Following on from my previous post on point rodding, I've now got stuck into the facing point lock lock bar. This is located immediately in advance of the king point to prevent the FPL being withdrawn if any stock was standing over the bar.

Using information from the Scalefour Society manual and further information and photos from Robin Whittle (of Barrow Road fame) I've made good progress with my 4 mm scale representation.

The bar is slightly the wrong proportions being a length of 0.82 x 0.82 mm Tee section but not too far out. It's mounted on wire pins set into the base board top adjacent to the rail. The pivot levers are from an Ambis FPL etch but I didn't bother with the associated support brackets as they're barely visible behind the pivots. I set the top of the bar 0.75 mm below the rail head to make sure that my 0.5 mm deep wheel flanges would be clear of it. This is perhaps a bit generous clearance as the real thing is about level with the bottom of the rail head in the lowered position. To get the bar to the required height I had to file the top of the inside chairs to 1.57 mm below top of rail and trim the bottom of the pivot levers which will be below ballast level when all is finished.

A minor inconvenience is that the bar crosses a base board joint, so the total length (50' - 6") is split with 140 mm on one board and the remaining 62 mm on the next.

Here's a photo of the longer section in position. Also visible (just) are the cranks for the operating rods (rods not yet done). The drive from the signal box lever is to the far (left hand) end of the bar.

At the other end of the bar is the attachment to the FPL bolt mechanism. This arrangement meant that any failure/breakage in the lock bar arrangement prevented the FPL (and hence the point blades) from being moved.