Dornoch Unlooped

Following on from the previous analysis of the Dornoch Firth Crossing printed in Issue 20, I offer some alternative proposals on the existing route. In a future issue I will be more specific on time gained if they are implemented.

Frank Roach, Rail Development Manager,
Highland Rail Partnership

1. Crossing Upgrades

The Far North line is unique in the number of level crossings - originally some 200 between Inverness and Wick. Some are farm crossings, some carry minor roads, some A roads and all are subject to rigorous safety appraisal. In a ideal world there would be none at all, but the cost of bridge construction might be rather high! Incidentally, sharp eyed travellers will have noticed phones appearing at many of the private crossings.

There are several crossings that could be upgraded to produce higher speeds.

Automatic Open Crossings Locally Monitored (AOCL - flashing red lights) could be upgraded to Automatic Half Barrier (AHB). Power plants are already in situ but a means of communication with the Signalling Centre in Inverness would have to be created. With the added security of barriers trains could pass at linespeed. Possible sites are Delny, Dalchalm, Hoy and Watten.

Many of the crossings are Open Gated. Some are due to be upgraded such as The Marrel and Acheilidh. However given the experience of Rovie Crossing near Rogart it does not always mean that investment gives speed. An Open Crossing here was upgraded to AOCL yet the speed through the crossing was reduced to 10 mph northbound.

It may be advisable to upgrade some Open Crossings to AHB where a gain can be achieved. Kildonan is the star (Open Ungated) as trains here have to stop at the crossing in case a road user may be there!

What's the cost? Rovie was converted to AOCL for £350k and Blackwater (near Strathcarron) will cost £700k for an AHB. What are the outcomes? Reduced braking, reduced acceleration, less fuel used = time gained. Acheildh has a severe speed limit in the northbound direction. It takes 60 seconds for the train to regain linespeed even going downhill!

2. Signalling

RETB token exchange takes one minute. A GPS type system recognising the precise location of the train could give instantaneous authority to proceed into the next section. However TPWS will require a stop at the stopboard.

3. New line

A direct chord from Halkirk would avoid reversal at Georgemas (4/5 minutes). A new station could be built at Halkirk allowing the closure of Georgemas. Signalling works would be required to create a Halkirk-Hoy section. The arrangement may be beneficial for freight movements at Georgemas.

4. Linespeed

There are perhaps opportunities to investigate 90 mph running between Invergordon and Tain which might deliver 2-3 minutes of time saved.