I must confess that I had trouble fitting the machinery into the available space

It turns out that I needed to increase the depth and width of the machinery spaces to reduce the length of the boiler rooms and engine rooms. I might well still have to increase the power output of the plant to decrease the size further. The ship is overweight, still, from what I really wanted and the powerplant is busting out at the seems. The only thing left to do is to increase the power output above 66 SHP/ton of machinery.