View Full Version : I watched that What the Dam Busters did after . . .

Loose rivets
31st Dec 2014, 01:27
Fantastic. It just got more and more ambitious.

After bombing the V2 'Dome' there was another very successful raid on a set of super-guns. I had no idea, utterly bewildering. Multi-story guns that fire more charges as the shell progresses up the barrel. Can anyone remember the name.

31st Dec 2014, 01:46
Where did you see it? Is it on YouTube?

31st Dec 2014, 01:52
Try googling V3 cannon.

31st Dec 2014, 03:52
I just watched it on Youtube, its called "What the Dambusters did next". Great program.

31st Dec 2014, 06:07
Hochdruckpumpkannone. Literally, High-Pressure Pump Cannon. And they were built at Mimoyecques, on Cap Gris-Nez. They were untrainable, aimed at London, range alteration was possible by varying the amount of charge.

General de Gaulle was most upset that the British thoroughly trashed the place because it was French territory. He didn't seem to mind what their sole use was.

There is a museum there and the gun 'pits' themselves are essentially tombs for the workers who were inside when 617 and IX Squadrons paid a visit.

John Hill
31st Dec 2014, 07:44
I think the 'Iraqi gun' was a different principle.

If I recall correctly. The barrel would be filled with a gaseous explosive and sealed at each end with something like 'glad wrap'. The projectile would be fired by a conventional gun through the gas filled barrel, detonating the gas as it did so. The projectile would be a loose fit in the barrel. Provided the projectile entered the gas at supersonic speed the explosion of the gas would never get ahead of the projectile which would continue to accelerate under the increasing pressure of the exploding gas.

tony draper
31st Dec 2014, 07:50
Dr Gerald Bull I think he met with a accident.:uhoh:

joy ride
31st Dec 2014, 08:16
I saw part of the Dambusters film (while working) then the "What the.." programme afterwards. I have seen both before, but worth a 2nd viewing. 22,000 lb bombs, what a load!

joy ride
31st Dec 2014, 09:35
If that German super gun had been completed and used the results would have been catastrophic. Thank heavens we had Lancasters and Grand Slams!

Pinky the pilot
31st Dec 2014, 09:41
I recall many years ago my late Father and I seeing a TV show featuring footage of a 617 Sqn Lancaster carrying and dropping a 'Grand Slam.'

Remember Dad commenting along the lines of that he didn't remember a Lancaster having such dihedral in the wings.:ooh: Then the grand slam fell away, the Lancaster's wings seemingly straightening and the aircraft itself suddenly climbing!:eek:

As I recall, the Grand Slam's weight was always quoted as either 22,000lb (or 10 tons) Anyone know just what was the exact weight?

31st Dec 2014, 09:53
That super gun is/was a very handy piece of kit. It was capable of putting a shell into space. I don't think low earth orbit though. However on launch of this projectile, no heat trace from a rocket for example would be detected. I am sure someone else has picked up the baton.

Yes Dr. Bull was eliminated for his efforts. Mossad?

31st Dec 2014, 09:55
9979kg, is that exact enough? Unless you believe the Rambo IV wiki that states its 200,000lb's. See "Grand Slam" bomb - Rambo Wiki (http://rambo.wikia.com/wiki/%22Grand_Slam%22_bomb) Must have needed a lot of boost on the 4 Merlins to carry that into the air ;)

31st Dec 2014, 11:40
a lot of boost on the 4 Merlins
What a fantastic piece of engineering the Merlin was, to be used in so many different aircraft.
Lots of things have been credited with 'winning the war', but the Merlin has to be well up the list.

31st Dec 2014, 12:46
There were other conventional long-range German guns in the Cap Gris-Nez area, with a range which easily reached Dover and caused numerous fatalities throughout much of WW2.

However, their maximum range was pretty impressive even without that special V3 "High Pressure Pump Cannon" action, which thankfully never fired at London due to those effective RAF bombing raids.

Between 0030 and 0400 hours on 13th June 1944, those conventional guns fired 7 or 8 shells which reached the Maidstone area, a distance of 50-60 miles. These were intended to add to the anticipated shock effect of the first V1 flying bomb attacks, which commenced around that time. One of the shells exploded about 500 yards from my family home, hitting a house on the corner of Hayle Road and Campbell Road and killing a woman in her bedroom. I saw the wrecked corner of the house the following day as I walked past it with my mother, and although only 5 years old, the sight of the house corner torn away, with sagging floor and patterned wallpaper with tilted pictures still hanging there has etched itself forever in my memory. The house is still there today, and one can still see where the new brickwork was built to refurbish it. A permanent memorial to the poor woman who certainly didn't expect to be hit by a German shell fired from France, when she went to bed the night before.

P6 Driver
31st Dec 2014, 14:27
If a Lancaster flew at a level (medium) altitude and released a 22,000lb weapon, how much would it climb when the weight is released?

31st Dec 2014, 16:46
Whatever an instantaneous 22,000b increase in effective lift would do. I'm sure some whizzo at the maths will be along to answer shortly.

tony draper
31st Dec 2014, 16:52
Surely a 22000 lb mass would carry some of the momentum off with it as it fell away?:uhoh:
I'm confused :{

31st Dec 2014, 16:58
MTOW (with 22000 lb bomb - and fuel) was 72000 lb, so, losing 22000 lb would leave 50000 lb (less fuel used).

The momentum of the bomb could be considered 'isolated' when attached to the aircraft (same velocity) and then when departed - just the vertical vector of the 'weight' needs to be considered.

31st Dec 2014, 17:01
But it also contributes to the overall drag of the aircraft/weapon combination. Once relieved of the weapon drag the airlift would accelerate if the engine power remained the same. That's what used to happen on my jet when I let bombs go.

31st Dec 2014, 17:07
Once relieved of the weapon drag the airlift would accelerate if the engine power remained the same.
All the better to get away from the scene of the bang.

31st Dec 2014, 17:19
The largest guns placed by the Germans locally were at the Mirus Battery in Guernsey. There were four of them captured off a WW1 Russian Dreadnought. They were refurbished by Krupp and had a range of 31 miles.

Batterie Mirus (http://www.festungguernsey.supanet.com/batterie_mirus.htm)

joy ride
1st Jan 2015, 07:31
The Me/Bf 109's engine had injection; had RR followed suit it would have denied us the opportunity of joking about Tilly Shilling's Orifice.

1st Jan 2015, 07:53
The ten ton Grand Slam had its limitations. Several were dropped on Lorient to try to knock out the concrete sub pens there. One bomb actually hit the target (an indication of the limitations of free falling iron bombs, even with the best sights available - admittedly dropped from 22,000ft) but despite hitting the roof of the concrete structure at the speed of sound and detonating correctly, the bomb did not penetrate into the U-boat pens below.

The RAF gave up bombing the pens, at Lorient anyway, and concentrated on sinking the U-boats at sea. Over 40% of U-boat losses were to aircraft, a figure as unexpected as the large percentage of ships sunk by U-boats' guns rather than their torpedoes.

Loose rivets
1st Jan 2015, 08:08
Yes, the sea was a good cloaking device.

Thanks for the answers, chaps. It was difficult to gauge the scale of the imagery, but the concept left me breathless. It seems the madman had ordered a very special killing machine to be built in those multilayer tunnels. Fantastic job destroying something like that, and of course, the brave 'intelligence machine' seemed to have guided us to the exact spot.

1st Jan 2015, 09:57
and of course, the brave 'intelligence machine' seemed to have guided us to the exact spot.

Yes, you are almost certainly right that Bletchley Park and the Enigma code breakers were involved in the intelligence, LR. But a simpler geographical factor may have also entered into the site location problem. The Cape Griz-Nez promontory was the closest part of enemy-occupied territory to England, and to its capital city. The County of Kent, where I spent the first 6 years of my life during WW2, wasn't dubbed "Hellfire Corner" for nothing. Because of its proximity to the enemy forces, they threw everything they could in our general direction with terrestial and naval artillery, dive-bombing and altitude bombing, fighter machine gunning attacks, and V1 flying bombs (over 1,400 of them crashed and exploded in Kent alone), and finally the supersonic V2 rocket bombardment.

But of course, we are all friends now ...

1st Jan 2015, 20:31
Ok for level flight, but those SU carbs made it absolutely useless in fighters...The SU had its problems, a problem not suffered by the Packard Merlin with its Bendix injection carb (fitted to various Lancs, P-40, Mosquito, Hurricane, Mustang, Spitfire).

1st Jan 2015, 20:47
603, perhaps this is the house.