OHLE 25kV or 750V DC third-rail

[Mojo]

I think this looks quite cool: -
http://www.maarten-otto.net/Thalys4532.jpg

 

[TheSlash]

Well i have just seen sufficent evidence in a demonstration today that you need to make a good 'earth' when you touch the 3rd rail or it won't do anything. Somebody repeatedly belted the con rail with a spanner, deliberately.

 

[Sprog]

Well i have just seen sufficent evidence in a demonstration today that you need to make a good 'earth' when you touch the 3rd rail or it won't do anything. Somebody repeatedly belted the con rail with a spanner, deliberately.

FUN! cratch:

 

[Dennis]

Well i have just seen sufficent evidence in a demonstration today that you need to make a good 'earth' when you touch the 3rd rail or it won't do anything. Somebody repeatedly belted the con rail with a spanner, deliberately.

Should get a few chavs to try this, only make sure the juice is on!
:violent2:

 

[TheSlash]

The juice was on...

 

[NumptyDriver]

in reply to theslash,

i too hold full AC and DC PTS, and regularly drive over / under both systems.

3rd rail is distinctly 'lo-tech'. the main day to day operational difference between the systems is that one slip can more easily be fatal in 3rd rail areas, ohle is out of the way. and ohle is more energy efficient, it's proven that high voltage/low(ish) current transmission is less 'lossy' than high current/low(ish) voltage. I too read papers and watch news, up here in the merseyrail third-rail area there are regular incidents. and dead badgers. maybe such incidents don't make the news down there.

roll on fuel cells.

 

[voyagerdude220]

in reply to theslash,

i too hold full AC and DC PTS, and regularly drive over / under both systems.

3rd rail is distinctly 'lo-tech'. the main day to day operational difference between the systems is that one slip can more easily be fatal in 3rd rail areas, ohle is out of the way. and ohle is more energy efficient, it's proven that high voltage/low(ish) current transmission is less 'lossy' than high current/low(ish) voltage. I too read papers and watch news, up here in the merseyrail third-rail area there are regular incidents. and dead badgers. maybe such incidents don't make the news down there.

roll on fuel cells.

It doesn't make the news around Lancashire, so I don't think Southerner's will get it

 

[Nick W]

Maybe the DLR third rail is the safest - tripping less likely to be fatal.

 

[uktrain225]

OHLE are no limits.If it use third rail, it only supply DC.If the trainis AC motor,It have to use VVVF!If OHLE,it can supply DC or 25kV AC.so use OHLE is better.

 

[Julian G]

OHLE is better than 3rd rail
Look at the examples of 1980 EMU
The pantograph produces a wonderful buzzing noise

 

[Jordy]

OHLE is better than 3rd rail
Look at the examples of 1980 EMU
The pantograph produces a wonderful buzzing noise

Hmmmm, wonderful :confused:

Jordy

 

[Tom]

OHLE are no limits.If it use third rail, it only supply DC.If the trainis AC motor,It have to use VVVF!If OHLE,it can supply DC or 25kV AC.so use OHLE is better.

Third rail CAN use AC.

 

[O L Leigh]

Third rail CAN use AC.

Indeed it can but, because there is effectively no current flowing at two points in the AC cycle, the peak voltage would need to be higher than 750V to give sufficiently high mean voltage to run a train. This in turn would lead to greater chance of short circuits with the CR so close to the ground and the running rails.

I would be interested to know whether there are any AC 3rd rail mainline systems anywhere in the world.

one TN

 

[Julian G]

I would be interested to know whether there are any AC 3rd rail mainline systems anywhere in the world.

one TN

West London Line
North London Line

 

[Met Driver]

West London Line
North London Line

Wrong. Both are 750v DC apart from the OHLE sections.