This locomotive was built in 1950 by Robert Stephenson & Hawthorn for Stewart & Lloyds steelworks at Corby in Northamptonshire.
Immediately after the Second World War Stewarts & Lloyds began a process of improving the ironstone branches serving the large iron and steel plant at Corby. One outlying ironstone pit at Harringworth was isolated from the main system, and ore from it had to be conveyed over a stretch of the LMSR. To obviate this the company extended their own system of quarry lines to reach Harringworth, and for this long-haul traffic they ordered seven powerful saddle tanks to their own detailed requirements.
This locomotive was one of that batch of seven locomotives (Works Nos 7667-7673) that was delivered to Stewart & Lloyds and became S&L 56-62. This locomotive became S&L No 62.
Two further locomotives (Works Nos 7761 & 8050) were built in 1954 and in 1958 bringing the class total to nine engines.
They became known as Uglies due to their short saddle tanks and larger fireboxes. These give them a somewhat ungainly appearance, but they are a more powerful locomotive than the Hunslet Austerities
| Austerity – J94 | Ugly | |
| Weight | 48t 5cwt | 53t 0cwt |
| Driving Wheels | 4ft 3ins | 4ft 0ins |
| Boiler Pressure | 170psi | 180psi |
| Cylinders | Inside – 18in x 26in | Inside – 18in x 26in |
| Tractive Effort | 23,870lbf | 26,850lbf |
All of the locomotives of this class were withdrawn from service in 1969 when they were replaced by diesel traction. Five of the nine locomotives have since been preserved – Works Nos 7667, 7668, 7671, 7673 and 7761.
Three of the locomotives (Works Nos 7668, 7673 & 7761) were bought by Keighley & Worth Valley Railway Preservation Society members and arrived at Haworth in May (7761) and June (7668 & 7673) 1969.
All three locomotives saw service on passenger trains on the Keighley Worth Valley Railway (KWVR) following considerable work on the bottom ends.
In 1982 7673 was sold to a member of the East Lancashire Railway Preservation Society after being on static display at Oxenhope awaiting boiler repairs.
The locomotive later saw service on the North Yorkshire Moors Railway in the 1980s.
In 2007 a member of the Spa Valley Railway purchased the locomotive and moved it to the Spa Valley Railway in January 2008. It then underwent an overhaul and was fitted with the boiler from classmate RSH 7668.
It then returned to traffic on the Spa Valley Railway in October 2010 and completed 10,000 miles before the locomotive was taken out of service shortly before the boiler certificate expired in January 2021.
Preserved British Steam Locomotives 