Dorchester-Moreton Single Track Section

[SpacePhoenix]

Why was the section of the SWML between Dorchester and Moreton singled and when (it's been single track for as long as I can remember)?

From one of the level crossings on Streetview it looks as if it could have been double track at some point in the past and is unlikely to have always been single track

 

[Polarbear]

As I recall, this was done as part of the electrifcaton of the line from Bournemouth to Weymouth in the 1980's. At the time, the timetable was developed so that there wouldn't be more than one train at any time between those two points.

It is as certainly double track when I used it in the early 1980's with 33's & 4-TC's. Happy days!

With hindsight, it was a short sighted decision as it will now be very difficult to expand services on that section. Also, when electrified, the power feed was done at minimal cost which means only single units can normally operate west of Poole.

 

[najaB]

With hindsight, it was a short sighted decision...

A statement that could be applied to many, many decisions - both on the railway and in our personal lives!

I'm sure that it was the best choice based on the money available at the time, and the predictions of future traffic levels.

 

[MarkyT]

A statement that could be applied to many, many decisions - both on the railway and in our personal lives!

I'm sure that it was the best choice based on the money available at the time, and the predictions of future traffic levels.

I suppose it has saved just over five miles of track at subsequent renewals, although that one remaining track gets twice the tonnage of each in a pair so perhaps the rails have to be renewed more often!

The single line can handle an evenly-spaced half hourly service with a bit of spare capacity remaining for the odd empty stock, special or departmental and as the only single track section on the whole route (apart from the fairly trivial example of Weymouth station throat) it is fairly easy to manage. Giving priority to up traffic, if a train just misses it's down direction slot, that would cause no more than 7 or 8 minutes further delay which should be recoverable in terminus turnback layover. So the case for redoubling would be very hard to make unlike, say, Cornwall where multiple single line segments of varying length at fairly random positions made service planning difficult in the first place and the effects of late running highly unpredictable, especially considering the larger variety of train operators and routes of varying lengths operating into Cornwall. The longest single section there, 7 miles from Probus near Truro to Burngullow near St Austell was redoubled in 2004.

 

[HowardGWR]

The excuses trotted out, in the Dorset Local Transport Plan over a couple of decades, for not redoubling and uprating the power supply are - less than impressive, shall we say. DCC is an organisation that is a road building one, rail is very much an afterthought, so they never offer any help with the investment needed but simply report it has not been made.

 

[steamybrian]

It was singled in the 1980s to save the costs of track renewals. BR looked at singling further sections between Moreton and Wareham but luckily that was the only section thus singled.
During the early 1980s a number of uneconomic lines were closed and others were singled of which a few have been re-doubled.

 

[didcotdean]

There have been timetables in the early days of singling (particularly on Sundays) which included a 7 minute wait at Moreton built in for some services. Probably try to avoid that these days.