Why ten secret Montanas would trigger a naval race

What happens if Thailand secretly unveils ten Montana-equivalent battleships in 1912?

Britain and the United States begin major construction programs, Germany loses its place in the naval ranking, and the supposed secret is undermined by the industrial footprint required to build the ships.

Ten Montana-scale ships would immediately reorder the naval balance and force the major powers to accelerate construction. Britain would probably enlarge the Queen Elizabeth programme and improve its follow-on battleships, while Germany and the United States react to being displaced. Armour plate, engineering labour, yards, and port visits make a project of this size nearly impossible to hide. Even after launch, ten battleships without destroyers, submarines, and supporting forces would remain a dangerously unbalanced navy.