| Year | 1989 |
| Date | 02-Jun |
| Volume | 162 |
| Issue | 3,850 |
| Page | 688 |
| Category | Road Locomotive |
| Part | 1 |
| Title | Sentinel Engine |
| Author | Alan Beasley |
| Notes | Reveals how he designed and built an Undertype engine for a 2 in. scale Sentinel Steam Waggon. The engine design, gears and gearing |