Nigel,
To answer your question I must delve into a little bit of history. Even before the US was actively involved in WW 2, the Maritime Commission, a governmental agency, began looking for designs to fill the anticipated needs of WW 2. It sent representatives to the UK and some European countries to find designs to supplement it's needs. Some designs that came back and were "tweaked" were to become Liberty ships ( British design), V-4 ocean tugboats ( based upon the Zwarrt Zee which escaped Holland) (200+ footers), and the Wind class of icebreakers. The Wind class was based upon a Finnish Baltic design that was very successful. However, The Baltic does not have the hard old ice that the Arctic does. It was not long into the Eastwind's first deployment to Greenland waters that the bow prop's vulnerability to hard ice was discovered. In 1945 when the "Winds" were turned over to the US Coast Guard, the bow prop were removed, with no effect upon their speed nor ice breaking ability.
I chose to model her in her as built configuration, it gives me one more get home prop when the weeds take over.
As soon as the ice melts here, I will post some pictures of her in her element.