Exact formula for ship size vs construction rate?

[jseah (OP)]

I noticed that constructing bigger ships gives you a construction rate boost. 

I have also noticed that this is not linear, 2x bigger ships do not give you 2x construction rate. 

Does anyone know the formula?  I have an... interesting idea.  =P

[Erik L]

I noticed that constructing bigger ships gives you a construction rate boost. 

I have also noticed that this is not linear, 2x bigger ships do not give you 2x construction rate. 

Does anyone know the formula?  I have an... interesting idea.  =P

Not sure of the exact formula, but the base rate occurs at 5000 tons.

[Father Tim]

Search the Mechanics forum for shipyard construction rates and you should find the post by Steve Walmsley (or SteveAlt) where he mentions the rate.

[Steve Walmsley]

For naval shipyards

Build Rate Multiple = Complex Capacity / 5000
Build Rate Multiple = 1 + ((Build Rate Multiple - 1) / 2)

For commercial shipyards, it is the same as above except the complex capacity is divided by 10 first.

Steve

[Thiosk]

Since we're on the topic of formulas, how are overhaul times calculated?

[sloanjh]

Since we're on the topic of formulas, how are overhaul times calculated?

IIRC, the clock unwinds at a 4x rate.  So if you've got 1.6 years on the clock, it will take 0.4 years for the overhaul.  I may be wrong about the 4x factor (it bounced around for a while, e.g. different rates for military and commercial ships back when commercial ships required overhaul), but you can check this on your own - simply put something into overhaul and see how long it takes.

John

[jseah (OP)]

Build Rate Multiple = 1 + ((Build Rate Multiple - 1) / 2)

Not quite understandable but here's my interpretation:

Build Rate Multiplier = 1 + ((Ship size / 5000 - 1) / 2)

Essentially, you halve the distance to one of the ratio of the ship size vs 5 ktons.  That makes sense. 

Above 5ktons:
1kton increase in size -> 10% (additive) increase in construction rate. 

Which means, your ship construction rate tech is incredibly important.  It affects the build time ratio of big ships vs small ships. 
Therefore, as your ship construction rate tech increases, the feasible size of ships increases. 

[sloanjh]

Not quite understandable but here's my interpretation:

Build Rate Multiplier = 1 + ((Ship size / 5000 - 1) / 2)

Essentially, you halve the distance to one of the ratio of the ship size vs 5 ktons.  That makes sense. 

Above 5ktons:
1kton increase in size -> 10% (additive) increase in construction rate. 

Which means, your ship construction rate tech is incredibly important.  It affects the build time ratio of big ships vs small ships. 
Therefore, as your ship construction rate tech increases, the feasible size of ships increases. 

Uhhh I don't see how you get the last paragraph from the above.  Why do you think it's not just BuildRate = ConstructionRate*Multiplier?

John

[jseah (OP)]

I am assuming that you are asking how I got the conclusion of big ship vs small ship ratio affected by ship construction tech.


Basically, each 1 kton you add to a ship, adds 10% of your base construction rate to the build rate of the ship. 

So the size of your ship that can be finished in reasonable time decreases and therefore you can build bigger ships. 
Small ships are even slightly less efficient.  (small ships have higher ratio of armour, crew and fuel tank to engines and systems compared to big ships)

[sloanjh]

I am assuming that you are asking how I got the conclusion of big ship vs small ship ratio affected by ship construction tech.

Yep.

Basically, each 1 kton you add to a ship, adds 10% of your base construction rate to the build rate of the ship.

If by "adds 10% of your base construction rate", you mean the rate without shipbuilding tech researched, I believe that this is not the case.  My recollection is that the Build Rate Multiple (RHS version ) multiplies the current shipbuilding rate, and I don't see anything in Steve's post to contradict this.

So the size of your ship that can be finished in reasonable time decreases and therefore you can build bigger ships.  
Small ships are even slightly less efficient.  (small ships have higher ratio of armour, crew and fuel tank to engines and systems compared to big ships)

To put it in concrete terms, let's say it takes 1 year to build a particular 5kton design.  For a 15kton design (that costs exactly 3x), it should take 1.5 years (3x the cost, but the rate is twice as fast since I just happened to pick numbers that give a total factor of 2).

You then research enough shipbuilding tech so that the original design only takes 8 months to build.  The 15kton design should take 1 year to build, i.e. 1.5 times 8 months.  If you're saying something different from this then we'll have to go back to the original thread and see.

John

PS - BTW, I'm pretty sure there's a subtlety in the formula Steve posted.  My recollection of the original thread is that he put in protection against getting a speed-up by building tiny ships in a high-capacity SY.  In other words, the 5kton design at the original build rate would still take a year to build even if you built it in a SY with capacity of 15kton.  So the formula he gave is probably the best case build rate.  You should use ship size rather than capacity in the formula to get actual build rate.

[jseah (OP)]

Yes, I meant that 10% of base, it's 10% of the base rate for a 5kton ship as displayed in shipyard tasks tab. 

And yes, I realize that the actual ratio for perfectly scaling ships does not apply. 
Also, I have been using ship size and not shipyard size. 

However, build cost does not increase proportionally to size.  Bigger ships actually cost less.
Example is my Chimera and Ettin class missile ships (6ktons and 10ktons respectively) where the Ettin costs roughly 1.5 times in shipyard-only components (vs 1.667 times in size)
When I move up to the 15kton cruiser class ships, perhaps after another tech level in shipbuilding, the proposed Demon class cruiser will probably cost around 2.2 to 2.4 times that of the Chimera. 

When your shipyard rate goes up, this makes the differences more pronounced.