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Arming Upkeep The Bouncing Bomb

J

jeffmorgan

Member
Hi Everybody. This is my first post and also thanks for the welcome and introduction.

I have a keen interest in military history, I am retired, and have been a member of my local "Military History Society West Australian branch" for a few years, at the moment I am compiling a presentation regarding the wartime history of

RAF 617 squadron, titled " The Dams and Beyond " . I have collected from many sources maps,photographs,and technical drawings and written references from quiet a few books on the subject.

There is only one piece of information that eludes me ! and that is when was Upkeep armed, I have read conflicting accounts as to when this was carried out. One source [Book] states that the bomb was armed in the air just before

crossing the Dutch coast, this was seen as a safety precaution after crossing the North sea/English channel. I understand that the three hydro static fuses fitted to each bomb would have to be unplugged or their covers removed to

expose the fuse chambers to water pressure [ 30 feet ] , but when one considers how Upkeep was slung beneath the Lancaster and that the caliper driving cup completely covers the location of the fuses, arming mid-air would be

almost impossible.

The other possibility states that the arming was carried out by ground crew prior to take off, and that the only fuse to be armed mid-air was the self destruct fuse which was activated by the pull of a lanyard when the bomb was

released [ time to explode after 90 seconds ]

I realize that this is only perhaps a minor point but it has been bugging me for sometime, and when the two conflicting accounts come from perhaps the two best books on the subject.


I feel that perhaps the second option makes more sense, but if someone may be able to shed a little more light on the subject i would be grateful.



Thank you. Jeff Lloyd.
 
Welcome to BOCN Jeff,
I am sure someone will have the answer to your question, but in the meantime here's one for you. One of the upkeep mines has RA2/1832 stencilled on one end, I large letters. D you know what it means I built a replica for museum near York but could not find out what it meant.
Hoping you can help.
Cheers
Gary
 
Hi Hangman. I don't know a lot regards ordnance stampings and markings, but I do know that all the bomb cylinder casings where manufacture by the Vickers works at Barrow-in-Furness and at Elswick and Walker on the Tyne and from there they were sent by truck under a police escort and at night to the Royal Ordnance establishment at Chorley in Lancashire to by filled with the explosive " Torpex" and then onto 617 at Scampton.

These markings may be from either one of the above factories. Jeff.
 
Hi Jeff, welcome to bocn;

According to the book 'Bombs Gone', 'When the bomb-aimer pressed the release button, the calliper arms moved outwards, freeing the spinning cylinder, at the same time arming the hydrostatic pistols.'........it goes on to say.......'To prevent defective bombs falling into enemy hands, a self-destruct time fuze was activated at the point of release'.

A quick look through 'Barnes Wallis BOMBS Tallboy, Dambuster & Grand Slam' indicates that only the self-destruct time fuze was activated at the point of release, suggesting that the hydrostatic fuzes were pre-set and armed by armourers.

One thought I have is that if the hydrostatic fuzes were pre-armed then if the aircraft were to ditch in the sea on the outbound journey then the risk to the crew of the aircraft would be great if the plane were to sink......at 30feet up goes the bomb!!!

I'm sure someone on here will have a definative answer for you......I look forward to seeing others views.

regards Kev
 
Thanks Butterfly. I appreciate the information and everyone else for their quick response. with regards these subjects, some long forgotten, its like peeling an onion the more you remove the more you discover !!
 
I saw a mounted bomb fuze safety fork for sale sometime ago.

It said it was from an Upkeep so I think there must have been some safety forks that were removed before flight.

This maybe for the self destruct fuze rather than the hydrostatic fuzes since it looked similar to other bomb safety forks that I have seen.

It was outside my main area of interest so I didn't buy it.
 
glevum said:
I saw a mounted bomb fuze safety fork for sale sometime ago.

It said it was from an Upkeep so I think there must have been some safety forks that were removed before flight.

This maybe for the self destruct fuze rather than the hydrostatic fuzes since it looked similar to other bomb safety forks that I have seen.

It was outside my main area of interest so I didn't buy it.
Click to expand...

Hi glevum, Di the fork look like the one I this artice?

http://www.google.co.uk/imgres?star...ed=1t:429,r:75,s:100&tx=70.780029296875&ty=74

Cheers Gary
 
Here's a page from the book of Peter Voss
 

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Yes Gary,

It looked like that.

You can see it in place on the Hydrostatic Fuze in Fusse2004's post above.

Will.
 
I have seen a drawing ages ago which showed an eletrically armed self-destruct fuze for Upkeep, being designed by a Gov Ordnance Dept. This got over the problem of allowing the spinning of the weapon immediately after arming, as a slip-ring was used. As I understand it, Barnes Wallis got tired of waiting for this fuze to be completed, so simply modified a standard pull-operated mechanical fuze, as used for flares! This is why an unexploded Upkeep may have been found by the Germans, as immersion in water would probably extinguish the pyrotechnic time fuze. Incidentally, not often mentioned is that Wallis may have originally intended to spin the weapon for use in blocking a canal, as the idea was that the weapon, spun in the opposite direction, would roll along the surface, until it fell into the canal, so overcoming a difficult aiming problem. This is shown in his British patent.

Martin.
 
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