• Registered: 2011-04-27
  • Posts: 4

Topic: Ship size vs hull size

Howdy, everyone -

I just recently purchased the game and I'm curious. I'm still reading the rules and I do have a quick question about design.

When trying to come up with a rough hull size based on say modern day naval ships, how would you go about doing it?

For example, if you wanted to create a frigate (from what I understand, they are typically up to 7200 tons in real life. Would you choose a size 7 hull to create one?

But then you get into the bizarre sizes, such as a battlecruiser which can range in size up to 45,000 tons.

Is there an 'average' hull size chart or general rule of thumb?

If this has been asked, forgive me.

Chris

  • Registered: 2022-11-14
  • Posts: 86

Re: Ship size vs hull size

When you have a large range of sizes like that, it would probably be best to come up with something that isn't so linear as saying that a 15000t ship is twice the size of a 7500t ship. The reason is that the Space Units to Hull ratio in the game is not linear. A hull size 20 ship doesn't have 20 times the space of a size 1. It has 49 times the space. Check out the chart on page 28 of the Core Rulebook.

I start by defining what the top and bottom ends of the scale are.
Because I tend to prefer smaller ships in general, for my Ironclad Armada conversion, I wanted my largest 15-16000t ships to be in the Hull 15 range with Hull 1 at around 100-250t. So I used the square root of the tonnage divided by 8 and dropped any fractions.

For what you are looking at, maybe something similar. Say square root of the tonnage divided by 15. This puts a 500t FAC at 1 or 2 hull (depending on if you want to round up or down) and a 100000t CVN at 21 hull. Or if you prefer larger ship sizes, maybe a divisor of 10 which would put the CVN at hull size 30 and hull size 1 at about 150t.

  • Registered: 2022-11-17
  • Posts: 18

Re: Ship size vs hull size

That should do it. It's generally not a good idea to go by raw tonnages alone, since a ships mass increases in a cubic fashion (a ship x that's twice as long as ship y has 2³ = 8 times the tonnage).

That's why this "If a spider/ant/flea would be as big as a human, it could..."-pseudoscience is rubbish: You can't just scale a design and expect it to perform as well as the original scale.