Bradford (Exchange) c1954 signal & telegraph

[SimonME46]

I'm building a model of Bradford (Exchange), platforms 1-5 in 7mm FS c1954, and am presently working on a mechanically interlocked lever frame, using a Modratec Kit, and their design software, Sigscribe. Many thanks to Harold from Modratec for all his help. I'll try to document in this thread, as a Spurr to finish the job!

 

The design idea is mechanically interlocked frame, with micro switches to change points (tortoise) and signals (servo). Signals have been largely built, I'll be doing the actuation using John Fitness methods.

 

So some pics..

 

Firstly, the signal box diagram as discovered on the www

[clecklewyke]

This looks like a fascinating project which I will be following with great interest. Is this the L&Y or the GNR side of Exchange?

 

I am modelling a fictional LNWR terminus in Bradford and my timetable is based on the platform working schedule of the L&Y side of Exchange in the 50s, which was published in "Model Railways" some years ago. Would this be useful for you?

 

Ian

[SimonME46]

The track plan was transferred to Sigscribe, interlocking design attempted, and submitted to Harold for checking. A few changes were recommended, and the kit was ordered. Now being a contrarian sod, I decided (against the design of the kit) that I wanted the point levers out the front, rather than behind the locking frame. It ended up working perfectly, but please bear this in mind with the construction photos.

 

Hmm. Not sure how to upload multiple pics on the iPad with captions, so please bear with me a post at a time.

 

Basic frame bolted together easily like a mechanic set.

[SimonME46]

Hi Ian,

Theoretically the exL&Y side, however I think that the overall roof/offices will in fact resemble the GN side, as the side entrance on the L&Y side is significantly more complex to model.

 

The article you mention, by John Cockroft was what got me started, back in 1994 I think, so it seems his hope that it would inspire models is being fulfilled. I'm bored at a conference away from home, otherwise I'd post up pics of progress to date.

 

Next pic is the levers all painted with the connector wires installed - note that they are all upside down, due to me building the thing backwards. This was resolved later

[SimonME46]

And the levers installed on the pivot rod with spacers.

[SimonME46]

Then the small springs and ball bearings were installed and the spacer tube between each lever installed. A few were sacrificed to the model railway gods on the floor...

[SimonME46]

Once all 30 levers were installed, the even (lower) tappets were fitted to their slots.

[SimonME46]

I forgot to mention-the locking frame will be located in a cutlery box, which is about the right size. To the rear will be micro switches, with cat 5 wiring/connectors to the layout. Pics of that will follow, when I get to that bit, but I thought I should cover off the box that this suddenly appeared in. I have an electronically (relay) interlocked box at present, but the levers are just DPDT switches, so no physical locking. This is attached to the baseboard via hinges, so can quickly be removed.

 

Next up, the locking bars were placed in order, and trimmed to size as needed.

[SimonME46]

The lower tappets were marked using a fine permanent marker pen through the locking bar holes.

 

Then upper tappets were marked out, with the direction that the slot needed to be filed out marked. I did make an error, but was able to swap tappets and got away with it.

[SimonME46]

Tappets filed-I used a respirator as I was feeling a burning feeling at the back of my throat. I pretty quickly got into a rhythm with a medium sized bastard file, and smoothed off with the back of a hacksaw blade as suggested,

[SimonME46]

Locking pins trimmed to size using a stop in the vice. I initially did these a bit too long and then panicked that I wouldn't have enough brass rod. Cutting them closer to size was a much better idea, and less filing down to height too.

[SimonME46]

Locking bars with pins being installed. The frame has been completed and tested, but I can't find any pics of that, so will have to wait until I get home to upload them. I'm now at the stage of trying to get the micro switches in place, as I wanted to do a DIY effort on that, which an may come to regret!

[clecklewyke]

Wonderful. When will you be exhibiting this in England? 

[SimonME46]

Funnily enough Ian, I'm thinking of popping over to live in Yorkshire for calendar year 2015. If all goes to plan, I'll likely pack up my worldly goods into a shipping container, in which case, that would actually happen!

[clecklewyke]

Funnily enough Ian, I'm thinking of popping over to live in Yorkshire for calendar year 2015. If all goes to plan, I'll likely pack up my worldly goods into a shipping container, in which case, that would actually happen!

Excellent. Look at Wensleydale, it's beautiful!

 

Ian

[SimonME46]

I'll certainly take a look at Wensleydale, Ian.

 

The below is a pic of the current relay based box. It operates the tortoises, but would not trigger the servos, as they are switching current, rather than closing a circuit

[clecklewyke]

Simon,

 

This looks superb.

 

At first glance, the two facing crossovers appear to duplicate each other - or is there a rationale for them?  I didn't think that the real Exchange had this feature?

 

Ian

[SimonME46]

Hi Ian

The 2 facing crossovers were certainly there, and are in the diagram in the first post.

 

Down West 77 enables direct access to platform 5/alternative access to platforms 3 & 4

 

Up West 79 enables departure from platforms 1 & 2

 

I've uploaded a pic of the box showing the cat5 connectors attached to the rear, and my mock up of the micro switches to be activated by the tappets. I'm not happy with this yet, they are spaced too far away from the tappets, so I may remove some timber from the support to enable them to be mounted without bending the actuators. The alternative is to mount them on the lever end as Modratec do.

[SimonME46]

I decided to go have another look at the Modratec Website, and have decided that their revised auxiliary switch units are better than anything I could build - for example, below is the one designed for the tortoise point motors, which I have in place. These are activated by the bottom of the levers, and just bolt in place.

 

One of the issues that I have is that there are indicator boxes for the 2 potential routes into the platforms, for 59/60 indicating platforms 1-4, and for 62/63, for platforms 3-5. I've done this already on the electrical signal box, but need to revisit this for the new box. Thus some of the switches will be triggering a DPDT relay, where one set of contacts will trigger the servo for the signal operation, and another set of contacts will provide earth for the indicator box.

 

Not sure how to set this out, but the positive supply will then be triggered by the following for each of the platforms;

1. 82N, 88R
2. 82N, 88N
3. 82R, 86N
4. 82R, 86R

     3.  84R, 86N

     4.  84R, 86R

     5.  84N

 

Thus on each of the above point levers, I will probably run a relay in parralell with the power to the tortoise point motors, that in turn switch the current for the indicator box lights.

[SimonME46]

Modratec are on leave until the end of May, so I decided to work on the signals. I have already done some work on the platform starters years ago, but didn't finish them. Turns out that was a good thing, as John Fitness methods make a lot of sense to me.

 

First off was changing the base up to 50mm x 30mm, and taking the opportunity to match the actuating rod holes to where they should actually be.

[SimonME46]

Next up was drilling out the lamps 3mm to take DCC Concepts warm white 3mm LED's. Not enough clearance on the back blinder, so I countersunk the rear of the lamp moulding with an appropriate drill. I've also drilled a hole for the LED +leads. I think I'll use more than 1,000 ohm resistor as I understand the lamps would be fairly dull in 1954-58?

[SimonME46]

Couldn't remember why I hadn't fitted ladders to th signals I gad part completed years ago. Then I pulled out the attempt and realized why-I had utterly failed to make a satisfactory job. Thankfully, RMWeb cam to the rescue per SteveAtBax excellent thread.

 

Many moons ago I used to make ladders using etched sides, or stiles, with individual wire rungs soldered in place.

No matter how careful I was, and how many jigs and aids I used, the result was always a bit disappointing.

I now use etched "ready to use" ladders, but with fine wire soldered to each stile to give strength and improved appearance.

So that will be next weeks job. I did manage to get the LEDs wired up today, with 5,000 ohm resistors. Not sure if they are a bit bright, so may drop the voltage down to 9v for the lighting.

 

Is anyone supplying the embedded controls from the DCC track bus wires or is that a bad idea?

[SimonME46]

Seeking some assistance from the resident experts.

I've attempted plates for the levers, but found precious little information on how the L&Y/BR(NE) might have described things (wording on each of the plates). I would be most grateful for some guidance! This corresponds reasonably closely to the diagram in post 1 above.

[beast66606]

Typically the description would be on the back plate - which went behind the frame on a board in the LYR case - the lever plates would only contain the pulls.

[jamie92208]

Try the NRM, They have the L & Y Signalling school railway which has it's own lever frame. I'm seeing one of the guys who help with it this morning at church so will ask him if he has any information on lever plates.

 

Jamie