Full steam again

In 1946 Paul Kiefer, chief mechanical engineer of the New York Central Railroad, set his latest steam locomotive, the potent, coal-burning 6,700hp Niagara class 4-8-4, against General Motors' brand new diesel-electrics. The Niagara could generate more power than three of the latest diesel-electrics coupled together. It could run the wheels off them while accelerating passenger trains as long as 30 modern British InterCity carriages with the alacrity of an electric.

The detailed report that followed revealed total annual running costs of $350,095 for Kiefer's finest and $359,478 for a twin-set of 4,000hp GM diesels capable of maintaining existing NYC schedules. As the construction cost of the diesels was nearly 50% higher than that of a Niagara, you might have thought that steam would have continued to rule the railroad roost.

Not a chance, even though the tests were conducted with oil as cheap as chips in today's terms. If, in fact, the NYC management had been forced to buy oil at the equivalent of today's prices, the Niagara would have won the day effortlessly. Or, would it? I don't think so, no matter how you looked at, or cooked, the figures. The problem facing inspired steam engineers like Kiefer and his contemporary, André Chapelon of France's SNCF - whose latest locomotive, 242 A1, was outperforming existing electric locomotives, was, as much as anything else, one of image.

Steam seemed old-fashioned, dirty and labour-intensive. It didn't have to be, but that was the perception encouraged by General Motors, the oil lobby and a new generation of fervently modernising railway managers.

This summer, though, is witness to two intriguing steam revivals. The first is the attempt by the British Steam Car Challenge team to break the world land speed steam record in a beautiful British racing green car. Fueled by Calor Gas, the turbine-powered racer should, with luck, steam across the Bonneville flats in Utah at 170mph, and very possibly top 200mph. The car's designers, led since 1999 by Bill Rich, a retired marine steam engineer, say that the "overall aim of the project is to promote education and awareness of clean burning fuels and ecologically sound technologies to young engineers all over Britain".

And not, you might say, before time. Today, the oil lobby that did for Kiefer's Niagaras is under the global spotlight. Oil is dirty and running low; it fuels war and public strife. A revived steam technology is one way forward, yet steam needs the kind of publicity boost Rich's team might just give it this August.

This summer's second steam adventure is the long-awaited debut of Tornado, a recreation of a 1948 London and North Eastern Railway A1 Pacific. This will be the first express passenger steam locomotive built in Britain since the Duke of Gloucester 54 years ago. Tornado, the result of years of hard work and campaigning by the A1 Locomotive Trust, will take her place alongside the restored Duke of Gloucester running mainline specials. While Tornado is hardly the latest in steam engineering, the locomotive will act as a flag-waver for this overshadowed technology while promoting new projects like David Wardale's super-efficient 200kph 5AT locomotive.

Even then, there is some way to go before steam technology sheds its image of "puff-puffs" and men at the end of platforms with too many Biros in their top pockets. In a sense, steam technology came too early for its own good. The existing land-speed steam record was set by a Stanley Steamer as long ago as 1906.

New fuel and power technologies need to be pursued and developed, and yet steam technology, as old as Hero of Alexandria's first-century turbine, may yet be back on the agenda, road, rails and record books.

· Jonathan Glancey is the Guardian's architecture [e-mail]