Construction of a Test Track

Tell us about your layout, where you put it, how you built it, how you operate it.
JFS
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Re: Construction of a Test Track

Postby JFS » Fri Jun 08, 2018 2:28 pm

Hello Colin,

In terms of working out the pull lists, it is just a matter of going through the sequence needed for each signal. So to take a departure from plat.2 (diag above) you would need to pull 4,14,15,9, (4,14 back), 5.3. They need not be fixed in that exact sequence of course - but pull the Fpls, set the point, FPLs back pull signals is the pattern.

You can see there is a bit of walking back and forth but not too much given it is a small box. Going into Plat 2. it is 4,14,15,9, (4,14 back) 18. This is a bit worse, but not impossible. But you can see that if you wanted to "improve" the ergonomics, it would be a bit better if points 9 and 15 and therie FPLs were a bit closer together in the frames. But lets be honest - there are slightly more interesting things to spend modelling time on :D

Given that there are 9 signals (plus the Advanced), two of which (12 and 11) signal 2 routes, there should a total of 11 such pull lists. (if I can still count!)

Best wishes,

Colin Parks

Re: Construction of a Test Track

Postby Colin Parks » Fri Jun 08, 2018 3:26 pm

Thanks for that explanation Howard.

I shall make a pull list, but had not considered the ergonomics too deeply - except for getting my fingers around the levers themselves. There is only a span of 200 mm overall.

More dumb questions: What does '4, 14 back' mean? Does it mean that the lever is pulled reverse and then normal again? Is this something to do with the mechanical functioning of the facing point lock and the switch stretcher bar to lock switches 14 and 15 in reverse?

I now have the book 'A Pictorial Record of Southern Signals' by G Pryer, so at least I can see the types of signals required. The only tricky one is the 3-doll bracket signal 18, 19, 20. Pryer shows a 2-doll bracket signal with entry to a goods yard. It has a short ringed arm, which what I suppose signal 20 on the diagram is meant to be.

Colin

JFS
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Re: Construction of a Test Track

Postby JFS » Fri Jun 08, 2018 4:42 pm

Colin Parks wrote:More dumb questions: What does '4, 14 back' mean? Does it mean that the lever is pulled reverse and then normal again? Is this something to do with the mechanical functioning of the facing point lock and the switch stretcher bar to lock switches 14 and 15 in reverse?



Sorry Colin - too much shorthand! It just refers to the FPLs - you pull the FPL, then change the points, then "put the FPL back" to re-lock the points. On many (perhaps most) railways, the FPLs work the other way - you Pull the FPL to lock the points and put it back to change them - this is referred to as "FPLs Stand Out". It is not so convenient on a model as the blue levers stick out to be caught on shirt sleeves!

On the Southern there was a mix - along the South Coast, at Havant they stood out, at Chichester they stood in, at Barnham - in, at Ford - out ....

Very Best Wishes,

John Palmer
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Re: Construction of a Test Track

Postby John Palmer » Fri Jun 08, 2018 4:55 pm

Alan Turner wrote:
The "Rule" is that a signal shall not be returned to ON until the train has passed over any facing points to which it relates. This is because the signal will lock those points and prevent the the lock being removed and so prevent their movement.

In fact it was a contravention of this rule that enabled the Hull accident to occur.

regards

Alan


A rule the disregard of which at Paragon was condoned by Management!

junctionmad

Re: Construction of a Test Track

Postby junctionmad » Mon Jun 11, 2018 10:56 pm

a question , do many people building model railways with lever frames , actually implement Locking levers, given that in practice there is no actual lock ?

JFS
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Re: Construction of a Test Track

Postby JFS » Tue Jun 12, 2018 2:31 pm

junctionmad wrote:a question , do many people building model railways with lever frames , actually implement Locking levers, given that in practice there is no actual lock ?


Well, I would not like to generalise, but I certainly have FPLS, for my blue levers to work, and I expect Colin will also!

DS Stretcher.jpg


(and they are a pig to do on double slips!)

You don't have to mad, but...

Best wishes,
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Le Corbusier
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Re: Construction of a Test Track

Postby Le Corbusier » Tue Jun 12, 2018 2:39 pm

JFS wrote:You don't have to mad, but... ....... but absolutely stunning :thumb

Best wishes,
Tim Lee

Colin Parks

Re: Construction of a Test Track

Postby Colin Parks » Tue Jun 12, 2018 3:46 pm

Um, I do not think that I shall be installing FPLs that operate like Howards masterpieces!

Of course, if the locking is already in place, then it could always be added later. My plan is to have all the blue locking levers in place and working with the locking frame, because that provides a safeguard against wrong moves or derailments. Given that there are no signals on the test track yet, (but thinking about the matter), the red levers on the frame will not be linked to anything either for a while.

There has not been much to show for all the fiddly work that has been going on recently, all of which has been related to switch operation on the third board. The work was complicated by the fact that in a fit of madness, the drive pins on the escapement units were fitted in the wrong holes, producing an alarming amount of throw on the switches. It proved possible to remove and re-solder the drive pins in the correct holes, this being made easier because the drive pins are shouldered and sat nicely in the holes. Howard's escapment units are very robust and survived the bending and adjusting rather well, with no ill effect and are now back in working order.

If that was not enough, having been a little extravagant with the sub-board etched cranks on the first/main board, I have run a little short of single crank bases. At first, it looked as if the crossover would be easy to link with sub-board rodding and no cranks, but a miscalculation with the handing of the scale-sized cranks above meant that the switches moved reverse/normal or normal/reverse! The photos show how a 180 degree crank was inserted to reverse the movement of the crossover switch at 15b. There is still some work to do to eliminate as much friction as possible from the rodding, as return (expansion) springs have yet to be fitted to the two rods shown and I do not want to be using anything too hefty for that purpose.

This shows the escapments with the 15b switches in the 'reverse' position...
IMG_8906 (2).JPG


...and here, normal. the crank and rodding are the best solution I could think of without using yet another crank base.
IMG_8905 (2).JPG


The red mark on escapement '10' is due to having run out of scale adjustment cranks and having to use a shorter throw version, resulting in needing more rotation on escapment unit drive pin. So this unit has a drive pin in the 'longer throw' hole. (I have since found Howard had included some other adjustment cranks on the etch which could have avoided this exception.)

The crank not being equalised in its movement from mid-travel of the rod is not good engineering maybe, but the top drive rod has enough clearance to operate the escapement without binding.
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Alan Turner
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Re: Construction of a Test Track

Postby Alan Turner » Fri Jun 15, 2018 3:17 pm

As a Midland Railway follower I don't need them - Economic Facing Point Locks are your answer!

regards

Alan

Colin Parks

Re: Construction of a Test Track

Postby Colin Parks » Fri Jun 15, 2018 3:32 pm

Hello Alan,

My point locks are theoretical as far as the model goes, but they will be on the frame. Your suggestion of economical locks would have been very economical if it had been Southern practice*, because I would have only needed a fifteen-lever frame!

* I think that the LB&SCR also used some kind of economical locks (Sykes?), with some surviving on the Bluebell Railway, but this type of lock was not retained on electrified lines as far as I am aware.

Colin

Tony Wilkins
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Re: Construction of a Test Track

Postby Tony Wilkins » Fri Jun 15, 2018 3:43 pm

junctionmad wrote:a question , do many people building model railways with lever frames , actually implement Locking levers, given that in practice there is no actual lock ?

On my layout Green Street, I omitted the switches for the FPLs from the lever frame for just that reason, even though they are cosmetically modelled on the layout.
The North London Groups' layout Bodmin does include the FPLs in the lever frame and does electrically lock the point motors by virtue of disconnecting the power feed when in the locked position. This does not of course prevent one physically pulling the point lever in the frame, but nothing happens as a result.
Tony.
Inspiration from the past. Dreams for the future.

Colin Parks

Re: Construction of a Test Track

Postby Colin Parks » Fri Jun 15, 2018 7:04 pm

Re. the FPL levers: there will be a locking function on the locking frame, so reversing the point lock lever will release the relevant switch. Revrsing the switch and replacing the FL lever will lock that switch in reverse. All will be clearer once I get to grips with the frame itself.

As with Tony's Green Street, the FPLs on the track will be cosmetic.

junctionmad

Re: Construction of a Test Track

Postby junctionmad » Sat Jun 16, 2018 8:00 pm

my lever frame is electrically interlocked , i.e. moving a lever that is locked will have no effect and at the base of each lever is a red/green led, red indicates Locked , moving a locked lever will cause the red led to flash and a beeper to sound

The locking will be running on a Pi Zero , and as we are using MERG CBUS system to communicate between the levers and the points and signals , its quite easy to render a lever inoperable

at 55 levers without lock levers, I think its big enough !

Colin Parks

Re: Construction of a Test Track

Postby Colin Parks » Fri Jun 22, 2018 10:41 pm

A short video of the new trackwork being tested, with the Class 73 going rather quickly over the crossover to begin with. Due to the lack of a lever frame, the rods for the switches on this board must be held while reversed, leaving only one hand free to operate the loco.




The return springs for the rodding on this board are actually pieces of 8 mm white elastic (at least for now). I tried tension springing, but it was just too stiff - even over a length of 150mm. As can be seen the elastic is simply hooked over screw eyes to the board end and stretched onto hooks soldered to the rodding at the other end. It provides a soft but strong enough return on the rods without straining the cranks and clevis joints too much.

IMG_8911 (2).JPG


The rodding run to the far switches is a distance of about 1500 mm.
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JFS
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Re: Construction of a Test Track

Postby JFS » Sat Jun 23, 2018 9:05 am

Colin Parks wrote:A short video of the new trackwork being tested, with the Class 73 going rather quickly over the crossover to begin with. .


Looking great Colin! Everything is very smooth and reliable - very well done, and great example to anyone who says that P4 does not work - especially as it is (for those who might have forgotten) your first P4 effort. Shows the value of a bit of care and attention to detail.

I have been distracted by another hobby of late - anyone who feels lonely modelling in P4 should try this game - out of the 80-odd thousand people who once did this to earn their daily bread, I am now the only one left!



Just to say, before everyone leaps to shout that the winding is a bit tight and the counterfaller is dipping, I know, and I have since shortened the quadrant top band a couple of teeth... Funny what you notice when you see it in a video!

Very Best Wishes,

ralphrobertson
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Re: Construction of a Test Track

Postby ralphrobertson » Sat Jun 23, 2018 12:43 pm

I hope you don't expect us to put a working model of this into Alpha Mill Howard! That is some machine there, I need to get over to Masson Mill one weekend, never been there but passed a few times. Will be in the area again next month so need to make a plan!

Ralph

ralphrobertson
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Re: Construction of a Test Track

Postby ralphrobertson » Sat Jun 23, 2018 12:44 pm

Sorry Colin, forgot to mention that your track is very impressive and I apologise for hijacking your thread.

Ralph

JFS
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Re: Construction of a Test Track

Postby JFS » Sat Jun 23, 2018 1:14 pm

ralphrobertson wrote:I hope you don't expect us to put a working model of this into Alpha Mill Howard! That is some machine there, I need to get over to Masson Mill one weekend, never been there but passed a few times. Will be in the area again next month so need to make a plan!

Ralph



Well, maybe not working, but ... Be sure to let me know before making a trip as I am only there one day a week - after all, I have a layout to build as well!

Very Best Wishes,

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Allan Goodwillie
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Re: Construction of a Test Track

Postby Allan Goodwillie » Mon Jun 25, 2018 6:11 pm

Hi Colin, :)

nice running achieved! Well done! Liked the fact that when the engine sets off at a rate of nots that it just flows across the cross-over. I always test from low speeds up to max. It should also be checked at different temperatures - we have had from time to time faults that have occurred when things warm up as they have this last week.

All good Colin! :)

Colin Parks

Re: Construction of a Test Track

Postby Colin Parks » Thu Jun 28, 2018 7:39 am

Thanks for your encouraging comments Allan!

Some of the track has been constructed over a range of temperatures from the frozen period in March to the warmth of May, whilst the main pointwork was laid in cool but not freezing weather conditions. The workshop where the layout is kept never gets too hot or too cold, nevertheless, I have been waiting for signs of any warping of the boards or distortion of the rails, but so far nothing has occurred (fingers crossed).

Perhaps having a maximum rail length of 500 mm has been worth the effort. This has entailed adding more droppers (loose in their holes) and extra rail joints. I have had experience of heat expansion of rails before, so some allowance for movement has been designed into this track.

All the best,

Colin

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Le Corbusier
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Re: Construction of a Test Track

Postby Le Corbusier » Thu Jun 28, 2018 8:13 am

Allan Goodwillie wrote:Hi Colin, :)

nice running achieved! Well done! Liked the fact that when the engine sets off at a rate of nots that it just flows across the cross-over. I always test from low speeds up to max. It should also be checked at different temperatures - we have had from time to time faults that have occurred when things warm up as they have this last week.

All good Colin! :)


Interestingly I have found a couple of areas on my track where gauge narrowing has occurred over the last 2 or three weeks that were fine before :shock: I have separated the chairs from the sleeper and re bonded to gauge and all is fine. Slightly confused as to why this might have happened with the warmer weather? Any thoughts out there :thumb
Tim Lee

Colin Parks

Re: Construction of a Test Track

Postby Colin Parks » Thu Jun 28, 2018 9:46 am

Hi Tim,

Re. your gauge narrowing, perhaps the plywood has shrunk slightly. It would not take much to make a difference. Fortunately for those of us using functional plastic chairs, the remedy is quick and easy.

Colin

Colin Parks

Re: Construction of a Test Track

Postby Colin Parks » Thu Jun 28, 2018 12:19 pm

By way of a change, I have been installing magnets in the track and Dingham couplings to selected stock. The 08 is the first loco so fitted. The Dingham design of dropper has been er, dropped and a Brian Kirby type dropper has been soldered to the loop coupling. This has been fashioned just like those previously made for Bachmann tension lock couplings, form .009" guitar string. The magnets are of the permanent type and have been upcycled from an old Geomag set bought second-hand for £4.00 from the local model shop.

My blackening skills are not the best, but once the dropper has been painted, the coupling will be quite unobstrusive.
IMG_8919 (2).JPG

Here, the coupling dropper has been activated by passing over the first of three magnets set between the sleepers. (Three magnets gives a decent magnetic field.) The dropper wire is approx. 1mm above sleeper level when activated. I am still thinking of a better way of attaching the wire to the shortened drop arm of the loop coupling, but a soldered joint as shown is the easiest I can think of for now.
IMG_8915 (2).JPG

The same viewed from above. The magnets are in the three bays in front of the dropper end.
IMG_8917 (2).JPG

Coupled to a wagon (will sort out the droopy buffer) with the latch coupling, the distance between buffers is acceptably close and closer than the Instanter couplings between wagons. I have pushed the design tolerances a little by setting the coupling hook 0.5 mm behind the buffer faces. Any further back and the loop would catch on the adjacent hook tip. There will be wagons with a coupling of each type per cut of wagons. By introducing Dingham-coupled wagons within a train, shunting can be achieved quite convincingly. Brake vans will have a coupling at each end and so will the locomotives. This does mean that stock will have to run in one direction, but look - no hands!
IMG_8918 (2).JPG

The final refinement is the addition of a .016" guitar string 'brake' wire to one axle on wagons and brake vans fitted with a Dingham coupling of either type. Fitting to a Grampus wagon with the underslung baskets is about as challenging as it gets, i.e. not very hard!
IMG_8920 (2).JPG

The brake wire creates enough drag for the wagon to stay in place when coupling up and also has the added benefit that wagons do not surge or bunch up when running in a train, with the brake van or other wagon at the rear keeping all couplings inthe train under light tension when pulled.
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Le Corbusier
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Re: Construction of a Test Track

Postby Le Corbusier » Sun Jul 01, 2018 8:08 am

Colin Parks wrote:Hi Tim,

Re. your gauge narrowing, perhaps the plywood has shrunk slightly. It would not take much to make a difference. Fortunately for those of us using functional plastic chairs, the remedy is quick and easy.

Colin

This does beg a question which I don't have either the experience or length of time within the hobby to answer. I had assumed that the cross lamination of ply sleepers meant they would be dimensionally stable. If as you hypothesise the plywood has shrunk .... then by logic it will increase when humidity levels rise again? Does this mean there will be a constant process of gauge narrowing and widening (presumably exacerbated if a display layout by changes of venue) dependent upon time of year and weather conditions? :? If that is indeed the case, does the layout in the end find a happy medium where narrowing and widening eventually sit within tolerance (hopefully) or will this be a never ending process (the argument for plastic sleepers?). :shock: I assume that this is not the case as evidenced by the many successful layouts on the circuit :) ... but could explain poor running on new layouts at there first few show appearances. :?:

Or alternatively ... is the plywood actually stable as I assumed and there is perhaps another reason for the gauge narrowing experienced ? :?
Tim Lee

JFS
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Re: Construction of a Test Track

Postby JFS » Sun Jul 01, 2018 9:02 am

Le Corbusier wrote:
Or alternatively ... is the plywood actually stable as I assumed and there is perhaps another reason for the gauge narrowing experienced ? :?


In my experience, ply is anything but stable - I have several propeller shaped bits of furniture-grade birch ply to prove it. To build a successful structure (i.e. a baseboard) from it requires careful use of bracing. But that said, I would be astounded if shrinkage of the ply were detectable over the 19 mm or so of track gauge.

I think most gauge narrowing with plastic chairs is due to the use of track gauges which grip the rail too tightly and hold it vertically. The chairs are then stuck down and, when the gauge is removed, the rails revert to the 1:20 inclination of the chairs - thus the gauge faces move inwards - ie under-gauge - and by about 0.5mm which is a lot!

There are quite a few types of gauges which cause this problem and I would go so far as to say that "most" layouts built with plastic chairs suffer from the problem UNLESS the builder used Exactoscale gauges - which by design, do not grip the rail at all. Since these gauges were designed by Len Newman, and it was he who first introduced plastic chairs, this is hardly surprising. The C&L gauges have springs which enable this grip-strength to be adjusted to a minimum, but the washers which define the gauge can then "stick". The absolute no-no is the triangular gauge which is non adjustable, and the slots are milled vertically - if you use one of these you will inevitably have problems.

Best Wishes,


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