Aftermath & Operational Issues

Low Force          Pilots                            TOT               Bombing Results 

EE 146     "D"          W/Cdr     J.B.Tait ( Ldr )   16:51         Bomb landed 10 yards short of Target
LM 492   "W"          Sq /Ldr   J.V.Cockshott     16:54        Bomb fell on west bank of Rhine river
DV391     "O"           F/O         P.H.Martin         16:43        Bomb fell as on overshoot 30-40 yards
PB 415    "S"  KC-S Sq/Ldr    D.R.Wyness   (+)16:52        Bomb presumably fell on east bank
LM 482    "K"  KC-Q FL/Lt      C.J.G.Howard(+)16:           unknown on 2nd bomb run
ME 562    "K"           F/O        J.A.Sanders       16:45        Bomb over barrge fell far side

High Force

EE 923    "M"          Sq /Ldr     G.E.Fawke (L)   17:05        3 Bmb.runs ,bomb fell west bank       

DV 393    "T"           F/O          A.W.Joplin        16:49        Bomb fell close of 2nd pier left of T

LM 485    "N"           F/O          F.H.A.Watts       16:44        Bomb was an overshoot about 50 yards
LM 489    "A"           F/O          J.Gingles          17:04        Bomb fell as overshoot on railway line( Alsace)
DV 402    "X"           F/O          J.L.Sayers         17:04        Bomb fell through bay door ,unknown
ME 554    "F"           FL/Lt        T.C.Iveson         16:48        Bomb fell left bank 400 yards of target
Unknown                FL/Lt        Castagnola                        Bomb fell between 1st & 2nd pear left 

Since most of the enroute portion of the flight was in Allied hands events  could
have been expected to Besancon and east part up to and close to Swiss border. 

The flight enroute to Kembs was spotted sveral times by the German Radars and 
Singnal Intelligence sites first east of Besancon , then by the Radar & Signal Intel
units on top of Mt.Felberg on Blackforest, city of Kandel ECM unit near Switzerland
and Lorrach and Rastatt Sigint units close to the target area. These units did not or 
could not alert the nearby Luftwaffe ops stations due to unknown reasons . 

 Mount Feldberg inSchwarzwald AA early detection unit

City of Kandel near Swiss border radio detection unit 

 Remains of Loerrach radio and signal detection unit site

According eyewitness the first 4 bombs detonated after 30 minuted within ingtervals
5 more after 12 hours one bomb failed to detonate and while detonating a day 
later it has killed a few people and injured several. Also according Swiss AA battery
two Mosquitos flew over the target at 17:35 and an other one flew from Blotzeim near
today's Basel Airport towards the target at 17:45 flown by F/Lt.Hanlon and circled
the target for PR purposes for a longer while. Also according Swiss paper Thurgauer
Zeitung a Mustang made an emergency landing at Alsace Habsheim NW of the Target 
which then and now had a grass strip for practice landings nearby the today's 
Basel Euro Airport.

The Swiss media reports were totally wrong  because the first Mosquito to
appear over the target at about 17:35 hrs was this of Hanlon which in absence 
of bomb detonations was unable to take any bomb plot shots then in order 
to avoid target flack elected to make a "holding " pattern over Blotzeim for about
10 minutes or so then return to Weil Am Rhein Kembs Barrage from the west into
SSE when the first delayed action bombs started to explode ( 30 minutes after being
dropped ) exactly as planned by 617 Sqd and set my ground crews.Eyewitness unaware
about delay fuses cunfused the explosions with a bomb dropped from Mosquito.

                Reconstruction : Mysterious second Mosquito reported by Swiss over the target (none)
Cookshott and Tate both delivered their Tallboys almost into the target . Hanlon's aircraft was not carrying any bombs at all and there was no second Mosquito which took off from Woodhall Spa on that day towards Kemb.Intriguing however is the report by a Swiss paper 3 days after the raid that a Mustang III attempted an emergency landing at nearby Habsheim .Indeed a 306th Sqd Mustang III was badly damaged by flack while diving on one of the German AA batteries on eastern side .The Mustang trailed smoke behind while departing towards Habsheim at low level that is why the interpretation that the aircraft made an emergency landing at Habsheim. As into the four Tallboys exploding 12 hours later , these reports sounds very unreallistic and does not make any sense at all . The bomb plot at 17:40-45 hrs shows 9 or 11 explosions around the target and near target area, an other explosion was ploted on the railway line on Alsacian side (Gingles ).The likelihood that one Tallboy did not detonate sounds more reasonable.

7 green dots are clearly visible Tallboys detonations, blue dots AA positions 

Dot near east bank is Tate's bomb, dot on uppper part of the barrage is Cookshott's 

bomb, 2 dots east of the barrage Martin and Watts an other invisible dot could

well be Wyness bomb. Dot far west of the barrage Sanders. Dot far west of barrage

between the pears are Castagnola and Joplin's bombs. 

Bottom green dot shows Gingles railway line hit , NE on the photo note a 88mm AA battery

Recon  2 September 1944

Recon 7.10.1944 note substantial defenses changes since last recon

Therefore out of the 13 Tallboys , 10 hit near traget area , one fell on the French railway in Alsace
one was Howard's bomb which may not have been dropped and finally Sayers bomb which fell through the bomb bay door and may not have detonated . This calculation suggesting that all bombs
were dropped more or less as planned and one did not explode (Sayers ).

                                           Parts of F/O Sayers Tallboy found on Riverbank

 This unexploded Tallboy is presumed to be this of F/Lt Howard (1946)

                                               

Mosquito 627 Sqd

KB 215 "H" FL/Lt Jan Hanlon 

Flt.Lt.Hanlon and Tice made two runs over the target 17:40 at 3000 ft and then 6000 ft eleven minutes after the last Lancaster and fighter left the target .One the first run they saw one bomb burst 200 yards South of the west end of the barrage ,soon followed by an other burst which appeared to blow out the westerly span. Water started to pour through gap and there were ripples extending 200 - 250 yards upstream. This is was Tice stated on a 
BBC interview some time later :   

"I was disappointed at first as there was nothing to see-- the waters wereplacid, 

and the dam unbroken. Then one of the 12,000-lb.'babies' - of the delayed action 

type --- exploded, and then another.The surface of the dam broke into ripples, then 

into little waves, then into huge waves.The dam broke  wide open,and the huge

 expanse of water began to spew through the rapidly widening gap."  This 

clearly indicates that the Mosquito did not any carry bombs .

Poor pre Raid British Intel & technical preparations

Given the excellent recon photo brought back by 541st Recon Sqd on Sept 2,1944 no further recon flight were sent to Kembs prior October 7,1944 raid. The bomb plot shot brought back by 627 Sqd dated October 7,1944 shows major defense changes at and around the target area without the crews being properly briefed about them. Further more numerous aircrafts were dispatched with serious malfunctions which temporairly jammed the bombay doors and in one case kept it fully retracted , thus forcing the crews to elect a second and third run over the target which led to a crew loss (Howard) and could have ended into a bigger loss. Also crews fatigue after failed Sept 11,1944
Tirpitz attack from a far Russian base may have played a substantial role into numerous operational issues experienced at Kemb.

    Poor German Radar & Fighter Coverage over Kembs

Given the importance of Kembs Barrage ,Luftwaffe had no Radars on site nor in occupied Alsace nor Luftwaffe had any fighters in readiness condition in the nearby fields at Colmar , Freiburg or Bremgarten . The chart beneath shows the Luftwaffe pre raid status.The raid bound for Kembs was already twice discovered enroute by the German Radars , first somewhere east of Besacon, then on Feldberg Mount in Black Forest and yet no actions taken on that Saturday . Beneath the German Signal Intel locations which discovered the raid.

Signal detection sites which intercepted the Kermbs Raid

Conclussions 

The attack was not a failure nor a huge success. The planes left target before

delay fuse detonated the 'tailboys'. Only one or two bombs reached its target 

just a Tallboy was enough to breach the barrage and release the water.
It would be two years or more before shipping on Rhine was restarted.

The Americans did not cross the Rhein while held up by German resistance
pockets further north and the 'Colmar pocket', was not eliminated that fast

until February 2nd 1945 , their first crossing was at Remagen in March 1945.

Captured documents confirmed that the German army had indeed intended to

open the Kembs barrage eventually  Schluchsee in the Black Forest, and open
the barrages in Laufenburg and German Rheinfelden.  

The importance of the mission was questioned throughout the years .The 
damages caused by Kembs barrage rupture on Mulhouse area are not really 
known .I always wondered if Wyness would have turned left into Alsace just 
two miles rather fly north for more than 10 minutes , would this would have 
saved his and his crew lives ?

Back in the 80's W/Cdr Tate when invited by the Historical Aviation Society of Alsace

to fly over the Kembs barrage on a light aircraft remarked that in order to breach Kembs

Barrage gates a group of four low flying Lancasters would have been sufficient to reach

the objective with lesser human and property loss than those of October 7,1944 .

References :

IWM, 617 Sqd Dumbusters,Luftwaffe Archives,

Colmar, Badische Zeitung, Basler Zeitung , 

Nazi Zeitung, Landes Archives BW , 

Australian  War Museum , 617 Sqd Ops History 
The Dumbusters