"DUKE OF GLOUCESTER" is a steam locomotive of historic and scientific importance to the heritage of this country, although its unique features had their beginning in Italy, many years before its conception. In 1911 at Milan University, Arturo (Arthur) Caprotti set out to change some of the inherent inefficiencies of the steam railway engine, specifically the way in which steam was admitted to, and from, the cylinders. He did this by completely redesigning the motor car poppet valve and the camshaft that operates it, then applying this, in huge size, to the steam engine. His invention was brilliant but flawed and only when it was developed in this country, by Tom Daniels a former Great Western Railway engineer, was it perfected in 1950.
In 1952, the Harrow and Wealdstone railway disaster resulted in the former experimental engine "Princess Anne" being destroyed and Robert Riddles, the last great steam locomotive designer, set out to build a new prototype for the future. "Duke Of Gloucester" was to be the first of and entirely new generation of express passenger engines, which would serve British Railways until the network was completely electrified. Riddles chose the British Caprotti valve gear for his engine, which emerged from Crewe Works in 1954.
On the Swindon Test Plant it was found to have the greatest cylinder efficiency of any simple expansion engine on record and subsequent trials showed it to be significantly more powerful than any comparable type. Regrettably after Mr Riddles retired, a decision was made to withdraw steam and replace it by diesel traction as soon as possible. This prototype was destined to be a "one-off".
In 1962, "Duke of Gloucester" was listed for preservation as part of the National Collection. Had this course been followed, the locomotive would now be on display in The National Railway Museum. However, the locomotive's boiler, theoretically as excellent as the cylinders, had exhibited mysterious steaming deficiencies at high outputs, the cause had baffled both technical experts and enginemen. It was thus deemed to be a failure and condemned for scrap.
Nevertheless, the British Caprotti poppet valve gear was considered to be of scientific importance. The complete left - hand cylinder was sent to the Science Museum, Kensington, where it remained, exhibited in sectioned form, until being put in store in 1998. The right - hand cylinder had been cut up and the rest of the engine, which retained just the third (centre cylinder), was stripped. The remains went to a scrapyard in South Wales to suffer a lingering, rusty death. The technology, skills and knowledge necessary to manufacture the two missing outside cylinders and their unique valve gear were thought to have disappeared, the cost of restoring the locomotive as a whole was considered prohibitive and why restore a "failure" anyway.
In 1973, the restoration of the "mutilated hulk" of "Duke of Gloucester" had become the "Impossible Dream" of a small group, the founders of our Trust - engineers, draughtsmen, a patternmaker and people with various skills from all walks of life. In the face of widespread scepticism, the locomotive was rebuilt from scratch, many aspects of the work involving new drawings, castings, forgings, machining and, all to often, the seeking out of new manufacturing processes or materials to replace those which were no longer available.
The Science Museum gave a grant of £6,000 towards the cost of new cylinders, but the rest of the finance had to be raised independently. The scale and complexity of the manufacturing work meant appealing to industry around the whole of the country. The engineering "world" was much more buoyant than it is today and responded magnificently to the cause. Significant help was given by British Steel, GEC and The Metalbox Company and was supplemented by a multitude of smaller companies, with work being carried out free or at greatly reduced prices. It is difficult to estimate the true commercial cost of restoration by the prevailing prices of the time, but it probably would have been in the region of one million pounds. Instead, the work was done on a "shoestring budget" with tremendous voluntary effort and without sacrificing quality.
Most importantly, in the course of the restoration, it was discovered that the chimney assembly had been wrongly designed, throttling the exhaust steam. The mysterious steaming problem had been found! A chimney of different design and much larger size was manufactured and fitted.
In 1986 "Duke of Gloucester" steamed again - on The Great Central Railway at Loughbrough and in the years that followed received many accolades. The 1986 award for achievement from The Association of Railway Preservation Societies, was presented by John Bellwood, then Chief Engineer of The National Railway Museum who said "You have rewritten history". The Museum showed its own appreciation of the achievement by inviting the locomotive to be "Guest of Honour" at the re-opening of the Great Hall in 1992 - the only privately owned engine to be present.
"Duke of Gloucester" ran again on main lines for seven years and continued to "rewrite history" - establishing a reputation for high speed running and feats of heavy haulage, with steam to spare and power in reserve. From the beginning it became a favourite on the famous Settle and Carlisle line, setting new standards of performance. 1995 saw it cover routes previously barred to steam traction for almost three decades including those from London Euston and Kings Cross. In October of that year, "Duke of Gloucester" climbed the notorious Shap bank on the West Coast main line and topped the summit at the highest speed ever attained with a heavy load. Weather conditions on the day were so atrocious the engine could not fully opened out, for fear of wheelslip!
