To convert this (or any) plans into the scale of your choice you just need to know the the size of the actual object. In this case the subchaser was 110' long, so I first convert that into inches (or cm) = 1320"; then I divide by my scale (56) = 23.57 (inches). If you have a adobe photoshop you can enlarge or reduce any line drawing in this manner. I've used this technique to build planes, tanks and boats