BR Standard Class 8

The single piece of standard class 8P British Railways (BR ) is a steam locomotive with the wheel arrangement 2'C1 ' (Pacific ) and a three-cylinder engine.

What is unusual about the 1954 -built locomotive is their evolutionary history: the construction was modified in some points from the plans, so the performance was unsatisfactory and was no further construction of the class. During the restoration of the defects were detected and fixed, and the machine is now considered most powerful ever spilled in the UK steam locomotive.

Formation

The new locomotive should according to the ideas of their constructor Robert Riddle, the Chief Mechanical Engineer of the BR, to become the new standard for high performance steam locomotives. The construction of a prototype was initially rejected by the Railway administration, as were sufficient locomotives of this performance class. Only when the Princess Anne (Princess Royal Class ) had to be scrapped after the serious accident in Harrow & Wealdstone station in October 1952, the building was approved.

Technology

The Standard class 8P was an enlarged development of the standard class 7MT. The planned performance would with a two-cylinder engine a cylinder diameter requires that the narrow gauge of the BR would hurt, so a third cylinder had to be provided. The inner cylinder was working on the first coupled axle, the outer cylinder to the middle.

The control of the built by Gresley three-cylinder engines, in which the movement of the inner pusher by means of a lever mechanism in which the two outer valve has been derived had been found to be problematic, and therefore the 8P was equipped with a Caprotti valve controller already at 30 locomotives Standard Class 5MT had been used. This Italian-born control design worked with rotating cams that were powered through cardan shafts. It allowed an independent control of steam inlet and outlet, which promised greater efficiency of the engine.

The locomotive was equipped with two different three-axle Tender senders until 1958 BR1E type, then a BR1J. They were equipped with a steam-powered coal pusher.

Designation

The steam locomotives of the BR were divided into performance classes that are composed of a digit ( 0-9 ) and a letter for the intended use. 8P refers to a locomotive of the second highest performance class 8 for passenger trains (the P stands for passenger).

In the class 8P some series were arranged, the BR had inherited from their predecessors tracks, such as the LMS locomotives of the Princess Royal Class and the LNER class A4, which is why the term "standard class " is used to distinguish. Often the term is also stated without P ( " Standard Class 8" ) because there has been no other BR standard locomotives of this class.

The locomotive was the train number 71000 and the name of the Duke of Gloucester. The allocated after restoration TOPS number is 98802, but which is still written on the locomotive 71000.

Use and withdrawal

The locomotive was the staff unpopular because the steam power of their vessel was found to be inadequate - further copies of the class were not built for that. There were also made ​​no serious attempts to remedy the defect, because the BR had already decided at the time of entry to completely replace their steam locomotives by diesel and electric locomotives.

The Duke of Gloucester was used on the less demanding North Wales Coast Line between Crewe and Holyhead in 1962 and retired.

It was considered to pass the locomotive National Railway Museum in York, but eventually only one cylinder with the unusual Caprotti control was perceived as worthy of preservation and display at the Science Museum in London. For equilibrium reasons, the possibility of the second outer cylinder was removed, and the locomotive should be supplied to the scrap yard.

Restoration

The locomotive was purchased from Dai Woodham, those whose family scrapyard business in Barry, who has become known for the rescue of more than 200 steam locomotives. Contamination, the Duke of Gloucester first on the wrong junkyard; this error has been corrected but, and the machine met in 1967 in a Barry.

In 1974 she was purchased by railroad enthusiast, and a 71000 Preservation Society was founded, which was converted to the 71000 Duke of Gloucester Steam Locomotive Trust 1977.

The restoration was initially as " impossible dream " and took 13 years. Many missing parts, especially the Caprotti control had to be procured or produced. Because one was the outer cylinder at the museum and the other was also dismantled and scrapped, this also had to be remade - because of the unusual control, the biggest challenge in this project. Notwithstanding the original design ductile iron was used here instead of steel. Also for the lack of a Tender a replacement had to be found.

During the restoration of the original flaws of the locomotive were identified and corrected. This was particularly two points:

• The chimney and the blowpipe were compared with other locomotives of this size is too small. In addition, they had installed a standard version in the construction instead of the recommended by the manufacturer of Caprotti control Kylchap - exhaust installation against the will of Riddles.
• The louvers on the ash pan had not been built according to the drawings and had to small cross-sections, which the air supply to the fire disabled.

The success of these corrections was already evident in the first tests: the boiler was now able to deliver 30% more steam, and the Duke of Gloucester is now considered the most powerful steam locomotive that has ever driven in the UK. In comparison tests, in which a 430 -tonne train a slope has been drawn up, it was clearly superior to the locomotives, Sir Nigel Gresley ( LNER Class A4) and Duchess of Hamilton (LMS Coronation Class).

The locomotive has the necessary for operation on main lines and safety equipment is regularly used special trains, where they can drive because of their performance also routes that other steam locomotives were closed for decades. To drive even with modern cars, it has been additionally equipped with a vacuum brake to the original air brake system.

The Duke of Gloucester is now based in Bury at the East Lancashire Railway.