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!

Magnetic mine firing unit.

A

Alan1

Well-Known Member
Premium Member
Latest acquisition at auction. Retains old label ""brain" unit of German Type G Mine" and reference Gos, so probably originated from HMS Vernon. Electrical components variously dated 9/43, 10/43 and 9/44, all with manufacturers code bpf, and aluminium frame stamped M1 ded M 15065. Late dates and high serial number make it unlikely to be a UK render safe item, so may have been retrieved from continental waters, or, perhaps, from a factory and never actually installed in a mine at all. Presumably from 1000kg Monika or similar if fitted. Technical description (Dr. E C Wadlow) is "Magnetic Needle Firing Unit" and illustrated in Mechanical Engineering Aspects of Mine Warfare.
Paid more than I wanted, but wartime technical equipment in terms of ordnance items are very hard to find now. I am gently collecting V1 and V2 parts, mainly from downed examples in the UK, have most of the V! fuzes etc, but impact nose fuze from V2 is proving to be very elusive. Even the glass cone, let alone the casing and connecting cable etc.
Alan1.DSCN0501[1].jpg DSCN0502.jpgDSCN0503.jpg
 
In reply to Alpini, who is, of course, right, the components were made by bpt and not bpf as I had mistakenly posted. Obviously need a stronger light bulb in the hall where I first looked at it! And to glevum, 260 hammer. Did you bid for it as well? And to Millsbomber, any help re positive id of original mine would be appreciated. I, too. thought it might be from a landmine rather than sea version, but I'm a bit out of my depth - no pun intended - with this bit of kit.
To all three of you many thanks, grateful to you.
Alan1
 
Thank you, I was wondering because "bpt" is the "Telefon- u. Telegraphenfabriks-AG, Kapsch & Söhne" which fits very well for making such a device. "bpf" would be the Pauker AG (Paukerwerke) which was famous for making very heavy machinery like friction presses or punching machines.
 
Morn Alpini, mny thnks for info, grateful to you. I tend to accumulate data and provenance on the more unusual items that come along.
Morn glevum, and it went for more than I wanted to pay as well. But not common, hence my squandering of the housekeeping (again). Looking at what some dealers want to charge for, eg, a relatively common 5, 23 or 36 from the Great War, it didn't seem to be hugely out of reason. Rest of items were all post war, 4.5 practice and the like, except for a number of 12" roundshot that were so heavy that I didn't bother to bid. Having had one rupture repaired I didn't want a repetition. Certainly the old label indicates Gosport, and they had a lot of duplicates and the like in their sheds when Chris was there.
Alan1.
 
It was interesting to see the two 155mm projectiles. I wondered if they were from the 155 TMF project
 
Don't know, out of period for me. Both were, from memory, fired eg's and both were pretty rusty. One made 38, the other 35 hammer. Same buyer, I saw him collect later.
 
I have these photos and some more of the type G sinker mine
 

Attachments

  • P1030974.jpg
    P1030974.jpg
    289.4 KB · Views: 52
  • P1030975.jpg
    P1030975.jpg
    316.8 KB · Views: 45
  • P1030976.jpg
    P1030976.jpg
    305.2 KB · Views: 50
  • P1030977.jpg
    P1030977.jpg
    330.1 KB · Views: 40
Finally found time to rat through the German section of the fuze library and came up with this eg of the LM Zus Z 34B, and a clock, wch, I believe, are both correct for the magnetic mine. The clock has a stud that is depressed by water pressure as the mine sinks and sets the escapement running. Note the panel cut out of the perspex cover, introduced to prevent render safe procedures involving the injection of quick setting fluid in the clock's works, wch was adopted as an alternative method of disabling the balance wheel. All this took some nerve whilst close to a really big charge of HE.
Alan1.DSCN0504[1].jpgDSCN0505[1].jpgDSCN0509[1].jpgDSCN0510[1].jpg
 
Alan,

The "Hydrostatic Arming Clock" is either a Mk 1 or Mk II if the timer goes to approx. 17 mins as shown between the red marks. (The later Mks function between 30mins to 6hrs + etc).

Here's a link to the one I posted back in 2013:

http://www.bocn.co.uk/vbforum/threads/85640-Any-thoughts-on-this?highlight=mine+mechanism

Drove me nuts trying to identifying this over the years and still can't find a diagram nor photo of one!!!!

Cheers
Drew
 

Attachments

  • Unknown1.JPG
    Unknown1.JPG
    92.5 KB · Views: 39
Morn Drew,
Mny thnks yrs, I've seen several pics of clocks, but none particularly clear. Tim sent me a tech description of the mine and render safe gag etc for the fuze, I'll try to see what that might say, and mechanical aspects of mine warfare has a pic wch you can make out if you know what you are looking for. Don't hold yr breath!
Alan.
 
Hi Drew,
Wadlow, Mechanical Aspects of Naval Mining, shows two clocks, one German, the other British, for sterilizers, wch he describes under a sub-para Arming and Sterilizing. The only pic of a clock from a German magnetic mine that I can find is shown in Summary No M S 688/40, Report on the Magnetic Firing System of German Parachute Mines, of Jan 1940, wch also contains detail of its operation from starting to stopping after 17 minutes and circuit diagram etc.
Tim kindly supplied me with that.
Alan.
 
Gag for No 34B bomb fuze.

Was ratting through yet another box of odds and ends and came across this gag. Date of 1971 seems very late, but presumably Bonnex and colleagues still had a need. Label reads:-
Throsper Eng Co Ltd
Patt No 15029 GAG
34B Bomb Fuse
3 off No 15148 Spindle
6 off Spirefix
22 Oct 1971

And the plastic envelope is marked "Tested Non Magnetic"

DSCN0526[1].jpg
 
You must log in or register to reply here.
Top