Official Blackstone Engine Website

A Brief History of Blackstone & Co. Ltd. - Part Seven.


Ralph Ley, the Chief Engineer, in 1968, came up with a design for a new vertical engine. It was intended to fill the gap between the P and E types. This was the BV, a multi-cylinder engine with a 7½” x 7½” bore and stroke. A prototype was built and successfully tested, but again the Stockport directors decided not to proceed. Their view was that business was such that the development of a completely new engine would divert time and money into non-profit making research.

Only the existing engine types were to have continuing development. This meant that the EV evolved into the Type E Mk1. with stiffer crankshaft and camshaft to allow for higher operating pressures. A cross-flow head was introduced with two overhead valves per cylinder.

During the early 1970s the works were turning out about thirty complete engines per month. Many of these went into Scottish fishing boats. Apparently this business was so good that a resident service engineer, fully stocked with spare part s and even spare engines was permanently based in Aberdeen. His job was to keep the trawler fleet at sea.

Then, in 1972/73, the Scottish fishing industry collapsed and with it the engine market in that division. On top of this setback came the Iran-Iraq war of 1973/74. The Middle East had long been a profitable market, especially for the P type engines. These were used principally for irrigation systems. From the nineteen-sixties the output of these engines had grown to over thirty per week. It was said that one could stand anywhere in Iran or Iraq and in the quiet of night hear the beat of a Blackstone engine at work.

Mirrless-Blackstone advertising literature.

Since the war an embargo on sales to this market it has largely been taken over by Japanese engine makers such as Mitsubishi. Apart from being able to offer their products at considerably lower prices, their products have also been more acceptable to the Islamic leaderships of these countries. However, their engines have been found to be less long-lived that the traditionally robust and simple to maintain engine as supplied by Blackstone. In the meantime cheap spare parts for many British built engines have been coming into the area from India. Generally, though, these have been of poor quality and move was made to lift some of the export restrictions to these two countries.

Despite the earlier decisions not to produce any new engines, in 1976 the compact Vee configured ESL was introduced in 8, 12 and 16 cylinder versions. Using the, by now, standard bore and stroke dimensions, 8¾” x 11½” this engine was capable of producing 125 bhp per cylinder. Many of the parts were interchangeable making for ease of production and to hold fewer spare parts.

The following year, 1977, Hawker Siddeley Group’s aerospace interests were nationalised: Mirrlees Blackstone Ltd. was divided into two companies, Mirrlees Blackstone (Stamford) Ltd. and Mirrlees Blackstone (Stockport) Ltd. In effect this made little difference to the running of the company. Although Stamford retained its own managing director, the company was still under the control of Stockport.


Two E type 360 kW auxiliary sets aboard Bibby Line’s MV Warwickshire.


Turbocharged and intercooled ESL8 generating set.
With a rating of 1250 bhp at 1000 rpm, output of 883 kW.

Nineteen-seventy-eight saw the introduction of the E Mk II engine. With the same bore and stroke as the original EPV designed as long ago as 1933 by Frank Carter, It was a development of the E Mk I. With a further stiffened crankshaft and camshaft and with larger bearings it was capable of operating at a higher level of supercharging. It could now produce a maximum of 180 bhp per cylinder at 1000 rpm. Compare this engine with Carter’s original EPV, which produced 40 bhp per cylinder at 600 rpm. Nearly five times the output. The Mk II pistons and connecting rod were similar to those in the Mk I but each cylinder now had four overhead valves per cylinder. The Mk II was fitted with external fuel pumps to prevent fuel oil contaminating the lubricating oil.

During the late 1970s the Stockport drawing office produced a general design for another completely new engine to be produced at Stamford. Designated MB 190, it was a 45o Vee with a 210 mm stroke and 190 mm bore. It turned out to be more complicated and expensive to manufacture than any other Blackstone product. It was built in four configurations; 6 and 8 cylinders in-line and 12 and 16 cylinders Vee. At 1500 rpm it developed 173 bhp per cylinder. Like the Mk II it had a four- valve cross- flow head and a very stiff three-part connecting rod. Although the engine itself was a success, it was too expensive to make and, at 1500 rpm, too fast for many of the company’s markets. Only about fifty engines were built before it was dropped. One application which could have saved the MB 190 was the use of the 12 cylinder Vee version to re-engine British Rail’s HST 125; the High Speed Train. These diesel train sets, which ran regularly on the east coast main line entered service in 1976. After about three year’s running the original Paxman Valenta engines began to suffer a number of problems, including fractured connecting rods and cracked cylinder heads. There were also problems with the turbochargers and manifolds. In 1979 B.R. approached Mirrlees Blackstone with a proposal for developing the MB 190 for rail traction. British Rail insisted that that the new engine would directly replace the existing engine with the minimum disruption to the engine layout and equipment.

MB190 V-Engine with generator for rail use.

Following trials, using a six cylinder engine to simulate the installation in the HST, which satisfied both the company and BR of the MB190’s potential, B.R. placed a £750,000 order for four engines. The first complete engine was delivered in April 1986. In fact five engines for HST use were built, four were installed in trains the fifth kept as a spare engine.

Four locomotives with MB 190 engines were put into service on the Western Region of B.R. where they performed adequately but not spectacularly so. For time a Blackstone engineer was based with the engines during the running in period. It seems that once he left these engines, being the only ones in the fleet, came neglected and received less attention than the others. No further MB 190s were supplied to B.R. As with earlier contracts B.R. wanted more service commitment that the company could, or would, afford to give. Where these engines are now, assuming they still survive, is unknown.

The general recession in world trade during the late eighties and early nineties, particularly in engineering, hit Blackstone’s as hard as anyone else. As part of the Hawker Siddeley Group they were subject to a major reorganisation and lost many of the 650 employees. Because of the loss of many important markets a fourteen per cent decline in profits was recorded for the first six months of 1991. This resulted in the take over of Hawker Siddeley by B.T.R. in November 1991.

British Rail Intercity HS125.

In 1924 the American tyre company B.F. Goodrich formed a British subsidiary, which subsequently broke away, in 1934, from its parent to become known as the British Tyre and Rubber Company. Until the nineteen-sixties it was just one of a number of firms competing in the rubber industry. Then, as was the case with Hawker Siddeley, a new philosophy of acquisition was adopted. Businesses in a variety of specialities; packaging, plastics, construction, etc., were taken over to become B.T.R., one of the world’s largest industrial groups.

During the winter of 1993/94 began moving engine production from Stamford to Stockport. The last engine left the Stamford works in March 1994. This latest upheaval meant that a large proportion of the workforce was made redundant, although a few were given the option of moving to Stockport. Only the foundry, spares and service departments remained at Stamford supported by a machine shop with about fifty machine tools. Here the castings were finished and some E range engines refurbished. A market for finished castings for engine manufacturers at home and abroad was developed.

The engine-erecting bay before B.T.R. moved engine production to Stockport in 1993/94

Coincidently an upsurge in demand from the Middle East for P type engines enabled the Stamford works to supply engines in kit for assembly in the country of destination. At this time, 1995, about 180 people were employed.

The last seven years have seen further changes in the ownership of the company. About five years after B.T.R. took over they found themselves victims of the continuing world wide down turn in engine requirements. The group split up and Mirrlees Blackstone (both Stamford and Stockport) became part of the G.E.C. Alstom group; an Anglo French consortium. This arrangement lasted about a year until MAN of Duisberg, Germany, took a controlling interest.

In 2002 MAN began closing down many of their outside operations because of the German economic situation. The effect on Blackstone’s of Stamford has been the closure of every department except the service section. The Ryhall Road site is now being cleared. Many of the buildings have already been demolished, including the ‘White Elephant’, which was the first pre-stressed concrete building in the East Midlands. Early in 2003 the last connection with the site ended when the Service Department moved to a new site.

For one hundred and sixty-five years the company has served the town of Stamford as employer and the wider world as manufacturer, for one hundred and six years from Ryhall Road. The Rutland Ironworks is no more but the quality of its products are still valued and celebrated by many people around the world.

All pictures & text © 2003 Michael Key


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