Actually, the principles of operating trains are almost the same anywhere in the world notwithstanding whether the train is driverless or otherwise. I’ll try to clear some misconceptions about trains which most people equate with driving a car on a road. In reality, they are quite distinct.
Briefly, our trains (with drivers) on the Green and Red lines (E/W & N/S) run on 3 modes – AM(Auto Mode), CM(Coded Manual) and RM(Restricted Manual). When the train is on RM, it’s driven manually with a speed limit of 18kph and below. If it exceeds 18kph, the train will trip meaning it will “die” off. The brake loop need to be re-set in order to move the train again. RM is always driven inside the train depot before the train is launched from the reception track to the mainline. When the track is down meaning there is no speed codes or when there are men at work on the track, RM is used to drive the train on the mainline. But it rarely happens.
Usually, our trains are operated on AM mode meaning in auto. From station to station, the train will move in AM (Auto). The driver simply presses the 2 buttons found on the console to activate the train. It will stop accurately by itself at the next station. Sometimes due to system glitch, it over runs or under runs a little causing the train to go out of alignment with the platform, the driver will have to adjust to the correct position in order for the train doors and PSD doors to open simultaneously. In AM, the train speed could go up to a max of 79 kph. Above that it will trip. There is always a safety buffer between this train to the next train based on the cascading speed codes which the system will automatically detect and adjust.
Next, if the train is operated in CM mode, the train captain will drive the train manually also based on speed codes. Depending on the cascading speed codes appearing on the speedometer on the console, the TC will operate accordingly. When AM mode is not working or if there are obstacles to look out for on the track or tree pruning near to the viaduct, OCC (Ops Control Centre) will instruct the TC to move in CM mode. When it’s raining, the train will also move in CM mode due to braking problems on the wet tracks.
Generally, we could say that the train is usually operated on AM mode. In depots, it’s always on RM mode. Once in a while when it’s raining or men working on tracks, CM mode is used to move the trains.
I was saddened by that accident near to Pasir Ris MRT stn where 2 young men from maintenance were tragically killed by an on-coming train running on AM mode. The 2 newly joined trainees – barely 2 months on the job were members of the maintenance team conducting some track inspection. The glaring fact is that the particular train was on AUTO which should not be the case. Those maintenance staff sought permission to access the tracks and OCC had given the green light for them to go down to the track to do some work, yet the train was allowed to operate in AUTO mode.
The TC did not know that there were men at work on the tracks. It came a shock to him when he saw those men on the tracks. By the time he activated the emergency brakes, it was too late. Unlike a motor car, the stopping distance of a train is much longer. Depending on weather conditions, speed of the train and the braking system of the train, it could take more than 100 meters before the train comes to a complete halt.
In almost 30 yrs of our railway history, I say that this is the most disastrous tragic accident involving the loss of 2 young promising men in the line of duty. I would say that our SOP and Safety Protocols for access to tracks over the last 30 yrs have served us well. There is nothing wrong with those safety doctrine as far as all comply with them.
There are many checks before the staff are allowed access to the work during revenue hours – when trains are running. Permission by OCC is usually granted after the peak hours when the headway gaps in between trains are longer. One hand signalman (he could be anybody – maintenance staff, station staff) MUST be present at the HeadWall (HW) of the station to warn the train driver that men are at work at the front on the track. Pls proceed in CM mode with caution, slow down to a crawl when the train is near to them. If men at work near to Pasir Ris station, the train proceeding towards Pasir Ris shall stop at Tampines stn with hand signalman at Tampines HW to alert the train driver. On every HW, there is a notice board. Above the notice board, there are Red, White and Amber flashing lights. The Amber flashing light will keep flashing when there is a message written on the notice board at the HW to alert the train driver.
Usually, the Amber light will keep flashing with the hand signalman flashing the Red flag to the train driver to stop at the station HW. The signalman shall communicate with train driver and instruct him to proceed in CM mode to the next station. The same hand signalman man will then wave the Yellow (Amber) flag for the train driver to proceed. The same hand signalman shall at the same time use the walkie talkie set to communicate to the maintenance staff at track side to inform and warn them of on-coming train.
On the part of the train driver, he shall slow down his speed to a crawl on CM mode when approaching the work party who shall then stand by the side of the tracks waving the Yellow flag (Bardic Lamp if it’s dark) to signal to the train driver to proceed. If there is no show of Yellow flag, the train will have to stop immediately!
The above SOP is usually adhered to whenever there is a work party on tracks during revenue hours (usually after peak hours). It’s quite common. Perfectly legit. The other option is for OCC to shut down the track circuits meaning removing all the speed codes. If that stretch of track has no speed codes, the train can only be operated on RM mode at the max speed of 18kph. But this is rarely practiced as it causes much delay to the trains running on the mainline with passengers.
Back to that fatal accident, if the above 2 SOPs were strictly adhered to, would that tragedy happen at all? From the above explanation, we could safely conclude that it’s human errors and lapses all come in alignment that led to the sad tragic of unnecessary loss of 2 lives.
Trains are so much part of our life that something like that happens, the repercussions could be far reaching. Tributes keep coming in on social media for the 2 young men killed in the line of duty maintaining our train system so that all of us could enjoy it’s convenience. Flowers by unknowns are placed near to Pasir Ris station – at the pillars below the railway viaduct of the death spot above. One of them was supposed to get married this Sat. Another was a father and son team working in SMRT maintenance. The whole nation is saddened by the needless loss of 2 young men cut down in prime!
To me it is a tragic accident that could be avoided with the right compliance to existing safety procedures and protocols. But many members of the public will take this opportunity to hurl criticisms at SMRT leadership. Key is fix the problem, not the blame. The PM has spoken and he hopes that such accident should not happen again! SMRT must do the right thing and go out of its way to provide assistance to the 2 families and be mindful of the sensitivities.