Not sure if this is the right forum for this but... Suppose you're a class 1 RR and your laying a double main line through the south west desert. There may be a rock out-cropping or two that you may need to go around but mostly you've got it easy... straight and flat. Your surveyors come upon an arroyo, gulch, dry wash or what ever you want to call it. You will need to bridge this gap because if fill is used it would just wash away eventually. Initially you sink piles and build bents and call it good, right? So at what point, if ever, do you replace your wooden "get it done" bridge with a more modern concrete or steel structure? I ask because I'm building a module and I'm wondering if a simple low wooden trestle would look out of place on a class 1 modern double mainline, after all it's just a dry wash. I guess the real question here is; whats out there now as opposed to what was there in the '30s? Any kind of information would be appreciated. Steve F
Well, you've probably heard of the recent trestle fire problems.( UP in Sacramento is the biggest that comes to mind. ) There are still alot of wooden trestles out there on class 1s. Following the transcon across AZ, I saw many many small wooden trestles over washes. Steel for larger ones, especially if they had roads underneath.
Many of the Class One main line wooden trestles have a ballasted deck. For new construction these days, they often will build the permanent bridge right at the start. Modern methods are failrly speedy. And doing it this way saves money. Boxcab E50
Thanks John, I don't think I've ever seen a wooden trestle with double track, so I think I'll diverge the tracks slightly and cross the wash with two trestles that are not quite parallel. Boxcab, how do they keep the ballast on the trestle? This must be a different layout than the ones I'm used to seeing. Steve F
Wooden trestles ATSF/BNSF has quite a few still on the transcon. Ballasted deck wood trestle with pile construction. Including double track on the double track areas. One was burned just recently just west of Belen, NM. The issue with double track ones is that rarely was track initially built as double track. So the construction and placement of the piles for the additional track will generally look different (from slight to major differences).
Steve- For those I am familiar with, usually a perforated metal tray. Steel bridges use a sectional concrete trough. Boxcab E50
You probably wont find any high 'spider-webby' wood trestles in use on mainlines today, but there are a number of short ones around here. Yes all have ballasted track. I will seed if I can find a photo of one that washed away one night over in Grand Prairie a while back. That line was abandoned shortly after that. I'll post it later.
Watash, is the photo of the bridge or what was left after the wash-out? Thanks everyone for all the information. I do appreciate it. Steve F
I used to drive by this trestle and bridge combination on the way to work. It is in north Grand Prairie or Arlington. After very heavy rains I discovered a couple of box cars were left sitting out over the water. It had rained all week end. The next Monday it was washed out. They had hauled off the cars when I got there, but took this photo of what was left. The line was closed and removed later.
Espee Sunset Route, now UP main line Los Angeles to New Orleans, single track bridge in San Antonio, Texas. I think there are a lot of these. This one is recently repaired and upgraded. Note it is not a ballasted deck.
Box Girder trestle combination, I wonder why? It will take some reverse imagineering to visualize this bridge intact. What is the sound of a pile being extracted from the mud? Thanks for the pic Watash Steve F
There doesn't appear to be any kind of cribbing or retaining wall as the track transitions onto the bridge. Seems to me this would led to a constant repairing/replacing ballast situation. Thanks for the pic Flash Steve F
Steve- If you look closely, you'll see there is a wall. Even so, a sill can still sink. It depends upon the fill underneath, drainage, etc. Boxcab E50
Girder bridge. Easy to install and maintain. Simple abutments. It also allows clearance for debris during flash times. Like these: Or
There is a few box girder bridges around here in eastern ILL, none double tracked. This one is south of Bethany, IL. over the Okaw river, on IL 121 There’s several small wooden bridges along that trackage between Mattoon and Decatur. And western IN., this one was over a highway in Dugger, IN, on the INRR. I think it was part of the IC at one time http://www.trainboard.com/railimages/showphoto.php/photo/42044/ppuser/4309 I’ve got a photo of the whole thing, but I can’t find it on here. It's still in our old putor and hasn't transfered it yet inch
Good point. Here is the other end of the bridge; there is a small retaining wall at the far right, barely visible. I would assume it is similar on the other end and maybe is now, as Boxcab50 says, obscured by rocks, etc.? The Texas "river" is in the first picture at the far end of the span, about two feet wide at the time of the photo. [Off topic edit] I always thought that a bridge like this with a road passing under one end would be a neat scene on a model railroad.
A reason you can barely see the end pile bent, and the timbers of the end sill- If there is fill piled against it on one side only, after a while, it can start pushing the sill and bent over. Thus, counterweight is needed to keep this from happening. So you see fill on the open side. Boxcab E50
