THIRD AVENUE EL wrote:Does anyone know what's with Metro-North's dislike of concrete ties? It seems that they are taking out concrete ties and putting wood ones back. Meanwhile, on the LIRR they're replacing wood ties with concrete ties. What gives?
Several northeast railroads got burned by bad batches of Rocla concrete ties, and took a bath on tie replacement when the company went bankrupt and couldn't warranty them. Amtrak took it on the chin, the MBTA took it on the chin. Through no fault of their own because it was the manufacturer's shoddy quality control, but it cost a fortune to replace them with nobody able to recoup damages from the company. In the T's case that was the second time in ~25 years that they'd been scammed by bad concrete ties requiring embarrassing whole-line replacements with weekend shutdowns. They banned them after that debacle and are 100% wood on their tracks (not sure if Amtrak still uses any concrete in Massachusetts or if all have been replaced). I don't know if MNRR had any purchases from Rocla or bad experiences with any other vendors. But they all of the commuter railroads here are justifiably gun-shy about it after the Rocla fallout. The railroads have either got to buy high-quality stuff from a very reliable manufacturer or have a lot of installations of them of varying ages and varying manufacturers so they're well-invested and well-diversified in that type of tie. NJT and LIRR have a lot more existing concrete scale motivating them to buy more concrete. It doesn't wash quite as well for MNRR, CDOT, or the MBTA to start converting when they're so overwhelmingly wood. They stock wood ties in enough quantity to get a good price point when they purchase new batches. No reason to change when scale and pricing are optimal for their needs.
Concrete ties perform more poorly in climates where the temperature hovers around the freezing point--and not too much above, not too much below--where the daily freeze/thaw cycle exerts maximum punishment. While they still generally have a much longer lifespan than wood, a concrete tie with any flaws in it will get shredded in relatively little time by freeze/thaw while wood's got more give to it in a freeze/thaw despite its lower overall lifespan. And when it's bad, bad batches like these Rocla ones...ouch. It's not that they're a bad idea for this climate, but more that a railroad in this region has to be well-invested in that type for the long haul and a lot of lines to realize the same cost/benefit ratio as other regions. In warm climates that stay mostly above-freezing during winter or very cold climates where temps stay mostly below freezing 24 hrs. a day they're a generally slam-dunk value despite the higher unit cost. They're not a bad value here...but because of freeze/thaw exploiting flaws in more ties the bang-for-buck isn't quite
as good here. If you're 90 or 100% wood, there's not a compelling reason to change or to retain a very small minority of concrete.