Hi,
I like the looks of concrete ties, not everywhere but on certain portions of a layout. So my question is. When did they start to appear on American railroads?
Primarily I’m interested in The B&O and the UP but just general info would be superb.
Thanks.
Magnus
Magnus
Concrete ties were experimented with beginning in the early 1900s. Some installations in the 1970s were poorly understood and the ties failed. Installations beginning circa 1980 were successful and that can be deemed the effective start date.
For new construction in the U.S., the installed cost of concrete or wood is virtually the same in most areas (the U.S. is a large country and in some areas one or the other is significantly less expensive). Concrete is more expensive and requires a more expensive fastening system, but by virtue of their broader spacing (24" vs 21") the price comes out the same. For new construction of main lines, controlled sidings, and transit (light rail, trolley, heavy-rail), concrete ties are now more common than wood. However, since concrete and wood ties cannot be mingled together indiscriminately, there will be an immense legacy installation of wood ties for main tracks for a long, long time. Wood ties are usually preferred for yards and industrial tracks because in that application they are much less expensive. There are also some applications where wood is a better choice, such as long bridges, derailment prone areas, locations with a different section modulus, etc. There’s no clear consensus on turnouts; some railroads prefer high-speed turnouts on wood and others on concrete, and a lot has to do with the specific application.
UP installed its first concrete ties at Crestline, Nevada, in 1982. I don’t know about Chessie System or CSX (B&O’s successors).
RWM
Can’t speak for the United States, but large-scale use of concrete ties started in Japan in the 1960s. One interesting phenomenon was that the ties were installed first, under existing jointed rail (with 2 wood ties supporting each pair of joints.) The ‘infill’ concrete ties were left on the ballast shoulder, then installed when the jointed rail was replaced by continuous welded rail. This is the appearance I will be striving for on my model right-of-way.
Chuck (modeling Central Japan in September, 1964)
Thanks guys. Well then it seems I have to stay clear of them, As I kind of suspected,
Magnus
Actually, the cost of wooden ties is substantially less, and use of new wooden ties still vastly predominate: 15.5 million wooden ties in 2007 vs. 1.5 million concrete ties. And the vast majority of those concrete ties are out west: 1.4 million. The industry forecasts through 2010 show no great variation on these figures, in fact they are rather static. While BNSF is a huge implementer of concrete ties, and UP to a lesser extent (but notably with BNSF on their newWyoming coal lines), rwith BNSF replacing much of its main lines with them. On the other hand, Norfolk Southern (certainly one of the more progressive and successful railroads), for example, is not a fan of concrete ties and uses them sparingly if at all. East of the
Here in Charlotte, our light rail runs beside and in the same right of way as Norfolk & Southern RR. NS uses wood, the light rail uses concrete.
[quote user=“shawnee”]
Actually, the cost of wooden ties is substantially less, and use of new wooden ties still vastly predominate: 15.5 million wooden ties in 2007 vs. 1.5 million concrete ties. And the vast majority of those concrete ties are out west: 1.4 million. The industry forecasts through 2010 show no great variation on these figures, in fact they are rather static. While BNSF is a huge implementer of concrete ties, and UP to a lesser extent (but notably with BNSF on their newWyoming coal lines), rwith BNSF replacing much of its main lines with them. On the other hand, Norfolk Southern (certainly one of the more progressive and successful railroads), for example, is not a fan of concrete ties and uses them sparingly if at all. East of the Mississippi, only 20,000 concrete ties were used in 2007. That’s not a lot in proportion. And a lot of that eastern number was probably for Florida East Coast, an eastern road that was ironically the pioneer in adoption of concrete ties throughout its system.
Shortline rarely use concrete ties.
So the preponderance and inexorability of concrete ties can be greatly exaggerated.
And there is a clear preference for wood in turnouts. Wood ties allow greater flexibility and impact absorption, so they’re much preferred for switch ties even over lines that use concrete otherwise . BNSF, for example, the largest user of concrete ties, laid 63,000 wood switch ties vs, 4,800 concrete switch ties.
There is indeed a significant cost differential in materials and labor in using concrete ties, and and where access to wood ties is readily available (like in anything, transportation costs count), wooden ties still predominate. It is interesting to note that in the areas where rot is more of a concern (southeast), with the exception of Florida concrete ties are rarely used. Rot is not the big issue vis-a-vis concrete
The B&O might have been one of the earlier experimentors with concrete ties. In the mid 1960’s I noticed some strange concrete cribwork on a B&O embankment near Ridley Park PA (between Chester and Philadelphia). One of the older trackmen told me they were old concrete ties that they tried but did’nt work out very well, so they took them out and used them for cribbing. You could see where tie rails had been attached. Don’t know when they were tried, but it looked like they had been there for many years. Maybe somebody else knows more about this.
Is that 21"/24" center to center or the spacing in between? And is that calculation based on a wider concrete tie (a bigger footprint on the sub bed) or the perceived structural durability of concrete over wood?
Is there a site that gives specs on concrete ties and some info?
Thanks
The measurement is centerline to centerline.
Tie spacing is an engineering decision that accounts for many significant differences in the materials. I think the easiest to explain are stiffness and strength in compression, both being greater in concrete than wood. The tie is a beam that takes the weight of the rail compressed under the wheel, and transfers it to the ballast section. The greater the strength of compression the less risk of the tie material crushing or shearing under the load, and the greater the beam strength the more weight the tie can transfer to the roadbed before it breaks.
Because it’s highly advantageous to standardize track maintenance machinery and track laying machinery, the 24" spacing for concrete was determined after a great deal of tests and prototype installations. The dimension is an economic compromise like all engineering decisions. Theoretically for some traffic levels, rail weight, ballast types, and subgrade performance you could increase the spacing to 24.2" or decrease to 23.1" or whatever, but the savings in materials would not be enough to pay for a custom tamper and the engineering design, and many other ugly problems that non-standardization creates.
90% of the main track wood-tie mileage in the U.S. since 1900 has been 21", but some railroads had a different idea. Today I don’t know anyone who is using something other than 21" for wood for main tracks except in unusual situations where there is a compelling economic reason to come off standard.
Concrete tie life is 50-60 years, nominal, wood tie life is 35-50 years, nominal. Some conditions accelerate tie mortality, both concrete and wood, and others extend it. I can point you to some Douglas-fir ties laid in 1906 that are still carrying traffic, albeit at very low volumes and low loads, and they are more
Info on concrete ties:
Major manufacturers are:
CXT: http://www.lbfoster.com/content.aspx?id=1916
Koppers (KSA): http://www.koppers.com/index.html
Rocla: http://www.roclatie.com/about.htm
Also see AREMA (American Railway Engineering and Maintenance of Way Association).
RWM
Wooden ties: Cheaper, easier to lay (especially in emergency situations), best for low-volume, lower-speed lines.
Concrete ties: Ideal for heavy-traffic, higher-speed mainlines, high capital cost but almost zero maintenance cost, fireproof.
If you model modern mainkine intermodal operations, concrete ties are almost a must.
Again, perhaps western, but not necessarily eastern.
I am no expert and I maybe wrong but:
I think there is something were missing about concrete ties vulnerabilty to Rain.
Not the Wetness, rather The physical pounding rain produces on them. It may not sound like much but I recall some contractors saying that exposed concrete on say ROOFS, are a bad idea (Aside from the weight.) something to do with Elasticity of Concrete versus Wooden Ties. Places in east/midwest get rain maybe 90 days of the year. Out west say in Southern cal there might be 25 rainy days.
The southwest being so arid, Concrete ties should be ideal.
I spent the first 45 years of my life in the northeast. I have little knowledge of concrete ties, but I do have some experience with concrete roads.
Water seeps into the surface of concrete. When water freezes, it expands. That expansion causes small holes in the concrete. Repeat the cycle. Now the new holes allow more water to seep into the surface, causing bigger holes. Repeat the cycle.
In roads the end result is potholes. I imagine the result in a tie would be even more dramatic.
Perhaps that is why we only see concrete ties in the land of the sun.
I have upwards of 18 years in the precast concrete feild, that is why this thread caught my eye.
Many factors will indicate the expected life of concrete whether it is precast (made in one location and transported to another) or feild cast (made in the final resting spot). For exposed concrete the 3 indicators most likely to forecast the life of the concrete is 1) COMPRESSIVE STRENGTH (basically taking a concrete sample of a specific size and applying pressure to it, typically from the top and bottom) 2) PERMEABILITY (determining the rate at which moisture will transfer thru a concrete slab, similar to a R-value rating for insulation but with moisture transfer instead of heat transfer) and 3) FREEZE/THAW DURABILITY (due to the physical composition of the materials used and how the concrete cures) which is directly related to the PERMEABILITY rating.
Large concrete surfaces with poor drainage (roads, driveways, parking lots) will tend to absorb more moisture from rainwater than a smaller surface would simply because the water will run off easier on the smaller surface. Having said that I doubt that the rainwater alone would have a detrimental effect on a concrete tie ASSUMING that it was properly engineered from a loading standpoint and from a manufacturing friendly veiwpoint.
Now we need to take into account any contaminates that may be involved in the area. If there is oil, chemical, road salts or similar substances spilled/applied to the concrete it may weaken the chemical bonds internally. A precast company I used to work at made water drainage structures for the Dept of Trans. for several different states (PA, NJ, DE, MD, and a few others). Some areas in NJ (for example)were required to use TYPE II cement in these structures, TYPE II cement has additives that add to the concrete’s resistance to salt prone areas. Types I and III cements were proven to not have the same resistance.
I’ll try not to bore you guys any more…
There’s very little “climate factor” in the lifetime of a concrete tie. Some of the largest users are in cold, wet, climates, such as Amtrak Northeast Corridor, Canadian National, Canadian Pacific, BNSF Stevens Pass, UP Blue Mountains. Lifetime expectancy is 50 years, and that is based on service experience. Northern Europe has millions of concrete ties.
Three things kill a concrete tie prior to its 50-year lifetime: derailments, shoulder abrasion/seat cracking, and structural failure due to inadequate roadbed maintenance. Concrete ties are much more susceptible to fatal damage from a derailment than wood, which is why concrete ties are not always a good idea in yard trackage. Shoulder abrasion/seat cracking problems have largely been resolved by better rail-tie fastening systems, keeping grit out of the rail seat, and redesign of the shoulder plate. Structural failure due to inadequate roadbed maintenance is solved with the proper subgrade, drainage, ballast, ballast section, and attention to tamping. Concrete ties do not like to be center-bound, a condition where the tie is supported only under the center and bends around that point under load. Wood ties are more forgiving but you can break them in two with center-bound conditions too.
RWM
Since I live in northern Sweden i can say that there are a lot of concrete ties up here in northern Europe. The “malmbanan” that is used to ship iron ore north of the arctic circle uses them to. Haven’t seen a concrete tie turnout though. But then I haven’t exactly been looking for them.
Thanks everyone who have contributes. Maybe I will “cheat” and make a portion of the mainline concrete anyways on my 50’s layout. I can always claim that they are experimenting with it.
Magnus
I used Northern Europe as Germany, France, Britain, Belgium, Poland, Russia, the Netherlands, etc., but maybe I’m wrong and that’s Central Europe? Or something else?
RWM