Dinorwic quarry
The Dinorwic Quarry (English Dinorwic Slate Quarry , Welsh Chwarel Dinorwig ) in the north of Wales was the second largest slate quarry in the world, only surpassed by the Penrhyn quarry a few kilometers away . Mining began at the end of the 18th century and was discontinued in 1969.
Position and extent
The quarry is located in Gwynedd County on the northeast bank of Llyn Peris across from the village of Llanberis . The area of the quarry, including the spoil heaps, extends for about 2 km along the slope and 1.5 km from the lake up the slope, with the difference in height between the lake, which is about 100 m high and the uppermost quarry level, about 500 m.
About one kilometer to the north is the Marchlyn quarry, which was only started in the 1930s, at an altitude of almost 500 m.
The eponymous village of Dinorwig is located about 300 m above sea level northwest of the main quarry.
history
Shale was first mined in the area in 1787, with the land initially leased from the owner, Thomas Assheton Smith I. The dismantling was initially hampered by transport problems and the war with France. After the lease expired in 1809, Smith himself took the initiative and combined the four existing quarries in his area into one company under his management.
The transport problems were solved with the Dinorvic Railway , opened in 1824 , a horse-drawn railway between the quarry and its own port in Y Felinheli , called Port Dinorwic. In 1826, 800 men were already working in the quarry and producing 20,000 tons per year - taking into account that the amount of spoil per ton of usable slate was usually at least ten times as large.
The capacity of the horse-drawn railway, which contained several inclines to bridge the height difference to the sea, soon proved to be insufficient, so that in 1848 a completely new line, the Padarn Railway , was put into operation.
At the height of production towards the end of the 19th century, the Dinorwic quarry employed over 3,000 men, in 1920 there were still 2,000. In this phase there were already problems with carelessly laid out spoil heaps, which hindered the mining, and became in the 1930s the somewhat remote Marchlyn quarry opened, but it turned out to be a bad investment. During and after the Second World War, the demand for slate continued to decline.
In 1966 operations practically came to a standstill after a rock fall in the upper part of the quarry. After the construction of an access road to the fallen rock that could be traversed by trucks, attempts were made to extract slate that was still usable, but this was unsuccessful, and operations were finally closed in 1969.
Material handling
The Dinorwic quarry had an extensive rail network, which was divided into various sub-networks, for which various locomotive designs were also procured.
The majority of the locomotives were in use on the approximately 20 levels of the stepped quarry, where rails were laid in a gauge of 578 mm. This unusual measure, also used in the Penrhyn Quarry, likely resulted from a two foot gauge, but measured between the centers of the rails.
The locomotives used in the quarry galleries - the first ones came into use from 1870 - were very small, weighed only a few tons and could also travel on provisionally laid rails with narrow radii. Initially, locomotives built by De Winton with standing boilers were used, but these were soon supplemented and eventually replaced by the more powerful so-called Quarry Hunslets . Of the locomotives supplied by Hunslet , the 13 examples of the Alice Class , which were procured from 1868, were best known, especially since they have been preserved without exception.
The main task of these locomotives was to move the slate to the inclined lifts and the unusable material to the spoil heaps. As a rule, they drove without a stoker, but most of the time the driver was supported by a boy whose job it was to set the points - and to be as fast as possible so that the driver didn't have to stop the train.
As a rule, a locomotive performed its service on a certain level and did not leave it, except for major repairs, because moving the locomotives over the inclined lifts was relatively time-consuming. That is why there were also smaller workshops and engine sheds on these levels; one of them, at 567 m above sea level, was the highest in Great Britain.
Most inclined lifts and funiculars use the gravity incline : This system, widely used in slate mining in North Wales, consisted of two parallel tracks and a large cable drum at the top. With their greater weight, the loaded wagons pulled the unloaded ones up, the speed was regulated by a band brake on the cable drum. In a variant of this process, the trolleys were pushed onto platforms, which in turn ran on (wider) rails (see picture).
The connecting line to the port opened in 1824 was called the Dinorwic Railway and was still operated exclusively with horses. It began about halfway up the slope, passed the village of Dinorwig and later contained several inclined lifts. At 578 mm, their track was the same as in the quarry itself.
When the capacity of this railway was no longer sufficient and because it ran over foreign properties, for which lease had to be paid, a completely new route was finally built along the Llyn Padarn , which had its starting point on the lowest level of the quarry. This line, called Padarn Railway , was built in the rare 4-foot (1,219 mm) gauge and opened in 1842 - steam locomotives were used from 1848. Four of the small wagons with slate plates were loaded onto a transport wagon. First, two very unusually designed two-axle steam locomotives took over the operation (see Fire Queen and Jenny Lind ), from 1882 they were replaced by three three-axle tank locomotives.
The height difference between the terminus of the Padarn Railway and the port was overcome with an inclined elevator, and in the port itself there was again a rail network with 578 mm gauge, where steam locomotives were used for the shunting work, which differed in some points from the gallery locomotives (e.g. the so-called port class ).
About halfway up the main quarry was the Allt Ddu Tramway , which was expanded around the turn of the century for steam locomotives , which led to a few small side quarries and roughly followed the beginning of the old Dinorwic Railway. Unlike the largely flat sections on the galleries, this section contained some steep gradients of 1:30 and steeper. The normal gallery locomotives were used on this section, but preference was given to those with a steam dome because this reduced the risk of water tearing on the slopes.
The main workshops for sawing of slabs of slate, the so-called Mills (Mills), lying at the lowest level at the sea shore. From there ran an approximately 1.5 km long connection route, called Tramroad for short in the quarry ( Padarn Peris Tramway in the map above ) , to the workshops in Gilfach Ddu and to the loading station for the Padarn Railway. Somewhat larger locomotives were used on this section than on the galleries, e.g. B. the so-called Mills Class .
Current condition
The lower part of the actual quarry on the lake shore was heavily modified in the course of the construction of the Dinorwig hydroelectric power station , but the higher galleries and the numerous connecting ramps have largely been preserved, although most of the tracks have been dismantled. The walls of the numerous buildings on the various gallery levels are also still there.
The National Slate Museum is now housed in the former main workshops in Gilfach Ddu . In a corner of the building complex (left in the picture) is the locomotive shed of the Llanberis Lake Railway , a museum railway operated independently of the museum, whose tracks (gauge 597 mm) are laid on the route of the former Padarn Railway. The railway's steam locomotives are former locomotives from the Dinorvic quarry.
Numerous other locomotives from the quarry have also been preserved, but only one of the five locomotives of the Padarn Railway. It is in the Penrhyn Castle Railway Museum .
The port in Y Felinheli has also been preserved, it now serves as a marina.
Individual evidence
- ^ A b c Cliff Thomas: Quarry Hunslets of North Wales. Oakwood Press, 2004, ISBN 0-85361-575-6
- ↑ Photograph of laden transport vehicles (1961) ( page no longer available , search in web archives ) Info: The link was automatically marked as defective. Please check the link according to the instructions and then remove this notice.
- ↑ Photograph of the inclined elevator at the harbor (1961) ( page no longer available , search in web archives ) Info: The link was automatically marked as defective. Please check the link according to the instructions and then remove this notice.
Web links
- Product and image gallery (english)
Coordinates: 53 ° 7 ′ 0 ″ N , 4 ° 6 ′ 0 ″ W.