Can modern railroad ties be made from other materials besides wood?

Question

If railroad tracks could be updated and modernized then what would be the material used for railroad ties?

Answer 1

Wood is the most commonly used material for North American track ties; however, concrete and steel have been used.

Concrete ties have a number of problems not prevalent in wood.  They're best suited for lighter applications (light rail and passenger lines), and don't hold up well from repeated poundings by heavy, long freight trains.  Dragging equipment will also shatter the ties.  A loose chain, sagging hose bag, or broken operating lever will scar and scratch wood, but it'll shatter concrete, and those ties affected will need replacement before the track is safe at anything above slow speed.

Steel ties haven't caught on in North America.  They're much more expensive than wood or concrete, and when you consider the hundreds of millions of ties a large railway uses annually, it negatively affects the bottom line.

Wood ties stand up remarkably well to heavy trains, high volume of traffic, weather, and will survive a fair bit of damage before warranting replacement.  Plus, they're inexpensive, plentiful, and in wide use across the continent.  They're treated with a preservative (creosote), which really lengthens their usable life span.

Answer 2

Metal ties were clearly seen in photography of post-earthquake

Kobe, Japan.  The rail and tie alinement remained even as shifting railbed broke connections and curved trackage like an amusement park might.  Europe was using metal ties but since steel making has shifted to Asia I expect Asians will experience resurgence in worked metal replacing substandard works.

The West declines into obsolescent.    Why concrete?  

I'd blame American-led capitalist cabals. They betrayed us.

Answer 3

In the UK all modern rail is laid with concrete sleepers ('ties'). Wood hasn't been generally used for many years. Some narrow gauge railways have used steel, but this has never become popular.

Answer 4

If railroad tracks could be updated and modernized, they'd be called AIRPORTS!  But as you well know, simply being "newer" does not make something "better".

Several technologies trying to prove themselves against wood:

- Steel ties, a fairly complex shape designed to stay put when set in ballast. Long term issues: corrosion and electrical isolation (since you now have a tie which conducts electricity.)

- Plastic ties.

- Composite (plastic+sawdust filler) ties.

- Concrete ties. Extremely heavy - a big plus in welded rail as it keeps the rail from moving around.  But brittle and fragile.  

Concrete is a brittle material like chalk.  Very strong in compression, very weak in tension (or bending).  Which is why they use reinforcing rod a lot.  Prestressed concrete ties take that one step further.  They stretch the reinforcing rod, like guitar strings, before the concrete is poured.  The tension in the rod is fighting the compressive strength of the concrete, making a very strong structure.  But a very fragile one, because it's a tension structure and the concrete is still brittle.  Like Hoghead says, they don't survive abuse.

Answer 5

Perhaps a little research would be in order before passing any judgment on American capitalism or those nasty railroad cabals insidiously skulking through the night with their antiquated wooden cross ties, forcing them on the unwary.

The truth is, concrete ties, while better suited to high speed track with lighter high speed trains riding on them, don't hold up very well when a derailment occurs.

Sometimes derailments escalate into a major pileup because a single derailed wheel or truck under a car starts the chain of events that follow.

When a single wheel or set of wheels hits the wooden cross ties, they will often continue on their way, in some instances for miles, before encountering a switch or grade crossing that is the last piece of the pile up puzzle.  This of course allows time that the train crew may be able to see or feel that there is a problem, or be alerted by one of the numerous automatic trackside warning devices.

So, one winds up with many wooden cross ties that are cut or damaged, oftentimes not even needing to be replaced.  Not so with a concrete tie.  They get hit with a wheel and, for lack of a better term, "explode."  Then there is no time to discover anything before the cars scatter all over h**l and back.

Wooden cross ties are treated with the preservative "creosote" which in many areas give them nearly the same working life as a concrete tie, and though I don't know the numbers for a fact, but I'd be willing to bet concrete cross ties can be had for a little less expense.  These savings are quickly eaten up in the cost of a major wreck, with the loss of equipment and lading, and the lawsuits that inevitably follow the deaths of those unfortunate enough to live near right of way sporting concrete cross ties.

Steel cross ties are in use in the US, but only in those areas where the cabals have lost control, primarily on bridges over waterways or viaducts.  Here, fire is a significant concern and a steel cross tie is much more sensible, given that these do not explode either, but cost is significant.

As wooden cross ties go, what is a defect for high speed is a virtue for lower speed, heavy freight trains.  That is, they have a certain amount of "give" to them.  Not wanted for high speed operations, but where heavy equipment is in play, there is a tremendous amount of force present where wheel meets rail.  

Look at a freight train passing sometime where the ties are not obscured by a grade crossing.  As each truck of the engines or cars passes over a piece of rail laid on wooden cross ties, you will see the entire structure take a little "dip" in the ballast.  When this happens, the force is being dissipated.  Were it not so, the wheels and draft gear would have to absorb this energy, again raising force levels.

This is what is known as "track / train" dynamics, and is very crucial.  The ratio between longitudinal force, "L" and vertical force, "V", expressed as L over V, is actually what keeps the equipment on the tracks.  The flanges on the wheels keep the trucks following the tracks.  As long as vertical force, the weight of the equipment, is greater than longitudinal force the train stays on top of the rail.  If "L" forces exceed those of "V", then the cars will be pulled off the rail on the inside of a curve when the slack is "stretched" (draft) or climb the outside rail of a curve due to "jack-knifing" when slack is compressed due to being bunched (buff).

Answer 6

Concrete