Was
built in 1942 to a design of 1902/3 by GJ Churchward, the famous GWR
Chief Mechanical Engineer, which proved so successful that it remained
virtually unchanged for 40 years. Although designed primarily as a
heavy goods engine, 3850 has already proved her worth on the WSR by
being able to handle the heaviest passenger trains over the line
unassisted. The engine is economical to operate in terms of coal and
water consumption and this is in no small part due to the fact that it
was designed to run at speeds of between 25 and 40 mph – just
right for a preserved line with a 25mph speed limit. 3850 is currently
in service, having already run more than 40,000 miles on the line since
entering traffic in May 2006.