A1 Steam Locomotive Trust 4-6-2 Locomotives in Great_Britain

Class Tornado (Locobase 10714)

Data from [] (last visited 3 August 2009) and Michael Binyon, "The steam train returns: caught up by the Tornado", Times of London, 9 October 2008. See Locobase 1067 for the 1948 Peppercorn A1s.

According to the A1 Steam Locomotive Trust: "Water is the most significant limitation with most locomotives hauling loaded trains at express speeds being limited to about 100 miles (160 km) between filling the tender. For the A1 class an average of 40-45 gallons (113-137 litres) per mile is to be expected. "

As originally designed, the A1s all had a distinctive Kylchap double-chimney for better draft. They were reportedly fast and economical engines, partly because they used Timken roller bearings on all axles and were fitted with relatively capacious 10"-diam piston valves. And their superheater ratio was among the highest in British service. All in all, thought the Trust, a good foundation for a newly built locomotive.

As the Times of London story describing the opening days of the completed locomotive's operation noted, this was by no means meant a straight path from concept to delivery. They had one advantage over many such projects, reports Binyon: "When the project was launched in 1990, more than 1,100 blueprints by Arthur Peppercorn, original designer of the A1 Pacific - Indian ink drawings on linen that were stored in the National Railway Museum in York - were scanned and catalogued."

Among the earlier pieces to be completed was the backbone: "The frame plates for the engine - the skeleton that determines a locomotive's personality - were cut from a single piece of steel and moved to a workshop in Darlington in 1994."

Yet building the Tornado would take much more time than originally envisioned: "It was hoped that Tornado would be built by the millennium. But ...every component [had] to be machined and moulded individually - with the generous support of engineering companies nationwide - and relying on volunteer labour." Milestones included casting the 80" drivers (1995) and the cylinders (1996). "But the boiler, the greatest challenge, took much longer. No British firm could do the job. Finally, after the launch of a +500,000 bond issue in 2004 to provide emergency funding, the order was placed with one of the last remaining manufacturers of steam-engine boilers, at Meiningen in Germany." Final cost to build the locomotive: 18 years and over +3,000,000.

According to Binyon, the design reproduces Peppercorn's original almost exactly. However, "There are a few innovations. A full electronic signalling and recording system has had to be tucked into the cab, under the driver's seat, so that Tornado can conform to safety regulations. Every movement of the regulator, every fluctuation in speed, can now be recorded electronically to provide a record of how the engine is driven."

The Tornado went into service in 2009 after being fully certified to run on main lines and established a full schedule of runs on most of the historic lines in the British Isles.