Cost of Loosening. Sand or sandy loam can be scraped without plowing. In loam a two-horse team and plow will loosen 400 cubic yards per day, at a cost of $3.50 for team, plow, and driver, and $1.50 for the plow holder, making a total of $5.00, or 11 cents per cubic yard. Sometimes the driver can also hold the plow, in which case loosening will cost about 1 cent per cubic yard, since the team will not do quite as much work as when there is a plow holder and also a driver. If the ground is hard it will be necessary to add another team and also a man to "ride" the beam of the plow. If the ground is not very hard, this force will loosen 400 yards per day at a cost of 2.1 cents per cubic yard.
Cost for 25-foot Haul. The cost of building an embank ment from a borrow pit at the side of the road will first be considered. For a 60-foot right of way and a light embankment, the length of haul or " lead " from center of gravity of the fill to the center of gravity of the cut will be about 25 feet. This distance will be a little more or a little less according to the height and width of the bank, and the width reserved for sidewalk; but slight difference in length of short hauls make comparatively little difference in the cost of moving the earth, because in the first place a considerable part of the cost of hauling is due to time consumed in turning and loading, and in the second place the cost of transportation is only about half the total cost of moving the earth.
On the road, an ordinary team will travel 220 feet per minute (21 miles per hour), but in scraping considerable time is consumed in turning, waiting to load, etc., and besides, the distance traveled is more than that from the center of cut to the center of fill; therefore the ordinary speed of the team is no guide in this connnection. Experience shows that a team will use from a minute to a minute and a half in making a round trip at the above distance, or, say, 1.1 minutes per trip. A foot vertically is equivalent to 10 to 25 feet horizontally (see § 74), and in estimating the length of haul this fact must be taken into account.
The scraperful will make 31 cubic feet of compacted embank ment, or will require eight trips per cubic yard. Therefore a team will place a yard of earth in the fill every ten minutes, or 6 yards per hour and 60 yards per day. In light loose earth, where it is easy fully to fill the scrapers, a team may make 70 yards; but if the ground is hard, or obstructed with roots and grass, 50 yards may be the maximum. Assuming a day's work to be 60 yards, the cost of hauling is $3.50 ÷ 60=5.83 cents per cubic yard.
One man will hold and fill the scraper for two teams at a cost of $1.50÷ (2 X 60) =1.25 cents per yard. One man on the dump will ditribute and level the earth deposited by six teams, at a cost of $1.50÷ (6X 60)=0.4 cents per cubic yard. One foreman will be required at, say, $2.50 per day, or $2.50÷ (6X 60)=0.69 cents per cubic yard. For wear and tear of scraper we may allow 10 cents per day for each, or 60 cents for the lot; and for wear of plow and cost of sharpening, say, 30 cents, making a total of 90 cents or 0.25 cents per cubic yard. In very hard ground the above prices may be doubled.
The total cost of moving earth 25 feet will then be as in Table 14, page 118.
Cost for 200-foot Haul. At this distance a scraper holder can fill for four teams. Each team will make the trip in about 31 minutes, and put in about 35 cubic yards per day. The total cost will then be as in Table 14.