Torpedo Stowage

[Mittelwaechter]

Afair - they were able to heat the electrics in the tubes - all forward and backward VII/IX. In a VII the 2 eels internal reserve stored on the floor forward and the two outmost eels of the four torpedos under the floor plates forward could be heated and maintained (i.e. charged).
The two torpedos stored under the floor plates, directly under the two internal reserve had to be steamers, because they were unaccessable as long as the two above were not removed (into the tubes).
The torpedos were heated in pairs - in a VII 4 heaters for 8 torpedos forward. All were constantly heated as it took some time to get them to temperature.
The backward internal reserve was under the floor but accessable and the tube and the reserve made a pair to be heated (afair!)
You mentioned the backward internal was not accessable/insufficiently accessable? Where did you get that information?

A type VII had to load at least four steamers - two internal forward and two in the deck containers. All other torpedos could be electrics in all variants.

I don't know much about type IX, but they had probably similar problems/conditions.

The ordered standard loadout was more than often subject to the availability of torpedos at the base.
An electric was way cheaper than a steamer and they prefered to use the steamers for surface units (fast/bubbles no problem, as the attacker was visible anyway).

The general storage layout of a VII didn't change over the war, but with the allied air superiority they didn't use the deck containers any longer. A late VII may have carried only 12 torpedos - dependent on the area of operation.

I donated all my sources in the 90's to the local library, but maybe you've got some inspiration for further research.

[Aktungbby]

http://www.shipwreck.net/pdf/OME_Papers_35.pdf Some useful diagrams showing the storage below decks The pics may be distressing for Kaleuns though

[LGN1]

Hi Mittelwaechter,

the original VIIC manual (http://www.uboatarchive.net/Manual/Manual.htm) states at page 50:

"G7a can be stored in all places except auxiliary stowage, because there the engine chamber would be positioned at the support point.

G7e can not be stored in both deck containers and in aft reserve stowage because access for maintenance is insufficient."

Regards, LGN1

[Mittelwaechter]

Well let's think about it. There was a support device in the forward torpedo room to hold two internal reserve torpedos on the floor level.
This device was in such a bad position, it made it impossible to store steamers on it?
Would they have relocated the device? There may have been some weird U-Boot design reasons to hinder a reconstruction, a relocation of this support device.
Would they have installed an adapter, something to divide the support point into two seperate support surfaces, sparing the desired area to enable access as necessary? (And what maintenance was necessary with a G7a possible in the tubes but not possible outside?)
This position is the overall best storage area in the U-Boot concerning access - safe on the floor, not under plates, not in the tubes. And here they managed to cause such a problem?

In the aft compartment they were able to remove a G7e torpedo from the tube to maintain it, but couldn't lift the internal reserve from under the floor to do it?
How did they ever manage to load the reserve?

I know the Germans were funny enough to document misinformation, just in case the papers went into the wrong hands. Not sure, if this is the case here.
Someone mixed aft and forward, Eto and Ato, above and under the floor plates in this documentation. Maybe per design, maybe a mistake in translation.
In the forward compartment, the underfloor reserve was limited to two steamers in both center positions, because this area was not accessable while fully armed.
This makes sense to me (as the information concerning the deck containers).

Any person responsible for torpedo stowage would have known what to put where, they wouldn't have had to check this documentation.
As you stated yourself, the situation 'suddenly changed' in 1943, because you found some documentation of two Etos in the aft compartment.


Greetings.

[Mittelwaechter]

Addendum: a major part for the armament section of your online document is the loadout configuration for a torpedo/mines mixture.

If they filled the aft tube(s) with mines, they may have left any heating and recharging equipment for the aft compartment at home. Here they would have been limited to an internal steamer reserve aft.

[LGN1]

Hi Mittelwaechter,

I have no idea why they didn't move/change the support point. Maybe it couldn't be done that easily? Or it was not a real limitations because u-boats anyway carried G7e in the stowage and not only G7a? I think it's a moot point to discuss this. We will not figure it out. From the document I conclude that (at least in 1940) it was not possible for whatever reason.

Concerning the aft compartment: Maybe they could do the maintenance, but it was too difficult/cumbersome and thus, the disadvantage of having a G7a was small compared to the maintenance difficulties.

The original German version states the same, i.e., there is no translation error.

I find it hard to believe that it's an intended misinformation. The document contains tons of reliable information which I would judge much more critical than the G7a vs. G7e torpedo stowage layout. Why should they fake this information and not the other parts?

Anyway, everybody can believe whatever he wants. But, I myself consider the document to be the best source for how torpedos were stored in the VIIC (at least in 1940).

Best, LGN1

PS: From what source do you have the information "the underfloor reserve was limited to two steamers in both center positions"?

[Mittelwaechter]

Hi LGN1,

we don't know how much of this document are facts or misinformation. There may be more variants of it with slightly different data. It's a possible way to find a leak/spy and to track the journey of a document.
The document was not necessary for daily use aboard and could read any information. Imagine a 'manual' for your NASCAR racer, stored in the glove compartment - stolen by a competitor.

I believe to remember - read in a book, report or online - they couldn't heat, charge and maintain both inner forward reserve torpedos located under the two stored on the floor. This would limit the space to Atos.
However, I have no positive reference to state it as a fact.

Regards

[Leoz]

Originally Posted by Mittelwaechter

Afair - they were able to heat the electrics in the tubes - all forward and backward VII/IX. In a VII the 2 eels internal reserve stored on the floor forward and the two outmost eels of the four torpedos under the floor plates forward could be heated and maintained (i.e. charged).
The two torpedos stored under the floor plates, directly under the two internal reserve had to be steamers, because they were unaccessable as long as the two above were not removed (into the tubes).
The torpedos were heated in pairs - in a VII 4 heaters for 8 torpedos forward. All were constantly heated as it took some time to get them to temperature.
The backward internal reserve was under the floor but accessable and the tube and the reserve made a pair to be heated (afair!)
You mentioned the backward internal was not accessable/insufficiently accessable? Where did you get that information?

A type VII had to load at least four steamers - two internal forward and two in the deck containers. All other torpedos could be electrics in all variants.

I don't know much about type IX, but they had probably similar problems/conditions.

The ordered standard loadout was more than often subject to the availability of torpedos at the base.
An electric was way cheaper than a steamer and they prefered to use the steamers for surface units (fast/bubbles no problem, as the attacker was visible anyway).

The general storage layout of a VII didn't change over the war, but with the allied air superiority they didn't use the deck containers any longer. A late VII may have carried only 12 torpedos - dependent on the area of operation.

I donated all my sources in the 90's to the local library, but maybe you've got some inspiration for further research.

Brilliant sir. Thank you.

[Mittelwaechter]

The logic is flawless as long as the facts are true. The equippment may have changed over times - or the heating was considered necessary only for 8 eels forward constantly.

Topp/U552 must have had a fifth heater forward - or the access to the two center reserve under the floor plates was sufficient, to charge the eels - contradicting the conclusion to have at least two Atos internal.

Things may have changed over times...