Operation Chastise was an attack on German dams carried out May 16 and 17, 1943 by the RAF Squadron No. 617; the squadron was later referred to as the “Dam Busters”.

 

 

 

 

 

Before WWII, the British Air Ministry had identified Germany’s industrialized the Ruhr Valley and specifically its dams as important strategic targets.  As well as providing hydro-electric power and pure water needed for steel making, the dams supplied drinking water and water for the canal transport system.  The methods chosen to attack the dams had been carefully selected.  Calculations indicated that repeated air strikes with large bombs could be effective, but this required a degree of accuracy Bomber Command had yet been unable to attain.

A specially developed “bouncing bomb” that had been invented by Barnes Wallis was used for the attacks.  His idea was to use a drum-shaped bomb (a specially designed heavy depth charge).  It would spin backwards and would be dropped at a low altitude for the correct speed and release point, skipping for a distance over the surface of the water in a series of bounces before reaching the dam wall.  The 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, then enable the bomb to explode against the dam some distance below the surface of the water:

“UPKEEP” BOUNCING BOMB (from “The Dam Busters” by Falconer)

 

 

THE VIEW FROM BENEATH THE LANCASTER’S NOSE - SHOWS THE BOMB IN PLACE AND PROTRUDING FROM THE CONVERTED BOMB BAY (Crown Copyright)

 

UPKEEP BOUNCING BOMB MOUNTED UNDER GIBSON’S LANCASTER (National Archives)

 

The Squadron was divided into 3 formations to attack. Formation No. 1’s mission was to attack the Mohne and then the Eder.  Following a successful attack on the Mohne, the group continued to the Eder.  The valley was covered by heavy fog but wasn’t defended.  After several runs, the final bomb breached the dam.

The Mohne and Edersee Dams were breached, causing catastrophic flooding of the Ruhr valley as well as the villages in the Eder valley.  The Sorpe Dam sustained minor damage.  Two hydroelectric power stations were destroyed, several more were damaged.  As well, factories and mines were damaged or destroyed.  Estimates were that 1600 civilians drowned (including 600 Germans and 1000 Soviet forced-labourers).  The damage was mitigated by quick repairs by the Germans; however, production didn’t return to normal until September of that year.

 

THE MOHNE DAM PRIOR TO THE ATTACKS

 

THE MOHNE DAM THE DAY FOLLOWING THE ATTACKS

 

EDER DAM MAY 17, 1943

 

The Sorpe Dam was the one least likely to be breached as it was a huge earthen dam, unlike the two concrete and steel gravity dams (the Mohne and Eder).  Only three Lancasters reached the dam.  The attack was different from the previous ones ~ the ‘Upkeep’ bomb wasn’t spun, and because of the topography, the approach was made differently as well.  Nine attempted runs were made but only a section of the crest of the dam had been blown off; the main body remained.

Of the 133 aircrew who participated in the attack, 53 were killed; this included 13 members of the RCAF.  Of the survivors, 34 were decorated at Buckingham Palace.  There were 5 Distinguished Service Orders, 10 Distinguished Flying Crosses and four bars, two Conspicuous Gallantry Medals and eleven Distinguished Flying Medals and one bar.

 

KING GEORGE VI VISITING SQUADRON 617 IN SEPTEMBER 1943

 

Did you know that of the 133 airmen that set out on the raids, 30 were Canadians?  In my next post, I’ll share this “Canadian Connection” with you.

In addition, the following titles are available in our Library for your research; you might also find them in your community library:

 

 

 

 

 

 

 

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