Hunslet Mills Class
| Hunslet Mills Class | |
|---|---|
Jerry M in the Dinorwic slate quarry in 1951
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| Number: | 2 |
| Manufacturer: | Hunslet |
| Year of construction (s): | 1895, 1898 |
| Retirement: | around 1960 |
| Type : | B n2t |
| Gauge : | 578, 610 mm |
| Length over coupling: | 5,315 mm |
| Width: | 1.83 |
| Total wheelbase: | 1,372 mm |
| Service mass: | 11.94 t |
| Friction mass: | 11.94 t |
| Driving wheel diameter: | 660 mm |
| Cylinder diameter: | 216 mm |
| Piston stroke: | 356 mm |
| Boiler overpressure: | 96.5 N / cm² |
| Grate area: | 0.33 m² |
| Radiant heating surface: | 2.04 m² |
| Tubular heating surface: | 15.9 m² |
| Water supply: | 1 m³ |
The two locomotives of the Mills Class of Hunslet are narrow-gauge tank locomotives that for operation in the Dinorwic Quarry were built. Unlike the smaller locomotives that were built for operation in the galleries of the quarry, the Mills Class was for traffic between Mills mentioned (mills) workshops where the slate has been processed, and the Umladebahnhof to Padarn Railway responsible. This connecting line was called the Tramroad , which is why the locomotives are also called Tramroad Class .
The first locomotive, initially called Vaenol (works no. 638), was delivered in 1895 and the second, Port Dinorwic (works no. 671), three years later. The locomotives replaced the older Dinorwic and George locomotives from 1870 and 1877 on the “Tramroad” . At the beginning of the 20th century, both locomotives were named after racehorses; from Vaenol was Jerry M , and from Port Dinorwic was Cackler .
In terms of construction, the machines largely corresponded to the typical Quarry Hunslets , as they were used in the Dinorwic quarry as Alice Class , i. That is, they were two-axle tank locomotives with an outer frame, saddle tank, short wheelbase, large overhangs and inclined cylinders. Except for the gauge, the Mills Class was enlarged in all dimensions compared to the Alice Class and also compared to the older Dinorwic and George locomotives . A characteristic difference is the cab floor, which is slightly lower than the circulation, and the boiler equipped with a steam dome .
Like the locomotives used in the quarry harbor, the Mills Class was equipped with spring-loaded central buffers and a device with which the coupling could be released from the driver's cab.
Cackler was retired in 1959 and sold to a private person in 1966, who occasionally ran the locomotive on a short stretch of track. After several changes of ownership, Cackler came in 1978 to the Thursford Collection , a museum in Thursford (Norfolk), where it was operated until around 1993 on a specially built, almost 1.5 km long route. Because of the decreasing visitor interest in the railway, Cackler has been statically exhibited since then, and the route has been dismantled.
Jerry M remained in use until the early 1960s and was sold to the Hollycombe Steam Collection in Liphook (Hampshire) in 1967 , where it had to be fundamentally refurbished due to the condition of the boiler, and a new boiler was eventually purchased. In the course of this work, the locomotive was retraced from 578 to 610 mm.
The work was not completed until 1983, and Jerry M has been operating without major problems ever since. In the course of its service life, it was retrofitted with an air brake ; the air pump was installed on the right in front of the driver's cab.
literature
- Cliff Thomas: Quarry Hunslets of North Wales , Oakwood Press, 2004, ISBN 0-85361-575-6