Pak75 Posted October 21, 2019 Share Posted October 21, 2019 (edited) Hi In my stash of kits is a U-boat Revell 1/144 Type VIIC/41 and while looking for information and inspiration on internet, i noticed something about representations of open outer bow doors and muzzle doors on torpedo tubes. Some models have muzzle door open against (in front) of open bow door - so outer bow doors must have opened first. Other models have open muzzle door behind open bow door - so muzzle door must have opened first. EG Muzzle door in front: Or Muzzle door behind... Anyone know which is correct sequence for opening of muzzle doors and outer bow doors? Thanks Edited October 30, 2019 by Pak75 Link to comment Share on other sites More sharing options...
whitestar12chris Posted October 21, 2019 Share Posted October 21, 2019 Hi Pak75 heres the answer to your question; http://www.ubootwaffe.pl/en/u-boats/equipment/torpedo-tubes-of-german-u-boats in short the muzzle and outer (shutter) doors opened simultaneously, so the first picture is the correct one. All the best Chris 1 Link to comment Share on other sites More sharing options...
Pak75 Posted October 22, 2019 Author Share Posted October 22, 2019 (edited) HI Chris Thanks yr reply. I must confess that i was considering posing this question on ubootwaffe.pl but as they don't speak much English i thought i would try here first. This is also a good site: http://www.tvre.org/en/home-page What started this was a purchase of RCSubs PE kits for this scale U-Boat. In the kit are optional doors or shutters - I asked RCSubs twice what they were for but got no answer other than if i thought parts were 'bad' to not use them. Incorrect text deleted Last night i found photo U-505 (a type IXc) which clearly shows muzzle door mechanism. Incorrect text deleted There is this one of U-505 which appears to show edge of open muzzle door resting against open bow door but this would mean the bow door opened first... or is is just the photograph angle? It would be a pity to have to conceal open PE muzzle doors behind open bow doors. Another thing that occurred to me is that U-505 being a type IX may have had different mode of operation for bow doors as photo suggests they might have slid forward somehow as they opened? However, RCSUbs (known for their historical accuracy) claim their torpedo PE set with optional shutters is suitable for all type VIIs but these shutters are not supplied in type IXc kits. Cheers Note bars on limber holes to prevent entry objects into bow compartment. Edited October 28, 2019 by Pak75 typo and incorrect supposition deleted 1 Link to comment Share on other sites More sharing options...
Modelholic Posted October 26, 2019 Share Posted October 26, 2019 I'd hazard to guess the outer (oblong) doors opened first, then flood the tube, then open the bow (tube) doors. This would be towards the finish of the firing sequence, and if the shot was aborted they wouldn't want water in the tube it'd have to be pumped dry to remove the torpedo for servicing which would be noisy and affect the sub's trim. As I understand it, submergence of the torpedo was kept to the absolute minimum before firing. Something to do with possible electric failures perhaps. Tom Link to comment Share on other sites More sharing options...
Pak75 Posted October 29, 2019 Author Share Posted October 29, 2019 HI My ceaseless pinging of internet and looking at countless U-boat images in trying to resolve this question was rewarded when I received an echo from Jerry Mason, the brains behind excellent www.uboatarchive.net site. Jerry confirmed that muzzle doors and outer bow doors/shutters are operated simultaneously by same hand crank from torpedo room. Outer bow doors are connected to muzzle doors by either hinge or linkage. Therefore whitestar12chris was correct in citing reference from http://www.ubootwaffe.pl/en/u-boats/equipment/torpedo-tubes-of-german-u-boats As U-boat development continued during the war, this simultaneous opening mechanism for muzzle and bow doors was refined for Type IX boats and then the Type XXI. So as not to confuse matters, I will make a new topic for these craft if anyone is interested and confine this thread to Type VII. Jerry also supplied a photo of type VIIc on a slipway showing bow doors open and muzzle doors completely hidden behind the open bow doors. This photo is apparently typical of type VIIc boats and Jerry has never seen any other arrangement. Therefore I have to conclude that second/bottom picture in my original post is correct. No wonder RCSubs would not answer my question as any detail of the muzzle doors from their kit is effectively hidden by open bow doors. The mechanism for this is detailed in a diagram in Westwood’s Anatomy of a Ship – Type VII U-boat. A hinge for the outer bow door is attached to the muzzle doors pivot hinge at one end and to a pin within a slot on the inside of outer bow door at the other. As muzzle door is cranked open, the hinge pin initially just slides in its slot in outer bow door, allowing the moving muzzle door to pass behind the still stationary outer bow door. The hinge pin eventually reaches the end of the slot and as the muzzle door continues to open, this forces the outer bow door to begin to move inwards until the fully open position is reached. An interesting detail that few modellers/manufacturers seem to have picked up on is that ends of torpedo tubes are angled inwards so muzzle door has to open less than 90 degrees. Cheers 2 Link to comment Share on other sites More sharing options...
raymic1 Posted February 13, 2022 Share Posted February 13, 2022 (edited) Hello, I just noticed this old post. I'm building the Trumpeter 1/48th Type VIIC as U552. The difference is that the Torpedo doors operate differently between the Type VIIC or/41 (U995) and the Type IXC (U505) On the Type VIIC the Torpedo opening is hinged and the Circular hatch goes behind and is not seen when the Tube doors are opened. On a Type IXC the Torpedo door slides forward similar to the US submarines of WW2 , and the Circular hatch is seen. So it depends which Type you are modelling Edited February 13, 2022 by raymic1 Link to comment Share on other sites More sharing options...
raymic1 Posted February 13, 2022 Share Posted February 13, 2022 On 22/10/2019 at 13:33, Pak75 said: HI Chris Thanks yr reply. I must confess that i was considering posing this question on ubootwaffe.pl but as they don't speak much English i thought i would try here first. This is also a good site: http://www.tvre.org/en/home-page What started this was a purchase of RCSubs PE kits for this scale U-Boat. In the kit are optional doors or shutters - I asked RCSubs twice what they were for but got no answer other than if i thought parts were 'bad' to not use them. Incorrect text deleted Last night i found photo U-505 (a type IXc) which clearly shows muzzle door mechanism. Incorrect text deleted There is this one of U-505 which appears to show edge of open muzzle door resting against open bow door but this would mean the bow door opened first... or is is just the photograph angle? It would be a pity to have to conceal open PE muzzle doors behind open bow doors. Another thing that occurred to me is that U-505 being a type IX may have had different mode of operation for bow doors as photo suggests they might have slid forward somehow as they opened? However, RCSUbs (known for their historical accuracy) claim their torpedo PE set with optional shutters is suitable for all type VIIs but these shutters are not supplied in type IXc kits. Cheers Note bars on limber holes to prevent entry objects into bow compartment. RCSubs, Oto is incorrect. His sets are made for a Type VIIC and you are correct the U505 being a Type IXC is different. However you can modify RCsubs ones and still use them if modelling U505. Link to comment Share on other sites More sharing options...
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