| Year | 1989 |
| Date | 07-Jul |
| Volume | 163 |
| Issue | 3,852 |
| Page | 39 |
| Category | Road Locomotive |
| Part | 2 |
| Title | Sentinel Engine |
| Author | Alan Beasley |
| Notes | Reveals how he designed and built an Undertype engine for a 2 in. scale Sentinel Steam Waggon. Cylinders, valves and cams, cam profiles used |