upgrading a ship to a nearly same design problem

[temuchin-]

upgraded a ship to the nearly the same design (11K ~ 11K) the game added 4 hours to the build time, swapped the build back, the game added another 3 hours to build time, swapped again for another 2 hours build time, swapped again for yet another +2 hours build time.

end result 6 hours became 17 hours build time. Completely ruined an empire when its entire build queue time is tripled. Not sure why at this time. Usually there is no major time alteration for build times when committing an upgrade (up to the point of making something a negative number if it has a lesser cost).

[temuchin-]

With the diminishing returns I am able to reduce construction on a ship to 0% from any previous percentage. This might be a game feature, will go through the code at a later date.