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A reducing machine in operation

A reducing machine in operation

The Modern Age

The new Royal Mint on Tower Hill, opened in 1810, was equipped with steam-powered machinery purchased from the great entrepreneur Matthew Boulton. With the factory dominated by flywheels and ponderous lines of shafting, the Royal Mint had truly entered the industrial age. Eight massive presses, separated by columns of oak, stood in the Coining Press Room, operated by a ten-horsepower steam engine. They were each capable of striking about 60 coins a minute and when all of them were at work the noise was deafening.

In the 1880s the factory buildings were reconstructed and the Boulton presses in the Coining Press Room were replaced by a double line of smaller presses from Heaton’s of Birmingham – a little faster but much quieter. With change and alteration becoming almost continuous, the old steam engines were finally replaced by electricity in 1907.

Melting and casting

Melting and casting

Steam powered presses in the Coining press room
Steam powered presses in the Coining Press Room

Perhaps the most significant development around the turn of the 20th century was the much increased use of the reducing machine in the production of master tools. Instead of having to hand-engrave a design at size and in the steel, an artist could now prepare a low-relief plaster model – usually around 150-250mm in diameter. A mould was taken from the plaster model and then electroplated with nickel and copper, yielding a reproduction in metal of the original model known as an electrotype. The electrotype was mounted on the reducing machine where its details were scanned by a tracer. The movements of the tracer were communicated to a rotating cutter which copied them at coin size into a block of steel. The resulting master punch would then be used to make additional tooling which would ultimately make the coining dies. Reducing machines continued to be used at the Royal Mint until the early years of this century.