Precision bombing, by the experts...

[Carl Schwamberg]

Originally Posted by Chukka

Heres an Interesting Exercise, I found this photo at
http://www.lib.uea.ac.uk/lib/libinf/...kerman/bau.htm

And it is described as 'Post-attack air reconnaissance photograph of a railway gun target, Wimereaux, March 1944'

I am guessing that the railway gun is on the rail line to the curved line from south west to east on the photo, or going by the craters, at the elbow of the curved spur line going off to the North. Any other guesses on where the gun might be, and hence how accurate the bombing was?

Tough to judge. My intial take is the bomb craters are nowhere near the tracks, but a much better copy of the photo is needed.

[At ease]

Originally Posted by Carl Schwamberg

Looking thu the literature I noted there was disagreement about hitting the marshalling yards, repair shops, and related warehouses. Part of the 9th AF/9th Bomber Command staff thought those would not produce the effect predicted. Initially the command choose those as the primary target & changed the target priority only after several months of watching the tracks rebuilt overnight and the flow of supply hardly slowed by roofless machine sheds & warehouses. As a squadron ordinance officer my father picked up on all this as it happened & recalled the dismay & disgust of the squadron and group pilots & staff as their efforts payed for little.

Again refering to my father, it took a direct hit by at least a 500 lb bomb & preferablly a 1,000 pounder on a key point in the bridges structure. Just one was enough, but from 10,000, 5,000, or even 500 feet @ 280 mph a am point of only a meter or two was 'difficult'. Most bombs missed and just scattering some pavement or knocking a secondary truss piece off would not drop the bridge. Additional training, more demanding techniques, and doubling or tripling the size of the attack was necessary to drop the many bridges. this is supported by the other annecdoatal evidence from within the 9th AF.

Zuckermans department, and the 9th AF leaders who choose the original target selection were refered by my father as "those knotheads'. From his mild mannered idom that was a grave insult. Dont know how deserved any blame might be for Zuckerman & the others, but his name has been disparaged by others concerning his estimates of the effects on targets. So, yes a close look at his writing for comparison would be interesting.

Carl, do you have any recollection of your father commenting on these

Guided Bomb Development
In an effort to overcome the weather predicament, programs such as the Glide Bomb (GB), Vertical Bomb (VB), and radar directed bombing were developed. Indeed these programs became the Army Air Forces’ third of three major AAF research and development initiatives.14 During World War II, these guided munitions programs led engineers to develop fourteen different weapons that sound very similar to the guided weapons of today, including optically guided and heat-seeking munitions.15 One of the more successful programs was the Azimuth Only (AZON) program, which appeared in two versions; the VB-1, a 1000 lb General Purpose (GP) bomb with a special nose cap and tail fins, and the VB-2, a 2000 lb version.16
According to the National Defense Research Committee (NDRC), the AZON improved accuracy by a factor of thirty, and was effective against long narrow targets such as railway bridges for which the system was designed.17 During testing “…with 108 bombs, the selected bombardier achieved 51 weapons within 50 feet of azimuth and averaged 88 feet short, for a CEP of 261 feet.”18
During the war, the Army Air Forces employed the AZON in three different theaters; the 15th Air Force in the Mediterranean, the 8th and 9th Air Force in Western Europe, and by the 10th Air Force in Burma.19 However, as was the case with unguided weapons, in actual combat conditions the AZON failed to achieve the same level of accuracy documented during training. In April 1944, the 15th Air Force initiated AZON bombing against railroad bridges in northern Italy, with generally poor results. In four missions against the bridges, only 10 of 73 bombs were direct hits.20 During late 1944 and early 1945 the results achieved by the 10th Air Force in Burma were significantly better. AZONs were credited with destroying 41 bridges and damaging 12 more, with average observed errors of 131 feet in azimuth and 207 feet in range. Throughout the course of the war the Army Air Force employed over 3000 AZONs in Europe and 1357 in Burma.21
http://74.125.153.132/search?q=cache...ient=firefox-a

[lcm1]

Originally Posted by Carl Schwamberg

Tough to judge. My intial take is the bomb craters are nowhere near the tracks, but a much better copy of the photo is needed.

Yes, that was my first impression Carl, not too good a photo though!

[Listy]

Originally Posted by At ease

That's what Tallboys were for

"The first 12,000-lb Tallboy bombs developed by Barnes Wallis were used on this night(9 June, 1944) by 617 Squadron in a raid on a railway tunnel near Saumur, 125 miles south of the battle area. The raid was prepared in great haste because a German Panzer unit was expected to move by train through the tunnel. The target area was illuminated with flares by 4 Lancasters of 83 Squadron and marked at low level by 3 Mosquitoes. 25 Lancasters of 617 Squadron then dropped their Tallboys with great accuracy. The huge bombs exploded under the ground to create miniature `earthquakes'; one actually pierced the roof of the tunnel and brought down a huge quantity of rock and soil. The tunnel was blocked for a considerable period and the Panzer unit was badly delayed. No aircraft were lost from this raid."
http://www.raf.mod.uk/bombercommand/saumur.html

Yes but go have a look at some of the other targets on the transport plan. Arnsberg Viaduct was visited several times, with both tallboys and Grandslams. It was still standing. Hitting a vertical target with a bomb isn't that easy.

Here we see Bielefeld Viaduct.

You can see the best efforts off the rest of Bomber command (and the 8th Air force I suspect) scattered about it. The Tallboys failed to have any effect, but it took a Grandslam to do that. That's 100m of span dropped. The Grandslam was a ten ton bomb, that was very near the limits of even 617 squadron's pimped up Lancaster's.

[Carl Schwamberg]

Originally Posted by At ease

Carl, do you have any recollection of your father commenting on these

Guided Bomb Development
........

No, his Group was not involved in any of that in 1944. Probablly not in 1945 either. In January or Febuary 1945 he volnteered for a slot as air liasion officer with the US 1st Army & spent until late April away from his Group.

[Gooner]

Culmont marshalling yards, 14-15th July 1944

[Carl Schwamberg]

Unfortunately my scanner is no longer working. I've a dozen or so excellent photos of medium altitude attacks by the 9th AF on bridges, marshalling yards, ect... A few show incrediblly tight groups that make the Bielefeld Viaduct bomb pattern look like a scatter gun. Ufortunately those took months of rigorus effort to achieve.