Wednesday 21 June 2023

S&T Work Week Report

S&T Work Week

By Robert Law

Last week between the 10th of June and the 17th. The S&T department, but well supported by others. Had a very productive week in pushing the plans forwards with Boat of Garten South Cabin. Unfortunately or not, it also turned out to be the hottest week of the year so far, with heavy thunder storms included. Despite all of this it turned out to be a very productive week and a chance for members to catch up with each other too.

Boat of Garten South Cabin enjoying the sun.

The work over the week was concentrated around making the Up platform bi-directional. This meaning that trains can be signaled from Aviemore, into either the Down or Up platform at Boat of Garten as a passenger move. To achieve this FPLs (forwards points locks) need to be installed and controlled form the signal cabin. There are two ends of points that are involved with this work. These FPLs, All be it are currently manually operated, were installed last year with a written procedure of use put in place. This alone has helped our signalers with the increasing amount of charter traffic, coming off the Highland mainline. But things need to be completed and the FPLs controlled from the signal cabin. 

The plan for the rodding of how the FPLs are controlled.

Before the week had even been set in the diary. Plans were drawn up and marked up on the ground. Like any other installation of this type, the expansion and contraction of the rodding in the forever differing temperatures that we have, needs to be accounted for. This is done quite simply with the “push” and the “pull” of the rodding equaling the same. Providing that the rodding all heats and cools at an even rate, the movement at the end of the rodding remains a constant. With some of the work already been done when the lead off table was changed back in November. (See previous blog entries to remind yourselves.) There is only 4 tables to be sunk in the ground. Two compensator cranks and two sleeve cranks. 

The rabbits have been busy digging there holes.

Each hole had to be dug by hand because of its location. Each hole being 770mm deep and 1500mm in length and breadth. Yes, we could have disconnected the rodding and use the digger. But unfortunately the clamshell bucket is too big to fit between the rodding stools and would have generated more work. Plus unfortunately the Scotsman was in and out twice within our week. Meaning that the signal cabin had to remain in use over the whole of the week. 

The base of the first compensator crank table.

This is the part that most people don’t see or realize it is there. To give the crank stability there are three layer of wood. The base at the bottom, two side members, then the top that the crank sits on. Yes, this could have been built up with concrete members in the ground and a steel plate on top. But this is not the Scottish traditional way and as this is a heritage Railway in Scotland. It’s good to keep the old ways alive. The ground that we are working in is very free draining with 300mm off top soil then foundation sand underneath. All other timbers in the ground, associated with this cabin are already between 30 and 40 years old and still holding well. 

First compensator crank fitted and ground leveled off.

With the base, level and at the correct depth, the top timber and crank are placed. The height is then confirmed to be correct, with the crank and drop lugs offered up the lengths of rodding in the stools. Once happy that everything is correct the top timber was fixed down to the base and the crank screwed down to the top timber. After checking that the movement is correct and not been held /rubbing on anything that it shouldn’t, the ground is back filled and cess cleaned.

Completed first sleeve crank, for the north yard FPL.

Second competitor crank completed, but missing its grease points.

Second sleeve crank, for the FPL on the crossover to the Down.

In the four foot of the crossover the final crank has been installed. 

Over the whole of this project, no rodding has been cut to size as the temperatures were to high, with the rodding been swollen compared to its normal length.

The other interesting part of this project that you might have seen in the diagram, is the installation of a new LMS lifting bar, for the protection, that the signalers can not remove the lock while the train is over ( in this case between) the points. The parts that we have acquired for this, were recovered from Nairn. When it was re-signaled in the year 2000. The 50ft lift bar is made of three part. Within the week we have managed to correctly install one part. With two more lengths to be fitted and jointed in the coming months.

This is the late 1930s plan that is being used for reference.

Not the best of pictures, but shows the first part of the lifting bar that has been fitted.

This video shows better what has been achieved with the locking bar.

Boat of Garten South frame

As you can see in the picture, there is several leavers that are missing from the frame. With the new FPLs and signals that are being installed the missing leavers will need to be replaced. Thankfully we do have some, that were used in Boat North when it had a 40 leaver frame within it. With the use of these stored leaver we can replace what is missing.

The spare levers cleaned up to be installed.

So it’s fair to say that a good amount of work has been achieved over our planned work week and that it has been very successful. Thanks is to be given to all those who came to help. It was much appreciated. Hopefully we can arrange another work week in the future.