BobKatThanks, Air Ministry – very helpful diagram. Point taken about the perspex on either side of the frame – it keeps on getting in the way!!
However our piece (the metal of which seems to be intact) now seems to be of the right length and with the right number of bolts. Maybe we are getting a little warmer? It is difficult to make out how the inner frame fits into the outer one in my picture, and whether the perspex did or did not overlap the inner frame. There may have been a small space? Probably just wishful thinking!
Not for the first time, we seem to be establishing what it is not, thereby narrowing down the possibilities of what it is!
Unless someone can come up with further clarification, I think we may have to move this from the “unidentified” to the “too difficult” box!!
BobKatPeter,
You’ve got me thinking again. What about the escape hatch? I have seen a picture, but don’t know whether its from a Lancaster. The short side seems to have the right number of bolts.
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Picture attached from ebay. Looks possible?
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Second picture attached – close-up from exterior.
BobKatAir Ministry,
That was pretty emphatic – many thanks – good to have an authoritative source! The best we seem to be able to come up with is that it might be related to a repair or modification to a perspex covering.
One thing that can be said is that the metal strip seems to match that used on the FN4 turret, and that would lend some credence to the theory that it could be a repair using available metal parts, and therefore possibly turret related.
Back to the “unidentified” box it seems to have to go!!
BobKatPeter , exactly as you say – it has no metal tabs, and that is what has left me wondering.
turretboy, many thanks for your comments. I assume you have no further thoughts about our piece 31 following my post #142? (This may be complicated by the fact that we might have an FN4 turret).
As I understand it, the FN120 was a variant on the FN20 turret introduced in late 1944. The Lancaster Manual (AP2062A) of May 1944 refers to the FN20 turret which, at that time, was presumably the standard rear turret fitting. As far as I can tell, its metal framework is quite different to what we are looking at – bolts more widely spaced, etc.
ED908 was built by AV Roe as part of a batch of mixed Mk.I and Mk.III Lancasters and was completed in around April 1943. I can find no reference to the FN4 turret ever being used on the Lancaster, but I suppose it could just be that some of this early batch of aircraft were fitted with the last remaining FN4 turrets previously used on the Manchester??
It is the picture below that I find so convincing. Everything looks right about the upright part on the right – the width of the metal, the spacing between the bolts, and their being offset to one side. Our piece is clearly not one of the lateral or diagonal supports – one has metal tabs, and they are both thinner with their bolts placed centrally. It is that bit of perspex that is sticking out to the right on our piece that seems odd. Could it be that the perspex overlapped the metalwork by a fraction to help provide a “snug” (??) fit to the door frame?
Hmmm ….. more head scratching I fear!
BobKatPeter, sorry to be the cause of more head scratching!!!
I have previously tried to find some close up pictures of the canopy in sufficient detail to show the bolt placings on the cross braces and supports, but so far without success. Nothing that I have found looks quite the same as what we have, except on the FN4 turret pictured…..
Do you (or does anybody) know if this turret was ever fitted to the early Lancasters? If so, then this would seem to be a possible answer.
BobKatSome identified items: 5 – Canopy/cupola framework
Thanks for your enthusiastic comments WV-903 – I will also have to try to find an appropriate Lancastrian brew with which to celebrate!
No more thoughts on item number 33 over the weekend. Most of the metal on the aircraft would presumably have been aluminium or steel. On the assumption that the piece has been correctly identified as being made of copper, then its use would most likely have been as a conductor of heat or electricity. What were those “H” shaped aerials used for, and would they have (what appears to be) a solid copper component? Or, changing tack completely, could it be part of a temperature measuring device???
It’s probably time to move on, but any more thoughts will be welcome.
Staying with the theme of gun turrets, this next item, number 27, was found some while ago, again not far from the Monica system junction box, so possibly from the rear turret? I have described it as an identified item, but it is slightly curious in that it does not quite seem to fit with the pictures I have managed to find of the main canopy and turret cupola framework.
The attached picture shows the piece photographed from both sides. It seems to be a double strip of metal bolted together with fragments of perspex, which protrude in both directions, attached on one side. It seems, therefore, not to be an edge piece that was attached to the main fuselage, but something from the central part of the canopy or cupola. Its bolts are placed off-centre, unlike pictures I have seen where they all, with one exception (see below), seem to be placed centrally.
If it is from the main canopy, I can’t see how it would have been attached to the spruce frame. If it was from the central part of a gun turret (if the rear, presumably the FN20), then would it not be expected to have bolt fittings extending on both sides of the metal strip? Here the perspex is attached by bolts passing straight through the metal strip, and the spacing between the bolts of the piece found looks a little closer than in the pictures I have seen of the FN20. At the right the perspex (seemingly intact with a straight edge) extends slightly, suggesting that this might be an upright piece and that the picture needs to be turned through 90 degrees to see how it might have fitted into the frame. The metal does not appear to have fragmented: if it has snapped, it was with a clean straight break. It has seven bolts along its length. It looks too short to be from the inboard end of the main rear turret frame of an FN20 turret and the bolts seem to be too closely spaced, although this is a point at which the perspex might overlap the metal strip?
I am drawn to the conclusion that it looks more like the upward frame from the inboard end an FN4 turret (pictured with acknowledgements to spitfirespares.com) which had a different style of framework, but I am not aware that these were ever fitted to the Lancaster. ED908 entered service in around April 1943 – perhaps early enough to have the old style of turret? It may be, of course, that I am wrong in my assumption that it was most likely to be from the rear turret, and it could be from one of the others – the FN5 front turret or the FN50 mid-upper turret, but neither of the structures of these seem to be quite right.
This is perhaps where turretboy’s knowledge would be of great help?
BobKatThanks for your thought, Peter. Maybe others will follow?
Air Ministry, that’s a fascinating graph – many thanks for that. As you say it establishes that ED908 was likely to be carrying the Monica system.
BobKatAn afterthought to the identification of the Monica aerial connection: we have both the junction box (seemingly bolted to a piece of fuselage, although the diagram suggests that the back plate is an integral part of the junction box) and the connecting socket for the antenna. If the aerial was not in place, then there would presumably be no need for the removable connecting socket still to be attached to the junction box. This would suggest that the Monica warning system was therefore on board the aircraft when it crashed.
Air Ministry mentioned DORIS (Department of Research & Information Services at the RAF Museum, Hendon) as a source of information for what equipment was on board. I have obtained Form 78 from them – this gives the history of the aircraft – built by AV Roe, with Merlin 28 engines, and its squadron allocations until reported missing, but nothing about the equipment on board. Curiously the information I have came from the personnel records of the Canadian mid-upper gunner! This was a marvellous source of information and included a copy of the telegram sent on 21 July 1944 from 582 Sqn to the Air Ministry. It gave the serial numbers of the engines and the airborne radar equipment carried, as well as details of the crew and their next-of-kin, etc. Much more information than is available from the UK personnel records released to members of the public (as distinct from next-of-kin). I have the Casualty report reference number (dealt with by No.1 MREU – the Missing Research & Enquiry Unit), but although there is a reference for these reports at the National Archives, they are not yet available for viewing.
I have some more information from France about item 33 (post #118). This piece was found close to the Monica junction box, so might well also have come from the rear turret area. It is made of copper or brass (“cuivre” translates as either!), is about 16mm, or a little more than half-an-inch, in diameter, and appears to be solid rather than hollow. It doesn’t seem likely to be part of the aerial if it is solid – maybe part of one of the guns???
Any ideas, anyone?
BobKatVery many thanks, Air Ministry, for the time and trouble you have taken in providing these details. I note your cautionary comments about switches and terminal blocks which could be from anywhere on the aircraft, but I think we can safely say that the Junction Box Type 25 with its reference number 10AB/288 is clearly listed as part of the Monica radar system.
I have a note that ED908 was equipped with IFF Mk.II (ARI 5025), Gee Mk.II (ARI 5083) and Oboe Mk.II (ARI 5582) when it was shot down. There is no mention of Monica, perhaps because its use on the aircraft had been discontinued following the discovery that Luftwaffe night-fighters were homing in on the broadcast – I don’t know exactly when in the summer of 1944 that would have been – but perhaps the receiver and transmitter had been removed, and maybe the aerial as well, just leaving the “permanent” connection point bolted to the fuselage? I can find little information about Monica Mk.II (ARI 5222 apparently with transmitter/receiver TR3207) and it would not be surprising if the Mk.III version (ARI 5617) replaced the Mk.I (ARI 5122), but unless some more pieces are found amongst the wreckage, we can only speculate as to which version was on board.
What seems to be apparent is that the Type 25 junction box was common to both systems.
Thanks again for your help.
BobKatJunction Box Type 25
The attached completes the picture of a splendid combined effort – many thanks to all those concerned, particularly the RAF Museum at Hendon for getting us on the right track with the details from AP1086, then WV-903 and the Duxford Radio Society people for their thoughts, Peter for the photographs, and finally Air Ministry for the diagram.
Another challenge for Laurent to find what, if anything, remains of the aerial!
Air Ministry,
Does your documentation have an AP number, or is it still recorded under its Secret Document (SD) reference as shown on the diagram? For future reference, would it be too much trouble to ask you to confirm whether the narrative (if you have it) lists all the major components with their AM reference numbers and, if so, whether you could let me know what they all are? I am specifically thinking of the Transmitter T3237, Receiver R3601, and Indicator Unit Type 116A, in addition to the Junction Box Type 25 which we already have and which would presumably be shown as 10AB/288 – and anything else listed.
BobKatThanks Air Ministry – that’s very helpful. I can’t immediately identify ARI 5617. To what piece of equipment does this relate? Yet another use for Junction Box Type 25, it would appear!
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Air Ministry, I have it from the National Archives index – Monica Mk.III. Many thanks indeed, just what I was hoping for.
BobKatPeter, a great picture. Now I can see it, I don’t think our piece is what I have circled in post #156. I guess what we have may be the connection between the aerial and its cabling which is fixed to the aircraft fuselage?
BobKatPost #118.
BobKatPeter,
That’s absolutely brilliant – very many thanks. I think I can see our piece in the centre of the aerial at the bottom of the picture. I will try to enlarge it.
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Enlargement attached – looks like it, albeit a bit indistinct!!
BobKatMonica
No further information seems to be forthcoming on my last postings. I assume from turretboy’s question that as item #31 was found to be aluminium and not steel, it is not likely to be part of a turret, unless it is part of the cupola or fuselage framework. If you have any thoughts, turretboy, I would be very grateful to have them please, even if they simply rule out the possibility of the piece being connected with a gun turret!
HOWEVER…..
I have managed at last to identify item #32. Looking through a listing at http://www.qsl.net/pe1ngz/airforce/airforce-raf/raf-homing&warning.html I found that a Type 25 junction box was used in ‘Monica’, Mk.I, the tail-warning radar device to detect approaching enemy night-fighters, before its use was discontinued in the summer of 1944 when it was discovered that the German ‘Flensburg’ radar could home in on the broadcasts.
Looking at the on-line index, I can see that there are a number of files available at the National Archives relating to Monica Mk.III. Does anyone have any information about Monica – for example a photograph of the aerial at the rear of a Lancaster, or an installation diagram showing the component parts and where the junction box would have been fitted? I have the components as a Receiver R3136, a Transmitter T3135, PSU type 284, Indicator type 116, aerial type 163, and junction box type 25.
I will keep searching and will post anything I can find.
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