Length of a standard piece of rail

[jsotto]

To Mr. Nelson's question, not up, but yes the rail cross section will slightly thicken when compressed in hot weather and thin when stretched, like very tough taffy. :-)

Jeff Otto

[dknelson]

In theory since the steel WILL expand or contract if it is firmly fixed in place then it has nowhere to go but up. So presumably the rail swells if it cannot lengthen.
Dave Nelson

[Anonymous]

I have worked on a rail gang in the snow - they used a propane burner to heat the rail. I also worked with a welder doing the thermite welds in the field (very cool) and repairing jointed rail. Repairing the beat down ends consisted of him building up the surface and me beating it flat with a sledge.

RH

[jsotto]

Sorry, dropped something on my keyboard before finishing previous post! :-)

From Dr. Hay's text:
"...credit for introduction of welded rail to steam railroad use is shared by the Central of Georgia Railroad with a tunnel installation in 1930, and the Delaware and Hudson Railroad, with the first true open-track installation in August, 1933."

Continuous Welded Rail (CWR) must be adequately anchored to prevent rail movement at each end of the "string". Thus there is no limit to how many strings may be welded end to end, only the practical needs for other purposes such as when signalling still required insulated joints, or Connolly joints at moveable bridges, etc. On the C&NW our rail trains happened to handle 1320' strings, but some roads had trains that handled lenths up to about 1440', as I recall. There is no magic to 1/4 mile except it is easier to say and approximate than to say 1440' or whatever footage your road 's rail train length was.

Rail temperature in direct sunlight will rise as much as 30 degrees above ambient temperature. For the C&NW (upper-midwest) territory, we figured rail temperature would vary from about -30 degrees F to 130 degrees. Our preferred rail temp. when anchoring was about 85 degrees, so it would be heated or cooled just ahead of the anchoring process in the rail laying gangs to achieve that temperature. You do not lay rail at maximum temp. or it WILL break apart in cold weather. Lay it too cool and the risk of sun-kinks from heat expansion increases.

Jeff Otto
C&NW Engineering Dept., 1974-1985.

[jsotto]

When 36' cars were the norm, rail was usually 33' in length. As 40-42' gondolas became common, 39' rails became the norm and painting the ends of shorter rails green was introduced. Other colors denoting other characteristics have been used to prevent misuse of both poorer quality rail and premium rail (intended for curves).

78' "double length" rail was often used starting in the late 60's for curve locations. This was the era where railroads were realizing the "rock-and'roll" problem caused by the introduction of 100-ton capacity covered hoppers (in 1963) whose truck centers approximated the 39' rail lengths in use. Sharper curves wear the rail head out faster than tangent track, so it was not as economical to use welded rail in such curves and the 78' lenghts prevented the rock and roll problem of 39' jointed rail.

Improved metallurgy and maintenance practices in recent years have changed the economic equations and most railroads now use premium rail continuously welded in curves.

From Dr. W. W. Hay's college text, " Railway Engineering, Vol. 1", I quote:
Welded rail was first used in street railways and some in Europe dating to the early 20th century. First use in steam freight service is credited to the Central of Georgia with a tunnel installation in 1930.

[Anonymous]

Howq many 1/4 mile sections of continuous welded track is normally allowed before you "typically" make a joint? I'm sure many things can influence this...but if you didn't have to stop the process for a turnout, cross-over, etc....how far might you go?

[Tilden]

A little off subject but it's a kick to see the MOW crews make weld joints with thermite. It's a kit, comes in a box, has several clay parts that fit around the joint and some soft clay like material to seal around the track. Then they put the clay tub containing the metal and thermite mix on top and light it. It's a nice firework. When done, they break it off, grind ithe joint smooth and walla, a solid piece of rail. Not the quickest thing to do but probally about as fast as a proper standard weld job and less equipment.

[ericboone]

My maintenance of way booklet from the Pere Marquette has diagrams for tie spacing using 39', 33' and 30' foot rail sections. However, the 30' and 33' diagrams (drawn in 1913) specify 75lb rail or less, making there usage most likely quite old. The 39' section drawing was done in 1926 and shown 90 lb rail, which is still quite light by today's standards.
My C&O maintenance of way booklet has an Advisory Mechanical Commitee (AMC) tie spacing diagram (drawn in 1934) showing 33', 37', and 39'. It also has AMC diagrams for rail anchor locations for the same three lengths of rail from 1935. The AMC diagrams do not specify a rail weight. (The AMC was a combined engineering group for the Erie, Nickel Plate, Pere Marquette, and C&O railroads.)

[Anonymous]

Continuous welded rail is laid at a very specific temperature, which I forget. (70s I think) The rail is either flame heated or water cooled to that magic temp where it will handle temperature related expansion and contraction all year long. Learned this when I worked on the UP some years back.

Mike in Boulder

[tomikawaTT]

The original question brings up another. Where did this short line get its rail? If new from the mill, it would have come in thirty-nine foot lengths. If used, from a nearby Class I road, it would almost certainly be shorter. Rails were pulled from high load heavy traffic lines when the ends became battered (because the joints were, and are, the weakest points). Frequently the pulled rail was shortened enough to remove the damaged section, then re-used elsewhere. I can easily imagine a short line buying substandard length steel at a discount from its Class I connection. Such rail would be 33 - 35 feet long.

During the transition era (1945-1955) Thermite welding (in place) of rail was only rarely used, and common use of 'Ribbonrail' was still a decade or so in the future. It is very unlikely that a short line would have been using either; most still don't. The Erie, the New York Central and even the New York subways were strictly short, jointed rail in the mid-50's.

[nbrodar]

On occasion the cold will cause the rail to break. This is more common during a fast drop in temperature. The track structure can't adjust quick enough and the rail snaps.

Up until 30 or so years ago, the welding technology wasn't good enough to weld the rail. Track gangs use special fusion welding equipement the literally fuses the rail ends together. And of course, CW rail is difficult to transport. 39' sections are easier to transport.

Nick

[Anonymous]

QUOTE: Originally posted by nbrodar

An amazing property of steel, it stretchs. Rail is typically laid in the hottest part of the year, so that it's at in maximum length. Then when it gets cold, the rail simply stretches, as it contracts. I know that sounds like an oxymoron, but that's how it works. There is also some room for expansion/contraction at any bolted joints (usually around breaks between blocks).

Nick

Amazing! True, if it is layed at the hottest day it will not expand any more, only contract. And contracting won't cause buckling. But still, wouln't this excess stretching cause rail or rail joiners to break?

Another question - why for over a century rail was laid in short peices and only recently long rails are being used. The trouble with joints was always biggest pain in the rear to maintain.

[nbrodar]

An amazing property of steel, it stretchs. Rail is typically laid in the hottest part of the year, so that it's at in maximum length. Then when it gets cold, the rail simply stretches, as it contracts. I know that sounds like an oxymoron, but that's how it works. There is also some room for expansion/contraction at any bolted joints (usually around breaks between blocks).

Nick

[Anonymous]

QUOTE: Originally posted by tjsmrinfo

welded rail as far as i know is 1/4 mile lenghts laid then welded together,

tom

I wonder how temperature expansion and contraction is handled?

[dknelson]

Obviously the "stored" rail trackside would match what is used on the main line or spur itself. If it was very old rail of that 35 ft length that is used, that is what you'd want to have in reserve
From time to time I have seen lengths of rail with one end painted green. My information is that indicates a length of rail shorter than the standard. So it might be that if a railroad usually used 39 foot rail but had need for some 35 lengths in a particular area, they might paint the ends green so they do not accidentally take the wrong length to the work site
I have also seen the lengths marked in chalk on the side of the rail but obviously if the rail is then cut and the chalk mark is not erased ......
Dave Nelson

[nbrodar]

Stick rail is 39' long (to fit in a standard 40' car)
Rail now comes in 80' lengths (to fit on a 89' flat car)
Welded Rail comes in 1/4 mile lengths (carried on special trains)

Most mainline rail is fusion welded so that may be "continous" for miles. CW rail provides a smoother ride and is easy to maintain, but is harder to repair. Stick rail is easier to repair, but harder to maintain and gives that rocking motion to trains.

Nick

[tjsmrinfo]

welded rail as far as i know is 1/4 mile lenghts laid then welded together,

tom

[WSOR 3801]

They do make rail in 80' lengths. Came in on a 89' flat, with short bulkheads. Don't have to stack up much rail before the car gets to its rated capacity. I helped the MOW crew unload some last year. Usually used for crossings, where you don't want a joint in the middle if it.

[BR60103]

39 feet was standard in the era of 40 foot boxcars/gondolas.
If you model earlier, match it to your cars.
Current rails still come in 39 foot lengths, until they're welded into mile long pieces.
I saw the railroad making long sections from used rail by cutting off the ends with the boltholes and then welding.

[Anonymous]

Second-hand rail, rolled in the earlier 1900s or before, would have been 35' in length. Some of that rail is still in use today.

[Anonymous]

The standard piece of jointed rail is 39 feet.

[deltamech]

I am building a layout of a short line in the late '40s/early '50s and I want to place several stacks of rail beside the tracks. To build the stacks, I need to know how long was a standard piece of rail.