Walter 63Hi Mike, the “third hole” you are questioning in your #60 post might not be a hole at all but some sort of reinforcement in that mounting bracket. All my photos only show the two holes you see in the photos made by me. As we are talking Frazer Nash turrets in your Lancaster project, you might note that these did not require the mounting bracket to be fitted to the guns. Instead a front mounting bolt was fitted as on the below drawings out of AP2799R Vol I, which deals with the FN4B turret. I’ve also included draxings of the gun attachments – the mounting bolt is secured in the slotted bracked of the front attachment.
Thanks to m3bobby for those trunnion pics by the way!
[ATTACH=CONFIG]229016[/ATTACH][ATTACH=CONFIG]229017[/ATTACH]
Walter 63Hi Mike, your drawing of the barrel casing & booster (let’s call it that, much shorter than muzzle attachment :o) looks spot on, brillant piece of drawing. m3bobby has a point re the total length but I assume the idea is to paste the casing to the gun body in due course so the extra bit wouldn’t be seen anyway. In fact, I think that if you add the thread protector ring to the trunnion block it would cover a little bit of the barrel casing. m3bobby, any chance of revealing the dimensions of te thread protector on your gun please?
Also, Mike, on the bottom of the casing near the booster there is a flat headed screw that secures the booster to the casing, on the Brussels gun this screw is secured by a bit of welding. Below pics should make that clear and I assume this is standard practice as I understand that the the booster was not to be detached from the casing by the armourers on squadron level.
[ATTACH=CONFIG]228422[/ATTACH][ATTACH=CONFIG]228421[/ATTACH]
As for your question re the trunnion block, I’m pretty sure it’s the barrel end you’re seeing. Below pics of part kits were found on the web and are reproduced for research purposes :
[ATTACH=CONFIG]228423[/ATTACH][ATTACH=CONFIG]228424[/ATTACH]
You’ll see that the barrel is of constant diameter at the muzzle end, necessitated by the fact that it has to slide in and out the booster during recoil. We now also see that the trunnion block appears to be one solid machined casting to which the gun body side plates are then rivetted.
Looking forward to your further updates.
Cheers,
Walter
Walter 63My pleasure to be of help guys!
m3bobby, thanks for explaining how you intend to tackle the casing, after reading it four times or so it makes perfect sence ;)! I always wondered how they made the barrel casing , assuming they would have rolled sheet material around a mandrel, cold forming around a mandrel must take quite a bit of force I gather. Wouldn’t they have had the same problem with the casing varying in thickness? Once you start the operation, any chance of letting us have some step by step pics please?
Cheers,
Walter
Walter 63Hi all! m3bobby, you’re starting to mix up the actors in this play, it’s Mike H who’s making the drawings :D.
Anyway, these are the dimensions I took some years ago when I was allowed to study a Browning at the Brussels Army Museum.
– length of barrel casing between blast adapter thread and muzzle attachment : 454 mm
– dia of barrel casing where it meets the blast adapter thread : 39.6 mm
– dia of barrel casing where it meets the muzzle attachment : 32.3 mm
– there are 6 rows of four cooling slots, the slots are 48 mm long and 11 mm wide, distance between two slots is 58 mm
– the rows of slots are alternating and on the Brussels gun the first slot of one row buts up against the blast adapter thread. The first slot of the next row
then starts at 53 mm from the adapter thread, the third row then starts against the thread and so on. Not easy to explain in writing, I hope you get the idea :rolleyes:
– the barrel casing is made of 2 mm thick steel plate.
m3bobby, it will be very interesting to see how you intend making that barrel casing, especially so as it is tapered. Do keep us posted please!
Cheers,
Walter
Walter 63Looking brilliant Mike, I’ve only played around with AutoCad in 2D so far and I am very impressed by your 3D art. Don’t forget you need to add 13 x 0.90″ holes close to the edge of the flange at the rear end of the flash eliminator though. These are used to insert a split pin, the round end of which will lie between two of the cooling fins on the muzzle attachment, this to prevent the flash eliminator from unscrewing itself when the gun is firing. Thought I had a photo of such a split pin in situ but can’t find it of course 🙁 . Looking forward to whatever next you’ll be treating us with!
Walter
Walter 63Thanks for that m3bobby, must have overlooked your no 30 post, all makes sense now! Nice collection you have there by the way! Just came accross another document that should be of interest here :
[ATTACH=CONFIG]227853[/ATTACH]
This gun is shown in turret configuration, where (officially) the thread in front of the trunnion block and onto which screws the blast tube adapter for wing mounted guns is protected with a protection ring. Compare with Turretboy’s drawing which shows the blast tube adapter. However, I have seen photos of turret mounted guns with the bobbin like blast tube adapter in place though that would serve not purpose other than to protect the thread. Good for Mike, the protection ring should be much easier to draw :).
Cheers,
Walter
Walter 63Hi Mike, what you are referring to as the booster is the muzzle attachment, into which the muzzle end of the barrel actually moves back and forth a bit during firing. I think that’s what m3Bobby is referring to as the “booster”, don’t know if it boosts anything though! None of my documentation seems to refer to it as a booster.
I admire your CAD skills Mike but the cooling fins on the muzzle attachment should be in the shape of inverted vees, not flat “plates” as you’ve drawn them. Attached pic from the series I sent you shows the exact shape of the fins .[ATTACH=CONFIG]227820[/ATTACH]
Keep up the good work and keep us all posted on your project!
Cheers,
Walter
Walter 63Mike, I’ve got a fair bit of reference material on the .303 Browning which I’ll be happy to share with you if you can let me have your e-mail address.
And yes, as you remarked earlier on, the barrel casing is tapered, something which is neglected in quite a few replicas, for ease of manufacture no doubt. Also, Turretboy’s drawing (hi Mike) shows the gun in its Mk I version with the early flash eliminator, I believe the Mk II version with the revised muzzle brake and flash eliminator is somewhat shorter overall. Attaching one of the many photos I took of a .303 years ago at the Brussels Army Museum, as a teaser 🙂 .[ATTACH=CONFIG]227671[/ATTACH]
Walter 63Graham,
Blenheim bomb bay doors had to be removed for the carriage of SBC’s as these extended too far downwards for the doors to close. 4 x 250lb or 2 x 500lb bombs were carried well within the bomb bay so the doors could properly close. I have a hunch that when a combination of 2 x 250lb and 2 x 250lb SBC’s were carried the SBC’s would be carried either side of the central keel plate with the 250lb bombs in the outside positions and that in that case only the inner sets of doors would need to be removed. Still have to find photographic evidence to confirm that hunch though!
As per AP1530 B, Vol I, the doors also needed removal when carrying 2 x 250lb type “B” bombs, B standing for Buoyant, but I do not know if these were ever used operationally.
As for the wing bays, those existed alright but were very small and mostly used to each carry 2 x 4in training flares or 2 x 4.5in reconnaissance flares. The carrier used inside those cells is a twin light series carriers. The bays were situated at the end of the centre plane roots just in front of the flaps.
Hope this info is of help.
Cheers,
Walter Lindekens
Walter 63Like many I was very sorry to hear of Graham’s passing.
My passion for the Blenheim was kicked off by his “The Forgotten Bomber” and when I acquired his unsurpassed “The Complete History” and learned some details of a particular Blenheim that had crashed near my Belgian home town I got myself into a research project that has been on-going for more than 10 years now. Early on I briefly corresponded with Graham about that aircraft and found him to be most helpful. He suggested I join the Blenheim Society which I promptly did and which gave my research a huge boost.
So thank you Graham for putting that wonderful aircraft back on the map and in the skies and for honouring the Blenheim Boys by doing so.
Blue skies Sir.
Walter
Walter 63Hi Hindenburg – I do have many of the pages from that one, as always the view I need is missing or tantalisingly made up from 3 pixels!
Here’s a pic showing where there needs to some sort of ‘guide’. The casting that the cartridges and links would fall into has what looks like two spring fingers that the guide might press into – there being no other obviouse way of securing a chute.
Cheers James
James,
You might want to know that the .303 Browning ejects the spent casings downwards, ie vertically. The spent links are ejected sideways into a metal link shute that is attached to the gun, the rear end of the chute simply lining up with the corresponding opening in the gun mounting frame. The empty casings fall down vertically after retraction from the breech. With the top cover of the gun open and the breech block in the rearwards position you can actually see right down through the gun. The open underside of the gun lines up with a corresponding opening in the mounting frame. Attaching a photo (internet find reproduced for research purposes only) showing such a link shute in situ.[ATTACH=CONFIG]220154[/ATTACH]
Hopes this helps a bit.
Walter
Walter 63Thanks Walter,
Any information available were the turret was found (UK or mainland Europe)
Flash not required here, A steady hand is good enough
Regards
Johan
Afraid not Johan, when I first encountered it at the museum back in 1995 it was labelled as being from a Lancaster. I then wrote them a letter to explain them what it really was and asked them if I could make a detailed photo study of it and they were happy to oblige, they changed the info placard too. Sadly they do not have any idea whatsoever of its origin, would have been nice to know … At the time I asked the RAFM if they could link a turret serial no to a specific aircraft but no, they can’t.
Makes for a superb display piece though hey?
Cheers,
Walter
Walter 63The Brussels Whitley turret is a Frazer Nash FN4A, brilliantly restored some years ago. Its origin could not be traced. The tail section it is mounted on is actually a replica, based on 1/72th scale Whitley drawings. I dare say I know this turret rather intimately, having taken dozens & dozens of detail photos when it was still unrestored, collection then topped up with pics taken during and after the restoration.
Nice photo by the way Johan! Did you use a flash? They don’t allow it you know:).
Cheers,
Walter
Walter 63[QUOTE=Air Ministry;1943162]Damn you Walter, you’re good! 😀
Blush – thanks Alan – started off with FN5, FN50 then FN7 and ended up with FN16!
Walter 63Hi Alan,
Pretty sure your item 3, the turret bit, is from a Frazer-Nash FN 16, as in Whitley nose turret.
Have I won:D?
Cheers,
Walter
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