Yesterday we received a call on our new Tip Line wondering if the Russians and US were working on submarine technologies that create an air bubble in front of the sub that allows it to travel 3x the normal speed.
Here's what our readers asked:
This is more of a "Is it true" tip?? Someone told me just last night that the Russian Navy & the US Navy are separatley working on "an air bubble in front of a ship (sub) can make it travel 3 times its normal speed & that it was already tested on a torpedo & it moved as fast as 300 mph under water. Is there any truth to this story?? I am not beleiving anyone or any story unless I see it posted here or on military.com. Can you let me what if anything you've heard about this. Thanks...I don't know much about subs, but I do know guys that do. So I sent this query on to our friend Joe Buff who had this reply (be sure to read his earlier post on DT regarding this subject):
Sounds like supercavitation. USSR/Russia has had supercavitating rocket torpedoes since the Cold War. USN also developed a good one prototype but decided not to deploy, preferring the mark 48 ADCAP torpedo. USN right now doing good work w. GDEB on "Underwater Express", a 100-knot manned minisub which would give a "really quick and sonar-deafening getaway vehicle" for SEALs near the beach/surf zone.Well, there you have it. Hope this answers the mail and please keep the tips coming...
The process uses rocket propulsion to get the underwater hull/vehicle going fast enough to create a partial-vacuum bubble around itself, eliminating water flow resistance against hull (but not the need to push water around and away from the bow/tip). Rocket engine burning fuel provides thrust allowing very high speed (200 to 300 knots for a sharp-tipped torpedo) not possible using a traditional rotating water screw (as in Ohio class) or pump-jet turbine (as in Virginia class).
I've not heard of this being applied to surface ships, where I think it would not work, and where air cushion, hydroplaning, or wing-in-ground-effect would give high speed much more practically. There are separately though things like "Prairie Masker" which emit bubbles (engine exhaust I think, not "air") to isolate hull noises from the sea to provide acoustic stealth for the ship against enemy subs & sonars.
-- Christian (with Joe Buff)