By Gavin Bowie
Industrial Arch. Review iv, winter, 1979-80, pp81-90.

Summary: This article first describes the prime movers surviving in three Irish distilleries, and shows how steam and water power were used in conjunction at two of them. The second section describes surviving stationary steam engines in other industries, and these are described in order of technological development, so giving an indication of the evolution of the stationary steam engine between about 1895 and 1940.

This article in part continues a tour of whisky distilleries of Ireland, which began with the description of the 'house-built' beam engine in Jameson's Distillery, Dublin, followed by an examination of the two McNaught compound beam engines in Power's Distillery, Dublin. Both distilleries are now closed, the former in 1969 and the latter in 1976,and all three engines are to be preserved in situ.

Traditional Irish pot still whisky was made in a way approximately similar to Scottish malt whisky, although in Ireland the grist contained ordinary as well as malted barley and the distillation cycle was more complex. After enjoying prosperity in the late nineteenth century, the Irish whisky distilling industry declined and was increasingly limited as local markets. In the early 1960's the last three working distilleries in the Republic amalgamated to form Irish Distillers Ltd, and a modern plant was subsequently established at Midleton, Co Cork.

The second section of the article describes surviving stationary steam engines in other industries, and is based on a brief survey undertaken with the help of the Royal Dublin Society in 1973-4. These engines are described as in February 1975.

The low efficiency of the external combustion reciprocating engine compared with its successor, the diesel engine, the increasing cost of fuel for the boilers, the difficulty of obtaining spare parts, and the labour intensive demands of steam engine plant, have contributed to the decline of stationary steam engines in Ireland since about 1946. There is little element of choice, or selective preservation. With regard to the following engines - rather they represent the few survivors.

Midleton, Kilbeggan and Tullamore Distilleries

At two distilleries, stationary steam engines worked in conjunction with waterwheels. Such a system was used at Midleton Distillery, Co. Cork until 1972, where two engines were on standby for a large waterwheel, but has been superseded by an electric motor drive. As Irish Distillers Ltd. are constructing a new distillery immediately upstream from the old one, the future of the old plant is in doubt, but the older of the two beam engines and the waterwheel, are currently maintained in working to order.

Prime movers were also combined at Locke's Brosna Distillery, Kilbeggan, Co. Westmeath, where a horizontal cross-compound engine supplemented the work of a conventional waterwheel. The Distillery closed in the early 1950s, but despite vicissitudes of time and changes of ownership, the prime movers, millhouse machinery and two mash runs remain intact within a compact structure, 'L' shaped in plan.

Daly's Tullamore Distillery, Tullamore. Co. Offaly, remains complete, but all of the old plant, for making pot still whisky, has been disused for some years. However, the owners plan to renovate the two-cylinder simple horizontal engine, and make the enginehouse safe for access to visitors.

Locke's small country distillery at Kilbeggan never produced more than 200,000 gallons pot still whisky a year, and contains little machinery that dates from later than the early 1880's. This is significant because the technology of whisky production in Ireland has altered greatly in the last fifteen years or so, whilst Locke's effectively fossilizes a process which remains unchanged for over 100 years. In fact the latest additions to the Distillery plant appear to be two mash tuns with their double stirring gear', installed in 1892. Parts of the plant represent a high standard of craftsmanship, as for example the seven oak washbacks, each 13ft diameter and 16ft deep, that were constructed by Locke's own workmen. Though disused in the early 1950s, the plant remained complete until 1966, when two Lancashire boilers were removed, and 1974 when the four copper pots stills, and the riveted copper worm cooling system, were taken out.

The distillery's external waterwheel can be seen upstream from the bridge carrying the main road over the River Brosna. It is 15ft. 6in. diameter and 11ft. wide, and has an undershot waterfeed; though long disused, it survives remarkably complete.

The internal gearing for this section of the Distillery remains intact, and shows the link-up of the waterwheel and the stationary steam engine. The wheel's axle-drive was transmitted, through you face gears outside and two inside the building to a layshaft carrying bevel gear drives for three pairs of millstones. These latter survive complete with furniture, on the loft above. The far end of the layshaft could be engaged with the main vertical millshaft, which carried the drive to machinery in all sections of the Distillery. The stationary steam engine also made a bevel gear connection, though this time via a coil clutch, with the main millshaft.

The horizontal cross-compound condensing stationary steam engine is, like the two McNaught beam engines in Powers Distillery, John's Lane, Dublin, a product of the Canal Basin Foundry, Port Dundas, Glasgow. It was erected in 1887, a year after the second of the Power's engines, and certain design features, for example the governor and its pedestal and the patent valve gear mechanism, are common to all three engines. Its two cylinders are located on two cast-iron bedframes which are separated by a central flywheel, 11ft. diameter. From the flywheel, the H.P.cylinder of 18in. bore x 3ft. stroke, is to the left and the L.P. cylinder of 28in. bore x 3 ft. stroke, to the right. The governor pedestal is located adjacent to the flywheel-end between the two sets of piston rod guide bars. The piston rod of the L.P. cylinder is continued through a stuffing box at its head-end to operate the horizontal air pump of a rectangular box-type jet condenser; this condenser is mounted on an extension of the L.P. side bedframe, making a compact arrangement. The steam engine drive shaft makes a right-angled bevel gear connection with a short length of shafting which goes through the millhouse wall to connect with the main mill gearing.

At Daly's Tullamore Distillery there is a two cylinder simple horizontal engine which has been disused for many years. It has two cast-iron bedframes each 19ft. long, and each carrying a cylinder of 20in. bore and 3ft. 10in. stroke. These are separated by a box-type jet condenser which has a horizontal air pump operated by a large crank-shaft-driven eccentric. The total width of the engine is 12ft. and the whole is mounted on granite blocks.

The 11ft. long connecting rods drive marine-type double cranks, on a built-up crankshaft supported by four angled main bearings. It is an odd feature of this engine that even at the low operating pressure of 12 p.s.i. (the existing gauge only goes up to 15 p.s.i.), where the expansive properties of the steam are negligible, expansion slide valves, worked by separate eccentrics and hand adjusted, were fitted. This type of valve gear could date from any time after the mid 1840s as it is derived from the Stephenson link motion. The two cylinders were supplied with steam by a Lancashire boiler and engine speed was controlled by a belt-driven Watt-type centrifugal governor through a butterfly valve up the main steam pipe. The drive was transmitted by the crankshaft through to the annexed mill and constant torque, maintained by a six arm. 14ft diameter flywheel. Rated at 125 I.H.P., the engine's driveshaft links with conventional underdrive gearing that is contained within cast-iron bursting on a square plan. The gearing for a set of millstones, on the floor above, is carried on either side of the bursting, and a pinion linking with the great spurwheel carries both a vertical mill drive and, via bevel gears, a horizontal lineshaft. Shafting linked with the latter works the revolving rakes in the two mash tuns, the three-throw pumps of the brewery and distillery and the distillery rowsing ???

There is a tradition that this engine was acquired second-hand from a steamship about the middle of the last century. This is an attractive theory but is unlikely to be correct: the only similar type of marine engine is the diagonal paddle steamer engine, where the cylinders are placed lengthways and are inclined upwards towards the paddle driveshaft, but this type of engine needs wrought iron frames to absorb the varying thrusts on the crankshaft whereas the cast-iron bedframes of the Tullamore engine would crack under such strain.

Although the theory that the engine originated in a paddle steamer is no longer tenable, there is still no firm evidence as to who built it and when. Lest the engine be given too early a date, it should be remembered that the simple low-pressure engine tradition remained well into the 1880s in Ireland.

Finally it should be noted that the Tullamore engine was designed not so much for economical fuel consumption as for reliability. In other words, the amount of coal used to raise steam in the boiler was less important than getting through the distilling season without a hitch or breakdown.