In 2014, ambitious plans were emerging for the modernisation of the main line from Yangon to Mandalay and the important Circle Line around Yangon in a major scheme with the Japanese Government through the Japan International Cooperation Agency.
During my visit to Myanmar in October 2017, signs of the modernisation work were apparent. Some point installations had been equipped with new Kyosan a.c. electric point machines but the earlier colour light signals and the Westinghouse miniature lever frame remained in use. Examples of the work in progress are shown in the pictures below.
Reinstated surface after installing new cables and signal post on platform 9 at Yangon (Yangon - Mahlwagon c/w)
New track circuit installation at Yangon Central Station (Yangon - Mahlwagon c/w)
New Kyosan point machine at Yangon. Note elevated mounting (Mahlwagon - Yangon Central Station c/w)
New Location Case Y10C (Yangon Central Station Movements 1-Oct-2017)
New Kyosan a.c. point machine at Yangon. Note cable termination box right foreground, still wrapped in green plastic (Yangon Central Station Movements 1-Oct-2017)
In May 2018, following a visit to Bago by car, I returned by train to Yangon. Near my destination, I could see the progress of the modernisation work. More point installations had been equipped with Kyosan a.c. electric point machines and the new signal posts had been fitted with colour light signal heads, although not yet brought into use, as shown in the pictures below.
Bago - Yangon by train 9th May 2018: Approaching Yangon Central on Down Main showing L: Replacement signal P7, not yet commissioned (3-aspect colour light with 'box' of 3x3 lights above), R: Existing signal P7 (Siemens).
Bago - Yangon by train 9th May 2018: Approaching Yangon Central on Down Main showing Down Local signals L: R141/R139, R: Replacement R141/R139 colour light with both theatre-type and 'box' of 3x3 lights above, subsidiary aspect below, not yet commissioned.
Bago - Yangon by train 9th May 2018: Approaching Yangon Central on Down Main showing L: Existing signal R140, R: Replacement signal R140 not yet commissioned (colour light with 'box' of 3x3 lights above)
Since all the new signal posts seemed to be near the old signals and carried the same numbers, it appeared that most of the modernisation work involved a renewal of equipment, rather than a fundamental re-think.
Before my next trip to Myanmar in May 2019, I had learnt that the replacement signalling equipment at Yangon Central Station had been commissioned, controlled from a new 'Operation Control Center' (yes, 'American' spelling) in another part of the station buildings. Doctor Hla Tun arranged an official visit on the day I arrived in Yangon, Sunday 5th May 2019. We first met the Yangon Station Master in his offices on platform 1, then one of his staff conducted us to the road approach side of the station buildings and an existing entrance to offices on the upper floors. The white-painted stucco of the post-war station building had become rather stained as is common in the humid climate but the walls in the immediate area of the Operation Control Center entrance had been nicely repainted.
The entrance to the Operation Control Center in Yangon (Myanma Railways 2019)
We climbed the steep stairs to the first floor and it was clear that part of the area had been recently partitioned off to form the Operation Control Center. Access was through double-doors with glazed panels and a security lock. Immediately inside the doors there was a deep step up onto computer sub-flooring. The Operation Control Center was windowless, artificially-lit and air-conditioned. In one corner, three men were working at a group of desks.
Operation Control Center, Yangon: Administrative section. Double access doors on right. Note deep step up to computer flooring (Myanma Railways 2019)
The actual control was being carried out in an adjacent corner of the room by two men seated at a row of desks with two computer monitors, each provided with a computer 'mouse', together with numerous telephones and two V.H.F. radio-telephones.
Yangon Operation Control Center (Myanma Railways 2019)
The signalman actually controlling trains that day on the the large computer monitor remembered my visit to the 'old' installation in 2014. A second signalman, with a smaller 'mimic' monitor, managed the frequent radio traffic. Studying the large colour computer monitor confirmed that the whole of Yangon Central Station had been transferred to the new control system, retaining the original signal numbers (prefixed 'R', presumably from a time when Yangon was known as 'Rangoon'. However, to the east, the vital junctions at Pazundaung, formerly a separate scheme provided by Siemens, were now controlled from Yangon with signals retaining their original numbers (prefixed 'P').
Operation Control Center, Yangon: Main signalling display at 09:53 (Myanma Railways 2019)
Yangon is a busy station and the position had changed after 8 minutes when I took the picture below.
Computer Monitor Display at 10:01, Operation Control Center, Yangon (Myanma Railways 2019)
Click for larger view.
Studying the above picture 'Computer Monitor Display at 10:01' allows a fair understanding of the design:-
Tracks: Tracks are represented on the screen by a thick line: white if the track is unoccupied, red if a train is present, yellow if a route has been set. Perpendicular lines indicate the ends of the track circuit and the track circuit number appears in the form 'R[number]T' (Yangon area), 'P[number]T' (Pazundaung area) or 'A[number]T' (Automatic area), plus some 'funnies' like 'ART', 'RT', suffix 'AT' (for approach track) and 'R65T' divided into two sections. In many cases, the same references as the earlier Westinghouse system are retained.
Points(turnouts): The current position of points is indicated by a continuous thick track line. A break in the track line shows the route is not set. A set of three inclined thin lines indicates the 'NORMAL' position and the adjacent reference in the form '108' is the reference number. For crossover points, a suffix letter 'A' or 'B' identifies the two ends. The same references as the earlier system are retained.
Running (main) Signals: Graphical symbols represent different signal types, including 2-aspect, 3-aspect and searchlight (R65,R66,R73,R74 shown as 1-aspect) running signals. Where a subsidiary aspect is provided, this is represented by adding to the symbol an empty 'right-angled triangle with one curved side'. When the subsidiary is 'off', a diagonal line is added to the symbol. If the signal leads to more than one route, a route indicator is normally provided, represented by adding a separate square to the symbol. The running signal number appears in the form 'R[number]' (Yangon area), 'P[number]' (Pazundaung area) or 'A[number]' (Automatic area). The same references as the earlier system are retained.
Ground (shunting) Signals: Represented by a 'right-angled triangle with one curved side' symbol, with an additional horizontal line which is replaced by a diagonal line when the signal is 'off'. The ground signal number appears in the form 'R[number]' (Yangon area). The same references as the earlier system are retained.
Limit of Shunt: This symbol, representing a physical Limit of Shunt board, is a square enclosing a disc and appears, unnumbered and inactive, on the Up Main and Up Local, in the rear of signals P3 and P5. Because of the long-distance trains starting and finishing at Yangon, a station pilot locomotive is kept quite busy transferring coaching stock between the carriage sidings and various platforms. I presume this type of shunting movement, authorised by a subsidiary signal, must not continue beyond the Limit of Shunt board.
'NX' pushbuttons: In traditional, mechanical lever frames, each lever is generally associated with a single set of points or a single signal. Earlier power frames retained this approach, but later approaches adopted 'route-setting' where a simple action by the signalman automatically set the whole route from one signal to the next (if safe to do so) before clearing the signal. One method introduced by Westinghouse was 'One Control Switch' (OCS) where each signal was associated with a panel of turn switches, with one switch for each route beyond the signal (there's a very brief description of 'OCS' in the section 'Sandbach' of the post here). An alternative development, called 'NX' ('eNtrance-eXit') placed push buttons or turn switches on a track diagram of the controlled area. To set a route from one signal to the next, the signalman simply activated the switch at the first signal (the entrance) and a similar switch at the desired next signal (the exit). Because of the operational simplicity, 'NX' became widespread. The picture below shows the arrangement of a typical conventional 'NX' panel at Insein signal cabin.
Insein Signal Cabin showing 'NX' control Panel
In modern systems controlled from computer monitors, there's no physical control panel required. The track layout, with 'virtual switches', is digitally generated on the monitor screen, as shown in the picture 'Computer Monitor Display at 10:01' above. The 'virtual switches' are the white circles with an alphanumeric reference centred on the thick lines representing tracks. I assume the desired button is operated by 'point and click' with the computer 'mouse'. Normally, a button would serve as the exit button for the route in the rear and the entrance button for the route in advance but there are a few routes without an obvious entrance button so I'm not certain.
Crank Handles, Yangon: Top left of the monitor are three crank handle releases. During failures or maintenance motor points can be operated locally by inserting a large special key, called a 'Crank Handle' and 'cranking' the mechanism by hand. The key is normally released electrically from the supervising signalling control when required and, until the key is returned, the signalling control will be unable to set routes remotely. At a station like Yangon, it's possible to divide the system into 'East' and 'West', so that releasing a crank handle for one end of the station does not prevent normal route setting from continuing at the other end. Under normal operation, the crank handle 'IN' virtual indication is displayed. When remote release of the key is authorised, the virtual indication crank handle 'PERMIT' is displayed. Once the key is removed crank handle 'OUT' is shown until the crank handle has been replaced. I'm afraid I didn't discover the scope of the 'Yangon Maintenance' crank handle.
Crank Handles, Pazundaung: Top right of the monitor are two more crank handle releases. I presume the 'Pazundaung' release allows points in the area to be locally operated by cranking but I'm not sure about the 'Pazundaung Maintenance' release. Since the screen display still shows a signal box symbol at Pazundaung (a rectangle enclosing a line representing a traditional lever frame with a 'dot' representing the signalman), it's possible there's some form of local control panel at Pazundaung for use under abnormal conditions.
KYI APPROACH ACK: Bottom left of the monitor is a 'virtual switch and lamp' which also generates an audible alarm when a train approaches on the Automatic Section from Khyee Myin Daing direction under Track Circuit Block rules.
KCR & KM APPROACH ACK: Bottom right of the monitor are two 'virtual switch and lamp' activated when a train approaches on the Automatic Section from Mahlwagon direction under Track Circuit Block rules on either the Circle Line or the Main Line from Mandalay.
Communication area: Across the bottom of the screen are reserved areas for messages issued by the system, plus a group of 'soft keys'.
Interpreting the 'Computer Monitor Display' picture above
From left to right and top to bottom:-
1. A westbound train from platform 6 West is occupying track circuit R1T, placing automatic signal A1 at 'danger'.
2. Track circuit R23T (platform 1) is occupied by a train.
3. Track circuit R24T (platform 2) is occupied by a train.
4. Track circuit R40T (track 9) is occupied by a train.
5. Track circuit R42T (track 10) is occupied by a train.
6. Track circuit R54T (track 8) is occupied by a train but adjacent track circuits R60T and R61T are indicating 'route set', suggesting a shunting move in progress.
7. Points 95A, 95B and 96 are shown 'REVERSE' in yellow, suggesting that they've been 'called' to that position. 8. Track circuit R68T2 (down local) is occupied by a train.
9. Track circuit P2AT (down goods Pazundaung) is occupied by a train.
We watched movements for a while as I took more pictures showing the whole computer monitor or an area of the screen. Some of the pictures aren't very good I'm afraid but you can find them here. I was only able to look at the new equipment room through the glazed panel of the door to the room so I couldn't learn much.
New Signalling Equipment Room at Yangon's Railway Operation Control Center (MyanmaRailways 2019)
At the invitation of the Station Master's staff, the Doctor and I had a closer look at some of the 'outside equipment' (signals, point machines, location equipment cabinets) to complete our fascinating visit.
New outside signalling equipment, Yangon Central Station (Myanma Railways 2019)
3-aspect colour light R87 with subsidiary aspect R103 at Yangon Central Station (MyanmaRailways 2019)
Two Kyosan a.c. electric point machines type NS-CM at Yangon Central Station, with a third machine and position light shunting signal in background (MyanmaRailways 2019)
Location Case Y12C at Yangon Central Station, described as a 'Signalling Box' and made by Daido Signal Co, Ltd. Appears to mount the Track Feeds and Track Relays for local track circuits (MyanmaRailways 2019)
Related posts on this website
Final day in Yangon and the Circle Line (visit in 2017)
Bago - Yangon by train (trip in 2018)
Return to Burma
Myanma Railways (Index)
My pictures
Myanma Railways 2019
The Circle Line (Yangon - Mahlwagon c/w in 2017)
The Circle Line (Mahlwagon - Yangon Central Station c/w in 2017)
Bago to Yangon by Train (trip in 2018)
