Bug or WAI? Shipyard building other classes - which classes are available

[cameroon (OP)]

I took a look in the known issues and did some searching in the bug reports, but so far I haven't come across anyone asking about this so I'm looking for feedback before I post it as a bug.

Version 1. 9. 5

I have a Naval shipyard tooled to build a 5701 ton ELINT ship with military engines and a 6000 ton-capable military jump drive.  Total BP 480. 4.

It cannot build a copy if itself with the same set of engines & jump drive, but 1 less fuel storage and swap the ELINT (100 cost, 500 tons, 15 crew) for a Thermal sensor (80 cost, 500 tons, 20 crew).  5670 tons, total BP 462. 3

But bizarrely, it can build (and refit to) a Commercial jump tender that is 4755 tons, has commercial engines and the same 6000 ton-capable military jump drive, total BP 240. 2.  It says the refit from the ELINT to Commercial jump tender would be 89.  Somehow.

I believe the multiple class build rules in C# are +/- 20% size and <= 20% refit cost, so I'm baffled by what this shipyard says it can build and what it can't.  It seems like a bug or bugs, but if it's WAI I don't want to waste the bug report reviewers' or Steve's time.

Thanks for any help/feedback/answers! 

[Pedroig]

+/- 20% size is correct.  Your problem is your Thermal Sensor is 80% BP cost of your ELINT module. which is not <=20% (Don't forget the 10% refit upcharge as well).  Meanwhile your Commercial Jump Tender refit cost is 89 which is <= 20% of your 480.4 BP cost of the "original" ship.  This is coming from the difference in cost of the commercial and military jump engines and that is it. 

For rounding error sake, using the ELINT as the base module means you would be able to have a 384 BP ship as the next "largest" cost ship.

Hope that clears it up.

[Jorgen_CAB]

Yes... this seems strange at times... but it is not he size of the components but the cost of them that counts over the components that are the same.

So just to take some arbitrary examples.

You have a ship that cost 1000BP and for the sake of arguments Engine is 300BP, JumpDrive 500BP, Seonsors 200BP.

If you replace the sensors with something that cost the same amount 200BP you will not be able to build it in the same yard as the refit cost will be slightly higher than 200BP which is more than 20% of the common components which is 800BP. The refit cost might be say 220BP.... that is more than 20%. But if you change the engine for a much cheaper commercial engine... say 100BP which might come to say 110BP in refit cost that is less than 20% from the 800BP the rest of the ship is worth.

As long as you replace components to cheap components you might be able to build them in the same yards. If you want to build two similar ships with a different sets of sensor suites you need to make sure the sensors are not too much of the ships total cost.

There is also the issue with technology cost... most components get more and more expensive while some stay the same. So... early technology ships usually have more leeway of construction in similar yards than later technology ships. The reason is because crew, engineering, hangars etc stay the same in cost and is proportionally a higher cost in low tech ships than high tech ships.

[cameroon (OP)]

Thank you both for your replies; one last question for curiosity

1st one: +/- 20% is for the whole ship size if i understand the rule (new with C#, hxxp: aurora2. pentarch. org/index. php?topic=8495. msg117467#msg117467) so shouldn't the commercial ship be excluded because it's outside of that 20% hull size difference range?

I've been trying to wrap my head around how to actually calculate the rest at least roughly, but honestly, I think I'll either space master things that make sense in my head or just build multiple ship yards (unless the UI gets the information about "Refit to" costs and such again).

[Pedroig]

Thank you both for your replies; one last question for curiosity

1st one: +/- 20% is for the whole ship size if i understand the rule (new with C#, hxxp: aurora2. pentarch. org/index. php?topic=8495. msg117467#msg117467) so shouldn't the commercial ship be excluded because it's outside of that 20% hull size difference range?

I've been trying to wrap my head around how to actually calculate the rest at least roughly, but honestly, I think I'll either space master things that make sense in my head or just build multiple ship yards (unless the UI gets the information about "Refit to" costs and such again).

1.  5701*.8=4560 so the commercial ship is within 20% size difference.

2.  Design the size first.  Then tweak to the most expensive version.  Now go back and adjust everything to try keeping the the build cost under Original build cost/1.2.  That should keep you in the ballpark.

[skoormit]

Thank you both for your replies; one last question for curiosity

1st one: +/- 20% is for the whole ship size if i understand the rule (new with C#, hxxp: aurora2. pentarch. org/index. php?topic=8495. msg117467#msg117467) so shouldn't the commercial ship be excluded because it's outside of that 20% hull size difference range?

The 20% is calculated against the class that the yard is tooled for.
In this case, 20% of 5670 = 1134.
The difference between the two classes is 5670 - 4755 = 915.
915 < 1134, so it meets the +/-20% rule for refitting.

I've been trying to wrap my head around how to actually calculate the rest at least roughly, but honestly, I think I'll either space master things that make sense in my head or just build multiple ship yards (unless the UI gets the information about "Refit to" costs and such again).

The UI has the information.
On the Shipyard tab, when you have selected a refit task, click the "Refit Details" button.
You'll see a cost list of the components that must be added.
You'll see the overhead charge.
You'll see the charge for size difference.

[SpikeTheHobbitMage]

The UI has the information.
On the Shipyard tab, when you have selected a refit task, click the "Refit Details" button.
You'll see a cost list of the components that must be added.
You'll see the overhead charge.
You'll see the charge for size difference.

That doesn't help when you are designing a base class that several other classes are to be built from, survey ships being a prime example.

[cameroon (OP)]

Thank you both for your replies; one last question for curiosity

1st one: +/- 20% is for the whole ship size if i understand the rule (new with C#, hxxp: aurora2.  pentarch.  org/index.  php?topic=8495.  msg117467#msg117467) so shouldn't the commercial ship be excluded because it's outside of that 20% hull size difference range?

The 20% is calculated against the class that the yard is tooled for.
In this case, 20% of 5670 = 1134.
The difference between the two classes is 5670 - 4755 = 915.
915 < 1134, so it meets the +/-20% rule for refitting.

I'm going to blame lack of sleep or something on how I was missing that.  I was looking at the BP figures when comparing the size % requirement! Where's a facepalm when you need one.

The UI has the information.
On the Shipyard tab, when you have selected a refit task, click the "Refit Details" button.
You'll see a cost list of the components that must be added.
You'll see the overhead charge.
You'll see the charge for size difference.

If it lets you dot he refit so you can see the values, sure -- I was referring back to the UI when designing a ship from the VB version though.

But the current UI element still helps, since I can look at some of the refits that are allowed and see where the total refit cost comes from and how the overhead is calculated.

Which of course, raises another question.

Changing things up a little; I can swap from the ELINT to a Cost 60 EM sensor that is allowed for refit (for the purposes of understanding where the Refit Total comes from); no other changes from the base ship.  Total tonnage difference is 21 tons.

So how does the total work, if these are the values that the Refit Details has? I would have expected summing the Cost to reach the Total but it doesn't.

Code: [Select]

Modification                        Amount       Cost
EM Sensor EM10-60                     1           60
Crew Quarters                         1           10
Refit Overhead Cost                               16.9
Size Difference Cost                              0

Total                                             84.4

The refit overhead is also confusing; I've seen "25% of the base modification" described in multiple places on the forums and reddit, but that doesn't seem to line up with anything that gets to 16. 9 here.  I've looked at the two indexed Refit posts in the C# change list and I didn't see any changes/details for the overhead cost.

Apologies for keeping the questions going and thanks tons to everyone -- it's all been super helpful.  Certainly there's enough understanding now to make a reasonable guess when looking at component swaps.

At this point my curiosity has gotten the better of me and I just want to understand it better

[SpikeTheHobbitMage]

I would have expected summing the Cost to reach the Total but it doesn't.

That smells like a bug.

[skoormit]

So how does the total work, if these are the values that the Refit Details has? I would have expected summing the Cost to reach the Total but it doesn't.

Code: [Select]

Modification                        Amount       Cost
EM Sensor EM10-60                     1           60
Crew Quarters                         1           10
Refit Overhead Cost                               16.9
Size Difference Cost                              0

Total                                             84.4

The refit overhead is also confusing; I've seen "25% of the base modification" described in multiple places on the forums and reddit, but that doesn't seem to line up with anything that gets to 16. 9 here.  I've looked at the two indexed Refit posts in the C# change list and I didn't see any changes/details for the overhead cost.

I suspect that the displayed cost for Crew Quarters is inaccurate.
If the actual Crew Quarters cost increase is 7.5, then the component total is 67.5 and the overheard cost is 25% of that (16.875).
It could be that the code that calculates the refit cost takes into account the cost difference of all crew quarter components, whereas the code that displays the list of components only lists the new components and their full cost.

[cameroon (OP)]

So how does the total work, if these are the values that the Refit Details has? I would have expected summing the Cost to reach the Total but it doesn't. 

Code: [Select]

Modification                        Amount       Cost
EM Sensor EM10-60                     1           60
Crew Quarters                         1           10
Refit Overhead Cost                               16.9
Size Difference Cost                              0

Total                                             84.4

The refit overhead is also confusing; I've seen "25% of the base modification" described in multiple places on the forums and reddit, but that doesn't seem to line up with anything that gets to 16.  9 here.   I've looked at the two indexed Refit posts in the C# change list and I didn't see any changes/details for the overhead cost. 

I suspect that the displayed cost for Crew Quarters is inaccurate.
If the actual Crew Quarters cost increase is 7. 5, then the component total is 67. 5 and the overheard cost is 25% of that (16. 875).
It could be that the code that calculates the refit cost takes into account the cost difference of all crew quarter components, whereas the code that displays the list of components only lists the new components and their full cost.

Since I'm not sure how the crew quarters math would work (new design had 1 more "Crew Quarters" and 3 fewer "Crew Quarters - Small"), I did a different refit test that only added fuel storage and the total is off still.

I would have attributed it to just a rounding error or truncating the value to a whole number, except the first refit test definitely has decimal costs heh.

Code: [Select]

Modification                        Amount       Cost
Fuel Storage                          3           6
Duranium Armour                       0.1         0.5
Refit Overhead Cost                               1.6
Size Difference Cost                              0

Total                                             8

Then I finally looked at the refit details for the allowed military -> commercial refit that started the whole journey

Code: [Select]

Modification                        Amount       Cost
Conventional Composite Armor          8.4         25.2
C-INTE EP80.00                        2           40
Refit Overhead Cost                               17.8
Size Difference Cost                              11

Total                                             89

Seems like there's something off somewhere, so time to write up a bug report I guess

[Omnivore]

Given the present system, about the best you can do without getting into 'exploity' grey areas, is to create a base design that has the desired size and performance of all the variants you wish to build.  Fill in the tonnage where the variants differ with high cost per ton zero crew requirement components.  Retool the yard for your base design and you should be able to build reasonable variants in that yard.

There are limits to that approach.  For example using it I was able to get a light carrier, a collier, and a fleet support vessel to all share the same yard.  However, similarly sized scout and escort variants still could not as they were just too different in the unshared component costs.

Ideally we'd have a system that was perhaps even more restrictive on size, hull armor, and speed rating, but totally ignored cost except for the actual building charges.   

If you really must get, in the above example the scout and escort designs to share the same yard, you might be able to do it but it starts getting into the grey area some would consider an exploit.  Change the base design to a size such that all desired variants are barely within the -20% size differential.  Then fill up the entire base design with high cost zero crew components.  Personally I prefer not to do this but it is possible and is the only way I can find to do the equivalent of an AC-130 Spector variant and a C-130 base transport in the same facility (such as was/is done historically).

Hope this helps,