2tugboats.com tug boat plans free pictures and ideas. plus, a free sample pdf for the keel for building your own 65. Caldercraft resolve – twin screw naval tug 1:48 scale due to the depletion of the naval tug fleet during the 1914 – 1918 war, the royal navy decided to replace the. Proven boat designs, and how-to information for boat building. boat plans are for beginners and have been built by thousands since 1953..