Thameslink - power changeover question

[russ p]

15 hours ago, St. Simon said:

 

Hi Russ,

 

Is this the Pan Raising restriction a flat 20mph or is it based on location? The rule book is that Pan Raising can be done at any location below 20mph (although this speed can vary by route but doesn't in reality), but can be done above 20mph when in a Safe Pantograph Raising Area as marked by the last two signs below:

 

 

Although it should be noted that not all of these signs are in use on Thameslink, and equally a new standard on Power Change-Over that provides further signage is being prepared.

 

Simon

 

Hi Simon the Pan can be raised at 20mph on any straight bit and free of junctions OLE it could be raised at higher speeds in safe Raising Area but its not something we would likely encounter other than if it was leaving an isolated area but other than if it was in multi with a 68 speed wouldn't be to great as on diesel they are gutless.  

I raise the Pan on the move when leaving Tilbury 2 container terminal.  I get the train upto 15mph , the speed leaving the terminal on diesel then put the pan up so once the train is clear it will quickly accelerate in electric mode

Cheers  Russ 

[jim.snowdon]

Both the Americans and the Dutch routinely run electric trains at line speed through gaps in the catenary required by lifting bridges. In the US case, the common technique on the ex-Pennsylvania RR 11kV system is to lift the wire to above the maximum pantograph height on either side of the gap. The pan just rises until it hits the up stop, then picks the wire up on the other side where it ramps down to normal height. The Dutch have instances where the wire is simply gapped and the driver instructed via lineside signage to lower and raise the pantographs at the appropriate points. The latter approach is very much the same as the 25kV AC -3kV DC/1.5kV DC changeover points where the French LGV networks interface with the Belgian and French DC networks.

 

[keefer]

There's a commuter system in (I think) the NE USA that uses EMUs, at certain locations they change between bottom-contact 3rd rail and overhead. May not be full linespeed but it's certainly on the move.

There are clips on YouTube but I can't remember the line/company.

[Mike_Walker]

19 minutes ago, keefer said:

There's a commuter system in (I think) the NE USA that uses EMUs, at certain locations they change between bottom-contact 3rd rail and overhead. May not be full linespeed but it's certainly on the move.

There are clips on YouTube but I can't remember the line/company.

That's Metro-North who switch between systems at line speed in the Pelham area on the Grand Central to New Haven line.

[keefer]

Thanks Mike.

YouTube clip, go to 02:44 for a changeover, overhead >3rd rail. After that there are changeovers from 3rd rail > overhead, the train practically in the station before the pans go up:

 

Edited December 26, 2022 by keefer