Water Wheel

The Water Wheel

Between 1870, when it was built by the De Winton company of Caernarfon, and 1925, when the smaller Pelton wheel came into use, this wheel supplied energy to all the Gilfach Ddu workshops. Today, its bulk still impresses. This is the largest water wheel on the British mainland: it is 15.4 metres in diameter.

The water powering the wheel comes from the Ceunant waterfall, above Llanberis, through cast iron pipes. The water then rises to the tank above the wheel (because the source is higher than the level of the tank). The wheel's propulsion comes from its rim rather than the axle and so the spokes of the wheel only serve to hold it together — rather like a bike wheel. By means of a system of cogs and pinion wheels, the energy from the water which flows from bucket to bucket on the wheel is transmitted along the line shafting to all the workshops on site.

The wheel is so finely balanced that it begins to turn the minute just one of its 140 buckets fills with water. The wheel itself is a testament to the talent of local engineers, and still works perfectly a century and a half after it was built. Like the incline, the wheel was restored in 2000 thanks to a grant from the Heritage Lottery Fund, and it works continuously. Don't forget to climb the stairway or go up in the lift to see it close to — that way you will get a proper idea of the immense power of a wheel which powered all the workshops' activities.

Despite its efficient design, however, by 1925 the wheel had become badly-worn though years of use. Every time the wheel broke down, of course, all work would come to a stop too while it was mended. Instead a Pelton wheel was inserted on a branch of the main pipeline, in the corner under the larger wheel. Although it is so much smaller, this was more efficient than the large wheel as it was powered by kinetic energy (from water rushing through a pipe which gradually got narrower) rather than water falling from a great height, as in the case of the water wheel.

The Pelton wheel has only been known to fail once, during the hard winter of 1947, when the water froze in the pipes from the Ceunant waterfall.

Energy in the Workplace

The energy created by the water wheel is carried to the various workshops by means of line shafting. The lines of this shafting system were effectively the workshops' arteries, the means by which lathes turned and hammers pounded, and saws and drills moved back and forth. They carried the power from the wheel to every part of the workshops, bringing life to machines that would otherwise lie still.