Plate XLIX.VIEW IN MAIN MACHINE SHOP.Larger image
Plate XLIX.
VIEW IN MAIN MACHINE SHOP.
Larger image
The pattern shop, where all work originates, is fitted with the usual pattern-making machinery, including a core-making machine.
The iron foundry, which was begun in 1790,[70]and around which the large engineering establishment has since been raised step by step, continues to do sound work. There are four cupolas, of a combined capacity of about 20 tons, and cylinders up to 120 in. in diameter are cast. These facts suggest the satisfactory character of the equipment.
The brass foundry is an equally important department, where first-class work is done. There are fifty-two crucible pots in use, varying in size up to 150 lb., and of a collective capacity of about 2 tons; also an air furnace capable of producing at one heat 12 tons of metal, for such heavy castings as are required for preparing shaft liners, large sea chests for naval ships, etc. The strength of Admiralty gun metal made in this foundry is up to 18 tons per square inch, with 30 per cent. of elongation in a 2-in. length. The foundry is served by an electrically-operated jib crane.
In the forge and smiths' shops a large amount of detail work is done, in units ranging up to 3 tons in weight. The hammers vary up to 15 cwt. power. A considerable amount of die-stamping is done in connection with auxiliary engine forgings, etc. All paddle-wheels are made in this department. The blast for the fires is got from an electrically-driven fan.
The machine shop, which was one of the first constructed with a completely glazed roof, occupies a site on a steep slope, one side being formed by a heavy retaining wall, asshown in the engraving on Plate XLIX., facing page 106. At the level of the top of the wall, which is 25 ft. high, there is the light machine shop, while at the end of the bay and over the annexe situated to the left of the engraving, is the brass-finishing shop. There is a 2-ton hoist between the erecting-shop floor and the galleries, so that no inconvenience, so far as transport is concerned, is involved by this arrangement.
Originally a stream ran down the hill and over the site on which the Works are located, and its waters have for many years been utilised as a source of power. A special 24-in. inward-flow turbine works in the conduit which conveys the water across the site, and this turbine develops continuously 80 horse-power. This serves to drive some of the machines in the boiler works. The turbine runs in parallel with a compound vertical engine, which drives the shafts actuating the groups of small machines in the engine shop. Many of the larger tools, however, are electrically-driven by separate motors, the current being transmitted from the central station already described.
The engravings on PlatesXXXIX. andXLIX., facing pages 92 and 106 respectively, illustrate the main machine shop, which has a width of 60 ft., and, with the adjoining bay, accommodates some of the finest marine engineering tools made. Perhaps the best indication of their efficiency is the fact that three weeks suffice for the machining of the parts of a complete set of engines to develop 2000 horse-power. The shops are traversed by five overhead electric cranes, ranging up to 40 tons lifting capacity.