The British built the extensive metre gauge railway network in Burma.
Around Yangon and on main lines there's double track which is being extended but much of the network is single track with passing loops.
Whilst the majority of the railway has fairly simple arrangements for the control of trains (see Railway Signalling in Burma: Part 3 - Control of Trains there are some signal boxes with conventional interlocked mechanical lever frames. I've seen two at Bago and two at Kyee Myin Daing on the Circle Line in Yangon.
Bago
Bago is on the double-track main line from Yangon to Mandalay and has two mechanical signal boxes - Bago South at the Yangon end of the station and Bago North, controlling the junction with the single line to Mawlamyine at the other end. The area has mechanical operation of points and semaphore signals.
I've only seen these boxes from a passing train or, in the case of Bago South, from a roadbridge but more details of both can be found on the International Steam Pages site here ("The Old Order Changeth" by Rob and Yuehong Dickinson) and here (Melvin Haigh's photographs on Rob Daniel's interesting 'Flickr' site).
Kyee Myin Daing
Kyee Myin Daing (called 'Kemmendine' by the British) is an important station on the Circle Line to the West of Yangon Central and retains two mechanical signal boxes. This is rather odd because in January 1946, an order was placed with Westinghouse Brake and Signal Company for a Style 'L' miniature lever frame for Kemmendine (see my post here). I've not been able to find out what happened to this frame although a hunch is that it might have been deployed instead a few stations up the line at Insein. The area has mechanical operation of points and retains some semaphore signals but the main line signals have been converted to colour light signals (the rest of the Circle Line has colour light signals), necessitating electrical detection of facing points in the main line. Whilst the rest of the Circle Line is track circuited, the facing points at Kyee Myin Daing retain locking bars on the facing points and track circuits do not seem to be provided in the area. The box at the north end has a gabled roof and spartan appearance, as shown in the picture below.
Mechanical signal box, north end of Kyee Myin Daing. The building next to the track in the foreground is probably a relay/equipment room since the main running lines have colour light signals.
The box at the south end is adjacent to the clockwise Circle Line and has a hipped roof. I don't yet have a picture.
Mechanical Operation of Points
Points are operated mechanically using steel tubes (as some British practice), as shown below.
Point rodding, showing tube couplers and vertical roller frames at Kyee Myin Daing.
Mechanically operated facing points at Kyee Myin Daing, with separate facing point bolt and locking bar (on left rail). The grey box on the left is electric point detection to control the 2-aspect colour light signal with two line-of-lights route indicators in the background.
Photographs
Bago Station.
By Train to Maymyo.
The Circle Line, Yangon (2013).
The above sets of pictures form part of the Collection Railways in Burma.
