Train Mountain Track Building update

[Glenn Brooks]

Jeff Mills, President of Train Mountain RR penned the following update describing TM’s current track laying activities, including why they decided to install steel rail. Jeff asked if I would post the article here on Chaski. And here it is:


Why Train Mountain Uses Steel Rail
By Jeff Mills
Recently I saw a post on social media with a question of why Train Mountain Railroad converted from aluminum rail to steel. To answer this question, let’s review our history.

The rail profile that Train Mountain uses is from the rail originally supplied by Railroad Supply. This profile has become known in the hobby as West Coast Rail. The original track installed at Train Mountain from 1987 to 1999 was aluminum West Coast Rail on Port Orford Cedar ties at 2”x3”x16” with 2” tie spacing. This track system could handle a 400 pound axle load and had an expected life of 10 years.

After 12 years of use, this aluminum rail was showing wear and a decision needed to be made whether to continue to use aluminum or make an upgrade. Based upon the kind of traffic and weather conditions Train Mountain experiences, an upgrade was required. In 1999, Train Mountain received its first shipment of steel rail. The rail was purchased from Switzerland and made in the West Coast Rail profile to be compatible with the aluminum rail in place. For over 15 years, the track panels have been constructed with recycled plastic ties instead of wood.

Steel rail has many characteristics that make it superior to aluminum. However, steel rail requires more tooling and more steps in panel construction. Steel rail is also more expensive per foot. The most favorable characteristic of steel rail is its bridging strength. This is important in freezing weather where frost heaving is a problem. Aluminum rail tends to hump from frost heaving and requires trimming in the spring. Steel rail must be pre-radiused before the track panel is constructed, one of the additional steps and tooling mentioned earlier. Pre-radiused steel rail holds it curvature better than aluminum rail which is radiused as it is laid. This is also why aluminum rail tends to kink at the joints. Another problem with aluminum rail is the outside rail of a curve tends to get a larger radius with use from the centrifugal force exerted on it. This causes gaps at the joints that can grow to one inch or more. In extreme cases, it has been necessary to stake the ties to prevent this movement. Of course, one attribute of steel rail is its resistance to wear. Aluminum rail has more thermal expansion and contraction than steel rail. Train Mountain can see a daily temperature swing of 50f degrees in a day and sees close to 80f degree seasonal temperature change. Steel panels are heavier at 100 pounds per panel as compared to the Aluminum panel at 86 pounds per panel. This additional weight helps to keep the ties in the ballast during freezing weather. Overall steel rail is less flexible which reduces the need for track trimming.

Train Mountain has found a 12” offset of the rails on each panel works the best as this offset reduces panel damage when handling the panels over a longer offset. Train Mountain use Spall rail joiners at all joints with the exception of insulated joints where a special rail joint has been developed by the signal crew. The Spall rail joiner is quick to install and does not need the drilling and installation of screws and nuts that the fishplate type of rail joiners require. This rail joiner greatly speeds up track installation.

Train Mountain has the Big Build Meet each September where we usually plan on laying a thousand feet of track a day. There is considerable prior planning, staging and ground preparation to accomplish this goal. Train Mountain is currently replacing our aluminum rail on wood ties with steel on recycled plastic. The track with wooden ties is up to 32 years old. The UV light has deteriorated the wood to the point that the wood will not hold the track screws. There is approximately 6 miles, or 30,000 feet, of Main track to be replaced. Sidings and yards will be eventually replaced with aluminum on plastic. We will not be adding new track until the Main Track replacement project is completed.

If you are interested in more about Train Mountain’s track or other general information, please visit our website at trainmtn.org. Go to the left tab to find Popular Documents and then select the Train Mountain Encyclopedia. Much of the information in this article came from that document.

If you have additional questions or wish to volunteer to work on track, please contact me via e-mail at jhmills51@hotmail.com, Subject ” Track Question “. I will answer any questions or refer them to a person who can provide that answer.

[ccvstmr]

It's amazing what a telephoto perspective will do to when photographing track work. Certainly hope that's not TM's "best" track in that photo. Think I've seen old-time washboards that had less ripples! Carl B.

[Mr Ron]

I understand there is a delicate relationship on full size railroads between the hardness of the rail and the hardness of the train wheels. Steel rail could mean more wear on train wheels. Have you thought about this as a possibility?

[Steggy]

Steel rail could mean more wear on train wheels. Have you thought about this as a possibility?

I hear this at regular intervals and would like to see this myth put to rest.

Aluminum oxide is highly abrasive and in fact, is one of the most commonly-used industrial abrasives. Anyone who makes the first run of the day around a railroad built of aluminum rail is using their wheels to "scrub" aluminum oxide from the railheads. As the aluminum oxide is tightly bound to the railhead, the wheels are being abraded, especially in curves.

In contrast, iron oxide is relatively soft and easily flakes from steel rails. Its effect on the wheel tread and flange is considerably less severe than the effect of aluminum oxide.

[Glenn Brooks]

Hi Carl,

I think what Jeff was portraying in the photo is that the old Aluminium track panels at TM eventually end up looking like the photo. The heaving are essentially frost heaves caused by repeated cycles of frozen water in the ballast creating small verticle icecycles that push the ties and track up out of the roadbed. There is also some significant expansion and contraction of the rail due to daily temperature changes. Although iam not sure if this creates much vertical movement.

Iam also just now wondering if the numerous train trips they experience on some sections of the RR also don’t contribute to the heaving - sort of like washboard dirt road condition caused by a lot of truck traffic. I’ll have to ask about whether TM has investigated the dynamics of wave motion on their road bed.

The newly relaid track is silky smooth these days, even on some sections that are now 2 or 3 years old.

Glenn

[Pontiacguy1]

When you are the one who actually has to work on the track and physically repair or replace damaged or worn rails, rotten ties,etc... you tend to figure out the best materials that give you the longest life and longest service intervals. This is especially true on large club tracks with lots of heavy traffic. It takes a lot of money and manpower to keep a large railroad in operating condition. I've also noticed that the ones that complain about your track the most are almost never the people showing up to actually do something about it!

As it is, I am sure that an awful lot of thought and research has gone into the choice of materials and track laying techniques used at train mountain. A lot of clubs around the country also use very similar materials and methods to what TM does, which says to me that they must work pretty good in a lot of places.

[rkcarguy]

Aluminum has a much larger expansion rate, and I wouldn't doubt that the lumpiness shown is due to the track getting "tight" and having no where to go except up. When figuring expansion rates, heat in direct sunlight has to be considered, not just ambient temperature. Here in the northwest it's very rare to see triple digit temps, yet metal surfaces in direct sunlight on a hot day with no wind could easily...slowly, fry an egg. Even with my steel rails, I'm calculating that I need 1/4" gaps @ 10' intervals to allow room for thermal expansion from 0*-180*.....if I calculated that right.

[Berkman]

Do you use ties that have the molded in tie plates? I'd assume this would keep the gauge in check better.

Also anyone experiment with using longer sections of rail, say 20-40ft sections instead of ten foot?

Is that common thought that the steel rail doesn't wear rolling stock wheels anymore than aluminum ?

[rkcarguy]

https://www.engineeringtoolbox.com/line ... _1379.html

This site has a good calculator on it.
If I run 10' sections of *steel* from 0*-180*F I get a growth of .259". So that's an increase of 1/8" per end, or 1/4" per joint. In aluminum this doubles to .497", so about 1/2" gap per joint @ 0*F. That's huge, like having a 4" gap in full scale, and a big minus for aluminum. I bet many are gapping their tracks too tight.

[Steggy]

Also anyone experiment with using longer sections of rail, say 20-40ft sections instead of ten foot?

At the ILS, we have some sections that are 20 feet.

[Steggy]

Jeff Mills, President of Train Mountain RR penned the following update describing TM’s current track laying activities...Train Mountain use Spall rail joiners at all joints with the exception of insulated joints where a special rail joint has been developed by the signal crew.

Are details about the insulated rail joint available?

[ccvstmr]

RK...that's right. Thermal expansion/contraction is easy enough to calculate...IF...you know the coefficient of expansion for the material. YES...the expansion for aluminum is nominally 2x that of steel. However, think your temperature differential is exaggerated. For the upper Midwest area, a nominal 100 deg F. delta T change is used. Don't know of any place on earth where the actual temperature is going to reach 180 deg F. Expansion coefficient for aluminum is... 0.0000126" per inch of material per degree. For aluminum rail this yields 0.151" (approx. 5/32") expansion for a 10 foot rail section. Steel rail...about half that amount. Using slip-fit rail joiners like the Spall...this may not be a problem. To the rest of the rail joiner hobby world, this means the rail end slots for rail joiner screws must be long enough so the screw doesn't shear from the expansion and contraction (don't forget to include the diameter of the screw when determining rail slot length).

Berkman...YES, longer rail sections have been used. Local club purchased 20 foot sticks of extruded rail years ago. This was done to reduce the number of rail joiners used/needed. The idea worked great. However, rail ends were punched with slots for 10 foot rails (5/16" x 3/16" slot). In hindsight, the slot should have been at least 7/16" long. The club also incorporated welded steel rail on track curves. Great idea to reduce rail wear compared to alum rail, but an extremely BAD idea when welded rail lengths reach 140 or 160 feet in length...WITHOUT adequate rail expansion/contraction provisions. If 20 foot aluminum rails are the norm for the railroad, then steel rail should be no longer than 40 feet. Obviously, someone forgot about expansion or didn't do the math properly.

Glenn...don't think I've ever seen track heave vertically as shown in the photo. Tracks usually end up expanding side to side when the gap between rail ends closes up from expansion. Washboard type track as depicted in the photo might be attributed to a poorly prepared subgrade (don't see tie ends exposed to suggested track heaving vertically). Found that after the right of way is prepared, a layer of ballast or coarse-r ballast material should be spread and compacted. That sub ballast can be contoured for slight super elevation in curves. Track was set on top of the compacted sub ballast. Ties are adequately supported then...IF...the ties are all the same height. Can even run trains at that time. Then ballast. Spot tamping may needed at that point. And NEVER...tamp ballast under the ties between the rails. Tamp ballast under the tie ends.

Pontiacguy...you're right. You don't learn the "best" way to build/install track overnight. What works in one part of the country might not work as well somewhere else. Different earth materials...different ballasts...different track designs. Let's not forget that Mother Nature can be a real byotch to work with as well. People generally do NOT want to spend much time on their hands 'n knees doing track work. It's a matter of working smarter...not harder. It's easier to do track work on a table than on the ground. Not all ground work can be eliminated (rail joints still need to be made up and maybe a tie inserted under the rail joints). Will add, if track people take the time and energy to prepare and build the railroad the best way possible from the start...very little time is needed thereafter to maintain the track. Allows you to spend more time riding on the track.

Experience can be a wicked teacher! Or as an old joke goes...Q: How did you get so much experience? A: Made a lot of mistakes. Q: Why did you make a lot of mistakes? A: That's how you get the experience! Carl B.