Should there be a horsepower limit?

[arkhangelsk]

When playing the new cruiser killer mission, I couldn't help notice how the game makes a 40 knot plus battlecruiser, forcing me to make a 44 knot monster to try and chase them. The game estimates the horsepower at about 355,000HP.

AFAIK, even with modern technology, between shaft loading limits and cavitation, we can't practically cram more than 70000HP (like a Nimitz class supercarrier) onto a shaft, and since there are usually a maximum of four shafts, we should be limited to about 280,000HP, at most.

Should we put in a similar limit in game, or in the long run limit it by tech level? It would seem to increase realism, it would help guide the AI, and give an incentive to build lighter ships that can go faster (since we are all limited to 280,000HP max).

[RAMJB]

The practical limit is more on power per shaft than on total power available.

We currently don't shaft the ship. At some point we may (or may not, not sure about what the devs have in mind about this) have to do so, specifying the number of shafts we want in a given design. Then things can get more detailed.

As for "we can't practically cram more than 70000hp on a single shaft even today", that's not strictly true. What's a problem is to cram all that power in a single shaft efficiently. That is, not wasting power because of loss of propeller efficiency. But there's no problem (other than the size of the machinery required) if you want to put a lot more power on a single shaft. You'll be wasting a big portion of it but hey, you CAN do it.

As for practical instances of it, the H-44 design for instance contemplated a mixed diesel-turbine machinery on 3 shafts for a total of around 270.000hp. That's already 80.000shp in a 1944-45 design. That's a paper design, but there were others that were not. The final design of the soviet Project 82 (Stalingrad battlecruiser) called for 280.000shp on 4 shafts (70.000 per) already in 1950 and several design proposals considered during the design process called for as much as 85.000shp in the late 40s. And Project 82, while cancelled on the shipyard, was actually being built to the mentioned specifications. 

I'm unsure as how to handle the problem. We don't even know how the game handles it. For all we know that battlecruiser you designed might have had 6 propellers (again, some instances of LOTS of those in several historical designs, built or planned  ). I'm not saying that is the case, I'm just saying we just don't know how the game does it and how it simulates the ship's shafting. First we need to know how the game handles it and then we can put forwards proposals to keep things credible. At any rate, yeah, right now things are a teeny wheeny bit ridiculous on that end ;).

Edited December 15, 2019 by RAMJB