At the end of the "forties" the company's eightieth anniversary was marked by an open day; it is a sobering thought that by now some of the smallest children seen here admiring the model of the latest 4B K engine are probably, since even this comparatively recent date, parents themselves several times over and possibly now employees of Dorman's.
    As the decade turned a significant pattern emerged for Dorman's post war trade. Prior to 1920, a list of Dorman's foreign customers would have been relatively small, a decade later the boast could be made that tens of thousands of Dorman engines are in use all the world over; and by 1952 85% of Dorman engines were directly or indirectly exported. An agency organisation had now been developed to cover every important trading centre in the world; a consequence was that Dorman was now doing very well. In the first five complete trading years of the peace the company's turnover by value increased annually to 58% by the end of the financial year 1952; this was achieved by a
corresponding increase

in staff of 45%. Judged by sheer output, productivity in 1952 had reached an all time level, which was surpassed again the following year, in the simplest terms, the order book was full, and the factory was working to full capacity. This is still the situation to this present day.
    The ghosts of the twenties slump and the thirties depression had been laid to rest, never to walk again. As if to usher in the new era, Dorman engined machinery was to be seen, in plenty, during the years 1950-51 helping to prepare the site for the Festival of Britain.
    The most significant feature of the nineteen fifties was the development of the new engine series which were to greatly expand the available Dorman power range, this was the consequence of a decision taken as early as 1946 when as many as four basic engine series had been provisionally outlined, ranging from a single cylinder 6 b.h.p. model to a sixteen cylinder diesel to produce 2,000 b.h.p.
The essential requirements for the new engine ranges was that

Priestman Crane

Serafini Pump



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Dorman Centenary CB 38-39 CB 44-45

intended to produce horizontal five and six cylinder models, and even a vee sixteen.
    In 1962-63 Dorman introduced turbocharged air to air charge cooling for the Q range of engines. In this system the charge air travels from the turbocharger via an intercooler, which is integral with, and cooled by, the same fan as the radiator; after being cooled the air then passes to the cylinders. The principle of charge cooling is that with the introduction of the cooled air, the air is rendered more dense resulting in a greater charge of air into the cylinders which enables more fuel to be burnt with a resultant increase in power.

   Air to water charge cooled engines require a constant flow of water with the necessary pump and an assortment of pipes; these are eliminated in air to air charge cooled engines thus permitting them to be a portable, self contained unit, hence the value of the work pioneered by Dorman, in this field.

their design should provide for the complete interchangeability of the maximum possible number of components common to all models, thus perfecting to a high degree the standardisation and interchangeability at which Dorman had set their sights and greatly facilitating the after sales spares service.

   In due course the present Dorman 'L' range was initiated in 1953 with the 'LA' engine; 17 years later a significant proportion of Dorman sales is accounted for by the 'LD' and 'LE' engines, its direct descendants. The power outputs covered by the 'L' range run from 20 to 250 b.h.p. approximately twice both the minimum and maximum output figures for the whole of the Dorman engine range in 1946. The 'Q' range was introduced in 1957 and comprised vertical, in-line, six cylinder, also eight and twelve cylinder, vee-form models, this is by no means an unusual choice of configuration but earlier it had been

Dump Truck

Visitors to a “Dorman Open Day” on the occasion of the firm’s eightieth anniversary at the end of the 1940s.

A Dorman 12QTCW diesel engine is fitted to the Le-Tourneau Westinghouse dump truck which is capable of transporting a load of 80 cubic yards, or 105 tons.

A Dorman 12QTCW diesel engine operating a Serafini pump in Italy.

Seven Priestman crawler cranes handling welded length of 36 in. gas main.  All the cranes have Dorman engines.

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