No.7 Merlin is a coal fired 2-4-2 tank engine. Works No. 296 it was built in 1998 by Exmoor Steam Railway. It is one six locomotives of this type to have been built at Exmoor which gradually all have got a little larger.
The engine was originally built for an abortive 12.25 inch gauge line in West Germany and ran about half a dozen times at Exmoor on the railway their until purchased for Rudyard in 2001. It was re-gauged to 10.25 inch gauge. Since arriving it has been a reliable and popular engine. It was given the name Merlin as part of a theme around the legends of King Arthur on its arrival at Rudyard.
Merlin engine has cylinders 4 inch bore X 5inch stroke. The boiler pressure is 150 Pounds per square inch and it has 11 inch diameter driving wheels. The valve gear has roller bearings throughout as do the axle boxes. It has a longer wheelbase than the earlier 3 engines built of this type.
Merlin has run every year since its arrival in 2001 and has twice had its boiler removed for repair. This task takes a day to dismantle the engine and a day to reassemble. The engine was fitted with twin pipe air brakes in 2003 as part of a programme to equip the whole railway. It has needed very little other repair work. It can haul a loaded seven coach train without difficulty. The boiler was removed and acid cleaned in July 2010. The engine was back in service in 10 days. In early 2012 it had some minor boiler repairs and was repainted a slightly lighter blue.
The main improvement to the engine was the fitting of sanders in 2008/9. This greatly improved adhesion in wet weather or in the autumn leaf fall season. Fitting of a steam chest pressure gauge is planned. A repaint to a brighter blue livery was carried out in 2012.