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David Roberts 2230/11/2020 20:22:38
14 forum posts

Hello everybody my name is David Roberts I'm new to this forum I'm building steam locomotive 0-4-0 5 inch gauge. I've had to start over getting a workshop together so far I've purchased a small metal turning lathe, a drill press bench mounted but decent quality and a twin wheel grinder I'm getting the lathe fairly well equipped with tooling. I'm hoping to build a railway at home 5 inch gauge ground level using 16mm aluminium rail and this is where the HELP comes in could you guide me to books or literature of any kind on the subject I could do with knowing what's the widest gap I could leave between the ends of rails at fish plates for expansion without the gap causing problems with trains going over it. Any help delaying ground-level rail aluminium the construction of points curves gradients all of this would be most helpful.
Thank you very much
David Roberts

SillyOldDuffer01/12/2020 10:54:22
Moderator
6681 forum posts
1501 photos

Welcome to the forum David.

Far from expert on 5" gauge railways but I'll have a go at answering the question in hope one of the experts will correct any mistakes!

  • Ideally a railway line should have no gaps at all. Wear occurs at the rail ends because wheels drop into the gap with a thud with most of the force concentrated on the far edge. It damages the tyres and stresses the suspension too. The force increases with size of gap relative to wheel diameter, axle weight, and the speed of the train. Full-size railways today usually lay continuous track because it lasts much longer, reduces rolling stock maintenance, and doesn't annoy passengers with clickty-clack.
  • The problem with continuous rail is heat expansion. Full size railways fit tapered sliding joints and/or stretch the rail on a cold day: on hot days the man-made stretch has to be overcome before heat expansion buckles the line.
  • How much expansion occurs depends on the length of rail, and the temperature range it experiences throughout the year. What's a serious problem if the track runs a few thousand kilometres across the Australian desert is unlikely to be an issue on a short UK garden railway.
  • In the same way, a gap unacceptable to regular heavily loaded full size freight trains at 60mph, wouldn't matter on a garden railway because it's lightly loaded.

There's an online calculator here. It suggests a 100metre length of Aluminium will expand by 66mm over a 30°C range. If the line is installed on a hot day midsummer with a small gap then the gaps will grow to a maximum in winter, when the railway is unlikely to be is use. What's riskier is laying the line in winter and calculating the gap based on predicted temperatures. Global warming appears to be responsible for what should be once per century extreme weather events: of the 19 top temperatures recorded in the UK, 8 have occurred this century. Highest shade temperature recorded ever recorded in the UK was 38.7°C in July 2019, compared with the average - about 17°C. Do you design for 17°C or 38.7°C?

Garden railway, I wouldn't overthink it. Be interesting to see what a club track layer says!

Dave

Edited By SillyOldDuffer on 01/12/2020 10:56:47

David Roberts 2201/12/2020 12:07:11
14 forum posts

Hello thank you for coming back to me I have always been under the impression that I would need expansion joints with gaps This is getting very interesting and curious to see if I get more replies especially from clubs with experience of 16mm aluminium rail.
I see that some of the words in my thread has been removed could you tell me where I went wrong please so I don't repeat it.
Thank you very much
David Roberts.

Steambuff01/12/2020 12:32:21
avatar
515 forum posts
7 photos

Hi,

Take a look on the PNP Railways web site ... Look at their Video on fitting fish-plates, they recommend 3mm for their aluminium rail.

Dave

David Roberts 2201/12/2020 12:59:21
14 forum posts

Thank you very much Dave I jest view the video very interesting and makes sense to me if I can learn how to set the gaps correctly during the cold winter there will be a gap full width during the summer the track would be used more often and there should be little or no Gap.
Thank you very much
David Roberts.

SillyOldDuffer01/12/2020 13:06:29
Moderator
6681 forum posts
1501 photos
Posted by David Roberts 22 on 01/12/2020 12:07:11:

...
I see that some of the words in my thread has been removed could you tell me where I went wrong please so I don't repeat it.

I don't think your post's been moderated because that leaves an 'Edited by' footnote showing who did it.

Maybe finger trouble, specially if you're on a small format device like a phone. My laptop's touchpad mouse gets me sometimes - I accidentally select text with my sleeve and then overwrite it without noticing.

Carry on! Might never happen again.

Dave

David Roberts 2201/12/2020 15:41:41
14 forum posts

Hello thanks again for coming back to me by the looks of things I messed up my own thread which don't surprise me I'm not very good the computer bit that's missing goes like this. I'm looking forward to getting the workshop together so I can finish the locomotive but I only started it 36 years ago when it first appeared in the magazine engineering in miniature.
My head spinning with the sheer speed of it all.
Thank you very much
David Roberts.

John Slater 101/12/2020 20:17:49
2 forum posts

Hello David

I suggest you will find the details you are after in a series of articles titled "Making Tracks" by Denis Monk that were published in Model Engineer beginning in volume 161 for 1988 and concluding in 1990.

Best wishes

John

duncan webster01/12/2020 20:26:49
avatar
2946 forum posts
34 photos
Posted by SillyOldDuffer on 01/12/2020 10:54:22:

Welcome to the forum David.

Far from expert on 5" gauge railways but I'll have a go at answering the question in hope one of the experts will correct any mistakes!

  • Ideally a railway line should have no gaps at all. Wear occurs at the rail ends because wheels drop into the gap with a thud with most of the force concentrated on the far edge. It damages the tyres and stresses the suspension too. The force increases with size of gap relative to wheel diameter, axle weight, and the speed of the train. Full-size railways today usually lay continuous track because it lasts much longer, reduces rolling stock maintenance, and doesn't annoy passengers with clickty-clack.
  • The problem with continuous rail is heat expansion. Full size railways fit tapered sliding joints and/or stretch the rail on a cold day: on hot days the man-made stretch has to be overcome before heat expansion buckles the line.
  • How much expansion occurs depends on the length of rail, and the temperature range it experiences throughout the year. What's a serious problem if the track runs a few thousand kilometres across the Australian desert is unlikely to be an issue on a short UK garden railway.
  • In the same way, a gap unacceptable to regular heavily loaded full size freight trains at 60mph, wouldn't matter on a garden railway because it's lightly loaded.

There's an online calculator here. It suggests a 100metre length of Aluminium will expand by 66mm over a 30°C range. If the line is installed on a hot day midsummer with a small gap then the gaps will grow to a maximum in winter, when the railway is unlikely to be is use. What's riskier is laying the line in winter and calculating the gap based on predicted temperatures. Global warming appears to be responsible for what should be once per century extreme weather events: of the 19 top temperatures recorded in the UK, 8 have occurred this century. Highest shade temperature recorded ever recorded in the UK was 38.7°C in July 2019, compared with the average - about 17°C. Do you design for 17°C or 38.7°C?

Garden railway, I wouldn't overthink it. Be interesting to see what a club track layer says!

Dave

Edited By SillyOldDuffer on 01/12/2020 10:56:47

If the rails are in full sun they get quite a bit hotter than air temperature, we've measured 55C on a really hot windless day. If the gaps are too small the rails buckle, been there done that. If you're ever going to have track circuiting then spacers between the rail ends are a good idea, otherwise the gaps can close up over time

Edited By duncan webster on 01/12/2020 20:27:12

David Roberts 2202/12/2020 11:16:15
14 forum posts

Hello John
thank you for the information the article sounds interesting having problems finding the volumes they appear in but after a Google search I found an outlet providing the drawings for these articles the name of the company is Sarik hobbies priced at over £30 I think it's a little expensive I've ordered it I hope it's going to be informative when I receive the drawings I let you know what I think. I like to find as much information as I can on the topic so I can assess a manner of approaching it to suit me the tools I have and the time I can allocate .
Thank you very much
David Roberts

David Roberts 2202/12/2020 11:28:45
14 forum posts

Hello Duncan Webster
thank you for your feedback on this topic the temperatures you recorded a much higher than I would have expected no wonder the tracks buckle. I'm trying to find the widest gap sensible to leave at the ends of rails and set to track so winter temperatures don't pull excessively on the bolts going through the fish plates and cause problem then during the summer I can observe expansion of the track and hopefully introduce expansion joints where needed. That's my thinking at present.
Thank you very much
David Roberts

David Roberts 2204/12/2020 12:29:07
14 forum posts

Hello everybody
HELP number two
what wheel profile could you recommend for a 5 inch gauge I've been looking at GL5 I don't know what other options are available I would also like to know what's the most popular standards of wheel profile.
I would like to have this information for building trackwork.
Thank you very much
David Roberts.

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