Just last year the Union Pacific had just replaced Thousands of ties on the Blair and Boone subdivisons. After the Wood ties are replaced with Concrete ties,what does the Railroad do with the thousands of older Wood ties right after they have been replaced. Does Concrete last longer than Wood? Why do Railroads use Concrete ties on switch tracks since concrete ties can crack under the extream weight from the constant pounding from a heavy train. I thought that Wood ties would flex much better under the extream weight from the train. I have seen that most track with concrete ties don’t flex (bounce) as much as the Wood ties. What gives? Plus with Wood ties,The rails are spiked,on the other hand,Concrete ties are cliped. Thanks,Allan.
Cannot tell you what is done with old wooden ties. However, pressure treated wood still deteriorates over time if it is buried in the ground. The flexing of wooden ties you mentioned is NOT desireable for trains. If this was so. you would see suspension bridges used on heavy duty railroads. The various designs currently used are intended to provide an unyielding support for the track and trains.
Poured concrete block does, indeed, have very little strength. However, prestressed concrete can support tremendous loads because the concrete always sees only a compressive (where it is extremely strong) load. This is accomplished by stretching the rebar prior to pouring the concrete. Once the poured concrete cures, the rebar is released. In attempting to regain its original length, the rebar now compresses the concrete block. The block will now not crack unless the generated bending moment force exceeds the residual compressive force.
If the wooden ties are still in decent shape, they’ll be recycled by the railroad–reused in places like yards.
I’m sure Mudchicken will be able to enlighten us on the ways that worn ties are disposed of these days.
There is, or was, a fleet of old coal gondolas running around with reporting marks WWEX–for Wood Waste Energy. That’s one possibility, once a number of environmental issues have been cleared.
Burn creosote–that’s got to be good for the environment [:)].
Some of the worst ones often end up in the landscaping market, or at least they used to. I’m not sure if they let the creasote out into the general market place anymore.
Concerte ties have disadvantages too. Put a train on the ground, and all the chipped ones need to be replaced. Wood usually survives derailments
Old wooden ties- highly valuable for residential retaining walls, right?
Believe me, Big Boy, those ties that make it to the landscape people are far from being “some of the worst ones”. At least they still look like ties!
Carl, next time I go to Menards I’ll have to look. I have this image stuck in my mind of large gray “wood like” objects, with all the creasote leached out, and huge checks and splits down the length. Very rustic, but not necessarily the best long term solution for holding back earth. It is possible that that was the reject pile after the customers had cherry picked off the better ones.[swg] The joys of self service lumber.
Another place where old wood ties go to die is railroad museum operations. They like to buy the ones just above landscape grade. Maybe Menards is buying the ones they remove.[:P][;)]
Much of the time they sell the whole lot to the highest bidder, who also gets to haul them away. Some are good, some are better, some are not. Most go to the landscape industry.
I’ve found that when I’m trying to find or follow an old, long gone ROW through Iowa,Minnesota or South Dakota cornfields,that the fences around the area will feature a lot of old ties as fence posts.
Seems to me that concrete ties (or in British, “sleepers”) are pretty much the norm on heavily-used European tracks.
I would’ve figured that they wouldn’t be long enough to make a good fence post- by the time you buried enough of it to make it stable, your fence wouldn’t even be three feet high.
I do have a question here, if the wooden ties did indeed flex, why wouldn’t the other bridges like the truss type bridge, the arc bridge, the cable stay bridge or the beam type bridge work, would the suspension type bridge be the only bridge that would work? I personally would think that the cable-stay type bridge would be better. Just curious.
Most so-called “contaminated” woods can easily be gasified for energy production. The contaminates are removed during the gasification process.
If I remember right, they are usually about 8’ long. I worked for a lumberyard that sold lots of RR ties. Inevitably, the customer was a grandpa, with his arm in a sling. He had a stock trailer that was full of manure, because he had just taken hogs to the sale barn. “Oh, and you fellers will have to slide them all the way to the front of the trailer, or the pick-up steers funny”[xx(]
When I worked for my Granfather in the 1960’s, the railroad gave the adjacent landowner first dibs on used ties. Grandad really liked the switch ties as they made great corner posts for his bull pens. At that point a typical used tie had an additional life as a fence post of 10 - 15 years. Pine poles were only good for about 8 to 10 years.
dd
ps- we also experimented with concrete fence posts - good life but they were to heavy to handle and too expensive.
Concrete vs. Wood ties are yet another thing the amazing John McPhee discusses in his two-parter on unit coal trains from the PRB (second part, NEW YORKER issue of October 10, 2005). He says the BNSF/UP shared triple track into the PRB region uses concrete and gives a couple of reasons why. I don’t think he addressed the role that rebar plays, but otherwise he seems to be pretty much right on the money.
Along with Dave pointing out the fact that the creosote would gasify in the high heat of a power plant, you should note you also get creosote from most low temperature burning woods; it is a natural by product, most common with the sap woods like pine.
Check you house hold chimney, and you will find the creosote that is released when you burn wood slowly at a “low” temperature, like a fire in a fireplace coating the flue and chimney, in fact, creosote build up fires are the most common cause of chimney fires.
Old high school science experiment, place a popsicle stick in a test tube, hold it over a low Bunsen burner, rotate it as the wood stick chars, and note the liquid that collects in the tube…natural creosote.
What is used on railroad tie is petroleum by product, and at high temperatures, it burns as clean as household heating oil…
Ed
Tie Tek produces a “recycled” tie that serves as alternative to wood and is cheaper than concrete ties. The company has been around a few years. They make the ties from post consumer recycleables such as milk jugs and tires.
http://www.natk.com/ttprod.html
There main customer is UP, but they recently got an order from BNSF. Looks like this might actually take off! There are some photos under the “investers” link…
I’ve seen some of them fence posts that still had tie plates attached.
Jeff