Identification of rare variant of G7 torpedo (Original german drawings)

[VC54002]

Greetings

I'm trying to find out in which variant of the G7 torpedo this engine could have been used:



Whichever variant of the G7 this is it was most likely sent to Spain as part of Program Bär since the documents were found in an abandoned naval base in Spain. In this page which shows the speed regulator you can see in the upper right corner Stellung(Position) translated into spanish (Oddly it is the only word translated into spanish in all of the pages that I found)



Spain received both the G7a(TI) and G7e(TIII) torpedoes but the other pages of the diagrams show parts that don't match any G7a manual. I believe this could be an early version since the cutaways aren't indicated with 45º lines and some of the mechanisms appear to be simpler than in other drawings of the G7a(TI)

If anyone has any information about the older variants of the torpedo please share them here. I would also like to know who designed or manufactured the engine for these weapons.

Regards
Adam

[VC54002]

Hi, I forgot to update this post with some of the latest findings about the diagrams for anyone who was previously interested in this topic. Here is what we know so far:

With a lot of help from Natter and some more searching we have found out that the diagrams represent most of the different mechanisms used in the G7v and G7v* torpedoes. This discovery has also unfolded some interesting information about the involvement of Spain in the development of german torpedoes in the late 1920s and early 1930s.

The direct involvement of Spain in the development of german torpedoes started in the late 1920s when the spanish businessman Horacio Echevarrieta decided to start a torpedo factory in Cádiz (Fábrica Nacional de Torpedos, F.N.T. / National Torpedo Factory) with a theoretical production capacity of 100 torpedoes per year and license-build german torpedoes, for this reason he asked for a "good and well-proven" design from the germans. Germany offered their 50 cm G7v torpedo and sent all the needed technical documents (The diagrams that I found are most likely a part of the information sent) but the Spanish Navy demanded a 53,34 cm torpedo which had become the international standard at that time.

Diagrams of the G7v and G7v* torpedoes:




As you can see the G7v and G7v* are very similar, the main difference was the new air flask used in the G7v* which could handle an increased operational air pressure of 200 kg/cm².

Due to the demand for a 53,34 cm torpedo, Echevarrieta decided to build and test some prototypes with the help of german torpedo experts but the whole project went bankrupt mainly due to very large amounts of the budget being spent in the initial stages of the project. There were also technical problems with the "Model A" torpedo prototype which was almost completely based on a design from 1918 that was adopted due to cost considerations compared to the more modern "Model B" prototype. The failure of the project led to the independent development of the torpedoes by the germans which resulted in the creation of the G7a(TI) that was fielded with the Kriegsmarine in 1934. The G7a(TI) reused many of the mechanisms used in the G7v such as the engine, with some minor improvements.

We were able to discover all of this thanks to the second part of the plans which I found after returning to the same place where I found the first part. Unlike the first fragments that I found the second part had numbered tags showing differences in the design of some mechanisms that show the model of the torpedo (G7v and G7v*) which allowed us to determine the variant. Although the drawings are in really bad condition most of the mechanisms and their parts are visible, the mechanisms which can still be seen are the following:

- Gefechtskopf (Warhead)
- Füll- und Absperrventil mit Wasserabschlußventil für G.A., Druckregler mit Ölgefäß, Maschinensperrung und Stauventil (Filling and shut off valve with water check valve for GA, regulating valve with oil tank, engine shutoff and over-pressure regulating valve)
- Kessel (Air Flask)
- Brenstoff- und Wasserkammer mit Kesselabsperrventil, Druckausgleicher und Ölgefäß für Maschine (Fuel oil and water chamber with air flask shutoff valve, pressure equalizer and oil tank for the engine)
- Hinterteil (After Body)
- Wasserdruckpumpe (Water Pressure Pump)
- Pumpenprüfeinrichtung (Pump Test Device)
- Oil Distribution Mechanism
- Ölgefäß Für Lagerschmierung (Oil Tank for Bearing Lubrication)
- Maschine (Engine)
- Kleines Ölgefäß (Small Oil Tank)
- Kühlwasserpumpe (Cooling Water Pump)
- Schußweitenschalter (Speed Setting Mechanism)
- Stoppvorrichtung und Rudersperrung mit Unterbrecherschmierung (Stop and rudder locking gear with lubrication oil flow interrupter)
- Tiefenapparat (Depth Control Mechanism)
- G.A. / Geradlaufapparat (Gyroscope)
- Brennstoffgefäßen (Fuel Tanks)
- Verdampfer (Combustion Pot)

Preview of the After Body diagram showing the G7v and G7v* tag:

Attachment 1268657

[VC54002]

Here are the scans of the diagrams in best condition:

Hinterteil / After Body


Wasserdruckpumpe / Water Pressure Pump


Pumpenprüfeinrichtung / Pumps Test Device


Druckregler mit Maschinensperrung / Regulating Valve with Engine Shutoff


Ölgefäß für Lagerschmierung / Oil Tank for Bearing Lubrication


Maschine / Engine


Schußweitenschalter / Speed setting gear


Füll- Und Absperrventil mit Wasserabschlußventil für G.A. / Filling and Shutoff Valve with Water Check Valve for Gyro.