[Archive] Questions on MRT/LRT
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Originally posted by SMRT 32373238:
Question with regards to CCL:
can the trains go any faster? for most of the journey for all 3 stages, the trains feel like they're going at 50kmh or below... apart from the crazy promenade bend of course, can't the trains go fast up to 80kmh at least? its a real bore sitting through slow CCL rides!
trains also pull in at rather slow speeds as most of you guys have noticed too!
Is it possible for Alstom trains to be programmed to speed into stations just like those on NSL and EWL?
Erm CCL maximum service speed is 80km/h and designed speed is 90km/h. So your wish is not granted. But most CCL 1 stations are simply plain too close to each other, especially the first 4 stations so it is kind of .....
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Originally posted by TIB1051D:
erm...you want the train to speed into the station and overrun by a train's length?
I think he's referring to how the C830s brake to about 5km/h with two doors behind, and then just slowly rolling forward into position before stopping. I agree, it is annoying.
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Originally posted by mrtdude5:
I think he's referring to how the C830s brake to about 5km/h with two doors behind, and then just slowly rolling forward into position before stopping. I agree, it is annoying.
DBG -> BBS, its the worst. The distance is shorter than the distance between Chinatown and Clarke Quay. 1 1/2 bus stop only!!! Should be 30 seconds. Because they decelerate and coast at 50km/h after the crossover. It takes 1 minute ++ instead!!
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Rumour says that C651 (Siemens) is to be refurbished this year. Why do I still see them? (They are quite common too)
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Originally posted by ZRchen:
Rumour says that C651 (Siemens) is to be refurbished this year. Why do I still see them? (They are quite common too)
Make the C651s worn out first, then justified to refurbish them =P
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Originally posted by ZRchen:
Rumour says that C651 (Siemens) is to be refurbished this year. Why do I still see them? (They are quite common too)
Make the C651s worn out first, then justified to refurbish them =P
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I saw this thing like a hole in the wall at The Central and there are plastic covers both of them. One says "Underground trainway Clarke Quay-Chinatown South bound" and the other says "Underground trainway Clarke Quay-Dhoby Ghaut North Bound". What are those for? Doesnt look like water hose to me.
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Originally posted by Larryteo:
I saw this thing like a hole in the wall at The Central and there are plastic covers both of them. One says "Underground trainway Clarke Quay-Chinatown South bound" and the other says "Underground trainway Clarke Quay-Dhoby Ghaut North Bound". What are those for? Doesnt look like water hose to me.
Underground tunnels? Tons of shophouses were demolished when Clarke Quay station was build and The Central was build directly above it
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Originally posted by Dragonaxe:
Underground tunnels? Tons of shophouses were demolished when Clarke Quay station was build and The Central was build directly above it
You mean these holes lead to the tunnels? but what are those holes for and why so small and located side by side and why in the wall of a shopping mall?
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Originally posted by Larryteo:
You mean these holes lead to the tunnels? but what are those holes for and why so small and located side by side and why in the wall of a shopping mall?
You see , tunnels do worn out after some time. CCL tunnels and stations were built to last 120 years only. After that they may be demolished and rebuild as the steel beam columns could have worn out. They could be because that when The Central was build on top of the NEL, the construction could have damaged the tunnels.
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Originally posted by Dragonaxe:
Lol, then Dhoby Ghaut ->>> Bras Basah.
SIAO MAN! After crossover decelerate to 50km/h. You go to the front of the train.
Depart from DBG pretend very fast, after crossover, go damn slow.
After the next station announcement ends, 20sec later, then they play the Dhoby Ghaut announcement, not 5sec, I remembered people kept on saying just 5secs only.
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Originally posted by Dragonaxe:
Actually, its SMRT fault thats why the C830s are so slow. You see C751As enter the train at high speed but don't overrun. CCL they enter slightly slower at 60km/h compared to C751A which is around 80km/h.
Slower trains -> Lesser electricity consumed -> Lower operating cost -> Win-win for operator
Yea I was guessing its the operator's fault. Are you sure that C830s enter at 60kmh and C751As at 80kmh? C830s feels way slower than 60kmh when entering, and C751As barely travel anywhere above 75kmh... I've peeked at the driver's console before.
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Originally posted by SMRT 32373238:
Yea I was guessing its the operator's fault. Are you sure that C830s enter at 60kmh and C751As at 80kmh? C830s feels way slower than 60kmh when entering, and C751As barely travel anywhere above 75kmh... I've peeked at the driver's console before.
Please take the station length in consideration. Circle Line is way shorter than North East Line.
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Originally posted by TIB1051D:
erm...you want the train to speed into the station and overrun by a train's length?
NSL and EWL trains generally do not overun stations. What I meant was is it possible for the Alstom trains to brake to a full stop just like NSL and EWL trains WITHOUT the super slow rolling past for 1 door (NEL) and 2 doors (CCL) at a slow speed before full braking?
To Samuel Lee: Yeap I know the service speed limit is 80 and my wish is NOT granted because the trains generally go way slower than 80. Even from DBG-->BBS, they can speed up to maybe 70 before slowing down rather than cruising slowly at 50 (or less?).
Even on EWL, though pioneer is really close to BoonLay (2 bus stops), the trains still go really fast.
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Originally posted by yellowflip999:
Please take the station length in consideration. Circle Line is way shorter than North East Line.
I'm not a scientist, but I remember learning that the smaller the mass of a moving object, the less inertia it has. This should mean it takes about half the effort to brake a CCL train right? Plus I get a feeling CCL trains are more powerful than NEL ones (there's this sudden surge forward when the train leaves the stations whereas for NEL trains I don't feel so much of a force)
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Originally posted by SMRT 32373238:
Yea I was guessing its the operator's fault. Are you sure that C830s enter at 60kmh and C751As at 80kmh? C830s feels way slower than 60kmh when entering, and C751As barely travel anywhere above 75kmh... I've peeked at the driver's console before.
You can't just say "I been in the driver's cab before! Its not 80km/h!"
I can also say that.
NEL/CCL trains are fully automated. I guess we need to revive the newcomer's thread. We have new train enthusiasts who don't know what is AM,CM,RM
You peeked at the driver's console. Very funny, I doubt the CSO would see you sneaking up from behind. Anyway when the CSO drive in CM, they tend to be late for schedule by a few minutes.
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Originally posted by SMRT 32373238:
I'm not a scientist, but I remember learning that the smaller the mass of a moving object, the less inertia it has. This should mean it takes about half the effort to brake a CCL train right? Plus I get a feeling CCL trains are more powerful than NEL ones (there's this sudden surge forward when the train leaves the stations whereas for NEL trains I don't feel so much of a force)
Yes, but you have half the braking equipment, thus half the braking power too.
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Originally posted by SMRT 32373238:
I'm not a scientist, but I remember learning that the smaller the mass of a moving object, the less inertia it has. This should mean it takes about half the effort to brake a CCL train right? Plus I get a feeling CCL trains are more powerful than NEL ones (there's this sudden surge forward when the train leaves the stations whereas for NEL trains I don't feel so much of a force)
The reason why they slowed down when entering the station is because now when they're braking, you are already like, falling backwards, so if it were to use more force to brake, everyone in the train would already fell down.
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Originally posted by SMRT 32373238:
NSL and EWL trains generally do not overun stations. What I meant was is it possible for the Alstom trains to brake to a full stop just like NSL and EWL trains WITHOUT the super slow rolling past for 1 door (NEL) and 2 doors (CCL) at a slow speed before full braking?
To Samuel Lee: Yeap I know the service speed limit is 80 and my wish is NOT granted because the trains generally go way slower than 80. Even from DBG-->BBS, they can speed up to maybe 70 before slowing down rather than cruising slowly at 50 (or less?).
Even on EWL, though pioneer is really close to BoonLay (2 bus stops), the trains still go really fast.
To your 1st paragraph : NSL/EWL have a back-up driver in the cabin as in the past, it was pure manual. I repeat, Pure Manually controlled. So if they overrun by accident, the operator can always contact OCC for permission to reverse the train to the CSP. BUT NEL/CCL trains are fully automated. FULLY automated ok? No Operator to control the train. If its overrun, its considered skip. But skipping is quite a hassle as you can't always say the train at the other platform arrives immediately. The SUPER DUPER SLOW cruising is a safety precaution to prevent the train from overruning the station. The inertia of the train might cause wheelslip and the train might still be moving even if the wheel is not.
To your 2nd paragraph : Its the operator's fault. Ask SMRT why they want to save $$. Their frequencies are so bad that they are 9 mins / train
To your 3rd paragraph : We have stations that are even nearer other than Pioneer and Joo Koon. Its around 800m from Boon Lay to Pioneer. From Dhoby Ghaut to Bras Basah, its around 400m. Its not about the train's flaws. Its the train capabilities.
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If you have the train 20m from CSP and it's still going at high speed, it would need to brake to 0km/h immediately (There are trains in other countries which can E-Brake 0km/h immediately). The force would be greater and if it's a locomotive. The trailers behind would "fly". The force has no where to go. So it is rebounded back to the other end instead. The force is also pushed downwards and against the force as a result of friction. Causing flat wheels too.
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Originally posted by Dragonaxe:
To your 1st paragraph : NSL/EWL have a back-up driver in the cabin as in the past, it was pure manual. I repeat, Pure Manually controlled. So if they overrun by accident, the operator can always contact OCC for permission to reverse the train to the CSP. BUT NEL/CCL trains are fully automated. FULLY automated ok? No Operator to control the train. If its overrun, its considered skip. But skipping is quite a hassle as you can't always say the train at the other platform arrives immediately. The SUPER DUPER SLOW cruising is a safety precaution to prevent the train from overruning the station. The inertia of the train might cause wheelslip and the train might still be moving even if the wheel is not.
To your 2nd paragraph : Its the operator's fault. Ask SMRT why they want to save $$. Their frequencies are so bad that they are 9 mins / train
To your 3rd paragraph : We have stations that are even nearer other than Pioneer and Joo Koon. Its around 800m from Boon Lay to Pioneer. From Dhoby Ghaut to Bras Basah, its around 400m. Its not about the train's flaws. Its the train capabilities.
I never encountered a 9 min wait for a train after the 6min off-peak frequency was implemented.
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Originally posted by wenjie639:
I never encountered a 9 min wait for a train after the 6min off-peak frequency was implemented.
I meant CCL trains
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Originally posted by SMRT 32373238:
NSL and EWL trains generally do not overun stations. What I meant was is it possible for the Alstom trains to brake to a full stop just like NSL and EWL trains WITHOUT the super slow rolling past for 1 door (NEL) and 2 doors (CCL) at a slow speed before full braking?
To Samuel Lee: Yeap I know the service speed limit is 80 and my wish is NOT granted because the trains generally go way slower than 80. Even from DBG-->BBS, they can speed up to maybe 70 before slowing down rather than cruising slowly at 50 (or less?).
Even on EWL, though pioneer is really close to BoonLay (2 bus stops), the trains still go really fast.
The slow cruise is an precaution to avoid overruns. Even the less experienced driver on the EWL/NSL do that. Try looking at approaching trains at the EWL EB and NSL platforms, JUR.
Trains have speed limitations due to curves, operational reasons, and other less common reasons including condition of track, and limited clearence.
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Originally posted by Dragonaxe:
To your 1st paragraph : NSL/EWL have a back-up driver in the cabin as in the past, it was pure manual. I repeat, Pure Manually controlled. So if they overrun by accident, the operator can always contact OCC for permission to reverse the train to the CSP. BUT NEL/CCL trains are fully automated. FULLY automated ok? No Operator to control the train. If its overrun, its considered skip. But skipping is quite a hassle as you can't always say the train at the other platform arrives immediately. The SUPER DUPER SLOW cruising is a safety precaution to prevent the train from overruning the station. The inertia of the train might cause wheelslip and the train might still be moving even if the wheel is not.
That was in the past... NSL/EWL is no longer pure manual, unless instructed to drive in CM due to rain or rail works, or during peak hours. The full braking on NSL/EWL is part of the AM mode what right? So I was wondering if the same concept could be applied to the Alstom trains. And yes they are FULLY automated. I'm not blind and I'm not an idiot.
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Originally posted by SMRT 32373238:
I'm not a scientist, but I remember learning that the smaller the mass of a moving object, the less inertia it has. This should mean it takes about half the effort to brake a CCL train right? Plus I get a feeling CCL trains are more powerful than NEL ones (there's this sudden surge forward when the train leaves the stations whereas for NEL trains I don't feel so much of a force)
As for acceleration, NEL trains slowly (relatively) increase power to full, while CCL depart at a lower power setting (CCL has no notches- it is linear), before going full throttle. This is why the acceleration feels different.