This based on a set of drawings in T4: Starships. page 40. These were done in Campaign Cartographer 3 with the Cosmographer add-on.
Ships: Patrol Cruiser
"Welcome to my GURPS Space site; these maps and other graphics are only for playing Space/Science Fiction type games. They are copyright and not to be used for other purposes. If you have them on your site, please remove them. Thank you."