5AT Legacy

The 5AT project was established in 2002 with the intention of implementing David Wardale’s concept for a high performance “advanced technology” 4-6-0 conforming to the dimensional outline of the BR Class 5MT locos of the 1950s.   The performance predicted (and estimated) for the 5AT would not only have exceeded by far the performance of any Class 5 loco, but would have exceeded by a significant margin the power and speed capabilities of any Pacifics whether of British or overseas design.


The predicted performance of the 5AT is summed up on the 5AT website as follows:

  • Weight of locomotive: 80 tonnes; adhesive weight: 60 tonnes; weight of tender (fully loaded): 80 tonnes;
  • Maximum continuous operating speed of 180 km/h (113 mph) with a maximum design speed of 200 km/h (125 mph);
  • High power to weight ratio: 1890 kW (2535 hp) at the drawbar (indicated power 2380 kW or 3200 hp) at 113 km/h (70 mph);
  • Indicated thermal efficiency: approximately 14%;
  • Operating range: 610 km (380 miles) between water-stops under average service conditions and 925 km (570 miles) between fuel stops;

5AT team members set up the AST Trust in 2012 following the demise of the 5AT Project, inheriting from it the knowledge and experience gained from extensive studies conducted for the 5AT Project, together with the Fundamental Design Calculations prepared by David Wardale for the 5AT locomotive, and a large amount of supporting documentation including several important papers written by Ing. Livio Dante Porta.

Both the 5AT Fundamental Design Calculations (completed in 2005) and the 5AT Feasibility Study (completed in 2010) are now available for sale through this website.