0 to 60! Just how nimble are today’s locos and units, and what’s the quickest off the mark?

Neville Hill catches a railtour bound for Yorkshire behind a pair of DRS Class 57/0s.

THE Class 57s were all rebuilt from redundant Class 47s, with the original Sulzer engine replaced by one from General Motors.

There was always debate over the power output of Class 47s, starting out as 2750hp before electric train heating (ETH) brought that figure down twice, eventually to 2580hp. The production Class 57s continued this pattern – initially rated as 2750hp, but with the Class 57/0s and prototype ETH

No. 57601 shown as 2500hp.

We take rated horsepower in this series as opposed to ‘power at rail’, where further complications are introduced, and the ‘57/0s’ are

theoretically some 7% weaker than their ETH Class 57/6 cousins by this measurement. No. 57603 has already appeared in this column, taking 76sec to reach 60mph with a light 125-tonne trailing load for an RE Factor of 11078.

Pathfinder had asked for Class 57/0 power from Bristol to York for its ‘DRS Class 20 Farewell’ tour on January 18 and was allocated Nos. 57002 and 57003 for the 13-coach, 480-tonne tare load (No. 57002 coincidentally being ‘our loco’ Rail Express).

The best place for calculating the 0-60 start was from Tamworth, which is level for three quarters of a mile, followed by an admittedly helpful fall at 1-in-484. The downhill stretch would not matter for a modern unit, which would be at or near 60mph while still on the level.

The gross load, including the two locomotives, weighed in at around 761 tonnes, more than three times our earlier Class 57/6 example, but with less than twice the power. The locos had exerted themselves on the Lickey Incline after a Bromsgrove station call, and the departure from Tamworth was similarly energetic to meet the need for recouping the five minutes-late deficit against the pressure of tight Saturday morning pathing.

Although the 132sec taken by the two ‘57/0s’ to reach 60mph was 56sec longer than that for the featherweight Class 57/6 trip, the RE Factor (which takes load into account and is therefore a better measure of performance than time alone) initially looked to be in the same range, but at 11515 it actually turned out to be slightly better.

E

Phil Precious Nos. 57002 Rail Express +57003 pass Colton, south of York, with the outbound leg of Pathfinder’s ‘DRS Class 20 Farewell’ tour from Bristol on January 18. These locos put on a good show and outperformed their Class 57/6 cousin in our time trial.