GNATs and Zerstorer Torpedoes

[_Sarcasticat_]

I was searching around Google for the Torpedos used of the Zerstorers (For the 1936A, specifically). I've heard much about the German GNAT (German Naval Acoustic Torpedo. A Torpedo that seeked out sound from the propellers of enemy ships and struck them. IIRC G7es was the best GNAT ever created by the Germans).

 

So.

• What Torpedoes were used by the Zerstorers. Were they GNATs? They say 533mm in the 1936A's armament tab in Wikipedia, but all the GNATs are 534s. 

[Im_The_Seeker2]

destroyers were too noisy to carry acoustic torpedoes, it'd be suicide to launch them

[_Sarcasticat_]

destroyers were too noisy to carry acoustic torpedoes, it'd be suicide to launch them

I was thinking the exact same thing, considering they were most effective on cargo ships and DDs lol. 

 

If I know anything about WW2 Germany, they were probably developing silent electric motors for Destroyers... 

[LoadnUrTube]

I was thinking the exact same thing, considering they were most effective on cargo ships and DDs lol. 

 

If I know anything about WW2 Germany, they were probably developing silent electric motors for Destroyers... 

 

Most of the noise comes from cavitation not the motors so electric power wasn't really done until much later when they started using hybrids.

 

Even in those cases most modern ships use a jet turbine to power electric generators, and those make plenty of noise transmitted through the ocean

[_Sarcasticat_]

 

Most of the noise comes from cavitation not the motors so electric power wasn't really done until much later when they started using hybrids.

 

Even in those cases most modern ships use a jet turbine to power electric generators, and those make plenty of noise transmitted through the ocean

The electric motors for the Type XXI U-Boat had a silent running mode that was undetectable by British radar and silent enough the T-11 GNAT wouldn't come back and bite them...

[QuicksilverJPR]

 

Most of the noise comes from cavitation not the motors so electric power wasn't really done until much later when they started using hybrids.

 

Even in those cases most modern ships use a jet turbine to power electric generators, and those make plenty of noise transmitted through the ocean

 

Modern USN warships all have turbines that in turn use reduction gearing to push shafts/props.

 

 Four General Electric LM2500 Gas Turbine Engines (GTEs) provide ship's propulsion. Each Engine Room contains two LM2500s, one propulsion reduction gear to convert the high speed, low torque output of the gas turbine engine to low speed, high torque output suitable to drive the propulsion shafting, and the related support systems and equipment. The port shaft connects 2A and 2B GTEs in Main Engine Room #2 and the starboard shaft connects 1A and 1B GTEs in Main Engine Room #1. When viewed from the stern, the port shaft rotates counterclockwise and the starboard shaft clockwise, producing outward propeller rotation. Since the GTEs cannot be reversed, the Controllable Pitch Propeller (CPP) system provides ahead and astern thrust by hydraulically positioning the pitch of the propeller blades.

 

And yes, those props make a crapload of noise....

[mr3awsome]

As far as I am aware, all WWII German destroyers used G7a torpedoes. 

[Chucklebutty]

A U-boat launched a gnat at my fathers ship in the battle of the atlantic, 

The captain had the presence of mind to drop a pattern of depth charges, and these explosions lured it away.

dangerous things!

[_Freddy_]

G7e family from information I have acquired - as they were electric torpedoes they did not leave the tell tale bubbles loved by films and as left by the wet heat ones like G7a which was the main torpedo carried by German surface ships in WW2.

 

The G7e was an electric torpedo that came in several variants (e = electric), not all were homing (the majority were not). 

 

G7e - standard

T2 - longer range (93 amp hours)

T3 - T2 with influence fuse

T3a - longer ranged T2 (125 amp hours)

T3b - used as propulsion part of Marder Submarine

T3c - torpedo carried by the Marder (shorter ranged and slower due to less battery capacity and mods)

T3d - Long range and slow speed designed for use in restrictive areas (programmed to circle or dog leg at the end of its run)

T3e - Midget sub torpedo

 

Then you have the 'homing torpedos'

 

T4 - Passive homing with slow speed (20kn)

T5 - Anti escort homing torpedo

T5a - modified T5 used by S/E Boats (longer range but slightly slower)

T5b - modified T5a used by submarines

T10 - wire guidance version, tested but did not really work

T11 - T5 modified to attempt to counter the towed noisemakers used by the allies. 

[_Freddy_]

The electric motors for the Type XXI U-Boat had a silent running mode that was undetectable by British radar and silent enough the T-11 GNAT wouldn't come back and bite them...

 

RADAR worked above the surface not below - I assume you mean ASDIC/SONAR

 

The Type XXI engines were designed to reduce noise - at 2 knots the boat produced no noise, its highest noise free speed was 6 knots and it could maintain that for 48 hours - there is no silent running mode apart from slowing down, same as modern subs. 

 

Parts like the Snorkel had an early form of RADAR absorbing material to prevent them being detected so easily