[Eratta] Underwater Speed?

[tjoneslo]

p253, bottom of the first column.

The maximum speed of a watercraft submerged is one-half its normal surface speed, but fuel consumption is doubled

This sentence should be removed as it's from an earlier draft.

 

[snrdg082102]

Submerged speed should vary with TL. Prior to the use of maritine nuclear power plants submerged speed was slower than surface speed. The invention of the snorkel allowed for faster speeds, not full surface speed, since the snorkel mast and any other extended masts/antennas could damaged or broken off. Another disadvantage to having a snorkel or any other mast/antenna extended is a higher speeds they would produce a wake, blowing stealth. Good catch, I am still looking over my copy.

 

[tjoneslo]

The reason this sentence needs to be removed is because there are two watercraft drivetrains, one for surface and one for underwater (which allows 1/4 the surface speed). The fuel consumption is for the powerplants, not for drivetrains, and the power plant fuel consumption does not vary with use location (though it should).

 

[snrdg082102]

Originally posted by tjoneslo:
The reason this sentence needs to be removed is because there are two watercraft drivetrains, one for surface and one for underwater (which allows 1/4 the surface speed). The fuel consumption is for the powerplants, not for drivetrains, and the power plant fuel consumption does not vary with use location (though it should).

Evening tjoneslo,

On a US nuclear powered submarine there is one main drive train used for both surface and submerged cruising. There is a secondary propulsion motor that is primarily used for maneuvering, but can be used as a very slow secondary propulsion (4 kts). Further the propulsion motor is driven by a diesel which provides emergency power in case the reactor goes down. Finally, there is the battery as a secondary and limited power source.