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Maximum Train Length (need to set this for automated layout)

Posted: Fri Apr 03, 2015 9:04 pm
by stevenfitch
Hi

Im in the process of designing an automated outdoor G Scale layout, i have already done this indoors with N Gauge.

I need to set a maximum train length which then determines my minimum block length for automation. (as when a train is 'in' a block the automation controller assumes it is fully inside it and not overhanging)

My current plan is giving me Blocks of 3.2m long so the maximum train length would be approx 2.8m long.

Roughly checking this would be allow me to run a Piko BR218 with 6 of their container / flat car wagons in tow.

Anyone got any thoughts or had to consider maximum length themselves, perhaps for storage, length of passing loop or similar?

Posted: Sat Apr 04, 2015 7:06 am
by bazzer42
I'm afraid it's all manual operation on the Vale of Fairway but a key consideration will be whether a 2.8m train held in a loop will allow another set of bogie wagons to pass when the bogie overhang of a reverse curve as it is driving through. If you follow that. If you are using tight radius curves the greater the overhang. At the tightest lgb R1 points are 2ft radius and I don't imagine N gauge points are that sharp!

The min/max length depends on the space you have. If you are planning on six bogies it should look good visibly and I'm jealous as six 4 wheelers is nearly a max here!
Good luck.

Posted: Sat Apr 04, 2015 7:24 am
by Big Jim
Thinking back to my days of building layouts in the smaller scales. What ever length of passing loop you build it is never long enough!
They will often need to be a fair bit longer than you think.
As Bazzer42 has said, watch the overhang with sharp curves. With large scale stuff it can be considerable.

Posted: Sat Apr 04, 2015 7:42 am
by philipy
To be honest I'm not 100% sure I know what you are asking. It seems to me that either you decide on the maximum length of train you want to run and design your loops to accommodate that, or else you build the loops first and then fit whatever you can get inside them.
Either way, it is the maximum length of the train that you can fit in a loop that decides the minimum length of the block on the running lines, I would have thought. Those factors are all down to your choice and nobody else can really advise you.

However my immediate thought when I read what you are proposing to do, was concerning the long term integrity of the wiring and detection systems when subjected to constant British weather. As I know from personal experience ( and I'm sure many others will agree), thermal expansion and contraction can play havoc with soldered joints, water WILL get in everywhere and potentially cause shorts and corrosion, not to mention spiders, earwigs, ants, etc, that will also get into places you wouldn't think possible.

Not trying to put you off doing it, but just be aware of all the possible pitfalls before you spend lots of hard earned cash. I made the transition from N gauge -> 4mm-> 16mm Garden and it is a very different ball game out of doors.

Posted: Sat Apr 04, 2015 8:26 am
by bazzer42
PS as Philip said it is a journey and I have given up with lgb etc outside as track cleaning became a chore. Radio control could be fitted to g scale diesels but it depends what you enjoy most in the hobby. I got to live steam and rc diesels 2 years ago but wish I had got there sooner.

Posted: Sat Apr 04, 2015 9:23 am
by Dr. Bond of the DVLR
The DVLR has to have short run round loops at each end because we don't have the space for long ones. As a consequence a maximum train length of 8 axles is usually the maximum, however as bogie vehicles have a higher axle density 10 axle trains have been known... so 4 vehicles is really the longest we can accommodate.

Posted: Sat Apr 04, 2015 9:30 am
by ge_rik
I concur with what's been said already. A lot depends on what type of railway you're intending to run. In G gauge, it could be a representation of a busy standard gauge mainline, or it could be a quiet narrow gauge light railway. If the former, then the length of trains will largely be dependent on the size of your garden and the size of your wallet. If the latter, then you can specify they maximum length of trains - eg on the Welshpool and Llanfair, they had only three bogie coaches and limited the length of goods trains to ten wagons (inc guards van).

On my own railway, passing loops can accommodate goods trains of eight or nine wagons (dependent on the wagon). However, sometimes I have to run longer trains dependent on how many wagons the pickup goods has picked up and are still waiting to be dropped off. So the train has to be split at some passing loops, which makes operation a bit more interesting.

Rik

Posted: Sat Apr 04, 2015 10:07 am
by stevenfitch
Thanks for the comments, the current plan is as below, im using Piko Radius 3 as my tightest and Piko Radium 5 points. That gives me a 1,240mm / 4ft radius.

As for wiring i am planning on housing all of the electronics in the garage in a cabinet with an anti condensation / frost heater installed and running all wires back to there, no soldering and splitting outdoors. The only solder joints will be to the track sections themselves.

The cable i am leaning towards is 7 core tow bar / trailer board cable as 3 wires are required for each section and i can then run the DCC bus for non detected sections and a 12VDC bus around too - It works fine using multicore alarm cable for N Gauge but some experimenting is to be done as too how much interference the cables within a multicore cause each other.

The stock will most likely end up as a mix of everything, probably staying away from full length mainline type coaches as i wont be able to fit enough in to make a realistic length train.

Image

Posted: Sat Apr 04, 2015 10:12 am
by andymctractor
There are less implications for loops that are too long than for loops that are too short. Make a good guestimate then add some generous leeway. :shock:

Also, Kevin Strong of 'Garden Railways' mag fame has written a series of articles on DCC and automation of garden railways starting in August 2013 edition. As I do live steam and onboard battery power for my locos I didn'take too much notice of them but clearly if it can be done in the US then perhaps it can be done elswhere.

Good luck
Andy

Posted: Sat Apr 04, 2015 10:46 am
by stevenfitch
philipy:109761 wrote: Not trying to put you off doing it, but just be aware of all the possible pitfalls before you spend lots of hard earned cash. I made the transition from N gauge -> 4mm-> 16mm Garden and it is a very different ball game out of doors.
The plan was to start construction about this time next year but I think i may put down a loop with a passing siding shortly in one area to test out various ideas and the automation. See what lasts to next year and what doesn't.

Posted: Sat Apr 04, 2015 11:01 am
by philipy
Steven,
That sounds a very good idea. I nearly suggested that in my earlier post, but didn't want to sound as though I was telling you what to do!

Posted: Sat Apr 04, 2015 3:40 pm
by stevenfitch
philipy:109770 wrote:Steven,
That sounds a very good idea. I nearly suggested that in my earlier post, but didn't want to sound as though I was telling you what to do!
Feel free to tell away!

Posted: Sat Apr 04, 2015 4:12 pm
by pippindoo
Just be aware of return loops on track powered lines, wiring can become complex!

Posted: Sat Apr 04, 2015 8:18 pm
by Soar Valley Light
Hi Guys,

I think you've given Steven some very good answers to a rather odd and very open ended question, particularly Phillipy.

Surely track section lengths and loop lengths are as fundamental a part of railway planning as are the type of motive power and the colour of the axle box covers (if you see what I mean). It's integral to how the railway will operate, if you haven't got that sorted then maybe that's the next problem to solve, rather than this. No matter how 'right' you get the length of your sections, operation will still be unsatisfactory if you haven't considered and decided on what you want your railway to do and what you want to do with it.

I hope you get it nailed and look forward to further reports as your line grows. The track plan looks very professional and impressive!

Posted: Sun Apr 05, 2015 1:26 am
by stevenfitch
stevenfitch:109769 wrote:
philipy:109761 wrote: Not trying to put you off doing it, but just be aware of all the possible pitfalls before you spend lots of hard earned cash. I made the transition from N gauge -> 4mm-> 16mm Garden and it is a very different ball game out of doors.
The plan was to start construction about this time next year but I think i may put down a loop with a passing siding shortly in one area to test out various ideas and the automation. See what lasts to next year and what doesn't.
Smaller plan has been decided on. I will first construct the section highlighted in pink below and run it as a shuttle back and forth to itself. That way if it does work to a satisfactory standard then at least i've already built some of the bigger plan.

Image

Posted: Sun Apr 05, 2015 1:30 am
by stevenfitch
pippindoo:109776 wrote:Just be aware of return loops on track powered lines, wiring can become complex!
Had a few of those to deal with on my automated N Gauge and after trying a few different reversing units i ended up going with the solid state variety.
In particular the OGAR On Guard Auto Reverser which can handle up to 4 Amps, should be plenty as only one loco in that section at a time - http://www.digitrains.co.uk/ecommerce/s ... erser.aspx