Originally posted by TIB1186Z:
Wrong. The time taken is in the range of 4-8mins. 4mins if the train had been stuck at a station due to a lot of people crashing the doors when the doors are closing or some signal problem.
I experienced a train craaawwwwwlliiiingggg from Khatib to Yio Chu Kang before a lot of times, but i dun know what is the reason. I guess is that SMRT wants to regulate the distance between the trains. Another stretch is Yishun - Sembawang, especially if there is a train changing tracks. Anyway, its utterly unbearable, and i think its only slightly faster than the Sentosa monorail at times.
it appears u happen to be taking a train during morning peak hours. train bucking is common during peak hours, where headways are as short as 1.5-2 mins (time required to travel a typical station's distance). all these delays are part & parcel of a non-fully-automated train operating system with short train-to-train distances. do remember that ang mo kio station, jus after yio chu kang station, is also a very busy with trains changing tracks a lot during evening peak hours as they turn in & out of bishan depot, or move to the middle train when they terminate at amk.
from my observation 5mins between same phase. let's take this phase as train departing. train departs yio chu kang at 0th min, enters at khatib at 4th min 15th sec, doors open at 4th 35sec, close & depart at 5th min. taking a new black KNS train and observing the time display (especially on-minute changes) will reveal so.
smrt trains move with predictable movements, like it will start accelerating here, decelerate here etc. these are strictly followed by every PTO to ensure the predefined time schedule (in this case 5mins) is met. during heavy-load but not peak hours (like after evening peak all the way up to 11pm) trains will move faster but this is compensated by the fact that they will stop longer at each stop due to heavier movements thus it's still the same travelling time in the end. trains can always move on to the fast mode to catch up if it is behind schedule.
in my many trips down from yio chu kang northbound, i have not experience a single hiccup, even during evening peak hours, worse than a 3-min wait on a train parked at yishun mrt NB, due to an impatient PTO driving from yishun's overlay track to the sountbound track before the train at yishun SB platform moved out, causing an ATP (Automatic Train Protection) panic & stalling all trains in that sector. any train that stopped along the tracks on the KTB-YCK sector moved off within a minute.
for southbound KTB to YCK (all best detected at 4th door),
normal: trains accelerate to yishun stadium, cruise until buillion park & accelerate uphill, cruises, brakes immediately at the point of teething sounds just after castle green, cruise until 3rd door jus enters the station before braking normally to stop.
fast: trains accelerate to yishun avenue 1, brake twice briefly at seletar intake station, accelerate about 3 times briefly on the way to SLE, accelerate way before uphill section until halfway up, then accelerate again until near end of bend, cruises or may accelerate one time more, brakes immediately at the point of teething sounds just after castle green, cruise until 3rd door jus enters the station before braking normally to stop.
for northbound YCK to KTB,
normal: trains accelerate till end of bend outside station, cruise at low speed, accelerate jus before castle green until near yio chu kang rd, cruise all the way to seletar intake station, accelerate briefly along the leftward bend, then accelerate from yishun ave 2 to after yishun ave 1, cruise, brakes when the front of train is about 20m away from station (4th door about a 2 seconds after it left the parallel).
fast: trains accelerate till end of bend outside station, cruise at low speed, accelerate jus before castle green until near yio chu kang rd, accelerate again along until lentor intake station, brake briefly once on the way downhill, then brake twice (or sometimes thrice) briefly under SLE flyover, accelerate about 3 times upon reaching small bridge leading to on-land rail all the way to the end of on-land rail, accelerate about 3secs after reaching viaduct from on-land rail until seletar bridge, accelerate along the leftward bend from after lentor intake station to yishun ave 2, then accelerate from yishun ave 2 to the S-bend reaching yishun ave 2, accelerate a few seconds along the straight rail along yishun ave 2, brakes when the front of train is about 65m away from station (4th door straight after it left the parallel).