| Year | 1991 |
| Date | 05-Jul |
| Volume | 167 |
| Issue | 3,900 |
| Page | 39 |
| Category | Countryman's Steam |
| Part | |
| Title | An Ingenious Differential |
| Author | John Haining |
| Notes | Discusses the novel and unusual crankshaft differential gear fitted to the chain drive Super Sentinel Steam Waggons. DG4 of 1931 owned by Pete Bowers |