(09-07-2015, 11:58 AM)Belg Wrote: [ -> ] (09-07-2015, 11:53 AM)jjlim84 Wrote: [ -> ] (09-07-2015, 11:21 AM)Belg Wrote: [ -> ]For all we know, this might just be a sad truth of our train system.
Just overheard, the power trip could just be an overload trip. I.e. our system cannot cope with this growing population.
So no surprises that it happened during the peak period when the load is the highest.
does this overload refer to the train takes more passengers than it should (a design weight problem)? Or the train runs longer distances or at faster speeds in order to meet the frequency at peak hours?
Yes, it refers to the train not being able to take more passengers than it should. Thus, it might explain why the MRT is moving about much slower than in the past.
I think it has to do with frequency / no. of trains as well.
MRT's way of handling capacity is to increase the number of trains running simultaneously on a single track, hence the interval time between trains is shorter (2 minutes). But the same track now has to cater to the electrical demands of more trains. With heavier trains in peak hours, the motor will need more electricity too.
In any case, a clear problem demonstrated this round is why should track fault on one line cascade down to another line? The fault should be isolated to one line and preferable, one section between stations. This would minimize the fall-out from any disruption.
Edit:
I saw the snippet of the press conference where the CEO tried to explain about maintenance issues. I wasn't impressed. Either he doesn't know or his engineers did not do a good job briefing him prior to it (e.g his attempt to describe the frequency of faults of an aging system).
All of them just know how to repeat they are concern , but incapable of fixing the problem . The irony is they still continue to keep their million dollar salary jobs .
(09-07-2015, 09:06 AM)yeokiwi Wrote: [ -> ] (08-07-2015, 06:15 PM)sgd Wrote: [ -> ] (08-07-2015, 04:59 PM)thor666 Wrote: [ -> ]I doubt it is engineering talent but maintenance costs. Downtime is a function of aging infra and costs.
it's a sign that the system is at it's limit.
It's like construction company having a van but because the management cheapskate so treat it like a big lorry and place impossible loads on it, everybody knows it will break down eventually. Changing the tires adding a tow carriage behind installing better suspension so what? it's still a van.
This is an unfortunate truth.
If you need to wear the same shoes everyday, how are you going to mend the holes on the soles?
It is by itself a hard engineering problem at this stage since the repair and maintenance time is limited to 12am to 6am.
And there are no alternate tracks and no alternate routes so that the maintenance crew have a longer time to do their jobs.
Maybe, it is time to pay some serious money to engage a japanese or german technical team. We have no such talents in singapore.
Metros in other country faced the same constraint. What is different here? Is it the weather?
The unfortunate truth to me is that they have not found the real root cause of previous breakdowns. I am saying this some sympathy because I know from experience it is not always possible to root cause every system breakdown.
Disclosure: Not a shareholder, not a regular train commuter.
I empathise with the rail engineers. As will most practising engineers.
Running through the fault tree and coming up with the agreed course of action; getting maintenance team to execute within the small turnaround window; analysing the incomplete results; and then updating the findings. As touzi pointed out, sometimes you are catching ghosts in the form of Can Not Duplicate or No Fault Found. If maintenance records/data of the past was not captured well, it becomes another hurdle for the engineer and his assistants.
I am a regular train commuter and I do not own shares in SMRT or Comfort Delgro.
If they are not serious to invest to find out the root of the problem , commuters should just accept breakdowns are just the norms. The problem is , who actually take public transports ? Know the answer, know why it will not be solved for so many years .
I was a bit taken back by the straits times one article on the ceo headings that say it is not possible to find and repair every flaw. I am shocked this means they are not interested to resolve it a technical issue. Attitude is not there already some more on national paper quite a disgrace for a ceo to say that.
This is not like finding every flaw in a art piece which is subjective. Here is pure science and engineering issue. Yhr thing about science is good is factual based on proven science basis. Can work means can work. Wear out can repair.
(09-07-2015, 08:01 PM)pianist Wrote: [ -> ]I was a bit taken back by the straits times one article on the ceo headings that say it is not possible to find and repair every flaw. I am shocked this means they are not interested to resolve it a technical issue. Attitude is not there already some more on national paper quite a disgrace for a ceo to say that.
This is not like finding every flaw in a art piece which is subjective. Here is pure science and engineering issue. Yhr thing about science is good is factual based on proven science basis. Can work means can work. Wear out can repair.
I am on software engineering. There is a common understanding among us, that no (commercial) software is bug-free, even after a very comprehensive testing.
I am not a rail engineer. I reckon, for a complex system, with many interlinks and couplings between subsystems, it is likely that a "flaw-less" system is close to impossible.
Don't know the root cause of a major problem, is a nightmare of every engineer. May be the CEO is wrong, be political insensitive on his comment, especially during the press conference.
(09-07-2015, 08:01 PM)pianist Wrote: [ -> ]I was a bit taken back by the straits times one article on the ceo headings that say it is not possible to find and repair every flaw. I am shocked this means they are not interested to resolve it a technical issue. Attitude is not there already some more on national paper quite a disgrace for a ceo to say that.
This is not like finding every flaw in a art piece which is subjective. Here is pure science and engineering issue. Yhr thing about science is good is factual based on proven science basis. Can work means can work. Wear out can repair.
agreed, this is rail engineering, not ROCKET launch into space...
CEO makes irresponsible statements, LTA CEO and TUCK YEW all in the same gang...
PM LHL better step in and wake them up, else all have to GO!!
PM Lee action pls!
Perhaps there is too much kiasuism.
trying to play safe to a very high degree the circuits, relays may have been set to cut off power way too soon.
Go back to settings and select a higher tolerance that triggers a cut-off.
This is not reckless but applying settings within a known range that is safe or that causes limited damage.
They knowingly increased loads, frequencies... but forgot all about increasing tolerance in safety systems.