I am laying out my Intermodal yard and realized that I have never seen recommendations for track spacing. This will be a yard that utilizes a Mi-Jack crane and possibly some side-loaders. The yard will be double tracked. I have the Kalmbach book by Jeff Wilson but he never states the track spacing within the yard. I guess this varies by the yard but is there a popular spacing used? Also, is a Mi-Jack crane only supposed to span one track and the truck trailer (assuming we are off-loading containers) or can it span two tracks and the trailer?
The NS intermodal yard at Albany, NY has a new MiJack loader that spans one track and two lanes of truck pavement. In this particular yard they unload one track and then go to the other with trailers spotted in two rows between the tracks. The tracks are spaced about 40 foot centers. This yard was not originally built for this service, it was an auto unloading facility first. The track spacings may not be the same as a modern intermodal facility. I know that the side loaders need more room to manuever than the MiJack style do, so a very wide spacing would be needed for both types of lifters. In small facilities I have seen tracks run on the far edges with pavement for side lifters and storage between them or with tracks in the middle and pavement either side with a MiJack straddling one or both tracks together. Any variation is possible.
A typical overhead crane installation stradles one track and two pavement lanes (sometimes the two pavement lanes are on one side, sometimes on either side of the track) There is a simple reason for this. The trailers or contianers will not all be facing the same way. Typically the truck lanes are set up so all the trailers facing one way go into each lane. This makes staging the tractors easier.
According to the construction plans for the BNSF Alliance Intermodal Facility in Fort Worth, Texas, the Mi-Jack crane operates on two 10' wide concrete "tracks" (they are 17" thick vs. 9" thickness for other paving) on 65' centers. This allows 11.5' for the tracks and 43.5' for the drive lanes underneath the crane. The spacing to the next adjacent track is 113.75' on center. The track to the east is spaced farther to allow for storage of the trailers. These plans were from the expansion of the IMF and reflect a minimum allowable spacing for a high traffic facility. The track spacing for the original 3 tracks was 270' on center. I will try to scan the section detail and upload it, but I may have a difficult time reducing it. RC Harris Roanoke, Texas
Thanks for the reply's and RC, thanks for posting that scan. It looks like I can be a little flexible as prototype yards are designed to fit the location and type of loading and existing trackage. I will draw out my available space and start putting in details of where things might fit. This will help determine the ultimate location for the tracks. Again, thanks for the responses.
