I was solicited to provide a proposal for some railroad layout. Never worked on a railroad all the live long day. Other than the curves are there any other variations to normal layout? I am assuming that I'd get a CAD file, so how hard can some layout be?
Railroad curves are banked using cant instead of superelevation. I'm not aware of any layout software that can calculate cant, so that may be a problem.
I do a considerable amount of work for the railroads, both design and construction. It really depends on what they are looking for. In most cases, the class 1 railroads do their own track work but contract the dirt out. In this case it is just like laying out a road with the exception that the stationing is usually based on chord definition. We usually work directly for the railroad and lay out the track post dirt work. Rarely do they want grade, the sub ballast should be correct and the cant or super-elevation adjusted for in the tamping operations. Most of the time we set nails with whiskers on center-line but are sometimes asked to provide offsets as well. Turnouts are also staked along with the corresponding point of intersection. This year alone we have provided track layout well over a mile of track in this fashion.
On the more technical side, we are currently working on a slab track project consisting of a around 20,000 feet of track set in concrete plinths. Here we are setting horizontal and vertical positions, gauge and super-elevation every 10 feet to very tight specs. We started in January and will be pouring concrete well into July with final as-built mapping scheduled for November. For this we have a very specialized trolley that links to our Leica MS50 to provide the positioning. Kind of like machine control with a couple of labor's acting as the machine.
> For this we have a very specialized trolley that links to our Leica MS50 to provide the positioning. Kind of like machine control with a couple of labor's acting as the machine.
Which trolley system are you using? We have used the Trimble GEDO and Vorsys in Dallas, Phoenix, Denver and San Fran with excellent results. A little blue birdy told me that they will be using one in San Diego soon. I have 16 track miles to do on the project I am currently on, it is a mix of UP and BNSF. I don't anticipate having dense enough control to make the trolleys a viable option here, man if I did though.. I might look like a super charger.
Roadhand,
We are using the Amberg system. Amberg recently released an IMU for their system which could possibly work on slab track. The trolley is great for slab track and the reporting is phenomenal. What I'm really looking forward to is using it for pre-design mapping.
Are you putting in the actual rail or just the road bed. As I said in my original post, we usually just layout the center-line and maybe some offsets. Rarely do they even want grades (I can only think of a couple of times in the last 20 years).
On the light rail projects we actually built the rail, (ballasted, DF and embedded).I am not sure about here just yet, I have never worked with the heavy rail before, it seems reasonable that they might want to do their own with their people; but I do know we go at least to the ballast because I have been asked about how we are going to track our quantities by some people doing some of the planning.
I got that call, too, Thadd. I reviewed the plans and specs and decided to hand it off.
Dtp
Did the fellow tell you that they may be starting in 2-weeks? We are picking up with other things and I do not really care for layout work. The uniquity of the project drew my attention, but I do not think we can dedicate the crew to train layout. I did offer as-builting with mobile lidar. That is more my speed.
The layout should really be no different from any other construction layout you do. The most important thing is to have good communication with the rail contractor and give them exactly what they ask for. There should be stationing on the plans, with the major geometry points labeled. When I layout track for our rail contractors, it is usually 3 times. The first time is on a 15 or 20 foot offset, 50 foot stations on tangents, 25 foot max stations in curves and all of the major geometry points (TS, SC, CS, ST, POS, POF, and vertical curves). This is usually just for the dirt work and sub-ballast, and tie layout. Next, I re-stake the same points, but on a 10 or 12 foot offset and put in offsets on both sides for the POS and the POF. The last layout is really just a check for final alignment while they tamp and line the new track. I typically write the top of rail elevations on the back of each stake and let the contractor do the grading off of on-site benchmarks.
This might be a little over for your purposes, but since I work for the Railroad that the contractors are doing the work for, I can devote as much time as needed to the project and baby sit the contractor if necessary as there is no budget involved for my time.
Let me know if there is anything I can help you with.
Sort of ironic my worlds of model railroading and surveying would come together.
I posted the jest of this topic on my MRR forum I frequent today. Amazing how many replies who knew exactly what you all are talking about. Guess I shouldn't be surprised. Many of them are former rail road workers.
I still have my HO scale (1:87.1) survey crew unopened. I'll bust them out when I build the mountain. I'm still working that idea in my head.
This ain't no poor man's hobby for sure!
E
Yeah, start in two weeks, and I am just now starting a two week project. It wouldn't fit, and I don't do that much layout anyway.