Rock and Roll

[STRR]

I did not want to hijack another thread so here is a question.

Big Dave, you said you like to offset the rail joints no less than 18". Many like to be exactly 50%, i.e. on a 10' piece of rail, the joint on the opposite rail is a 5' down the line.

Question: Do you experience much rock and roll in your train and/or riding cars? With the joint 50% offset, at the proper speed, any slight dip in the joint will get the cars rocking from side to side as they cross alternating joints. On the other hand, with 0% offset, any dip in the joint will get the cars bucking forward and backward at each joint. Longer rail sections, and/or different speed will lessen the effect. The big boys use the 50% offset method but you can sure see the cars rocking as well.

Please post your views on this. I can see both sides of the story and would like to hear what others have done or plan to do when laying track. I understand the need for proper joint/splice bars and good ties at the joints, but the joint will always be the weakest part of the track.

Thanks in Advance,
Terry Miller

[Fender]

Another factor to be considered is the length of the cars. In prototype practice, if the rail length is about the same as the distance between truck centers, and the joints are staggered, then a harmonic oscillation can get established. As a car sways to the left when hitting a low joint, it then sways to the right about the same time as it hits a low joint on the right. If the car length is not the same as the rail lengths, then this oscillation is not as strong.
I guess this can be either good or bad from a model perspective, depending on whether or not you want to re-create this aspect of full-size railroads!

[ccvstmr]

Terry,

You're welcome to use a 50% offset between the two rails if you want. HOWEVER...as the track runs thru curves, you will get what's called "rail creep" (not to be confused with some of the persons installing the track). The inside curve rail will appear to grow in relation to the outside curve rail. Depending on the curve length, the rail joints can catch up with one another.

When rail joints are directly opposite one another, the rail will tend to "kink" at the joint in curved track. This most definitely will cause wheelsets to derail. Having a "solid" rail opposite another track joint helps "support" the jointed rail...if you can follow that line of reasoning.

A typical rail offset (as Dave noted) is in the 16-18" distance. This is already longer than the wheelbase on most trucks. With a well constructed subgrade, sagging or pumping joints normally don't occur. With our lighter cars (compared to real railroads)...rock and roll at joints is mostly eliminated.

Most persons building track will build track panels with parallel ends...and then shift one rail in the field to allow for rail end stagger. The track panels can be built with one rail fastened tight...and the other loose so one set of screws can be removed to slip the rail...and then re-inserted after the rail ends are joined.

Some clubs/people use "slip-fit rail joiners" which usually means parallel rail joints. I don't agree with that approach...but if it works for them...they're welcome to continue that practice. Track kinds are unavoidable in that case.

My recommendation...if you're building track, start with a 16-18" rail end stagger. If you're using 10 foot rail sections...cut a rail section in half (as needed) and slip that in the track when you find the stagger less than 16-18". This eliminates rail end cut-offs if maintaining parallel rail ends and minimizes rail waste.

Make sense? Hope this helps. Carl B.

[steamin10]

ya, Carl is on it here, the roller coaster humps should be maintained out during the season, so that is not a hairy problem. What is a problem is track that must move with temperature in the summer, and the track will surely get kinky where the joints are close across from one another. The rails wont expand smoothly, and you get a definite angle rather than a smooth curve. that is the basis of my statement for the offset. Running at 50% offset doesnt hurt, and ignoring the perfect spacing keeps you from trimming rails all the time around sweeping curves.

One of those Hoe handled ice chipper/scrapers is really good for tamping the ballast under the ties. Sometimes a lift by hand and a few tamps will raise the track a bit, and put the stone under the ties. It is better to underdo it, than too much though, for obvious reasons. Always use a pocket level across the rails, the eyes can fool you easily. you dont want a bunch of twists, or rockin like the Toonville trolley..

[STRR]

Carl and Big Dave,

Thank you for your replies. You are the first to adequately explain the reasoning behind the offset joints. I knew there must be a good reason or the real railroads would not have used that method.

As for the 18" offset, I think I will need more than that as my gauge is 18". If you are using 18" with 7 1/2" gauge, then I should be pretty much in the ball park with 3'-4' offset. I sure don't want to have to deal with the kinks.

Carl, I understand the rail creep concept. Being as I have used rail to lay, I can pick different lengths to make the appropriate offsets. I am definitely not against cutting a rail if necessary. I will need to "dress" up some of the pieces before they can be used anyway.

Thanks Again Gentlemen,
Terry

[steamin10]

I did not know you were doing Grand Scale, you have fewer compromises allowed with 'real' sized track. If you are using stell rail, it is more forgiving in some ways, but tougher to unbend kinks. Being stronger to begin with can be worked to advantage.

Nix the little scraper for that sized track, you will turn into a real gandy dancer with a piece of one inch bar, about as tall as you, to poke between the ties and drive the stone down. it is most important to bed the ties without pockets beneath, as of course, the train weight will settle them. I have seen the mistake made of running heavy trains over unlevel track during construction, bending the aluminum rails a alittle, and that causing leveling problems.

It is my opinion that the bed of stone should be prepared and raked to a reasonable level, and the panels laid upon it, and final filling of the ties space just after. I have worked on track laid on bare ground and the ties filled by a hopper car, and the track raised and leveled through the stone from there. It seems to take longer for the track to stableize, and the uneven ground can spring the panels in the vertical, making for a small headache on leveling for a time, until the rolling action relieves the springyness. It takes less stone, but i think the benefits are modest, compared to getting track stable. Most people forget the smoothness of running a machine on rails, depends on a good road to start with, or you will be testing the ties and breaking strength of delicate parts.

[STRR]

Big Dave,

My plans were to get the dirt work done to nearly level and compacted reasonably. Lay a sub grade of recycled concrete road base, compact, level, compact, and check for level. From there I had not decided whether to lay track on the road base or to put down some ballast first. Your recommendation for ballast first will be seriously considered based on your experience. That makes a lot of sense. The only problem I see would be if I can get the track down on the ballast and still have it level. Your way would sure save a lot of time and work jacking up to level through ballast. My plans were to use a pneumatic long reach scraper from horror freight to do the tamping. Planning on welding a piece of angle iron across the blade for better compaction, less cutting action. Although, it might work OK right out of the box. I'll have to check that out.

I have a bunch of 8lb and 12lb rail I plan on using. While it is real steel rail, it isn't that large and I still have concerns on kinks. I currently have about an equal mix of hard and soft wood ties cut. I am planning on one hard, two soft, one hard type rotation. Should make for a pretty stable track. Our 5" scale loco weighs in at a ton so weight isn't a problem there. I would like to build some larger stuff in the future so I want to be sure the track is well done. I sure don't want to have to take it up and re lay it.

I appreciate all your comments on track laying with steel rail. I have read a lot and laid a little. So, I know just enough to be dangerous. I just want to be sure I get it right the first time. Too much work to do it over.

Thanks Again to you ALL,
Terry

[Greg_Lewis]

Since you're doing 18 inch gauge, you might want to chat with the folks at the Hillcrest & Wahtoke RR in Reedley, CA. The phone is: 559.638.2762. They have experience not only on their own rr but on others as well. Ask them how to contact John Bishop, who was employed full time for a while both in Reedley and also constructing a 15-inch rr. many miles long in Missouri. John supervised laying lots of track there and will have a wealth of knowledge. If you can't find John on your own, p.m. me and I'll find him.

[steamin10]

By all means network and get all the insights into such a large time consumer. There are smart ways to do this REAL construction work, that are easy.

One thing that may help is putting together a drag box, filling it with stone, and dragging it along, leaving a bed the width and shape you need. A fast striking with a tine rake will level out bumps caused by unlevel ground beneath. About 3" drop from the gate at the rear is about right for good application, at a minimum.

The box is best built of steel, but a heavy plwood box and steel gate will serve for smaller jobs.

A 4 wheel drive or tractor is required, to move the box, along with a bucket to move the material. You can borrow a tractor from a friend or rent one if need be.

I hope if you use wood ties you dip them in a treatment. I use copper napthenate, it is rather expensive, a gallon does about 300+ ties for 1.5 scale. 2 x 2 x 12 -14 inch soft wood. I put the treatment ina mortar box, throw in the ties roll them around and they are out in about 5 minutes. End grain picks up a lot, side surfaces less, but all get a green shade. There are arguments pro and con about what is best, thats ok. It comes to money and availability. I have used discarded motor oil diluted with about 20% diesel. Stinks at first but repels water and bugs, for about 5 years. I collect the wood for free from various job sites where scraps are free for the taking, just ask. I have tried 'peeler cores' that are treated, and they are dismal. Used for lanscapes and fence posts, they rot in about 5 years in my swampy area. That is not agreable to me.

[tomc]

Terry, how long is your typical rail section? Our 12lb comes in 30 ft lengths and we couldn't lift the panels if we pre-built. With your nice subgrade, you can layout the ties, put down one rail and then do the other. Put more ties down and join up the next piece. Joints can be offset a couple of ties but the Maine 2fters did butt joints so it wouldn't rock at joints that sank on one side. Either way will work as long as the ties are firm against the ballast. We use gravel and after tamping have hardly any problem with sway till the super elevation goes out from frost or soft fills. Then releveling puts it back right. We don't have a nice firm subgrade as it cost to much so have to watch cross level at curves where we elevate a rail.

Tom C.

[STRR]

Tom,

Most of the rail is in 20' pieces. Even that short, with 4x4 ties, I don't think two men could pick a panel up and place it. A crane, fork lift, or tractor to do the hoisting would be needed. A crane I have, but access may be a problem. I have settled on building in place.

The sinking joint problem is the reason behind this thread. I believe the guys have a pretty good solution, offset the joints but not far enough to become a harmonic with the average speed.

As with every building project, it will only turn out as good as the support you build in on. The foundation (sub grade) has to be solid or you will never have a smooth track without a ton of maintenance. I prefer to put the labor into the beginning of the project. Then, sit back and enjoy the results.

I figure to grade and compact the dirt work. Bring in good road base to build up to sub grade. Compact and grade into a "sidewalk" to build on. At this point I think I am going to take the advice of putting down ballast and building track on top of the ballast. With a little additional ballast, where needed, I should be able to grade the track pretty easily. Ballast between the ties, and outside the rails, tamp, and refill as needed. Sit back and enjoy for a while until everything "settles out". Align, grade, tamp, and ballast again. I figure I should be good for maybe 5 years if the frost or clay doesn't heave things around too much.

Thank you all for your help. I appreciate your consideration.

Good Luck,
Terry

[ccvstmr]

Terry,
I think you've got the right idea....put all your time and effort into constructing your "base"! Sub-grade...fill, dig, groom, line, level (super elevate slightly in curves) and compact. When you're satisfied that "sidewalk" is a good as it gets for your railroad...then it's time for the next step. Bring in the sub-ballast and prepare that surface. Depending on the size rock you're using will determine how well it compacts. Again...line, level, elevate...but that should be as close to a smooth surface as possible to install your track. THEN...install the track. If you can't build track panels...you'll have to do it like the Transcontinental RR....one tie at a time (properly spaced) and then drop a rail...and then move on. In your case, progress moves at 20 foot intervals. After the track is down, you can start running on that right away if you don't around to ballasting. After all...the ties should all be sitting on a groomed and prepared surface (assuming all your ties ARE the same height). The ballast at that point is just a decoration... but will eventually "hold and restrain" the track.

You mentioned "pumping ties" at rail joints. Make sure you've got a tie under every rail joint for support. You're obviously building in a larger gauge and scale. Weight distribution or more appropriately...weight support...becomes a more important factor.

Hope that helps. I think you're heading in the right direction. Take the time up front to build your track support structure and it'll be a long time before it needs more attention. One last item...make sure any low areas are well drained. The whole point of the track base is to keep water (standing or flowing) from undermining the right-of-way. As such, if you need to install drain pipes...bigger is usually better. Look at your land and determine which way the runoff is going. Plan accordingly.

Hope that helps. Carl B.