Towards the end of the last season we started having trouble with the locking of Winchcombe Points 19. Investigation revealed that the facing point lock casting was moving around due to the timber under it being life expired. I tightened the bolts holding it down and for reliability had to file the lock slot for the normal a bit wider. Whilst not rendering the points unsafe that did put them outside of the blade tolerance for setting the point lock, so a repair was required before the new season. Seeing as these points had been in place for over 20 years and that the stretchers and sole plate were second hand, had home made insulation and a lot of packing to make them fit, and were effectively life expired we decided to replace the lot.
S&T removed all the connections (drive, locking, detection and stretchers) and took them away for cleaning, restoration or stripping for usable parts. P-Way then came in and replaced several life expired timbers, including the one under the sole plate, and fitted a new sole plate. The sole plate is a metal plate which sits under the toe of the points, on top of that timber, and has pre drilled holes and end stops for the point chairs. In this case it also has an insulator built in because this section of track is track circuited. The point lock casting also sits on this plate and is drilled through it. The purpose of the plate is to hold the toe chairs and the lock casting in perfect register so that the gauge cannot alter and the casting cannot move relative to the rails.
S&T then returned and fitted the locking stretcher, along with an insulation kit at one end (track circuiting again) and detection lugs for the mechanical signal detection for facing moves. We also fitted two packing pieces to set the toe spacing within tolerance. This set the switch blades the correct distance apart, so we could then fit the new drive and intermediate stretchers. These are fitted to one blade, and the other blade's connecting bracket is also fitted. The stretcher bar is then offered up to the connecting bracket and marked and drilled to suit the spacing, before being fully bolted in place. This now solidly connected the two switch blades together again. We next fitted the refurbished drive connecting bar, which is driven from a sliding crank which allows alteration of the throw distance and has a bottler adjuster in its length which allows correct positioning of the blades in normal and reverse. We re-used the original parts for this, but fitted a new and correct insulator kit in its length (the old one being track pad rubber and 20mm water pipe, those were the days). This made the points operable from the box for local shunting.
The next job was to fit the facing point lock casting, which Richard C and I did yesterday. The casting was placed on the sole plate with the locking stretcher running through it, and positioned so that the starting slots in the new locking bar were in the correct places for normal and reverse point settings.
We then marked round the casting with chalk so that we could be sure it hadn't moved during the next part of the operation. We had previously had some 'top hats' made. These are stepped ferrules with outside diameters of standard sizes, 3/4" in this case, and a 6mm hole through the middle and in this case allow us to accurately pilot hole the sole plate for drilling (we also used them on the stretcher bars).
Once we'd piloted the holes we slid the locking casting along the lock stretcher out of the way and brought in the mag drill.
This allowed us to accurately drill the sole plate to the correct size for the fixing bolts. Finally we used a wood cutting flat bit to drill the timber, which showed the timber to be solid and healthy all the way through. Normally the fixing bolts would be pushed up from underneath, but this is a horrible job if the timber is already in situ, as you need to tunnel under at sufficient depth to knock the 8" long bolts up through the timber. Nowadays we use stainless steel bolts and nuts, which undo easily after time, so we decided to push the bolts down through the casting and put the nuts (along with 70mm square plates and washers) on the bottom. These fitted well and were duly tightened up, we use locking nuts to avoid them coming loose. Should future checking reveal a loose bolt it is reasonably easy to dig out and get a spanner on the nut below.
The above photo shows the finished job with the casting bolted in place. You can see the bottle adjuster and new insulator on the drive bar, the new drive stretcher, the locking stretcher with detection lugs (blade extenders) (with new insulated rodding couplings) and insulated packing on the right, the sole plate with its insulator to the right, and the facing point lock casting bolted in place.
The next job is to offer up the locking bar, mark the locking stretcher and 'accurately' cut the locking slots. We don't want to get this wrong as this is a pass/fail when you carry out the periodic point inspections. Once this is done the lock bar can be reconnected to its drive and the points will lock once again. After that the final part will be to reinstall the refurbished mechanical detection so that the passenger signals for facing moves are detected.
As well as all this we have signal G17 at Gotherington stripped for refurbishment and continue to move parts and tools into the new workshop, more on those later.
