Can't figure out why AI ship is a BC

[generalvikus]

A pretty straightforward question for you guys: could anybody tell me why this ship is classified as a BC? The year is 1919, and when I tried recreating it in the ship designer the game keeps telling me it's a BB. In case it matters, it's a completed ship currently located in the Carribean, not a stolen design plan.

[slipstream]

Posted by generalvikus

A pretty straightforward question for you guys: could anybody tell me why this ship is classified as a BC? The year is 1919, and when I tried recreating it in the ship designer the game keeps telling me it's a BB. In case it matters, it's a completed ship currently located in the Carribean, not a stolen design plan.

I'm not sure why it's a BC for the AI player. I think the reason it won't be for you is because no BC can have more than 12" belt armor, IIRC.

[generalvikus]

Yeah, the 12 inch limitation is why I would expect that this ship wouldn't be a BC. As I understand it, a BC must either have 6 or fewer guns, or 12 inches or less of armor.

[aeson]

The 12" belt limit on battlecruisers with a design speed no greater than 30 knots and a main battery disposed in three or more turrets or of eight guns in two turrets goes into effect in January 1916. Battlecruiser designs can have belt armor thicker than 12" if they predate the 12" belt limit, if their design speed exceeds 30 knots, or if they have no more than seven main battery guns in no more than two turrets.

If the ship commissioned in 1917 or earlier, then its design certainly predates the 12" belt limit as the ship would have had to have been laid down no later than June 1915 to complete by December 1917. If the ship commissioned in 1918 or 1919, there is a possibility that the design predates the 12" belt limit, as ships laid down in December 1915 nominally complete in June 1918 but might be delayed for some months and so commission late in 1918 or early in 1919; very seriously delayed ships might commission in the early 1920s, though that is not very likely, especially for a wealthy power like the USA. If the ship is not the first of its class, then there is an increased likelihood that the design predates the 12" belt limit; you can lay down ships to a design for something like five years before the design is hidden in the 'build ships' menu and the computer sometimes - not often, but sometimes - orders ships to designs that are several years old.

Also be aware that there is some degree of inaccuracy in the information that the Almanac provides; the error is usually no more than +/-1 knot of speed and +/-1" of armor, but can sometimes be more:

Hector and Invincible are both incorrectly listed as being capable of just 19 knots in the Almanac while Hector's sistership Achilles and Invincible's sistership Illustrious are correctly listed as being capable of 25 knots. That's a six-knot error; it'd only take a four-knot error for Intrepid to be a 31kn ship. Two example 31kn 3223x14" battlecruisers with 13" belts, one designed in the 1916 Britain savegame you provided in the other thread and one designed in a 1928 USA savegame that I have:

I personally don't think that these are particularly likely designs - the computer typically doesn't use short range, cramped accommodations, and speed priority on the engines, especially on American ships, tends to put a bit more armor on the secondary battery, and would probably use TP2 or TP3 rather than TP1, and the 1916 design would I think be more likely to have 3-3.5 inches of deck armor if the computer designed it than just the 2 inches I gave it - but they replicate the known (or at least suspected) qualities of Intrepid on 33,000 tons at 31 knots and are at least at the edge of the computer's design space. Not sure that they're actually within the computer's design space due to the things I mentioned above, but they're close.

There's also a slim possibility that a ship such as the 31kn example battlecruisers show above would only make 28 or 27 knots in service, though it'd need to be bulged. A 31kn ship should make 28 knots if bulged, or 27 knots if it's bulged and got the 'failed to make design speed on trials' event (which does happen to the computer's ships; the design files have a designspeed and a speed entry, and the two numbers will differ by 1 if that event - or the 'exceeds design speed' event - fired for the class). If it's too new to have been rebuilt with torpedo bulges, it might possibly have been affected by a bug which causes new construction to have torpedo bulges if you were looking at a design which included torpedo bulges before you created the design for the new ships (the bulges can still be removed in a refit normally), though I don't know that that bug affects the computer at all.

[bcoopactual]

aeson has it. If I could add, the 12 inch belt/31 knot go/no-go for BC/BB that goes into effect in January, 1916 only affects designs that are finalized (clicked on the save design button and confirmed) on or after that date. If the design was finalized before that date you can continue to build new ships to that design after January, 1916. You can also rebuild an existing ship of a earlier than Jan/1916 design, i.e. change machinery, after Jan 1916 and then build new ships to the rebuild design as well. However you cannot right-click on a prior to Jan/1916 design on or after Jan/1916 and use the open design feature (usually used to get a design discount) and create a new design. The AI will flag the ship and change it to a BB if it fails the 12 inch/31 knot test.

So as an example from my previous game:



Yorktown was a late 1915 design.  I could build new Yorktowns as battlecruisers for the rest of the game if I want because the design was finalized before Jan 1916.

I could also go in and rebuild the ship making whatever changes are legal, save it as Yorktown (R 1919) as a BC and rebuild the old ships or build new battlecruisers to the Yorktown (R 1919) standard for the rest of the game.

However, if I right-click on Yorktown and use the open design feature to make a new design, say Antietam, even if I don't change anything, because it's after Jan 1916, I won't pass the 12 inch/31 knot test and the program will tell me it has to be changed to a BB.  It's just a quirk of the sliding bar system between BC and BB. 

Hopefully that helps and wasn't just redundant to aeson's already excellent explanation.  

[generalvikus]

Thanks for clearing this up, aeson and bcoopactual - you guys are always on point!