Signals and Telegraph
Stephen Muirhead
Work is continuing to provide the Up loop at Boat of Garten with bi-directional signalling, which should simplify the operation of the Royal Scotsman traffic. Incremental milestones have been achieved over the Winter starting with the point rodding run now complete but not connected. The signal wire run, including a new intermediate table, has also been installed. This is to change the direction and the order of the signal wires leaving the signal box so that they arrive at the point detector and the signals in the correct order. This prevents any snagging of wires, which could make the signals harder to pull.
The detector for the South yard points has also been installed over the Winter and is ready to go into use when other parts of the project catch up. The detector at the crossover points needs to be moved to line up with the new signals that are being installed. The signals are being moved further from the line to maintain a safe distance from the structure gauge on the Up loop to the tip of the new signal arm. The new table for the crossover detector is in and ready to be tied down once the final placement has been achieved.
The largest achievement so far is the installation of the lattice signal post. There are other lattice signal posts on the railway dating back to LMS days, but this is the first one we have installed ourselves. Over the Winter, shed staff and volunteers helped with sandblasting the signal, giving it a coat of rust protection paint and an undercoat of white paint. The P-way team has also assisted with transporting the signal post back to Boat of Garten on a ballast train.
Surprisingly, erecting the signal was a very straightforward task. First, a 1300mm excavation was required to accommodate the foundation casting. Strict attention was paid to getting the base level, as this would ensure the lattice post would be vertical. The hole was then backfilled and packed so that the foundation casting would not move when placing the lattice signal on top.
At this stage, the table for the shunt signals was placed on either side of the lattice signal foundation. Once everyone was happy with the mockup placement, a date was set for a joint team effort between S&T and P Way to lower the signal post onto the foundation casting. Thankfully this was within the lifting capabilities of the Colmar machine, which made light work of lifting it into position. Once it was sitting on the foundation casting, the two collars were moved down the post. The post tapers, meaning that the collars get tighter and grip the post onto the foundation casting when pressed down - very simple technology but very effective.
A further small project has just started, with the goal of installing new Omnibus Phones at both Aviemore Station North and South Ground Frames. Further updates will follow with more information on the S&T blog accessible from the SR Website.
The new ABCL (Automatic (Half) Barrier Crossing, locally monitored by the Train Driver) was given its annual test in early March. The only defect found was the complete loss of the double white line road markings over the new rubber deck units after the Highland Council’s Winter road gritting. Fortunately, a new white lining product has recently been approved by the crossing deck manufacturer, and an agreement has been obtained to place an order.
The Dalfaber LC Maintenance Agreement with Highland Council is now very close to being signed off, and in recognition of this, the Council has paid the maintenance charge for the new crossing's first year of operation. The next challenge at the crossing will be to plan and implement the first lifting out of the rubber deck units to carry out rail fastening and insulation inspections, coupled with repacking of the track as required.
Pre-season maintenance comprising Facing Point Lock (FPL) testing, oiling, greasing, signal lighting, key token machines, electrical releases and Omnibus Phones has been carried out at all sites, with nothing of immediate concern found.