What's new
British Ordnance Collectors Network

This is a sample guest message. Register a free account today to become a member! Once signed in, you'll be able to participate on this site by adding your own topics and posts, as well as connect with other members through your own private inbox!

Johnny Walker bomb

B

Bellifortis

Well-Known Member
Hi,
recently i was able to peruse a german navy Bomb-disposal Manual. This is dated 1942. But, like all bomb-disposal manuals of that time, it was arranged as a loose leaf file/ring binder system. This was necessary because all the time new information was aquired. This navy manual had to be updated at the minimum 2 times a year. In this manual the "Johnny Walker Bomb" was named a "New British Bombmine". It contained a good foto of the bomb and 2 views of the fuze. The fuze-fotos show the fuze with the safetypin-labels attached, like it came new out of its storage box. Where could the german navy have aquired such a Top-Secret item ? I could not see up till what date the changes in the manual were added. The german EOD, at that time, had a good idea of the function of the fuze, but apparently did not realize that the bomb had an oscillating function. They thought that hydraulics only had a time delay function for the fuze.JW Bomb fuze.jpg
Regards,
Bellifortis.
 
the JW bomb was only ever dropped on the attack of the Tirpitz in the kaa fjord in Norway.according to the book "bombs gone"the development and use of british air weapons the germans never produced a drawing or info on this bomb and the remains of one werent found until 1987.
 
Hi,
you see, that the info in the book is wrong. See the above foto from the the german navy demining manual of 1942. There have been additions to this manual till 1945, so I do not know when the info about the JW-bomb was added. It includes a full explanation of the fuze workings, full measurements of the bomb. The only thing the germans did not seem to have understood, is the oscillating movement. Thats always the problem with info written by someone. You have mostly no means of verification. The more info we are deluged with, also the more false info gets into the system.
Greetings,
Bellifortis.
kiwieod said:
the JW bomb was only ever dropped on the attack of the Tirpitz in the kaa fjord in Norway.according to the book "bombs gone"the development and use of british air weapons the germans never produced a drawing or info on this bomb and the remains of one werent found until 1987.
Click to expand...
 
1989rjb said:
Interesting.......Norman (Bonnex) any thoughts?
Click to expand...

Thoughts, yes, but I was as surprised as Bellifortis to see the labels on the fuze images. One explanation might be that the images were included in amendments to the manual after the war (as alluded to by Bellifortis). Another explanation could be that a JW Bomb was recovered complete with pins and labels after the raid which might suggest that the safety arrangements were left in place until the aircraft was close the target. Is this a possibility? I don't know enough about the disposition of the bomb in the aircraft to know if this is at all possible but I am inclined to think it might be a good idea. The raid was 1944 of course so 'explanation 1' is still needed.

According to a note from Macrae's Papers (Held in the Churchill College Archives, Cambridge) the development of the JW Bomb started in August 1942, design cleared in April 1943 and 100 were delivered in July 1943.

I did make some minor contributions on MD1 bombs to'Bombs Gone'. Arthur Hogben (co-author) did know one of the German EOD people and I expect Arthur was advised about the existence of German documentation on the bomb. I do know that the authors tried very hard to determine the actual operational use of the MD1 air delivered weapons - not an easy task.

See also http://www.bocn.co.uk/vbforum/threads/28752-Johnny-Walker-Bomb
 
Last edited:
Bonnex said:
Thoughts, yes, but I was as surprised as Bellifortis to see the labels on the fuze images. One explanation might be that the images were included in amendments to the manual after the war (as alluded to by Bellifortis). Another explanation could be that a JW Bomb was recovered complete with pins and labels after the raid which might suggest that the safety arrangements were left in place until the aircraft was close the target. Is this a possibility? I don't know enough about the disposition of the bomb in the aircraft to know if this is at all possible but I am inclined to think it might be a good idea.

I did make some minor contributions on MD1 bombs to'Bombs Gone'. Arthur Hogben (co-author) did know one of the German EOD people and I expect Arthur was advised about the existence of German documentation on the bomb. I do know that the authors tried very hard to determine the actual operational use of the MD1 air delivered weapons - not an easy task.
Click to expand...
Hallo,
@TIM, who did a lots of research on this special bomb should be able to give some knowledgable answers. 1.) How many bombs were built and used ? 2.) when was this bomb used for the first time and when was it used for the last time. There were quite a few duds, even on land. So many, that even quite recently one was found, rather intact, in Norway. Regarding the 2 safety pin labels : I assumed up till now, that these were removed and exchanged with safety-wires with strops attached to the bomb-throwing-mechanism of the plane, by an armourer, at an airfield, before lift-off. The Navy bomb-disposal manual, the foto came from, was dated 1942 with 17 additions up till ? (1945 latest). Just before I found another description of the bomb, in the german "Minenräumvorschrift No.13" (Minedisposal Manual No.13) dated 1946. There it is called "British Bombmine A". This contains the same fotos. All are readable online, but not downloadable. The manuals have been transcribed into modern HTML format. Many, even german young people, have problems reading the old german typescript. I personally even like it and have no problems at all. So I prefer reading the original. The safing instructions given in the manual say: You should have at hand 2 pieces of wires, one thin one, the other a little bit stronger. Then you should depress the smaller plunger on the right side of the fuze far enough, so that you can insert the thin wire through the horizontal holes and so keep this plunger depressed. The big central plunger should never be depressed or even touched (danger of detonation) and the strong wire should be inserted through the horizontal holes and the plunger to safe the fuze. Because of all this I assume, that the safety-labels, like with all other british bomb-fuzes, are removed before lift-off of the plane.
regards,
Bellifortis.
 
Johnny Walker

Hi,
I just realized that I have the manual myself in my digital library. This one is even later (I presume Sept.1944), than the one I took the fuze foto from. This means, that rather precise bomb particulars were known by german navy EOD, most probably on or before spring 1944. I wanted to show you the complete 3 pages, but , they are in TIFF-format, which BOCN does not accept and I do not know how to convert it to JPG or PDF.
Greetings,
Bellifortis.
 
The image is not of an actual item, it looks like a drawing from a manual, perhaps the Germans had obtained one by sneaky means.
 
As yet, I haven't found the contracts for the J.W. Bomb. I've seen a figure of 400. They took 144 on Op. Paravane.

As for the 'Transit Pins' I think there is two possible explanations -

1) Human error, which is highly probable as the attack was flown from Russia, the ground crew were flown out there and it was far from ideal conditions (as described in the post Attack report).

2) The transit pins shown on the German document are incorrect. The right hand pin should be read 'This pin to be removed after Gas Pressure Test'. I strongly suspect that the German equivalent of MI10 must have had a good supply of these and two were utilised in the photograph to add further detail.

Bellifortis mentions that these photographs come from a German Naval Bomb Disposal Manual, they probably didn't see fit to share the information with their Land based counterparts as it was, so to speak a naval store. Arthur Hogben's German EOD contacts were presumably all land based and thus would have been unaware of their Naval colleagues' findings.

TimG
IMG_0008.jpgDscf0339.jpg
 
Thanks Tim for your explanation. That is correct, Navy , Army and Airforce are 3 different teams and specalisations. Every munition being used in water is Navy responsibility , with a few exceptions. I do not know how that is handled in Britain. Even today an Army "Feuerwerker" is not taught anything about naval mines. Before I checked "Tirpitz" on Wikipedia. They tell of 24 tallboy attack on 15.9.44 , 32 Lancaster attack on 29.10.44 and then the deathstroke on 12.11.44 with again 32 Lancasters which dropped 29 Tallboys with 2 direct hits. No more info. How often were the JW-bombs used ? In my digital edition the JW-bomb article of 3 pages is stamped "Change 118" which I narrow down to before 16.9.1944 In the online version the JW-bomb item is "Change 117". So these descriptions and fotos were made before the above 3 attacks. By the way, the whole www does not know an english translation for the german word SPERRWAFFEN. Langenscheidt , Cambridge , Duden = 0 That's crazy ! Google comes up with a childish "locking arms". The german Wikipedia has no article about Sperrwaffen, but a few words to lead one in the right direction. The manual I quote was issued by the Sperrwaffeninspektion. The JW Bombmine belongs to the group of Sperrwaffen. What is the correct term in english for SPERRWAFFEN ? I'm quite shure that this manual was translated at the end of the war, because it was important for the postwar demining effort. All belligerents inventory is covered.
Regards,
Bellifortis.
P.S.: I made a scan of the 1.page. Please Tim, have a look at the picture of the bomb. How was it made ? What's your experts thought ?
 

Attachments

  • JW-Bomb SCAN.pdf
    362.6 KB · Views: 33
Last edited:
Hi @Snufkin,
yes, I foloowed that discussion. The reason I asked @tim to have a look at the picture of the german manual is, that I have no experience with original british labels on fuzes. So, I can not discern if a picture is a good artists paintjob or a real foto. In a lots of international munitions literature, especially US, you find many items that are the result of technical intelligence and so only exist on paper and not in reality. I was surprised to see such a detailed picture of the JW-fuze in a german WW2 demining manual. The above inputs by different members sheds some new light on the subject.
regards,
Bellifortis
 
In all probality a photograph. I find it inconceivable that the Germans didn't recover an intact bomb. The Lancaster crews that dropped the J.W. bombs reported that a number landed on land. This was a daylight raid and as the J.W bomb was parachute delivered, the crew on the Tirpitz would have witnessed these landing. Furthermore, post attack, there would have been a substantial number of parachutes floating in the fjord, plus explosions from the J.W. bombs detonating when their gas supply exhausted. The Germans would have to investigate this aspect of the attack to ascertain that there was no further threat to the Tirpitz or other vessels using the fjord. If they didn't find any in the fjord they would have found some of those that landed on land.

As for Sperrwaffen, would Blockade weapon make sense?

TimG
IMG_0010.jpg
 
TimG said:
In all probality a photograph. I find it inconceivable that the Germans didn't recover an intact bomb. The Lancaster crews that dropped the J.W. bombs reported that a number landed on land. This was a daylight raid and as the J.W bomb was parachute delivered, the crew on the Tirpitz would have witnessed these landing. Furthermore, post attack, there would have been a substantial number of parachutes floating in the fjord, plus explosions from the J.W. bombs detonating when their gas supply exhausted. The Germans would have to investigate this aspect of the attack to ascertain that there was no further threat to the Tirpitz or other vessels using the fjord. If they didn't find any in the fjord they would have found some of those that landed on land.

As for Sperrwaffen, would Blockade weapon make sense?

TimG
View attachment 144716
Click to expand...
Hi Tim,
as to the translation, that's how I would translate the term: "Blocking Arms" or"Blockade Arms", your "Blockade Weapon" would also be correct. I just was intrigued that the whole WWW did not come up with a translation. Regarding the Tirpitz raids, Wikipedia gives as the first date 15.9.1944 . The manual was brought out around 16.9.1944, so the info on the JW-bomb was prepared at some time before that date. Do you have any info when and where this bombmine was used, especially the first date of use is interesting ? The description of the JW-bomb appeared already at a more early date as "Deckblatt 117"(117th change of the 1942 edition). To get an exact date, I would have to find an archive with a complete, well kept manual. Mostly these "Deckblätter"which show the date of the change are thrown away once the change has been included.
Regards,
Bellifortis.
 
There may have been a confusion among the German EODs between the Johnny Walker and the Buoyancy bomb - this last one was use successfully against the Bismark - the JW seems to have been a more complex development of the BB bomb, but on the same "oscillating air-dropped mine" principle .
250lb Buoyancy Bomb data.jpg 250lb Buoyancy Bomb drawing.jpg 250lb Buoyancy Bomb.jpg
 
You must log in or register to reply here.
Top