These were double-ended camelback locomotives with small drivers. They were used to haul freight trains through the tunnel that connects Port Huron, MI with Sarnia, ON on a ruling grade of 2%. Originally built as tank engines, they were later give tenders to increase their capacity. The side tanks were also removed. Later, they were fitted with conventional cabs.
| Wheel Arrangement | Road Numbers | Builder | Year | Locobase Entry |
|---|---|---|---|---|
| 0-10-0 | 598-601 | Burnham, Williams & Co. | 1891 | 2850 |