Decoding a Bombing Plan

Hi Air Ministry

Here is a copy of the form that I have finally managed to get a copy of. See what you think.

I think I was over eager about two flashes – I should have read it as switch position 1, station 16 a Flash. I just read 1 and 16 flash!

Cheers
James

Hi James,

If I’m interpreting your last but one post correctly, the total bomb load was 1 x 4,000lb. Cookie, six Small Bomb Containers, each loaded with 150 x 4lb incendiaries and six more, each loaded with 12 x 30 lb incendiaries.

A visual check for hang ups could be made from the bomb-aimer’s compartment. There were two small windows through which he could shine a torch into the bomb bay.

I’m not sure your interpretation of the sequence of events is entirely correct.

It looks as the task of the Bomb Aimer is more than just pressing a button when a Cookie is involved. After pressing the button to start the sequence he might have waited to feel the aircraft lift as each bomb releases. Perhaps he held his breath hoping to feel the rise when the cookie dropped. What if he didn’t feel it? Did he check the Bomb Bay anyway just to see? Were there two flares – one for the first salvo and the second for the second which he might have delayed pulling the PEG for – well how long?

James

Hi Air Ministry

It’s a pity that you don’t have it any more, however I’ve re-visited the form following your comments and the sequence looks like this:

Selection 1 – Position 16 – Flare – going first?
Selection 2 – Position 1 – 6 x 12 x 30 – what would these have been – phosphorous or something else?
Selection 3 – Position 7 – 6 x 12 x 30
Selection 4 – Position 8 – 6 x 12 x 30
Selection 5 – Position 13 – 4000lb Cookie – First release and it should go now
Selection 6 – Position 13 – 4000lb Cookie – another pulse – just in case the last one didn’t go?
Selection 7 – Position 9 – 6 x 12 x 30
Selection 8 – Position 10 – 6 x 12 x 30
Selection 9 – Position 13 – 6 x 12 x 30
Selection 10 – Position 13 – 4000lb Cookie – Yet another pulse – belt and braces?
Selection 11 – Now hits the PEG BEFORE activating position 11? Is this to check it has gone or to give a longer delay that 0.5 seconds?
Selection 11 – OK the Bomb Aimer has pulled the PEG and the rotor carries on – now different stores are dropped – POsition 3 – 6 x 150 x 4 – must be phosphorpus surely?
Selection 12 – 6 x 150 x 4
Selection 13 – 6 x 150 x 4
Selection 14 – 6 x 150 x 4
Selection 15 – 6 x 150 x 4
Selection 16 – 6 x 150 x 4

That seems to be it! The cookie dropped to blow the roofs off, followed by the phosphorous bombs just as the stories relates.

The Stirling had an electrically released flare replaced by the tri-cell much later.

I am not certain that the bomb sheet relates to a Lanc, but it does look as if the whole sheet is now decoded – many thanks to all

James

Someone with the device itself could answer the question of what effect the PEG has 🙂

Quite possibly, but having sold mine some while ago, I cannot comment! However, I think that the “stop” on the modified distributor was to avoid the need for the bomb-aimer to physically hold the contact arm to halt the bomb dropping. It was something to do with the release of a mixed load of H/E and 4lb. incendiaries, with widely differing terminal velocities. This last bit is cited in Despatch On War Operations by Sir Arthur Harris.

AP1095 fully describes the Mk. VI Distributor but makes no reference to flare release.

Neither will you find any comfort from the Lancaster Vol. I. I have several editions (early and late, different Marks, etc) and none refer to a bomb station 16. None give an explanation of the photoflash bomb dropping arrangement, or show any circuit wiring for the flare chute. Early Lancasters had a single flare chute which was manually controlled. Mod. 430 introduced a multi-cell flare chute but I have never seen any details about this device, i.e. whether it was mechanically or electrically controlled, or both.

I have details of the Tri-cell Flare Chute contained in AP1664 (Bomb Carriers). This appears to have been a “standard” type, suitable for installation in different types of aircraft as it has a Stores Reference of 11A/2030. This device was capable of mechanical or electrical operation. There was also a single Flare Chute, Mk. V, for which I have no details, but I believe both could take the 4.5″ Photoflash flare. Here is an extract from AP1664, Bomb Carriers, describing the various release methods of the Tri-cell chute. However, according to Sir Arthur, the chute was not ready for service before the war ended!

So we still have some way to go on bomb station 16 in my opinion.

Hi Bobkat

Thanks for the reply.

The AP for the distributor would supposedly have a long technical description of the function and operation of the distributor and hopefully describe what the PEG quadrant does. The circuit doesn’t have any of that sadly.

Cheers
James

OK

Looks like station 16 would be the electrically operated flare chute at the back. O.G. probably means ‘own group’ (including Halibags).

Anyone have an AP that describes the Distributor?

Cheers
James

Hi Air Ministry

Someone with the device itself could answer the question of what effect the PEG has 🙂

The answer to station 16 could lie in the circuit diagram of the Lanc, I don’t have one sadly.

Given that the only purpose of any of the Bombers was to drop bombs the whole subject seems a little unresearched. Now it’s going to bug me! I’m wondering how much the Bomb Aimers were involved in the calculations, did they just learn to use the Bomb Sight by reading the instructions, or was there more to it?

Cheers
James

I don’t know enough about bombing methods to explain why the device might have been used – was it to stop the rotor or pause it for some tactical reason?

Also, bomb station 16 on a Lanc? I’ve come across it before and wondered about it but have never had the time to investigate it in depth. One thought occurs – the Avro Twin Adaptor, a device which enabled two bomb carriers to be carried at one bomb station. Would one such device, if fitted on an operation, create station no. 16?

I doubt there are many bomb-aimers or armourers left to ask!

Abadonna

I think that you may be right

Phil

Also a good thought!

Cheers
James

Safety ht 5000. Will that be the minimum height at which to release the bombs ie 5000ft. If dropped lower than that then potential damage to the aircraft, I think I read minimum for a cookie was 4000ft

Hi Air Ministry

PEG 11 – Brilliant, far too esoteric to have guessed that meaning, however doesn’t that mean that the stores 12 to 16 wouldn’t have been released? On the form there are definitely stores up to Station 16?

Still don’t know where station 16 was either?

Cheers
James

You have some obvious stuff there, including terminal velocity, safety height, etc.

DISTR .5 suggests to me the setting of a .5 second delay on the bomb distributor, i.e. .5 delay in the release from each bomb station.

Also, I have a feeling that P.EG. No 11 might actually be PEG No. 11. Some distributors were modified with an extra quadrant into which a peg could be inserted to stop the rotor at a certain position on its travel.

By chance, the one I had in my collection and which I photographed for use in my Illustrated Guides, Vol. 2 had this mod. and the peg was still in situ at the No. 11 station!

I would have thought Angle might be the Bombing Angle i.e. the angle between vertical and the target at moment of bomb release.

Hi Denis

I would bet that you are right, also TV has been suggested as Terminal Velocity – backed up by an article in flightglobal. Angle seems to be the angle at which the bombs hit the ground and safety hieght perhaps some fuzing setting. DISTR possibly the timing between releases – half a second.

PEG. No is still a mystery.

Cheers
James

I think the spelling of cookie is just simply a spelling mistake. 433 were a Canadian squadron who operated Halifaxes and finshed the war on Lancasters. While H’bag might well be his version of shorthand for ‘Hallybags’, the nickname for Halifax bombers, might the H’bago actually be H’bags ??
just my take on it and not a reliable source 🙂