single and double chimneys. Double chimneys were fitted to all of the
single chimney locomotives between May 1957 and November 1958.
The original engines were built using countersunk rivets and so give a
smooth appearance to the frames. Many photographs show a gradual change
to rivets with a visible head as the frames were repaired.
Fitted from March 1937.
Two types; the original with a press clip fastener was replaced, from November
1937, with the locking handle type.
Extra casing access
doors each side of the smokebox:
From April 1938 some engines were fitted with these doors which had two hinges
on their top edge. From 1939 these ‘2-hinge’ doors were replaced by a longer ‘3-hinge’ door; all 35 engines receiving them.
Lamp bracket -
smoke box door:
From March 1941, the top lamp bracket was moved 9" down the door.
between June 1941 and October 1942 the skirting both in front of and behind the
cylinders was removed from all the locos. This revealed that some of the
locomotives had the GNR pattern valve guides ahead of the cylinders, which are
Bogie dust shields:
At first, two small dust shields were fitted to the front of the bogie. From
about 1941 these were replaced with a continuous one.