This sketch is based on two iconic designs of the specialized vehicles from the famous action rescue series Thunderbirds (1965).
The two machines seen here are Thunderbird 3 (International Rescue's space rocket) blasting off while Thunderbird 2 (the organization's giant transporter) flies over their secret base, Tracy Island. The look of the machines was based on the designs created by model makers Derek Meddings and Mike Trim.
A series of artist pencils were used on a sheet of 22.8" x 30.4 paper.
First, a light sketch of both Thunderbirds 2 and 3 was made.
Secondly, light shades were added to the two machines to define texture and contours.
Some aspects of the line art were enhanced using artist pencils. The look of Tracy Island was sketched in.