I've seen that a lot of the new construction si being done on concrete ties. I'm curious to know whether US railroads also do turnouts on concrete, or do they still use wood ties? I noticed this here in Iraq, where the lines are laid on concrete ties, but the turnouts are on wood. What is the American practice? Side note: probably European in idea, but even on the wood ties, the Iraqis use clips instead of spikes.
This is commonly done in the US as well. Most concrete track in the West will be accompanied by wooden turnouts, mostly because the custom ties needed for turnouts become very expensive without the economies of scale for the miles and miles of continuous mainline. Having said that, concrete turnouts do exist and are becoming more commonplace. A recent trip to the Powder River Basin revealed many in place and several in process of being installed. Also, the Alameda Corridor in LA has concrete turnouts throughout.
Same over here in the UK. Technology for concrete turnouts is starting to be used, gradually. "Standard" Concrete ties have been in use from the 60's (maybe even before?) but turnouts were always wood, mostly because they vary a lot more than plain track. Clips of some variety are the standard fastener for flat bottomed rail over here, wether on wood or concrete. I'm not sure we use spikes at all. ("Traditional" UK track has a bullhead rail which sat in chairs bolted to wooden sleepers, with a wood block or metal clip holding the rail in place on the chairs.)
saw several about to be installed while on vacation. took pictures, but they didn't turn out . this was between lusk and orin wyoming.
UP recently replaced long sections of track on the Cascade Subdivision in Oregon. The ties are still wood, but they are using clips instead of spikes. Mike
The way I understand it, clips are used with concrete ties because there is no other way of holding the rail to the tie. You can't drive a spike into concrete. Clips will also let a rail "float" a little, so the rail will not pull loose from the ties. Watch a rail that is spiked to a wooden tie, as a train truck goes over it. See the rail move up amd down with the passing of the trucks. This is what pulls spikes loose. Clips will give a little and keep the rail firmly on the ties.