Performance Examples

Predictions of 5AT Operational Performance in Practice


Dr David Pawson has prepared several performance predictions for the 5AT based on the performance predictions generated by Professor Hall’s Perwal software.His predictions cover operation of the 5AT over two famous rail routes in the UK, one covering Crewe to Carlisle (over Shap Summit) and the other from Kings Cross to Grantham (over Stoke).  The tables below summarise the results of four 5AT runs hauling loads of 375 and 500 tonnes gross at maximum speeds of 145 and 177 km/h (90 and 110 mph).  (Fuller details of his predictions can be access here).

Crewe to Carlisle
227 km
375 tonnes gross
145 km/h max
375 tonnes gross
177 km/h max
500 tonnes gross
145 km/h max
500 tonnes gross
177 km/h max
Journey Time 1 hr 44 min 1 hr 37 min 1 hr 47 min 1 hr 44min
Average Speed Start – Stop 138.0 km/h 140.3 km/h 126.5 km/h 130.8 km/h
Average Indicated Power 1753 kW 2065 kW 1970 kW 2138 kW
Average Drawbar Power 1115 kW 1348 kW 1350 kW 1491 kW
Water Used per 100 km 6.79 tonne 7.67 tonne 7.92 tonne 8.45 tonne
Total Water Used 15.44 tonne 17.42 tonne 17.98 tonne 19.18 tonne
Kings Cross to Grantham
169.7 km
375 tonnes gross
145 km/h max
375 tonnes gross
177 km/h max
500 tonnes gross
145 km/h max
500 tonnes gross
177 km/h max
Journey Time 1 hr 14 min 1 hr 06 min 1 hr 16 min 1 hr 10min
Average Speed Start – Stop 138.0 km/h 154.2 km/h 140.3 km/h 144.5 km/h
Average Indicated Power 1552 kW 2061 kW 1748 kW 2158 kW
Average Drawbar Power 940 kW 1250 kW 1160 kW 1431 kW
Water Used per 100km 7.40 tonne 8.76 tonne 8.76 tonne 9.91 tonne
Total Water Used 12.56 tonne 14.87 tonne 14.86 tonne 16.82 tonne

David Pawson offers the following commentary on his spreadsheet model:

“There are two separate parts to the simulations: the times and speeds; and the consumption estimates. The times and speeds are broadly a combination of:

  • Newton’s laws;
  • (largely) accepted locomotive and coach resistance values, and
  • known gradient profiles.

These are therefore pretty reliable illustrations of what the application of around 3000 IHP to the trains will deliver in terms of times and speeds.

The consumption figures are less exact. They are based on theoretical models that are inherently sound, but do not take into account all sorts of factors that would likely pertain in the real world. They should therefore be viewed as ‘preliminary indications’ of what might be achieved in ideal circumstances.”