How fast is modern rail laying? - Trains Magazine

tree68 wrote:

1435mm wrote:  tree68 wrote: Interesting question.  To refine it a bit (this would likely be an MC question, or 1435mm) - let's compare to that 10 mile stretch that got laid in a day way back when (which, I'm sure, would define 'sketchy' construction).  Given appropriate approvals, adequate supplies of materials, and no special considerations (major cuts/fills/bridges/etc), how long would it take to lay 10 miles from first cut with a bulldozer (or other earthmover) to last spike, given todays methods and standards?  That "10 miles in a day" was laid on a prepared grade and of course was a stunt.  If you wanted to do a stunt today, this could certainly be bettered.  Working on a prepared grade today, and wanting to make good production but not take undo risks or spend gobs of money, I would be happy with 10,000 feet. S. Hadid No question on the stunt part - I was focusing more on the 10 miles as a distance, and looking for 'real world' numbers - the stakes are out (MC's done surveying), but no earth has been moved.  We're assuming that leaves relatively minor grade work - some cuts and fills to smooth out wrinkles - sub-grade (foundation) preparation, maybe laying asphalt (if it's to be used) then setting track and ties and ballasting.  Given an "average" workforce, when can I expect to use my new track?

There are dozens of assumptions built in:

1.  We have only culverts and bridges of small and medium size (up to 80 foot spans, no pier more than 30 feet from streambed to top of pier).  We have no bridges over a navigable waterway. 

2.  We're building 100 miles, so there's some efficiency of scale.

3.  We're wanting to get this done expeditiously.

4.  We don't have any grade separations.

5.  We don't have any urban construction.

6.  We don't have any serious subgrade issues that require freezing or massive excavation and replacement of inadequate materials.

7.  We don't have to put in a signaling system; just power-assisted turnouts at sidings, detectors, and a few active grade-crossing warning devices.

8.  We have no deep cuts or high fills (more then 30 feet).  We don't have any sidehill construction, retaining walls, rock scaling, or tiebacks.  We have no heavy rock work, just consolidated soils and mudstone that we can rip with a D11.

9.  We can actually get delivery on the ties, rail, turnouts, OTM, bridge beams, H-pile, and grade crossing equipment from the suppliers upon six months notice.

10.  We don't have any labor shortages, nor are we in a position where we have to compete against larger projects for the same people, machines, and materials.

11.  Design has been completed, permits obtained, and survey and geotech is completed.

12.  We've got the cash to pay the contractor in the bank and don't have any disbursement restrictions from our bankers.

13.  We're in a climate that permits soil compaction at least 240 days a year (not too wet in the spring, not too cold in the winter).

Given all these assumptions, the time from Notice to Proceed to Trains Running is 16 months.  The bridges are the Achilles Heel; if we could start early on those (or we didn't have any) the time would be reduced to 12 months.

(FYI asphalt as a subballast is uncommon and has only to my knowledge been used where suitable crushed rock was not locally available; generally crushed rock is cheaper.)

S. Hadid