I know I'm new to the game, but I find the Continual Constant Expansion of shipyards to seem to be somewhat overpowered. Maybe its the civil engineer in me, but I find it hard to picture a shipyard tripling or quadrupaling the size of ships it can handle while constantly operating and building ships.
So, one suggestion would be that this Continual Constant Expansion mode could operate at some fraction of what could otherwise be constructed, in order to reflect the difficulties of working around an open and operating shipyard slips.
Another suggestion would be to
a) The shipyard capacity expansions that expand by a fixed amount go faster than the continual expansion. But they also close one or more slipways while they are working. I'd offer the player/admiral two options for doing upgrades.
1) Full shutdown. All the slipways of the shipyard are empty, and stay that way during the upgrade construction. This is the fastest form
of construction as the crews aren't having to work around anyone else and have full ability to just get in and do the job.
2) Rotating shutdown. One slipway at a time is closed for upgrades. Effectively, when this mode is selected, the number of slipways is
reduced by one. It can only be begun when this number or fewer slipways have ships in them. The time for the construction is the time to do one slipway, repeated for the number of slipways. Ex: a 4 slipway naval shipyard of 3,000 ton capacity wants to add 1000 tons per slipway. The number of slipways is temporarily reduced to 3, and the expansion can only begin when there are three or fewer ships in the slips. The time it takes is the (time to upgrade one slipway) x 4.
3)Then, you'd have the slowed down continual constant expansion from above as a still slower alternative, but one that occurs while the shipyard never misses a beat.
Adding new slipways can always be done without effecting the existing slipways.
Anyways, that's my $0. 02 on what I think shipyard expansions should look like. This would give choices to the player. If its peaceful, he might want to shut the whole yard down and upgrade it quickly. If he needs to be churning out warships while upgrading, he could pick either of the two slower options. Or, maybe risk the full shutdown, and fewer new ships in the short term, if they want to build bigger ships sooner in the longer term?
And while providing more interesting choices, it also feels a bit more realistic to someone who's worked around construction sites all his life and knows that working around something you have to keep operating is always slower and more of a pain than when you can just go dominate the site, build the stuff as fast as possible, and then leave.