Jonathan_S wrote:However the real difference in swapping in the USN is that the only modern battleship the US had at the time of the Bismarck fight was the USS North Carolina (commissioned just a month earlier). She was about as fast as HMS Prince of Wales and HMS Hood (in '41 condition), but none of the other US Battleships were. So she'd either have to try to keep up with Bismarck solo or else stay in formation with one of the 21 knot Standards and watch Bismark steam away.
Be careful about assuming US BBs were slower than their European contemporaries. The US from before 1900 published design speed with full load, not maximum speed (almost all US warships can exceed their published speed if ordered to do so). Most European Navies at the time of the Battleship arms race published a top speed that was from sea trial with light load. As an example I have seen published top speeds for the Iowa Class of both 27 Knots and 33 Knots.
Even the Nevada may have been able to keep up with Bismark, mostly because Nevada would likely have had half full fuel tanks.
I believe that the most likely scenario if a pair of Nevada class BBs tangled with Bismark in 1940 would be first a long range slugfest much like what happened, followed by a race toward France where Bismark tries to break contact, but the Nevadas pulling 22+ Knots are able to hold contact long enough to vector other ships in to engage Bismark at least enough to force her to maneuver and thus stay well below top speed. This would end in a protracted periodic running gun duel as other ships forced Bismark to dodge torpedoes or maneuver around other RMN Battleships.