The Lentran Loop
One of the items on FoFNL's wish list is the provision of a loop at Lentran. I thought some observations about an additional loop to ease train operations between Inverness and Dingwall would be of interest to our readers.
Prior to RETB signalling a loop was provided at Lentran when the line was converted to single track from Clunes to Clachnaharry. This was an excellent location for a crossing point for trains between Inverness and Muir of Ord and its main drawback was that it was too short for long freight trains coming off the North at night (changed days!). Another problem was that on the UP leg of the loop was a set of sprung trap points, which made any shunting movements rather awkward. Why the loop needed to be so short I don't know, as the trackbed existed, it having been a double line, so it was only a case of selecting the length of track and putting points at each end. The most likely reason was that it was required to operate the loop from a single points cabin using manual rodding to change the points which limits the distance from lever to points, otherwise a motor would be needed at one end or two cabins operated by one man. A rather antiquated system which most loops north of Dingwall used.
The benefit today for installing this loop with its hydraulic sprung points (HSC) would be to cross trains halfway between Muir of Ord loop and Inverness Station, enabling trains to be dispatched north without having to either wait for a late running southbound train to arrive or to further delay the southbound train at Muir of Ord when dispatching the northbound train on time which exacerbates the problem of missing connections east and south.
Lentran is almost half way between Inverness and Muir of Ord and for simplicity in the following example I will assume the journey time is 10 minutes Inverness to Lentran and 11 minutes Lentran to Muir of Ord. There are many scenarios that will develop with late running trains between Inverness and Muir of Ord but we will take the example of Train A waiting at Muir of Ord to travel to Inverness and at the same time Train B is ready to be despatched from Inverness to Muir of Ord. Under the current situation one of those trains will incur a delay of 21 minutes whilst waiting for the other to traverse the section. If it is the northbound train that is delayed we now incur problems the whole length of the line as it will be out of place at the planned crossing points and if it is the southbound train there is an increased risk of passengers missing connections and there is every chance that it will be the southbound train that is running late and causing all the problems. But, with the Lentran Loop both trains can be despatched towards Lentran at the same time with the northbound train arriving first and waiting 1 minute for the southbound to cross thereby saving the further loss of 21 minutes.
This is for crossing purposes only, nothing would be gained for trains following each other as Clunes is a token exchange point and as soon as a train passes clear of the prescribed point the section is then clear for the next train to follow. The next thing is we would lose some time by having to go over the HSC at the mandatory reduced speed. Is it value for money? Possibly not. But it is an essential part of the infrastructure and has only been denied to keep the cost down of the original RETB scheme. I'm sure your committee will make strenuous efforts to have this anomaly rectified.