Busting the Dam

We raised our glasses to Heroes today in the Tavern.  53 who did not return from Battle and 80 who did. It is the anniversary of a costly but technically brilliant effort  - The Bouncing-Bomb attack on several German dams on the night of 16th May 1943.

Here is what was Top secret film made by a german soldier during his vacation, risking his life. Filmed at the early morning of May 17th 1943 from the north end of one of the the dams. Our German-speaking friends will be able to understand the commentary.

Operation Chastise was an attack on German dams carried out on 16–17 May 1943 by Royal Air Force No. 617 Squadron, subsequently publicised as the "Dam Busters", using a specially developed "bouncing bomb" invented and developed by Barnes Wallis. 

The Möhne and Edersee Dams were breached, causing catastrophic flooding of the Ruhr valley and of villages in the Eder valley; the Sorpe Dam sustained only minor damage. Two hydroelectric power stations were destroyed and several more were damaged. Factories and mines were also either damaged or destroyed. An estimated 1,600 civilians drowned: about 600 Germans and 1,000 mainly Soviet forced-labourers. The damage was mitigated by rapid repairs by the Germans, but production did not return to normal until September.

Before the Second World War, the British Air Ministry had identified Germany's heavily industrialised Ruhr Valley, and especially its dams, as important strategic targets: in addition to providing hydro-electric power and pure water for steel-making, they also supplied drinking water and water for the canal transport system. The methods used to attack the dams had been carefully worked out. Calculations indicated that repeated air strikes with large bombs could be effective, but required a degree of accuracy which Bomber Command had been unable to attain in the face of enemy defences.

The mission grew out of a concept for a bomb designed by Barnes Wallis, assistant chief designer at Vickers. Wallis had worked on the Vickers Wellesley and Vickers Wellington bombers. While working on the Vickers Windsor, he had also begun work, with support of the Admiralty, on a bomb designed initially for attacking ships, although dam destruction was soon considered.

Wallis's initial idea was to drop a 10 long tons (10 t) bomb from an altitude of about 40,000 ft (12,200 m). This idea was part of the earthquake bomb concept. At that time, no bomber aircraft was capable of flying at that altitude or carrying such a heavy payload. A much smaller explosive charge would suffice, if it exploded directly against the dam wall below the surface of the water, but the major German reservoir dams were protected by heavy torpedo nets to prevent just such an approach.

Wallis's breakthrough was to overcome this obstacle. A drum-shaped bomb—essentially a specially designed, heavy depth charge—spinning backwards at over 500 rpm, and dropped at a sufficiently low altitude at the correct speed and release point, would skip for a significant distance over the surface of the water in a series of bounces before reaching the dam wall. 

Its residual spin would run the bomb down the side of the dam toward its underwater base. Using a hydrostatic fuse, an accurate drop would bypass the dam's defences and then enable the bomb to explode against the dam some distance below the surface of the water.

Led by 24-year-old Wing Commander Guy Gibson, a veteran of over 170 bombing and night-fighter missions, twenty-one bomber crews were selected from existing squadrons in 5 Group. 

For our non-British friends, a Wg Cdr is the same rank as a Lt Colonel. 

He was 24. 

These crews included RAF personnel of several different nationalities, as well as members of the Royal Australian Air Force (RAAF), Royal Canadian Air Force (RCAF) and Royal New Zealand Air Force (RNZAF), who were frequently attached to RAF squadrons under the British Commonwealth Air Training Plan. The squadron was based at RAF Scampton, about 5 mi (8 km) north of Lincoln.

53 of the 133 aircrew who participated in the attack were killed, a casualty rate of almost 40 percent. 

Thirteen of those killed were members of the Royal Canadian Air Force, while two belonged to the Royal Australian Air Force.


A lad dropped by to show us his research. The heroes of yesterday remain alive in the minds of the interested young. 

Our heritage is in good hands.

Drink up. I shall refill so you can raise them again to absent heroes.

Pax