Wednesday, 6 September 2017

More Tension

Tuesday 5th Sept

Four of us at Broadway today to make a bit more progress under the Signal Box in the locking room.
It has been decided to add two more signal wire adjusters to the lines for the Direction Indicator (the most northerly signal at Broadway). This on the face of it was a relatively straightforward job but took us most of the day to sort out.
Upstairs John P fitted the adjuster bodies to the floor. This required a bit of repeated measurement (measure at least twice before cutting and drilling holes!) to ensure that the tails to which the wires attach line up with the  wheels on the levers and to avoid the floor joists.

and here they are eventually poking through underneath .

The end of the signal wire will attach to the loop with a shackle. The wire will then pass under a pulley down below and then up and over a second pulley on the lever tail up above. Finally the wire will come down again and pass under a third pulley before going out through the tunnel. The raising or lowering of the adjuster then tightens or slackens the signal wire to compensate for excessive variations in temperature. I think I mentioned in an earlier blog that this mechanism is used for signals further than 300yards from the box- the direction indicator is about this distance away.
So, to complete this installation we need to fit an additional steel plate to the floor channels to mount the additional 3rd pulleys.
We positioned this first to mark out and drill the mounting holes to attach it to the  front C-channel the additional holes required to re-mount the existing rollers had been pre-drilled back at the workshop and matched up well.

Then to  mark out and drill the 3 holes to mount each of the two new pulley assemblies:

And then bolt the whole lot back into place. We just managed to get the nuts onto the bolts without having to  take out the lower "wildlife proofing" board which would have been impossible to get back in with the plate in position.

The next board up needed a small slot cutting for it to sit comfortably over the plate - so now all secure again - job complete until we come to fit the signal wires - more slots needed for these!

While all this was going on Malcolm was continuing with the locking ..........this will continue for a good few weeks yet!

And outside for most of the day  Steve W was going through the platforms with the dumper carrying new ballast up to the north end - should give P-Way a good day's track laying work tomorrow!



  1. Good progress. Although we had tensioners on the SVR when I was there, we didn't have any at Highley, where I was; and so I never saw any in action, so to speak. This was mainly due to our homes and starters being more local to the box than 300 yards and our distants being fixed, the only workable distants at that time were for boxes which switched out. Really interesting blog and great pictures. P.S. would it be possible to see a picture of the box diagram as it will be when Broadway opens for business next year? Regards, Paul.

  2. The box is currently resting in the locking room of Winchcombe signal box. Stage one will be to give it a trial fit at Broadway but the diagram has yet to be produced (proper GWR stencils required and all that!) It's about 10 ft long and as far as we know it originally came from either Honeybourne West Loop or Stratford Evesham Road Crossing.

    1. Kevin Simpson on the SVR has a full set of BR(WR) stencils from Reading signal works. I believe they originally belonged to the late Dave Whittamore. Maybe you could bribe him to draw the diagram for you then re-draw those in the other boxes in proper Western style!

  3. What length of slack would you expect to have to take up on a hot day over the 300 yards to the signal?

  4. The expansion of a 300 yard length of steel wire for an increase in temp of say 15 degrees C would be about 2" Quite a bit of slack. Similarly going in the opposite direction from say average daily temp of 20 deg C down to freezing this would shorten the wire by 2.6". The longest mechanically operated signal on our railway is the Gotherington distant , as far as I can recall is about 1300 yards from the box , so with extremes of temp this would be the worst case scenario.