Fixing The Pulleys

 Tuesday 22nd Feb

Three of us today at Toddington on concreting duty.  Luckily an electric concrete mixer was available, so that made life much easier. 

We have two sets of six pulley wheels to fix in position. These direct the signal wires under and across the track to the detector and the bracket signal (two for the main arms and two for the call-on arms)

And finally the detector unit is positioned on its plinth. This is secured in the concrete with 4 bolts, the heads of which are sunk in. 

Neil C spent the day fitting and connecting new cables for the track circuits.

A shot of the tamper passing the signal box on its way to the North end of the station while we were having a tea break!

Curly

Mainly Digging

 Tuesday 15th Feb

Five of us off to a very wet Toddington today to continue with the re-fitting of rodding, etc. to the new pointwork south of the station.

Because it was so wet we had to postpone the mixing of concrete for preparing the bases for mounting the detector unit and pulley wheels - just made do with digging holes for the shuttering:

The rest of the day was spent digging in the concrete rodding stools. Quite a strenuous job getting into the fresh ballast and making sure that we kept a good alignment at a constant height relative to the track. 

We managed 7 stools before we decided to call it a day.

All the connections to the FPL have now been made - just needs a small modification to the locking  slots and some adjustment to the throw of the blades and its good to go.

Back in the signal box locking room Neil C has wrestled back into position the electric lock for lever 26 (the one with the mangled pen inside!). Space is extremely limited here and was a bit of a challenge getting it back in and bolted up. Its the one with the grey cover poking out.

Hoping for better weather next week - 

Curly

Toddington Refit

 Tuesday 8th Feb

All hands on deck now to get the new Toddington pointwork reconnected to detectors, signals, rodding, etc. So five of us off there with the diesel railcar trailer loaded for action.

There's quite a lot of work to do here now that the new  pointwork has been re-positioned.

John P and Neil C concentrated on refitting the FPL (lever 11) , stretchers and angle cranks , all of which needed a fair amount of drilling- some through steel and some through sleepers. 

We had taken the precaution of bringing the portable generator with us but we didn't need to use it as there  was , luckily, a mains connection in the adjacent pit and we had a nice long lead to oblige!

Note the multicoloured environment with the brand new yellow  stretchers! Note the insulated joints for track circuiting.

Meanwhile on the platform 2 side there was Malcolm W, John B  and myself dealing with the metal plates for mounting angle cranks onto concrete blocks which have been roughly positioned and need fine tuning to get everything in the right position .

Then followed the problem of getting the point rodding stools (most of which had been removed) back in perfect alignment relative to the track. So, forward with our hightec  equipment -- a large plank (remember the film with Eric Sykes and Tommy Cooper) with attached locating devices! This was very effective.

Getting the alignment of this angle crank to match up in both directions is proving a bit tricky with the mounting plate perilously close to a drain cover.

 

Most of the  concrete rodding stools that were removed to facilitate the track replacement have to be repositioned with freshly dug  holes in the ballast.

Work will continue with more of our colleagues tomorrow and Thursday . More serious shovelling to look forward to!

Curly

Unlocking the Lock

 Monday 7th Feb

The following is a detailed description of the resolution of a problem with an electric lock from Toddington signal box courtesy of Neil Carr.

For a while now the lever lock on lever 23 at Toddington controlling the point machine for the North siding has been intermittently sticking requiring the cover to be removed, and a brief bit of S & T assistance to the lock mechanism. Often the lock appeared stuck, but then freed when pulled manually  and worked happily once again.

Since the box is currently closed , whilst much point replacement work is happening, the chance was taken to unwire and remove the lock - a Tyers large lock with contract drum. That in itself isn't a five minute job, as there are many connections,  and the lock is well hidden behind the locking trays. These locks have more travel than a standard lock,  having several locking positions   and are driven directly from the lever via an actuating arm  clamped to the lever shaft; therefore they are usually found behind the normal locking and among the signal wires.

The lock was then brought back to the  S & T Coach to be stripped, cleaned and reassembled. 

Given that the lock intermittently jammed up, and then worked for a period once freed  I was expecting to find some dirt or swarf in the mechanism 

 What I actually found  amazed me. At some point in the last few years a signalman must have dropped a plastic pen down through one of the lever slots in the frame; against all odds this had bounced into the back of the lock mechanism and had been comprehensively chewed up by the locking bar moving up and down as the lever was operated. Now and then bits of plastic must have jammed in the lock bolt mechanism  preventing the solenoid from being able to pull the bolt from the lock. 

Whilst the lock was apart the entire mechanism was cleaned of old oil and rubbish ( and pen) the contacts on the contact drum were stripped and cleaned and the lock was set up correctly with the contacts all operating in the correct positions. It was then reassembled clean and dry of oil and grease

This photo gives a good idea of the physical size of these locks, the locking bar is just over a metre long.

Looking right to left we start with the top of the locking bar (they are mounted vertically) where the actuating arm from the lever attaches. Next we have the coli and lock closed connections, then the lock bolt itself , followed by the solenoid coil with the lock actuating arm above it. Energising the coil pulls the iron block at the left hand end of the coil tight to the coil, and via the arm withdrawsthe lock bolt from the locking bar. This locking bar has three positions; as shown it is locked in "Normal"   where the lever is normal in the frame and the points would lie in their normal position.  Underneath the coil you will see a very long slot cut in the bar, when the lock is energized, and the lever moved away from normal the bar is drawn towards the right ((in this picture , in reality it is lifted upeards) until the lock bolt drops into that long slot. The bar then continues its travel until the lefthand end of that long slot hits the lock bolt. The lever is then in the 'Reverse Check' position, and the contact for operating the points reverse is made.

Once the points have moved and been detected in reverse the lock will again energise (automatically via the ele trial locking) and allow the lever to be moved fully reverse  where it will again be locked

Moving from reverse to normal is the same procedure as above , only going the other way. 

The large casting on the left hand end of the lock body is the contact drum. This has a series of pairs of contacts over rotary contact rings, rotated via a gear wheel and a long angled slot in the locking bar. These contacr boxes can have many contact rings and many different lengths and positions of rings - allowing contacts to be made at various positions of the locking bar and for varying durations of its travel. 

An in-depth description of the varying contact combinations is probably touch detail for here, however, suffice it to say.that this contact drum is configured with four contact rings; providing contacts for the Normal, Normal Check, Reverse Check and Reverse lever positions.

The astute of you will however notice that this drum has eight sets of contacts, although only four are used. These locks can have drums which are much longer and can carryall least twice as many contact rings

I hope you found this Informative!

Curly ( on behalf of Neil Carr - S & T Electrical Engineer)