Built alongside the smaller 40 ft wheel, Lady Isabella was designed and constructed by engineer Robert Casement in 1854. The design is a pitch back shot and each of it’s 168 buckets has a capacity of 24 gallons generating around 200 horse power. The rotary movement was transferred to horizontal via a crank to give a ten foot stroke on the 200 mtr long flat rod which ran along a viaduct to the inverted Tee rocker at the collar of the engine shaft. This rocker then changed the direction from horizontal to an 8 ft vertical stroke in the Engine shaft for the pump rods. The wheel received her supply of water channeled in Lades or Leats as the discharge from other water powered machines further up the glen. Today, the wheel under the ownership of Manx National Heritage, has no function other than that of a tourist attraction as it would have been in Victorian times but still turns gracefully in the summer months. The pumps have lain idle since 1929 and the pump rods have recently been disassembled by the Laxey Mines Research Group. DIAMETER
72 FT 6 INS
22 MTRS CIRCUMFERENCE
228 FT
69 MTRS WIDTH
6 FT
1.83 MTRS AXLE
LENGTH
17 FT
5.18 MTRS AXLE
DIAMETER
21 INS
.53 MTRS AXLE
WEIGHT
10 TONS CRANK
LENGTH
5 FT
1.52 MTRS LENGTH
OF STROKE
10 FT
3 MTRS STROKE
OF PUMP
8 FT
2.44 MTRS REVOLUTIONS
2 - 4 PER MINUTE NUMBER
OF BUCKETS
168 HORSE
POWER
185 – 200 The raising of water from the depths of the mine was via the Engine shaft, so called because it contained the pumping machinery. This shaft was 247 fathoms in depth below the adit and contained five plunger pumps at 50 fathom intervals. Typically of Cornish design but much smaller at about ten inches diameter, these pumps were of the pole plunger and clack valve type, so named due to the noise they made when the valves snapped shut. On the down stroke of the pump rod, the plunger forced water through the clack valve into a rising main and to the next pump 300 ft up the shaft. After the five stages of raising the water, it was finally discharged into the main adit which ran to the river.
COMPRESSORS For a hundred years, the ‘old man’ had toiled and tolerated blistered hands as the passages were driven further into the hillside using the time honored method of hammers and chisels. No ordinary chisels but three feet length and known as ‘jumpers’ a distance of one yard a day would be gained as two men known as ‘beaters’ hammered at the steel rod which was constantly being rotated by a third man, the ‘borer’. Charged with black powder, the fuse lit, the miners would beat a hasty retreat to a safe haven to await the bang and the thick dust that followed. The introduction of air powered rock drills to Laxey in the late 1870’s increased the work tenfold and by 1880 the company was running eleven Ingersol Sergeant drills in various parts of the mine. A constant supply and high volume of air was required to work these ‘wonder machines’ and so a compressor house was built over the river up glen beyond the Welsh shaft. Again, like all the other machinery on the site, the power source was water, driving an 80 HP Fourneyron Macadam turbine located in the basement of the building. A series of gear wheels drove four large compressor heads. Each cylinder was double acting and ran at about thirty strokes per minute giving an air displacement of about 700 cubic feet per minute. The air was delivered to the mine via Welsh and Dumbells shafts through a four inch pipe. The building also contained a small beam engine which could have been coupled to the compressors in time of drought but it was never used and was broken up for scrap. The compressors ran effectively until 1928 when they were scrapped and replaced by a high efficiency Ingersol Rand ES class machine which was purchased by the company from an unknown mine in Camborne, Cornwall. Only the shell of the Compressor house along with an air receiver remains today but the machine beds are still visible in the undergrowth.
THE TURBINE By 1890 there were several turbines of the Mac Adam Fourneyron type in use at Laxey of which two were operating compressors. The design and principle was very simple with the first of this type being produced by the Mac Adam brothers of the Soho foundry in Belfast in 1850. It is not known if the Laxey Mining Company purchased directly from Belfast. The machine having an efficiency between 75 / 85 percent delivered approximately 80 horse power into the vertical drive which would then be adapted to work various machines. The two remaining at Laxey are those of the compressor turbine and the winding turbine in the machine house.
THE
MAN ENGINE A ten hour shift, a thousand feet of ladders to climb to grass, the same the next day and the day after. The possibility of a cage to ride in like the coal mines of Britain was out of the question as the shafts of many metal mines weren’t vertical. The entire mine was on a slope or ‘hade’ of about 18 degrees off the vertical. The development of a man - riding machine or ‘Man Engine‘ first started at the mines in the Harz Mountains in Germany when miners drove spikes into the pump rods and rode up and down to the various levels….. a practice banned in Britain’s mines. In 1881, work started on the construction of a man engine in the Welsh shaft at Laxey mine and the machine was set to work in 1883. A heavy wooden rod of 10 x 7 inches ran to the 200 fathom level on roller wheels fixed to the shaft walls every 5 fathoms. Attached to the rod were a standing platforms 20 inches square spaced every 12feet and corresponding fixed stagings in the shaft. The rod would reciprocate up and down with a twelve foot stroke about six times a minute allowing the men to hop on and off between the various stagings. The weight of the rod was balanced by huge Tee rockers at various stages in the shaft. In the case of Laxey, a descent to the bottom would take about twenty five minutes. Many of the Man Engines in Britain were powered by steam engines or water wheels but Laxey was powered by a water pressure engine mounted fifty feet down the shaft from the surface.
WATER
PRESSURE ENGINE Water pressure engines were widely used in the mining industry and for a variety of reasons, Laxey being no exception other than this machine was very much a home brew affair with no cast markings to be found anywhere. Supported on four timbers of pitch pine, ten feet in length and sixteen inches square, the main lifting cylinder dominates the chamber in which the machinery is housed. The venture was probably a joint plan as the high pressure water feed branched off the compressor feed pipe further up the glen which was installed only the year before. Altered several times in it’s construction, the machine ended up as two engines in one, a low pressure engine controlling the high pressure feed for the main engine. Water was admitted to the underside of the main 24 inch piston at 90 PSI giving a lifting force of 18 tons. When near to the top of the 12 foot stroke, a lever was tripped and the low pressure engine moved the cut off valve to cover the inlet feed and expose the exhaust pipe, the weight of the wooden rods then pulled the piston down, forcing out the used water to drain away. As the main piston reached near bottom of it’s stroke, a second lever was tripped to reverse the low pressure engine and move the cut off valve to cover the exhaust pipe, allowing water to freely enter the inlet once again. The cycle continued for about one hour at six strokes per minute until the men riding the engine reached their working levels in the mine. 160,000 gallons of water would be used in this time.
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