These Canadian-built General Motors locomotives have become the UK’s standard heavy freight traction. This is a long-established design, first supplied to the UK as Class 59 in 1985, later being updated for the EWS order of 250 locomotives supplied from 1998, and still gaining new orders. The design is also popular with “open access” freight operators in Europe, thanks to it’s reputation for reliability. The Class 66 features a General Motors 12N-710G3B-EC two-stroke engine, delivering 2385 kW (3,200 hp). A 6,550 litre fuel tank gives a range of 1,200 miles. The Porterbrook fleet includes 12 Class 66/6 which use a 83/15 gear ratio instead of the standard 81/20, offering a better “heavy haul” performance, but reducing the maximum speed to 65 mph. Reliability is the Class 66’s great asset, with miles per casualty figures often around 250,000, which is orders of magnitude better than the older locomotives they replaced.