A manual of the principles and practice of road-making: comprising the location, construction, and improvement of roads, (common, macadam, paved, plank, etc.) and rail-roads. By W. M. Gillespie ...

422 APPENDIX D.
Six men can work to best advantage in loading wagons. They
can fill a wagon containing ~ cubic yard in 2 minutes. Unloading and other delays take 3 minutes, and 100 feet at each end for a
turning space should be added to the hauling distance. The horses
travel at about the rate of 2f miles per hour, or 220' per minute.
Work done in a day of 10 hours, by a pair of horses, working on
a level road, with a common wagon:
Distance in feet.... 100 200 500 1000 1500!2000130005000
Cubic yards per day 61 53 40 28 21 17 12 8
Constant per yard.. 0.16 h. 0.19 h. 0.25 h.
Up a slope of 100' per mile (= -) only 3 as much can be drawn.
Up a slope of 260' per mile (1 in 20), only i as much can be drawn.
D. Railway Work.
Work done on a rail track with horses kept constantly moving,
and hauling on a level three loaded cars, containing 1 yards each,
at 21 miles per hour.
Distance in feet..... 1000 2000 3000 4000 5000 10000120000
Cubic yards, per day. 225 127 90 69 56 29 15
LIMITING DISTANCES.
A limiting distance for any mode of transportation is that at
which that mode becomes more expensive than some other mode.
The first means of moving earth very short distances is by throwing it with the shovel, which can be done 12' horizontally and 5'
vertically. For twice that distance two men may throw twice,.
and so on. The scraper is cheaper for more than 12'.
For long distances and heavy work, rails should always be laid
on which one horse can draw several cars, which can be dumped
where desired.
There is a certain distance at which the various modes of transport become successively more expensive than some other. This
limit is best found by putting tabular results of'experiments in a
diagram.