RL question... speeding up and slowing down

[LoBlo]

Okiedookie, question here for the RL bubbleheads...

So your on a 6000 ton sub at moderate depth going 30knots and your captain orders all stop. How long does it take for the sub to actually come to a stop?

Ingame there are pretty good decellerations, but I'm thinking that a RL sub isn't made of paper... those things are huge and heavy and it would probably take a while to bleed off speed in RL..

Anyone have any experience that would like to share. Also... I'm thinking that it should probably take a 6000 ton sub a couple of minutes to reach "max" speed (though in about 30 seconds it would probably have achieved 2/3 of its max).

thanks
lb

[Henson]

It depends on the boat. Even boats of the same class have different screws and configurations (for example, dihedrals with external countermeasures) that can change that.

Tridents take forever to do any maneuver. 688s much less so.

[Sub Sailor]

If you just shut the throttles and coast-a long time- dead stop probably 30 minutes or more.. If you go from flank to all back emergency, on average 5-6 minutes and the noise and vibration is a bitch. You practice this a lot for loss of lube oil drill.

Ron Banks MMCM(SS), USN(Ret)

[Bubblehead Nuke]

Originally Posted by Sub Sailor

If you just shut the throttles and coast-a long time- dead stop probably 30 minutes or more.. If you go from flank to all back emergency, on average 5-6 minutes and the noise and vibration is a bitch. You practice this a lot for loss of lube oil drill.

Ron Banks MMCM(SS), USN(Ret)

5 or 6 minutes? Dang.. you were on an OLD boat.

[LoBlo]

Hm... clear as mud huh?

Well if you can't talk about it because of "top secretcy" or whatnot that's fine. Though it doesn't seem like there's anything secret about it. Its just a matter of experience with large ships (of which I have none).

... okiedokie then... well lets open it up to ANY large ship about 6000 tons ( I guess a medium sized cargo ship would do?) Anyone with ANY experience with large ship maneuvering that can comment on how long it would take the ship to slow to... say 3 knots from full speed of say 15knots?

[Sub Sailor]

Bubblehead nuke;
Yes I was on an old boat, I am old, so what is your point? Was my number high or low. If you are going to tell me it took you longer, then on a real loss of lube oil you must have had to replace bearings.
Bubblehead I went on my first boat in the early 60s, most of those boats are gone now, but we got the job done.

Ron Banks MMCM(SS), USN(Ret)

[Looney11]

A 4600ton frigate (M-class or Karel Doorman, RNLN) will go to top-speed (roughly 29 knots) in under 2 minutes and will stop itself in 1 boat length by going full reverse on the pitch of the proppellors. Been there, done that.

This should give you a nice view of the manouvrebility (dreadful word btw) of todays frigates.

[Bubblehead Nuke]

Originally Posted by Sub Sailor

Bubblehead nuke;
Yes I was on an old boat, I am old, so what is your point? Was my number high or low. If you are going to tell me it took you longer, then on a real loss of lube oil you must have had to replace bearings.
Bubblehead I went on my first boat in the early 60s, most of those boats are gone now, but we got the job done.

Ron Banks MMCM(SS), USN(Ret)

IIRC, our criteria was 30 seconds.. from the loss of lube oil siren till a stopped shaft and that was from a flank till a stopped shaft. The REAL PITA was HOLDING the shaft still. As the boat slowed you had to back off the throttles to compensate for the lower drag. You did not want to put it on the lock till you were pretty slow.

I have LOTS of respect for the older boats. The Skipjacks and Permit classes were tiny. Yes, they were lightyears ahead of some of the S-class boats but I have to tell you, *I* got claustophobic when I got to tour a few. The fact that they kept going and going and GOING was what impressed me. They had much smaller plants, smaller hulls, but the same sized if not larger hardware.

And hey, I am getting old. There was no slam involved sir.