Researching for a forthcoming campaign I wanted to know the speed of cargo ships travelling in convoy across the Atlantic. I came across a U.S. based website which stated that a coal burning ship could travel at “twelve knots per hour”.
Since one knot is one nautical mile nautical mile per hour, 12 knots per hour can only be a rate of acceleration, therefore I deduce that the 3043 miles from New York to Liverpool would take around 22 hours and the ship would arrive travelling at a little over 250 miles per hour.
An astute captain would put the engines astern somewhere in mid ocean.
General Whiskers' semi-historical wanderings 