penny wrote:The Peeps were caught with cold nodes. But all through the series, and here as well, it is suggested that time can be shaved off of the process of going from a cold wedge to getting it online. What exactly is done to shave time off of the process? Diverting power maybe?
I suppose I should add that shaving time off of the entire process is not without its drawbacks, since safety protocols are mentioned.
At any rate, I do not understand why the amount of time that can be shaved off is not predetermined.
I'm assuming it's a risk vs reward trade-off.
If you follow the book it'll take X time, and that's a process that'd be designed to not only be safe for the ship and crew but also to avoid excessive reduction in the service life of the nodes.
If you're willing to abuse the nodes and push the risk to engineering up a little, and wear a lot of service life off the nodes, you can probably dump carefully controlled extra power into them to warm them up faster.
If you're willing to run a higher risk of blowing a node (and being dead in the water) you can shave even more time off by pushing them even harder.
You could possibly analogize it to a steam warship bringing up it's boilers. If all the boilers were cold it might take as much as 24 hours for a WWII BB to get up to full steam. Because it takes time for the boilers to warm up and you're constantly circulating water (and then steam) through the system as you steadily bring the temperature and pressures up -- to make sure everything warms up in sync and you don't get excessive stress in the boilers, engines, or piping from uneven heating or thermal shock.
If you have a source of steam (like boilers that are already lit off) you can run through the boilers to pre-heat them you can many hours off that, though there's a bit more risk that something will fail (or at least shorten it's service life) by warming up too quickly or too unevenly.
And in an absolute emergency you could try and crank the boilers up even faster, even without a source of steam. But you're really likely to shatter the fire bricks that insulate their walls, or shatter a pipe, or even turbine blades, from differential heating.
And of course there were a number of stages between totally cold and full steam at which you could hold the boilers; say holding the ship at 4 hours readiness. So the boilers would be on, just with the heat turned down, and much of that pre-heating already done. (Although for a steam warship if it wasn't expecting combat it might have only enough boilers lit off to quickly bring it up to cruising power; which is usually less than a quarter of the boilers you'd need for flank speed. Diesel and later gas turbine power plants would start up much, much, quicker and could also adjust power levels more quickly without the kind of pre-planning it took on a big steam plant)
So in both the steam plant and the impeller nodes it would seem that the more time you shave off the "book" time the higher the risk that something will go wrong. And that's why there's no fixed time savings because the engineers are making a judgement call about what this particular ship's propulsion can take, today, without breaking. (Something that would change over time as the plant got worn at toward the end of its service life; how many times it had bee stressed, how good a state of repair and maintenance it was in, whether it was on the stronger or weaker side of the allowable material tolerances, etc.)