All North American Class Is use concrete ties by the hundreds of thousands. Substantial mileage of North American high MGT lines are now laid with them, and most new main track and controlled siding construction is concrete tie.
The installed price for an out-of-face installation of concrete ties and timber ties is virtually identical in price at present, if purchased in large quantities and installed by mechanized gangs. The price of timber ties has been climbing rapidly. Factors that affect the pricing include:
Because concrete ties require out-of-face installation the economics of replacing timber with concrete is not good except in heavy curve,and/or high MGT territory where timber ties become spike killed from rail transposition on curves, and/or where experience shows that timber ties have trouble holding gauge, and/or where the timber ties are due for a high number of replacements.
UP has been installing concrete ties on much of the south bound Joint Line particularly the single track section south of Palmer to at least the northern end of Colorado Springs, as well as the southbound main to the north of Palmer, at least through the sag. There's another large section to the north as well, on the southbound main from South Littleton on down to near Sedalia.
The trend has been toward aluminum gondolas (rotary dump) because these are light and cheap. BNSF has been buying 240 of these cars a year since the mid-1990s. Net weight is as low as 40,000 lbs. for some of them (which are drawbar connected in five-packs), and they gross 286,000 lbs., meaning they carry a net of 246,000 lbs. of coal. Not bad as compared to a conventional three-pocket hopper with a tare of about 60,000 lbs. and a max gross of 263,000, for a net load of 203,000.
The customer will usually dictate the type of car they want their coal delivered in. If they have a rotary dumper, they will want the rotary dump cars. But, many power plants do not have a rotary dumper, such as the Xcel Valmont plant here in Boulder, the Xcel plant just west of downtown, and I think the Xcel plant that is west of Santa Fe and south of Florida. Those plants need bottom dump hoppers. Joe also sees “drop bottom gondolas”, which are 5 bay hoppers that the entire floor essentially opens up on. They’re aluminum, with high capacity, and the gates on the bottom open automatically via compressed air. There’s a paddle on each side that actuates the gates as the cars are pulled slowly through the unloading facility. Look between the cars and you will see two air lines, one for the brakes and one for the gate opening mechanism.
The power plant makes a trade-off between the lower cost and higher capacity of the gondolas, but a more expensive rotary dumper, vs. the drop bottom gons more expensive maintenance by a dump facility that is a hole in the ground with rails over it.
Many of the trains you see are privately owned cars. If the reporting marks have an “X” on the end, the cars are privately owned. For example:
You get the idea. Sometimes its kinda fun trying to figure out what they are. The utility will negotiate a contract with the railroads for the transportation. Sometimes you will see a train of private cars being pulled by BNSF, and a couple of months later it will have UP power, or vica-versa.
Finally, those old steel hoppers are still in service because they are going to old power plants that only have a pit dump facility. I suspect UP gives the utility a price break on the contract if they use those old cars because UP doesn’t have to spend money on new cars. Some of those cars are 30 years old.
I like the shiney aluminum unit trains, but they don’t stay shiney and clean for very long.