The main British Navy yard for arming British submarines with Tridents is Coulport. Trident missiles are small nuclear warheads and British nuclear submarines are armed with 16 Tridents on each voyage, alongside other weaponry such as anti-ship torpedoes. They are capable of carrying more Tridents, but there is no need for them to unless there is a direct threat of nuclear war.

Yes.

Power House League.

god of sea,horses, tridents and underwater monsters

Unless you are playing with custom weapons mods, then no. There are a few pitchfork-like weapons, though, but they're quite weak. If you want tridents and other cool weapons, install one of the many Mount&Blade mods, found at the Taleworlds Forum