BNSF is moving their storage tracks from downtown out to the edge of our city. Two new tracks about a mile long run parallel to the existing main.The existing main, put in 100 years ago is graded level. The 2 new tracks that are 50-100 feet away are not. They follow the lay of the land-up,down,up,down, pehaps 2-3 feet. If they were going to spend the money to put in new storage tracks, why would they not make them level?
They are storage tracks - not main tracks so you save money where you can - grading costs money!
My career spent it’s first half on and around Chessie System facilities - railroads that had enough revenue over the years to ‘optimize’ their rights of way - using cuts and fills to have sustained grades, rather than undulating track structures.
When I went to Jacksonville and had the opportunity to view ACL, SAL and L&N rights of way - they were mostly laid ‘on the top of the ground’. Railroads in the South had to do their expansion after the Civil War just like Northern railroads did, however the South had lost the war and the investment in Southern railroads was more limited than those in the North. Grading costs money, no matter the era it is done in and the South didn’t have sufficient investment base to do anything more than get their roads to the intended points by the cheapest means possible.
Murph: Adding to what BALT already pencilled-in:
(1) The tracks are more than 25 feet away from the main. Good thing - you can now work while another train passes on the main. Bet the side tracks/ storage tracks are more than the minimum 15 foot track centers as well.
(2) Suspect the tracks are lower as well and slope towards the middle to keep cars from rolling out (and finding Mr Derail). Some of that “lay of the land” also will create the uneven-ness of the grade as the light vertical curves drop the track and bring it back up. Looking at curved and not quite parallel track will exagerate the differences. Also, drainage will play into the final design which in turn has an effect on your up and down along with your construction economics. (how much topsoil had to be exumed/relocated to find some foundation capable good 'ol dirt?)
(3) Wonder if the folks in Kansas City (system engineering) also made accomodations for at least some light expansion in placing this facility. It probably got meeting-ed to death prior to final design and actual construction.
“+1” to MC’s comments. Additionally:
Even when the track is level, the parallel drainage ditches often have a grade (slope) engineered into them so that they’ll drain to a low spot for discharge, such as to a pipe or culvert under the tracks, or a stream. Following the lay of the land provides that required slope without any additional effort.
Earthwork quantities - and presumably costs - vary as the square of the height of the fill/ depth of the cut. So an additional incentive not to do any more of that than you have to.
A good principal of grading and track alignment / profile design is that the volume of excavated ‘cut’ material (Cubic Yards) should equal the volume of the embankment ‘fill’ material; otherwise, you have to either ‘waste’ the excess cut, or ‘borrow’ from someplace else to have enough fill. Achieving that goal may have also influenced the grading plan and profile.
- PDN.
A civil engineer I used to work with called this “balancing your dirt”. Must have been fun in the mountains of western AR where we worked.
I remember doing a lot of that type of math in surveying class in high school. 20 years later, my brother was using high tech equipment to measure volumes of coal piles utilizing aerial photography. I bet cut and fill problems are a little easier to figure nowadays.
Wouldn’t an overabundance of ups and downs cause a fair amount of issues with slack in a storage yard where you’re pushing around cars?
But the speeds are low, so the problems are manageable.
Key word - STORAGE not switching.
When constructing the Santa Fe’s 44 mile Williams - Crookton line change in the Arizona mountains (1959-1960) the concern was to minimize gradient changes and thus reduce the ‘wear and tear’ on car components that had historically been prevalent in this mountain terrain. Historically there had been too many knuckles broken, derailments and other operational difficulties where it was difficult to reach the site and restore operations. Santa Fe designed the new line with a 30 mile segment with a 1% gradient for the entire distance and it intercepted an opposing gradient of 0.85 % which was margenalized with a 10,000 foot verticlal curve to minimize the effect on train handling. This Transcon Line as it is now recognized has 70 MPH freight trains through these mountains.
Yes there was lots of ‘waste’ to dispose of and it was used in some cases to control drainage from the creeks. There was also lots of ‘borrow’ necessary but the extra costs of all this are offset by the efficient operation, now 57 years and counting.
My experience in NW Iowa was showing me topsoil/organics typically down to a depth of 8-12 ft. You got rid of that stuff somewhere and found more suitable material to build track foundation (cut or fill)…Is the topsoil that deep around there? (kinda hard to balance dirtwork with organics/topsoil in the mix)
(used to load up my P/U with that Iowa topsoil on my returns to Denver so I could actually grow stuff in my yard which otherwise was like farming brick.)