Re: What do they all do? @SkippyBang
'Nice vids on Youtube of an Arleigh Burke vessel doing a high speed turn, and its worth watching to see how quickly these things can go and how fast they can turn'
I'm not 100% in the drive system on an Arleigh Burke, it appears to be two gas turbines per shaft, this is similar to the T22 I did some of my training on. Although they were fast all that speed wasn't available straight away, up to around 14-16kts could be achieved with one gas turbine per shaft* but to get up to 30kts+ you'd have to bring the other engines online. This can take a few minutes, and generally because of the higher fuel consumption you wouldn't have them on as a matter of routine. So although they are fast, in a normal cruising state it could take a couple of minutes before you could even start accelerating, although at that point it is quite impressive.
Having said that, generally when you're approaching a more challenging shipping situation, e.g. entering harbour, confined waters, a shipping lane, you'd have every everything up and running** to give the minimum response time if you needed a sudden burst of speed etc. I don't know what the USN routines would be exactly in those situations so it's hard to say how they compare, and I'm not sure how close the McCain was to the actual shipping lane when the collision happened***.
*You could also do a similar speed with two on one shaft, basically most combinations worked, some would have a minimum speed you literally couldn't go below.
**There are also dual hydraulic pumps for steering motors, multiple generators, etc. that normally alternate in use. Everyday is back up test day in the navy.
***I went through the Dover Straights on a T42 which is one of the busier traffic separation schemes, the Captain decided the simplest thing would be to go through at max speed so we were always the overtaking vessel.
Biting the hand that feeds IT
