Edinburgh Carstairs line speed restrictions

[dalmahoyhill]

the general line speed between edinburgh and carstairs is 95mph. however there is a restriction over linhouse viaduct (just after midcalder junction) of 70mph. does anyone know why?

the line curves sharply in a double S away from the junction but the restriction appears to be only over the viaduct. is there some structural issue with it? i have walked under it and i am a civil engineer and it looks fine to me. it surely leaves diesel units struggling to reach line speed climbing up to cobbinshaw?

other question is have network rail or British rail every considered rebuilding carstairs junction to increase line speeds from Edinburgh? why has it never happened? It seems an easy win. certainly edinburgh to the WCML southbound would seem easy and relatively cheap to construct, there already appears a semi finished trackbed.

 

[142094]

other question is have network rail or British rail every considered rebuilding carstairs junction to increase line speeds from Edinburgh? why has it never happened? It seems an easy win. certainly edinburgh to the WCML southbound would seem easy and relatively cheap to construct, there already appears a semi finished trackbed.

There was some talk of this recently on the forum, with part of the old alignment being brought back into use to allow the fast trains to pass the slower ones. Unfortunately can't remember what thread it was.

 

[DaveNewcastle]

Probably this thread : Sharp curves on the Network, way back in December!

Carstairs gets a good critique there. The old avoiding lines (one to the north and one to the south) both get mentioned on here from time to time. I always appreciate the few moment's silence when even the air-con shuts down as we coast through the 2 adjacent neutral sections at 15mph!

 

[dalmahoyhill]

thanks for the link, i read the other section.
i was wondering if BR/ railtrack/ network rail * delete as applicable ever considered or worked up plans to speed up carstairs junction, what the costs were and if they ever advanced it, why did they it get canned. it seems such and easy win.
i would ask the same question of morpeth curve as well, the line slows down from 100mph+ to 60 and back up to 100mph.

 

[DaveNewcastle]

The layout at Carstairs has been evaluated from time to time and never seems to be much of a priority. There are several reasons (though you are quite correct to suggest that any land aquisition there would be very innexpensive, comparitively).

Firstly, the junction layout and speed restrictions have negligible impact on the main through route - the West Coast MainLine.
Secondly, the Mid-Calder line junction marks the traditional regional boundary (East meets West!) and there will always be interface issues at regional boundaries.
Thirdly, traffic using the Mid-Calder line (esp East to West northbound to Glasgow and South to East northbound to Edinburgh) will have to cross opposing running lines and threfore are highly likely to be restricted anyway. (Don't you often see stationary freight there?)
Fourthly, (and I don't completely understand why) there is an extended neutral section or two neutral sections depending on route, probably all related to the above.
Fifthly, much of the passenger traffic using the Mid-Calder line (East Coast's excellent high speed services) is subject to increasing competition from the other 3 high capacity Edinburgh-Glasgow routes.
Lastly. The pulled the old track up long ago. And relaying old track always seems to cost a fortune - not to mention the unimaginable signalling costs at such a complex interface.

Yes, I too would appreciate a faster junction there when using the Mid-Calder line, but I wouldn't let it near the top of any list of priorities!