Expansion gaps

I can tell you the story about how I got it wrong, if that would help? :-)

Regards, Greg.P.

Oh go on then :-D

Guy

I added a 34' x17' garage to my property - typical cheap/nasty NZ type with wooden frame and steel cladding. The idea was to have a main baseboard across one end, 1' wide baseboards down each side and a removable bridge section across the doors. (Room for 4 cars and workshop space in the middle) My first year discovery was that the internal temperature moved over a range of

+/- 10 degrees C of the outdoor temperature range +40/-5 degrees C. In that time I had built eight 4'x1' baseboards and laid a double track main line, a passing station and a short branch-line. The track, including ballasting, all got laid in spring while temperatures were moderate. When summer came those 32' feet of straight track expanded and the wooden baseboards shrank so I spent some time shortening rails to avoid some serious problems. After that I got sidetracked onto various household problems and in insulating the garage walls, so the layout got ignored for a few months. The next time I ran any trains was late autumn - the train ran very well until it got to the passing station, which was situated on the last three baseboards. "CRUNCH". Closer observation revealed a full quarter inch gap between the first turnout and the next length of rail! All my carefully gapped rail joins along the full length of the layout were hard pressed together and the total gap had all arrived at one point. Murphy's law perhaps, or the 1:100 gradient caused all the rail lengths to move down-hill?

Regards, Greg.P.

I sniped a bit . I built one in the cellar hand built soldered track. It contracted all wavy .

Story is that the Each summer the VOR had to remove a section from the bottom and add it to the top each winter

LOL!

Tee-hee!

Note to self: superglue the top bits of the incline :-)

So, did you cut gaps in the rails, or just leave spaces at the joiners? That does seem like the obvious solution, put a bit of ten thou Plastikard between the rails when laying the track, but I wonder if that is enough? My temperature variation is a bit less than yours but not much, and the layout is 12' square.

Hmmm, not as silly as it sounds!

Well, on 4 foot long baseboards you end up with: /yard length / 1 foot length / baseboard gap/...

Curves have to help - as on the prototype the track will move fractionally sideways under expansion. Just the compression of the rail fixings sideways has to equal a few millimeters.

Calculating my layout:

5 x 4 foot modules = 11 rail joints at about 10 thou = 110 thou Baseboard timber movement in opposite direction would be double the rail movement = 220 thou. 110 + 220 = 330 thou total which equates to the rail gap that derailed my train!

Of course, that 330 thou is at the median temperature so the difference between

-15degrees c and 50 degrees c could be double that distance.

I think a good case is made for screwing pc board sleepers at each baseboard end and soldering the rail ends down! In that case, all the expansion/contraction on each 4 foot baseboard is going to appear between the two lengths of flex track.

Greg.P.

"Just zis Guy, you know?" wrote

My layout is in a insulated loft room and wherever possible I lay my track in the summer, and use a 10 thou piece of sheet plastic to keep the track ends apart.

Despite quite significant changes in temperature I've never had any problem with track expansion.

John.

Spot-on, John, as always. Thanks. This is exactly my situation (the loft does get seriously hot, and I had track wandering all over the place because it was all laid butted tightly in winter - d'oh!

So, 10 thou at the joiners it is. Should give a nice "diddly-dum"[1] as well :-)

[1] Not to be confused with dum-di-dum-di-dum-di-dum...

In message , John Turner writes

It's also worth investigating the Peco sliding expansion joints (assuming they're prototypical for the layout). Although they're only supposed to be for aesthetic purposes, they actually do the job well and are used to good effect on an HO garden railway I'm involved with.

"Just zis Guy,

Or Do wha diddy, diddy dum, diddy do.

-- Cheers Roger T.

Home of the Great Eastern Railway

"Roger T." wrote

Manfred Man would have liked that! ;-)

John.

Interesting thread this. Made me think. Has anyone tried soldering long lengths together in hot weather to emulate the modern prototype tensioned track?

Ken.

"Tensioned"? I understood the theory was to weld at average temperatures and to ensure that the rails were restrained under expansion/compression. Is the system in Britain different to New Zealand?

Regards, Greg.P. NZ

Seeing as we're into expansion gaps, solder track on curves, cut expansion joints on straights. Never - NEVER - use plastic rail joiners. They are the Devil's spawn. Oh, check two other things:

1. Temperature range in the layout room, and
2. Is the layout room air conditioned? You may need to watch shrinkage in timber caused by the dehumidifier action of the A/C unit. The track stays the same length, but the baseboards shrink a little under it, giving exactly the same result as expansion of track in hot weather. I know this one... :-(

Steve Newcastle NSW Aust

Getting a little away from track expansion, but on the subject of rail joint noise (clickety-clack), has any one ever filed little nicks in the railhead at scale 60 or 45 foot lengths, to give the effect of full size rails. Nicks would only need to be made in one rail, not both. I've thought about doing this, but have been too lazy to try it out. I'm talking, of course, of the period before long welded rail came into general use. Regards, Bill.

The message from "William Pearce" contains these words:

Works OK if your stock has metal wheels. I tried the idea on an early development of my current layout - it worked but I didn't extend it to the whole layout. The length of rail I used is now in a siding where it produces an interesting sound as wagons are shunted in, providing I'm not playing something loud-ish on the CD player...

Ah, looks like I may have misunderstood. Anybody else out there know what the process is?

Ken.

A problem with that idea is the we generally remember hearing the clickety clack from beside the track or from inside a carriage. In that situation we heard ONE clickety clack, whereas with an HO model and nicks at 45 scale feet we would hear ALL the clickety clacks for the entire train at about equal volume.