Search found 195 matches

by andrew jukes
Mon May 18, 2009 8:30 am
Forum: Track and Turnouts
Topic: Tortoise Auxiliary Switches
Replies: 28
Views: 11836

Re: Tortoise Auxiliary Switches

I was talking to the chap on the ZTC stand at Wells some time ago and he said that if you are using the internal switching on the Tortoise the higher current used on DCC would over time cause the contacts on the PCB board to 'smear' (his word) and you would loose the switching capability. He theref...
by andrew jukes
Sun May 17, 2009 10:33 pm
Forum: Track and Turnouts
Topic: Tortoise Auxiliary Switches
Replies: 28
Views: 11836

Re: Tortoise Auxiliary Switches

It's interesting how the type of layout influences the trade-offs made. I'm obsessed with how long it takes to install each of a large number of turnouts and finding things that minimise the time taken and the risk of having to go back and rework anything. From that point of view, PCB headers and 8-...
by andrew jukes
Sun May 17, 2009 2:33 pm
Forum: Track and Turnouts
Topic: Tortoise Auxiliary Switches
Replies: 28
Views: 11836

Re: Tortoise Auxiliary Switches

I've been looking at the detail of the design more closely and have come to what might seem a rather extreme conclusion. If you look at the marks made by the wipers on the pcb tracks, it is clear that for three of the four wiper pairs, one of the pair is running right on the edge of the track. If pr...
by andrew jukes
Fri May 15, 2009 10:31 pm
Forum: Track and Turnouts
Topic: Tortoise Auxiliary Switches
Replies: 28
Views: 11836

Re: Tortoise Auxiliary Switches

Thanks for the comments. Trawling back through the email lists, the suggestion of problems was principally from Martin Wynne and it did relate to damage under fault conditions. In the absence of any other bad experience, it sounds like I should just keep on installing Tortoises straight from the box...
by andrew jukes
Fri May 15, 2009 9:34 pm
Forum: Track and Turnouts
Topic: Tortoise Auxiliary Switches
Replies: 28
Views: 11836

Re: Tortoise Auxiliary Switches

What is all this worry about a couple of ohms, or are you using DC control, where it just might make a slight difference? Tim From the mutterings I have heard, the alleged failures were under fault conditions. If there is next to no resistance anywhere else in the circuit, 1 ohm could be enough to ...
by andrew jukes
Fri May 15, 2009 5:10 pm
Forum: Track and Turnouts
Topic: Tortoise Auxiliary Switches
Replies: 28
Views: 11836

Tortoise Auxiliary Switches

From time to time I've heard comments about the weakness/poor design of the Tortoise auxiliary switches but have pressed on regardless believing they couldn't be that bad as the Tortoise has become such a standard piece of equipment in the US. My plan has been to use them to switch crossing polarity...
by andrew jukes
Wed Apr 22, 2009 10:10 pm
Forum: Materials and Techniques
Topic: Ballasting track - Johnsons Klear
Replies: 15
Views: 6944

Re: Ballasting track - Johnsons Klear

Tony Just wonder how hard the resultant ballast layer is? I am laying plastic sleepered track on cork, glued with Evostick flooring adhesive, and (experimentally) ballasted one stretch using granite ballast and the traditional dilute PVA with a dropper method. The change for the worse in the sound p...
by andrew jukes
Wed Apr 01, 2009 6:56 pm
Forum: Semaphore Signals
Topic: Transition from semaphore to MAS (and vv)
Replies: 12
Views: 8077

Re: Transition from semaphore to MAS (and vv)

I should have been more curious about the blank pdf. I just assumed it was an alternative way of sending appendix D. (but why would you do that?!). The text seems to answer all the questions, so thanks for the laboriously made pdf. It seems I was partly right on the colour light to semaphore transit...
by andrew jukes
Wed Apr 01, 2009 9:58 am
Forum: Semaphore Signals
Topic: Transition from semaphore to MAS (and vv)
Replies: 12
Views: 8077

Re: Transition from semaphore to MAS (and vv)

Thanks, Keith - that's perfect. In terms of a model representation, it seems to me the three methods are logically identical and not that different from normal co-located starter and distant signals. The important point is that the indications at each of the transition signal positions are controlle...
by andrew jukes
Mon Mar 30, 2009 9:31 am
Forum: Semaphore Signals
Topic: Transition from semaphore to MAS (and vv)
Replies: 12
Views: 8077

Re: Transition from semaphore to MAS (and vv)

Thanks, Keith - very interesting. The splitting 4-aspect colour lights on the down fast at Coventry were a surprise. In terms of my question, the Leamington line looks to offer most. At Gibbet Hill, it looks like lever 30 works as an up distant and lever 4 (if I could be sure of the symbols!) is the...
by andrew jukes
Sun Mar 29, 2009 9:41 pm
Forum: Semaphore Signals
Topic: Distant Signal Locking
Replies: 17
Views: 11370

Re: Distant Signal Locking

My computer based equivalent of this, with full track-circuiting, will be for any stop signal to be able to be placed in a special condition in which, once passed by a train, it remains clear but restricts the use of the stop signal in rear. The fundamental reason this is needed on a model is that, ...
by andrew jukes
Sun Mar 29, 2009 6:55 pm
Forum: Semaphore Signals
Topic: Transition from semaphore to MAS (and vv)
Replies: 12
Views: 8077

Transition from semaphore to MAS (and vv)

The context for this is the same as my question on distant signal locking - wanting to simulate the operation of signalling using a computer based interlocking, controlled with an IECC style computer screen. I need to know what the options are at the boundary between a traditionally signalled block ...
by andrew jukes
Fri Mar 27, 2009 6:13 pm
Forum: Track and Turnouts
Topic: P4 Track Co Standard and Gauge Widened Bases
Replies: 17
Views: 6753

Re: P4 Track Co Standard and Gauge Widened Bases

I know it's narrow gauge but I don't think that will have any affect on it but when I was working on the Welsh Highland I am fairly certain the tight curves had cant and gauge widening applied to them. My point was that you've got to think of them separately, not that you can't have both. If you wa...
by andrew jukes
Thu Mar 26, 2009 12:21 pm
Forum: Track and Turnouts
Topic: P4 Track Co Standard and Gauge Widened Bases
Replies: 17
Views: 6753

Re: P4 Track Co Standard and Gauge Widened Bases

I think cant and gauge widening should be thought of in quite separate compartments. Gauge widening is all about coping with the mismatch between vehicles, parts of which are really designed for straight track, and the sharp curves they are often asked to run round. Wheelsets with large diameter whe...
by andrew jukes
Wed Mar 25, 2009 7:34 pm
Forum: Semaphore Signals
Topic: Distant Signal Locking
Replies: 17
Views: 11370

Re: Distant Signal Locking

Thanks Keith. All clear now (and comprehensively backlocked!)

Regards
Andrew
by andrew jukes
Wed Mar 25, 2009 11:46 am
Forum: Semaphore Signals
Topic: Distant Signal Locking
Replies: 17
Views: 11370

Re: Distant Signal Locking

Turning to 'my neck of the woods', it seems there must have been plenty of locking of the up stop signals by distants. Post-1931, Welwyn had an up outer distant (at Woolmer Green), splitting distants for Digswell jct. between the tunnels, more splitting distants with the Welwyn up home at the north ...
by andrew jukes
Tue Mar 24, 2009 9:55 pm
Forum: Semaphore Signals
Topic: Distant Signal Locking
Replies: 17
Views: 11370

Re: Distant Signal Locking

Thanks, Keith. It wasn't the requirement that the distant must not be clear unless all the stop signals are clear that was in doubt, only what happens when you want to reset any stop signal. I was uncomfortable with stop signals being locked 'clear'. The rationale you give would still be covered if ...
by andrew jukes
Tue Mar 24, 2009 8:21 pm
Forum: Semaphore Signals
Topic: Distant Signal Locking
Replies: 17
Views: 11370

Distant Signal Locking

I am trying to sort out how distant signals are meant to work so as to be able to simulate the operation of a semaphore signalled block within a computer based interlocking, controlled on an IECC style computer screen - an odd mixture you may think but it happens to be what I want! Some things are c...
by andrew jukes
Tue Mar 17, 2009 12:33 pm
Forum: Track and Turnouts
Topic: P4 Track Co Standard and Gauge Widened Bases
Replies: 17
Views: 6753

Re: P4 Track Co Standard and Gauge Widened Bases

I promised to come back with some measurements from my layout - sorry for the delay. The FastTrack gauge widened track I've laid is all at least +0.2mm. In a few places, it is very close to +0.2mm but generally there is some play with a +0.2mm gauge but a +0.3mm gauge is definitely tight. So I recko...
by andrew jukes
Thu Mar 05, 2009 10:20 pm
Forum: Track and Turnouts
Topic: P4 Track Co Standard and Gauge Widened Bases
Replies: 17
Views: 6753

Re: P4 Track Co Standard and Gauge Widened Bases

This thread got me to register at last! FastTrack was designed before my involvement with Exactoscale, but I have used lots of it for 'behind the scenes' track. No running experience yet so my approach, though thought through, has yet to be proved successful. I am intending to run large six- and eig...

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