Technical Question - Engines

Uboatace · 12-13-06, 02:34 PM

The following only applies to the type VII subs as my knowledge on other types is limited.

There were two makes of diesel engine used they were the Germaniawerft & the MAN,

They were fundamentally the same in appearance & HP, both were six cylinder direct reversing engines.

The main difference was that That the GW was supercharged (shaft driven) & the MAN had a turboblower. (turbocharger)

The horsepower ranged from 2310 to 3200 depending on year & variant, at a maximum of 485 RPM.

The bore And stroke was 40 cm x 46cm.

When snorkels were fitted the reversing cams were removed & replaced with snorkeling cams to overcome the increased exhaust back pressure, so reversing had to be done using electric engines as the diesels could no no longer run in reverse.

When the snorkel dipped under water it took about sixty seconds for the engines to consume the air in the boat but the effects were felt much sooner due to the sudden pressure drop inside the boat.

I hope this is of interest & helps answer a few questions.

12-13-06, 02:34 PM	#12
Uboatace Nub Join Date: Sep 2005 Location: UK Posts: 4 Downloads: 0 Uploads: 0	The following only applies to the type VII subs as my knowledge on other types is limited. There were two makes of diesel engine used they were the Germaniawerft & the MAN, They were fundamentally the same in appearance & HP, both were six cylinder direct reversing engines. The main difference was that That the GW was supercharged (shaft driven) & the MAN had a turboblower. (turbocharger) The horsepower ranged from 2310 to 3200 depending on year & variant, at a maximum of 485 RPM. The bore And stroke was 40 cm x 46cm. When snorkels were fitted the reversing cams were removed & replaced with snorkeling cams to overcome the increased exhaust back pressure, so reversing had to be done using electric engines as the diesels could no no longer run in reverse. When the snorkel dipped under water it took about sixty seconds for the engines to consume the air in the boat but the effects were felt much sooner due to the sudden pressure drop inside the boat. I hope this is of interest & helps answer a few questions.