Wednesday, 18 October 2017

More at Winchcombe

Tuesday17th Oct

Eight of us on site at Winchcombe today. One team carrying on with sorting out the faulty cable across the tracks from the signal box and the other preparing some more parts for the signalling at Broadway.
A lot more ballast digging to prepare a trench for the replacement cable (a 20 pair armoured).

The cable will pass under the siding track through the orange plastic tube. This piece of cable will be approx 25 metres long to join the existing lineside box and the new (smaller) one pictured last week.
It has now been buried in position and will be connected up as soon as poss on a non-running day so that we don’t cause any disruption to operations.
We are now interested in finding out exactly what and where the fault is with the old cable. So, another ingress has been cut into it (at the position of the piece of covering grey tubing pictured below):

And then having bared the suspect wires carry out the magic pulse test -

This indicated that there is a fault approx 2 metres away in the Toddington direction. At this position the cable passes underneath water and electricity supply cables so we can’t pursue any further investigation until we have cut and dragged it out. You can just see the tubes carrying these services coming out between the sleepers:

A bit more tidying up for the Cheltenham cable with some additional trunking 

And a view of the spaghetti of existing  connections inside the cabinet. 

Part two consisted of organising some more fittings for Broadway.  Once we have fitted the steel plates for mounting the angle cranks for the point rodding and the pulley wheels for the signal wires we can start to line out their positions. To assist with this we have prepared two of the fabricated steel  rodding stools and bolted on a four wheel set of rollers: 

 The screwed rod bolted at right angles to the feet will serve to anchor them in a concrete “boot”. The height at which they will be set is determined by finished sleeper surface. The face onto which the roller sets are bolted will be level with the sleeper and spaced in the gap between the sleeper end and the platform wall. A length of point rodding laid on these two sets of rollers will then give us a good datum for positioning of the fittings. 

Here are a few of the bits in the process of being cleaned up:

and some of the speed restriction signs destined for Broadway

and some of the lineside cabinets now undercoated - silver and black top coats to follow:


Wednesday, 11 October 2017

Cable Hunting

Tuesday 10th Oct

A Cable fault lineside of Winchcombe Signal Box was the subject of  today’s labours under the direction of Neil C. Two cables go under the tracks from the box and needed digging out of the ballast - one is the Toddington communication cable and one is the Cheltenham communication cable. A very time consuming and awkward job to tickle the ballast out from under numerous rails.

But after much concerted digging all was revealed

There has apparently been an intermittent fault on the Toddington line for some time so a bit of testing was now required to try and determine the location. The clever bit now follows!
From the cable end connections in the Signal Box, an electrical pulse is sent down the suspected faulty wire using a Time Domain Reflectometer (wow!). If there is a break/fault this pulse is reflected back down the wire and the instrument measures the time this takes thus giving a measure to where the fault lies. This indicated that there was a fault within 38 metres. So.....further digging ensued to try and locate the Toddington cable circa this distance:

Next stage was to bore into the cable to uncover the “offending wires” inside. This means cutting off the covering sheath, cutting through the steel armour and the plastic insulation, to eventually bare the wires in question and to carry out a short circuit test. All this led us to believe that we could remove a length of cable between 25 and 38 metres from source - this would enable the existing cable to be connected into the adjacent lineside box and a new piece of cable to be installed from this box to a new box beyond the 38 metre point. In the last picture the savaged cable is temporarily protected with a piece of plastic tubing. A freshly prepared lineside box now ready for a bit of concrete:

Neil will need a few hours of quiet concentration to reconnect cables when the railway isn’t running!
A new piece of cable is now standing by 

To protect the cables running under the tracks, concrete troughing has been installed. This will give protection from  burning coal which can  cause damage  and makes it evident where cables are 

Back at the workshop we have been restoring more lineside cabinets which will be required around Broadway to connect all the cabling that will be required there


Wednesday, 4 October 2017

Plating Up

Tuesday 3rd Oct

Six of us in action at Broadway today to carry on with the preparation of the concrete block for the signal wire pulley wheels opposite the signal box against the wall of platform 1.
We decided on quite an unusual and heavyweight solution to support the 4 lengths of C-channel which are to be set in the concrete to support the steel plates (2-off 8ft long x 18” wide).
To support them and prevent them  from moving during the concrete pour they will be bolted to two lengths of channel sitting on the base of last weeks excavation.
First step to cut up the pieces from the (approx 20ft long) piece


The large angle grinder made light work of this


Six pieces required. Keith L with the four short bits for debuting


Then a bit of marking out and drilling for the bolt holes. Jim P in charge

And here are the two completed assemblies

Now I hope you can see what all this was about with them finally in position

Then onto the concrete pour. I reckoned we needed just over half a cubic metre to fill it so it was a good job we brought the mixer with us. Keith L slaved away keeping keeping it fed with aggregate and cement off the back of the pickup. 

And here’s the finished job with just the upper halves of the C- channel showing above the surface of the concrete. 


While we were in the mood for moving and drilling large lumps of steel we turned our attention to the opposite of the (almost! ) tracks to configure the four 9” C-channels that we brought up last week.
These required positioning on top of the channels which are already cast into the tunnel floor so that 
they protrude out to be level with the top of the platform.
Marking out and drilling  required to match up with the existing holes 

And then bolted in position. 

 Limited access!!

 We already have the two large steel plates which were then manhandled on top of the four channels. Not yet bolted down - a job for the magnetic drill next week or we may now wait until the ballasting has been done. These plates will protrude out a little further over the ends of the channels. 

 Obviously a good place to sit for a tea break! and still plenty of room for wheels and angle cranks.

While all this was going on we managed to avoid the dumper truck on its many journeys ferrying ballast up to the fast approaching northern railhead- in fact I believe we have featured in the Extension Blog this week -  Jo paused for a photo shoot as we were about to start pouring concrete!


Saturday, 30 September 2017

Those wretched resistors

At last we have managed to move some components that were always physically in the wrong place to somewhere where they made more sense.

We have a 2 50 line paxes,  at two signal boxes, these are linked (Tied )by two tie lines in each direction. The book says that  the  line resistance  must be more than 500 ohms so there are these padding resistors; but they were mounted on the side of the Main Distribution Frame and the plan is to update that with a more modern Krone Block. This will give us more reliable access to lines and make mistakes  in tag counting less likely.   But that is still some way off- a job for the winter shutdown.

These resistors were augmented by surge arrestors . These had not operated in the last 20 years since all our cables are buried so I think that they were just Belt and Braces- just in case.  The problem was to understand the Strowger mindset and correctly interpret the diagram.
The notes call for many changes in a tie line circuit that make it very different from a normal " subs'" line so firstly we copied that part of the drawing, then tippexed in all the changes and overlaid it on the original thereby making, in effect, a Tie Line Diagram.

This took a bit of time but was most helpful. The trick then was to find the correct tags on the rear tagstrip and no, the line circuits are not the same numbers as the numbers that you dial, so it needed both Kevern and I to operate the pax by sending a call to the other pax and then seeing which line circuit operated as the call came back again. Eventually, after advising all the Users that the ties may be interrupted for a short period,  we had all the answers. Sixteen jumpers and  an hour with the soldering iron later, and Voila' the mod was done. Like all electrical type work its not very visual . If you do it properly there's no sparks or bangs! but here's a pic of the rear tag block.

 And after testing we left everything working as normal.
When I started this , being used to Post Office drawings I didnt realise the significance  between
  tag - and tag -'. Now I do!
The job of upgrading that original "MDF " into a modern system moves a lot closer.

Thanks for reading and thanks to Kevern for all his help

Mike S

Wednesday, 27 September 2017

Preparing for Pulleys

Tues 26th Sept

Once again off to Broadway today.
We have now taken delivery of four lengths of 9" C-channel which will be used to mount the steel plates which will carry the pulleys and angle cranks coming out of the signal box tunnel --  ALSO a plate is also needed opposite the tunnel at the base of platform 1 to carry the pulleys that will direct the signal wires northwards and to the wooden signal post at the south end of platform 1.
Here we have the channels loaded to deliver to Broadway. Quite substantial lumps - should keep everything rigid !

So, one of our objectives today was to mark out the position for a concrete base along the wall of platform 1 and prepare some shuttering for a concrete block. First of all we dug out the old ballast over a 16 foot length (enough width to cover wires coming from the levers at the ends of the lever frame - and of a width to clear the ends of the sleepers which will appear in the not too distant future).
In doing this now it will avoid us having to dig through another 18" of fresh ballast

Jim P did most of the hard work. Breaking up an shovelling compacted ballast keeps you fit!

We used platform 2 as a workshop to cut up some old 15mm plywood and prepare the shuttering

Then positioned it in the trench.

The height of the  the concrete has been measured from the top surface of the platform allowing for a bit of adjustment when we set the C- channel in the concrete. There will be 4 short lengths of this at right angles to the platform wall on which two steel sheets will be fixed. We hope to do the concreting next week.

Meanwhile down in the bowels of the Locking Room Malcolm and John P have been carrying on with the fitting of the electric locks. Each lock has to be clamped in position to make sure that all the bars and couplings move freely - then mark through the back plate for drilling and bolting.

All 16 are now mounted , but a bit more adjustment and drilling required next week on the last one.

Beginning to look the business but a lot more work still required in the locking trays above (and we haven't even mentioned electrical wiring and cabling yet!)


Wednesday, 13 September 2017

Block Shelf Stabilisation

Tuesday 12th Sept.

Off to Broadway again - 3 of us plus Andy D who has been slaving away at Toddington machining the couplings to join the tappet blades to the electric lock bars, but more of this later.

The Block shelf  in the signal box needed additional support to remove its tendency for lateral movement and a central column for vertical support. This central support doubles up as a cable duct to cover the multitude of wires that will eventually feed down from the shelf. Here's the wooden box support which has been assembled and painted since lat week - note that it has a hinged cover to provide access from the window side

Some holes needed in the floor to feed the cabling through, John P in action with a 25 mm dia cutter - 2 holes should suffice - after measuring , a pilot hole tells us that we are missing the joists below

Then into position and adjust for vertical. A couple of screws through the Block shelf  and two into the floor to  secure it into place.

Having now got a pretty sturdy vertical set up we now need a bracket to stop horizontal movement. Here's one we made earlier

This has been attached to the side of the Block shelf and the central window frame and provides a very rigid fixing - it is now impossible to move the shelf in any direction even with a hefty push.

Meanwhile down below in the locking room Malcolm and Andy D were checking the fit of the newly machined couplings and pins to the tappet blades at each position where an electric lock is to be fitted.  

The bars which operate the locks and attach to these couplings  have to be lined up for the coupling holes to be drilled and dowel pins fitted - note that these are then  secured with split pins 

This jigsaw to be continued.

I found a spare  signal wire adjuster before departing for Broadway this morning and took a shot to hopefully give a better view of what one looks like. The central screw has a length of about 2 feet and provides  a significant amount of adjustment. Operated by a removable handle on the top (not shown) which raises or lowers  the looped bar  below.