Danielo
Member
I was on a 'Southern' LM 350 yesterday from H&W to Shepherd's Bush. I times the voltage switch over at 25 seconds. It seems to be a lot quicker than the Electrostars. Is this the case?
-
Our booking engine at tickets.railforums.co.uk (powered by TrainSplit) helps support the running of the forum with every ticket purchase! Find out more and ask any questions/give us feedback in this thread!
Dual voltage Desiros and Electrostars
- Thread starter Danielo
- Start date
- Status
Sponsor Post - registered members do not see these adverts; click here to register, or click here to log in
R
RailUK Forums
jv3531
Member
Probably find its to do with the control system in use. The TMS has alot to do with how the trains handle things, some take longer than other and some have to be vertually reset before they can proceed.
It could also be signal state playing a factor in the delay.
It could also be signal state playing a factor in the delay.
73110
Member
If an Electrostar is at Farringdon doing the changover from AC to DC, it can take up to 4 min's to do the changeover. Reason for this is if the unit is in the station by itself then it will be drawing too much current from the third rail, somehting like 800v+. Now if this happens the train doesn't like it and wont turn everything back on because of the high power coming in. The train won't let the voltage in if it's over 812v I think.
Now, if there is a train in the other platform or directly in front of it then it will just take about a minute or so as the other train will be sharing the voltage in the station and the computer will let the lower voltage 'in' so to speak without fear of overloading.
I have no idea though about the 350's.
Now, if there is a train in the other platform or directly in front of it then it will just take about a minute or so as the other train will be sharing the voltage in the station and the computer will let the lower voltage 'in' so to speak without fear of overloading.
I have no idea though about the 350's.
mackenzie_blu
Member
I will admit the changeover on the 350's is quite quick and the CIS screen keep going unlike the Electrostars.
As for the reasoning for the delay at Farringdon, whats the reason they have problems changing power when its an 8 car? I'll have to check how often the problem happens with 4 and 8 car mix.
Thanks for the information about the voltage problems, quite interesting to hear that.
73110
Member
For the same reason really. Too much power in the third rail. The current has to come below 800v I think or the thrain throws a wobbly.
Don't know about that to be honest, only ever had one cab ride in a Eurostar and that was on DC hundreds of years ago!!! You can however do the changeover on a 319 on the move both ways if you really wanted to be daring!
Danielo
Member
You could be right there. I don't remember the Eurostar having to stop being entering the tunnel from the UK side before the days of HS1.
That's right - E* initially changed over east of Saltwood Tunnel, and later on the Gravesend West branch. In both cases changeover was on the move, normally at around 60-70mph.
ISTR there was one occasion when the pantograph on a London-bound train didn't stow correctly leaving the CT, and a minute or two later it had an intimate encounter with the footbridge at Sandling
ISTR there was one occasion when the pantograph on a London-bound train didn't stow correctly leaving the CT, and a minute or two later it had an intimate encounter with the footbridge at Sandling
Danielo
Member
Is the Eurostar switch done instantaneously, or is there a short neutral section between the two voltages?
87015
Established Member
Used to be at least one "daring" Connex crew, was a bit of a shock the first time it happened!
73110
Member
I was at Farringdon years ago when a set of empties came though. Didn't stop at all. The pan just about went down before he went under the hook at the end of the wire. My mouth was wide open watching it go!!
westcoaster
Established Member
hope it was a brecknell willis
and not a stones faiverly(boy are they slow to go up and down):roll:--- old post above --- --- new post below ---
was told there were also a few silverlink metro drivers, that would drop on the move in there 313's
Last edited:
Touch and go. Yes the CIS stays on, but one 350 I was on on the 14th of this month took around 90 secs to complete the proceedure.
On the other hand, I like you have had a changeover in March at sub 20 seconds. The average, having had 4 return trips now, was to my mind around 30 secs. Still quicker than the average of 45 secs for Electrostar.
O L Leigh
Established Member
I've said this before on a number of ocassions, but it would appear it needs to be said again. You can drop a pan on the move but you can't raise one. If you do you risk damaging the pan and/or the OLE, and possibly even causing a dewirement. The ONLY exception to this is Eurostar which has a more sophisticated pan and better OLE.
As for newer generation EMU's changing voltage, the time taken would be down to the TMS. I'm guessing that this interval would be the same as that when the unit goes through a neutral section, as the TMS needs a little breather whenever that happens. Any problems with voltage overload is likely to be sorted via a software update.
As regards Farringdon, just why is the voltage there so high? Admittedly the 3rd rail can be anywhere between 650-750 volts so there is always likely to be a bit of variation, but 800+ volts sounds a bit much.
O L Leigh
As for newer generation EMU's changing voltage, the time taken would be down to the TMS. I'm guessing that this interval would be the same as that when the unit goes through a neutral section, as the TMS needs a little breather whenever that happens. Any problems with voltage overload is likely to be sorted via a software update.
As regards Farringdon, just why is the voltage there so high? Admittedly the 3rd rail can be anywhere between 650-750 volts so there is always likely to be a bit of variation, but 800+ volts sounds a bit much.
O L Leigh
73110
Member
It is actual fact mate! On the MITRAC it shows you exactly how much voltage is coming in through each MCM and ACM. (Motor Converter Modules and Auxiliary Converter Modules)
It takes mere seconds to shut off, go through the section and put the power back on again through a neutral section. On the 'Traction Status Screen on the MITRAC the MCM and ACM indicators go from green to yellow for a few seconds obviously whilst they have no power through the section.
Whatever a "TMS" is it needs a bigger breather at Farringdon than it does at a neutral section.
O L Leigh
Established Member
Sorry, I wasn't inferring that I didn't believe you. I was saying that 800+ volts sounds like a bit much for the trains. While I don't sign 3rd rail stock, I would imagine that might just be enough to trip out a unit's surge protection.
Then clearly Electrostars are better than Desiros in this respect.
The reason why I said this is that 25 seconds, which is the time delay quoted by the OP, sounds about the same amount of time as GE's Cl360's were offline after going through a neutral section. Through successive software upgrades this time has been reduced, but a Cl360 still doesn't come completely back to life for an appreciable period of time after going through a neutral, even after the VCB has closed again. It strikes me that this is, therefore, a TMS-related issue rather than a hardware problem. I'm guessing that certain systems go through a self-test routine whenever the power supply is restored after an interruption and that the TMS won't restore full power and control of all systems until they have all reported in that everything is still fine with them.
O L Leigh
73110
Member
Ahh right. Strange things these trains eh!
Bring back the old slam door stock, basic air and amps!
Bring back the old slam door stock, basic air and amps!
O L Leigh
Established Member
What do you mean "bring back"...? What do you think a Cl317 is...? 
O L Leigh
O L Leigh
Danielo
Member
Or just get the whole thing done by DMUs and do away with voltage switch overs
asylumxl
Established Member
The 377s on the Thameslink route take ages to switch over compared to the 319s.
Would be a good idea to add something to Farringdon to drop the voltage to eliminate delays?
Would be a good idea to add something to Farringdon to drop the voltage to eliminate delays?
Or wire up the Southern region.
delt1c
Established Member
- Joined
- 4 Apr 2008
- Messages
- 2,125
Ahh right. Strange things these trains eh!
Bring back the old slam door stock, basic air and amps!
The 317's were the 1st electric stock for the route. they were the electric class which started of the 3rd generation of EMU and are therfore probably over engineered and a lot more solid than the later designs.
No slam door emus have worked the services.
Daimler
Established Member
Tell me about it!
6 mins at Farringdon on Thursday! Made the following train late! It's a good thing they aren't trying 24tph with 377s!
asylumxl
Established Member
This morning, several Bedford trains were delayed by about 22 minutes. From what I saw traveling Southbound, they appeared to have been all 377s. Must have been stuck at Farringdon.
mackenzie_blu
Member
Tell me about it!
It's a good thing they aren't trying 24tph with 377s!
If Bombarbier get the Thameslink contract then we will be doing with Electrostar Mark 2!
That was due to signalling problems at East Croydon delaying everything going through this morning. At it height offically 30mins delays were up on the boards. meaning it was likely higher.
Last edited:
asylumxl
Established Member
Danielo
Member
So, who wins? Electrostar or Desiro?
- Status