city thameslink OHLE?

[heart-of-wessex]

I read on the thameslink page that OHLE is extended to city thameslink station. i havent been there to see but does this mean the changeover of power will be here and not farringdon or are the desrio city units maybe having a design so they can change power on tge move between these two stations?

cheers,


James.

 

[Aictos]

The changeover from AC to DC and vice versa will happen at Farringdon, the reason why Smithfield sidings and City Thameslink is equipped for both AC and DC is if for example a service from Bedford has issues changing over from AC to DC at Farringdon then it can continue to City Thameslink and go into the sidings there to clear the line.

This applies for services originating from the Southern as well.

 

[heart-of-wessex]

Ah i see thanks for that! you say it applies from the south direction does that mean they will change first at city TL and use farringdon if it doesnt work at the former?

 

[westcoaster]

The changeover from AC to DC and vice versa will happen at Farringdon, the reason why Smithfield sidings and City Thameslink is equipped for both AC and DC is if for example a service from Bedford has issues changing over from AC to DC at Farringdon then it can continue to City Thameslink and go into the sidings there to clear the line.

This applies for services originating from the Southern as well.

Smithfields is still dc only, and will stay dc only. Any unit that can't change over will change ends in city, and go back north, any unit that can't change to ac at farringdon will go back south to smithfields.

 

[ole man]

City Thameslink is wired now,the ole ends about 100metres of the end of the platforms,smithfield sidings is only dc,and as far as im aware its staying that way,im currently working between farringdon and city thameslink on the resignalling to make it bi-directional,the change from ac to dc is still at farringdon,so the signs on farringdon say.
The next big job on thameslink is to lay track and ole the two tunnels just north of st pancras int(canal tunnels) which will come out on the ecml near where ctrl goes over the top,im there this weekend and will take some pics and might walk through them

 

[DJ_K666]

Yeah that'll be excellent as I'd like to get a closer look at the Canal Tunnels. You can't really see a lot of detail on Google Earth...

 

[Aictos]

Smithfields is still dc only, and will stay dc only. Any unit that can't change over will change ends in city, and go back north, any unit that can't change to ac at farringdon will go back south to smithfields.

Thanks for the correction,

 

[londonmidland]

Where does this tunnel lead to, It's next to Kentish Town or is it St Pancras? Well one of them locations and it say's Tottenham something...

 

[ChrisCooper]

In the past trains which failed to switch from AC to DC would run to Moorgate and then reverse to head back north. That option was lost when the Moorgate branch closed, hence the desision to extend the OHLE to City Thameslink where trains could also reverse. There is no ability to reverse a southbound train at Farringdon.

Canal Tunnels will link the Thameslink route at St Pancras to the East Coast Mainline.

 

[ole man]

If you go to st pancras int,look just north of the edge's of the platforms you will see 2 tunnels one either side,they might be covered with blue tarpulin,they will link thameslink to ecml and enable trains to run to cambridge etc,have been told there 740m in length and when you drive towards kentish town from kings cross there on the right hand side just before where the ctrl and nll go over the top,dont go past cemex or you've gone to far

 

[broodje]

How will the Thameslink lines connect with the ECML? Will it be a flat crossing, or will there be some kind of dive under/over?

 

[yorkie]

How will the Thameslink lines connect with the ECML? Will it be a flat crossing, or will there be some kind of dive under/over?

I'm reasonably sure it's a flat crossing onto the slow lines, south of the existing flyover. So a train going south that has to cross the Down Fast will fly over the Down Fast (as at present) and and then cross the Down Slow, on the flat, but this won't be a problem if the vast majority of trains on the slow lines are using the Thameslink tunnels. I also believe that the tunnels between the ECML and MML to St Pancras (low level Thameslink platforms) do not conflict with each other (it would be totally unworkable if they did!)

 

[Dreadnought]

Where does this tunnel lead to, It's next to Kentish Town or is it St Pancras? Well one of them locations and it say's Tottenham something...

The tunnel you are thinking of is Tottenham North Curve Tunnel No1 which is before Kentish Town when going into St Pancras. This leads onto the GOBLIN line between Gospel Oak and Upper Holloway.

 

[swt_passenger]

The northbound OHLE between City Thameslink and Farringdon is not energised, it is earthed temporarily (alongside Smithfield sidings) to allow for a temporary fix for a clearance problem with Southeastern 465s and 375s entering Smithfield sidings.

Following the reinstatement of the bay platforms (an equivalent turnback facility) at
Blackfriars in March 2012, works will be undertaken to remove the permanent earth,
the in-line section insulator and adjust the OHLE to its design height, thus allowing
north bound services to undertake the DC to AC change over at City Thameslink.
This will need to be covered by a further Network Change Notification at that time.
It should be noted that it is not intended that Smithfield sidings should close. They will
remain as a bolt hole for use by Class 319s and 377 Electrostars – given that these
two types of rolling stock do not have the clearance problems suffered by class 465
Networkers and 375 Electrostars. The sidings will not be usable by the proposed
eventual fleet of 12 –car fixed formation trains.

So the operating procedure when everthing is up and running is that southbound changeovers will normally happen at Farringdon, with failures running to City Thameslink to tip out passengers (bigger platform?) and returning north on AC via the trailing crossover just south of Farringdon. Northbound changeovers will normally take place at City Thameslink, 12 car failures will then run to Farringdon on DC and return over the same trailing crossover as mentioned earlier.
Northbound 8 car trains will still be able to use Smithfield sidings as a bolthole if it is decided to just get them out of the way, and return them south later - I suspect that when the 24 tph is running this would be the normal case...

PS - just saw the OP's question about changeover on the move, and this was a definite requirement of the Thameslink stock ITT technical spec.

 

[jopsuk]

How on earth do 375s have a clearance problem whilst 377s don't? They're the same train?

 

[swt_passenger]

How on earth do 375s have a clearance problem whilst 377s don't? They're the same train?

Discussions elsewhere thought it might be something as simple as a roof mounted aerial being too long, or something similar, but there was never a categoric answer.

Presumably easier to pull the catenary out of the way for a relatively short period, rather than change all the necessary units.