Hi Mike, on type IXD2, the fuel oil was stored in tanks outside the pressure hull (in the saddle tanks). Some of them were fuel oil tanks only (Treibölbunker), some of them were used as fuel oil tanks, but when fuel oil was used, they were converted to ballast tanks (Tauchbunker) and some of them were regulating tanks, used for temporary fuel storage (Regelbunker). I have marked location of
Forum: Technology and Operations

Hi, look for pictures of U 534. -- Regards Maciek
Forum: Modeling and schematics

Hi, "as far as I know, the torpedo tubes equipped with FAT torpedo setting gears could not be used with LUT torpedoes" Here is evidence for my argument: BdU Current Order with distribution of FAT and LUT torpedoes: For the similar behavior of FAT and LUT torpedo you can look here ("Emergency setting T IIIa - Lut I" ) : -- Regards Maciek
Forum: Technology and Operations

Hi, well, of course, LUT torpedo could be set to run as FAT torpedo. A far as I know, there was never designed LUT TDC - the gear visible for example in bow torpedo room of U 995 is only LUT setting panel. The values for setting LUT torpedo were evaluated basing on tables. One more thing - as far as I know, the torpedo tubes equipped with FAT torpedo setting gears could not be used with
Forum: Technology and Operations

Hi, one more thing about speed while lying mines. In the book "U-Boats Attack!" by Jak Schowell, there is a story "Mining the lion's den", describing mine laying operation performed by U26 in September 1939. He claims, that U26 - while mine laying - did not exceed speed of 3 knots. The books by Jak Showell rely heavily on the KTBs, so we may assume, that mines
Forum: Technology and Operations

Hi Juliet, interesting question... The upper deck of U177 and U178 had never been modified as Schnelltauchback, so it is not this case (btw. Schnelltauchback seems to required removing two most forward containers). These boats also were never equipped with Snorkel (this required removing three stb containers). Looking at these photos: (U177 - ) (U188 - ) I would say, t
Forum: Technology and Operations

Hi Juliet, the difference in the number of external torpedoes could be made by Schnelltauchback modification, when cut in the forward upper deck forced removing some of the containers. The other cause could be installation of Snorkel, when some containers had to be also removed. Second question - circled "containers" are covers for exhaust gas valves and silencers/mufflers.
Forum: Technology and Operations

Hi Manfred, there were two connections: first for suppling compressed air while charging compressed air flasks, and second for suppling compressed oxygen for the air renewal installation. How it looked like? I have no idea, but I suppose it was rather ordinal connector. In the first period of war, there was also one salvage valve (second was in the aft part of conning tower casing) an
Forum: Modeling and schematics

Hi, zakarpatska Wrote: > I assume that the mine must have been ejected fast > enough and the submarine traveling slow enough > that there was no danger of collision between the > submarine and the mine. It would still be > interesting know the speed of the subamrine and > ejected mine during the mine laying operation. The speed of ejection - interesting question. T
Forum: Technology and Operations

Hi, great pictures. I have got question - where did you get this photo: ?? Was it taken inside forward battery automatic switch (at port side, between control room bulkhead and commander place)? -- Thanks, regards Maciek
Forum: General Discussions

The primary hydrophone of German U-Boats was Gruppenhorchgerät (G.H.G) - kind of array of microphones located around the forward diving planes. For more info see this document: -- Regards Maciek
Forum: General Discussions

Hi if you mean head of KDB device, located on the bow (near capstan), it is invisible on many photos, because this hydrophone device was installed only in first years of war (till middle 1943). After than, it was abandoned. This mast could not be elevated or lowered, and was very vulnerable to depth charges. See: -- Regards Maciek
Forum: General Discussions

Hi Pat very nice item. This is so called "Doppelbild-Entfernungs-und Zielkurswinkelschätzer" - double prism stadimeter, used to range finding and estimating angle on bow. It was used in pre-war attack-periscopes (probably on type II boats). You can see it as a part of Vesikko control room periscope: In war-time U-boats, double-prism range-finder was abandon, and the range
Forum: General Discussions

In fact, in this case, the boat gained 2*2,07 cbm + 2*11,3 cbm + 2*13,3 cbm (respectively capacity of negative tanks, ballast and fuel oil tanks 2 and 4) = ~53,34 cbm of displacement. -- Regards Maciek
Forum: Technology and Operations

Hi, Don Thomas Wrote: ------------------------------------------------------- > Is there an equation relative to the amount of > water the submarine displaces while on the surface > to its speed? Can't give you detailed data, but here is some information: The KTB for U-604's 1st patrol: 28 August, 1942, 04.20: "During the pursuit, at the suggestion of the
Forum: Technology and Operations

Very interesting. Congratulations! -- Best regards Maciek
Forum: General Discussions

Hi WilhelmGustloffMuseum Wrote: ------------------------------------------------------- > Does anyone have a pic of the bow of the Type VII > at sea to see if the capstan is a permanent mount > or is removed when the boat is away from dock? My > buddy's model is an early war version so it has > the t shaped radar antenna near the bow, capstan > would be near that.
Forum: General Discussions

Hi Simon Simon Wrote: ------------------------------------------------------- > I was wondering was anyone able to found or have > the measurement of the 33 MAL 800 E & 33 MAL 800 W > battery cell? height (without connection terminal): 993 mm width: 381 mm length: 478 mm -- Regards Maciek
Forum: Technology and Operations

Ken Dunn Wrote: ------------------------------------------------------- > There were multiple cables that connected to the > torpedo while it was in the tube including the one > that transmitted the information to the gyro > gidenance system in the torpedo. They were > supposed to automatically retract when the torpedo > was launched but sometimes they didn't.
Forum: Technology and Operations

Hi Take a look at this report: In chapter "Zeiss Fixed Eyepiece Periscope" you will find informations you are looking for. use search engine on the site www.uboatarchive.net - in the interrogation reports there are also some useful informations. You can also see "U.S. submarines through 1945: an illustrated design history" by Norman Friedman (available by go
Forum: Technology and Operations

Hi Here you have list of such incidents: The most amazing is case of U-864, which was sunk by HMS Venturer. -- Regards Maciek
Forum: General Discussions

skipperbill Wrote: ------------------------------------------------------- > How was a torpedo charged while in the tube? German electric torpedoes had to be withdrawn to be charged. The torpedo tubes were fitted only with gears for heating torpedo batteries. -- Regards Maciek
Forum: Technology and Operations

ROBERT M. Wrote: ------------------------------------------------------- > SnakeDoc, et al: > > The torpedo piston has guides that travel in > machined grooves on the inside wall of the torpedo > tube. Toward the breech end, these grooves taper > until they disappear near the muzzle end of the > tube, limiting the travel of the piston; this > allows the impulse
Forum: Technology and Operations

Hi cave mac Wrote: ------------------------------------------------------- > hello, what year was the snorkel attached and used > ? just WW II or both WW I and WW II? Well, good question. First, operational application of snorkel was done by Germans, in the end of 1943 (first trials in the end of August 1943, first combat patrol in the begining of Jaunuary 1944). But in 19
Forum: Technology and Operations

Hi Robert ROBERT M. Wrote: ------------------------------------------------------- > When the boat launches torpedoes, the breech doors > are wide open, allowing seawater to flood the tubes. > The flooded seawater weighs more than the launched torpedo, > correct? Well, in case of german U-Boats, torpedoes were launched by means of piston (to avoid air escape). So duri
Forum: Technology and Operations

Hi Wayne NEEBLAMMERS Wrote: ------------------------------------------------------- > This sounds like negligence or/and incompetence on > behalf of the submariners:- > > What should have been the S.O.P.? After launching salvo? To flood compensating tanks and (if necessary) move water from aft to forward trim tank. After breaking the surface? Give orders: all hands for
Forum: Technology and Operations

One more thing - in "T.I.C" term can be a typo, originally it could be "TLC" (designation of these landing crafts, among the others HMS TLC-18 (A 18), which was sunk by U-331). -- Regards Maciek
Forum: Technology and Operations

Hy Wayne According to the (see events after passing Straits of Gibraltar) it could be designation of Landing Craft. -- Regards Maciek
Forum: Technology and Operations

Hi take a look at this: The procedures were saying, that when "man battlestation" (Auf Gefechtsstation) order was given, the gyros of the torpedoes had to be checked if set to 0 deg. So if launch was ordered (assuming that tubes were flooded and bow caps opened), the torpedoes could run in the U-Boats heading direction. By the way - such launching procedure (aiming by means
Forum: Technology and Operations

Hi jcrt Wrote: ------------------------------------------------------- > Is the date these U-boats, U398, U1017, U857 and > U879 were in contact with BdU or another U-boat > before they went missing? john Try search on these sites: First contains decoded and translated messages, the second is translated BdU KTB, which contains records about messages sent by U-Boats. -
Forum: General Discussions