, with the angle it bounced off the water at, would help determine the length of a bounce.
In February, 1943 Barnes Wallis was told to prepare these bouncing bombs for an attack on the Mohne and Eder dams in the Ruhr. The Dambusters Raid took place on 16th May 1943. The cylindrical bombs, that spun at 500 rpm, were dropped by Guy Gibson and the 617 Squadron at a height of 60 feet and at a speed of 240 miles an hour. The rotating bomb skipped over the water and exploded while sinking to the base of the retaining wall of the dam. The bombing produced heavy floods and badly damaged German production in the Ruhr.
To use the bouncing bomb the pilots had to fly very low and seven out of the 19 aircraft that took part in the raid were brought down by German anti-aircraft guns. The RAF could not sustain such high losses and the bomb was rarely used again during the war.
Neville Barnes Wallis, the son of a doctor, was born in Ripley, Derbyshire, on 26th October, 1887. After leaving school at sixteen he started work in a shipyard on the Thames. In 1908 he transferred to a shipyard in Cowes and began designing ships.
In 1919 Wallis was recruited by Vickers to design airships. Together with his long-time friend, H. B. Pratt, he designed the R.9, the R23 and the R.26. He was also chief engineer on the R.80. Unlike the traditional Zeppelin, this airship had a streamlined look. However, in 1921, the Chief of Air Staff decided to bring an end to building airships. Vickers continued to feel that airships had commercial potential and in 1924 Wallis was commissioned to produce the R.100. It was larger than any other airship built and did not make its maiden flight to Canada until 1930. Later that year the R.101 crashed killing 48 members of its crew.
Airships were now considered too dangerous and the project came to an end. Wallis was now given the task of designing planes. This included the Wellesley that went on to set a non-stop distance record of 7,158 miles in 1938. With the threat of war Wallis began work on the Wellington Bomber. (2, 3)

Spartacus Education, 2004, Bouncing Bomb (Digital archive). SWX8852.

Moorcroft, Lucy, 2004, WWW page designed by Lucy Moorcraft and hosted by the School of Chemistry, University of Bristol (Digital archive). SWX8851.

<1> Le Pard, G, 1995-2003, Dorset Coast Forum Maritime Archaeological Database, Single Find 5 (Digital archive). SWX8707.

Record last edited

Sep 6 2024 4:38PM