Drag Scrapers. On short hauls up to about 50 feet, a team with drag scraper may handle from about 4 to 7 cubic yards per hour, and one man will load for 2 or 3 scrapers, depending upon the distance. If the lead be 100 feet, the drag scraper should move from 3 to 5 cubic yards per hour, and one man should load about 4 scrapers.
Wheel Scrapers. Small (number i) wheel scrapers have a capacity of about 1 cubic yard of compacted earth, and for a haul of no feet may be expected to give about the same results as drag scrapers. For longer hauls, about one minute of time of team and driver will be required per trip for each zoo feet of additional distance, or about 5 minutes for each yard of material moved.
The large size (number 3) wheel scraper may be con sidered as carrying 1 cubic yard at a trip. A snatch team and extra man, or two extra men, will be required to load. These will load a scraper in an average of from one minute to two minutes. Two or three min utes may be allowed for loss of time of scrapers on each trip in loading and .unloading, and one minute for each no feet of haul. Thus, with a lead of 300 feet, a trip would be made in five or six minutes; 10 or 12 trips per hour, or from 3i to 4 cubic yards per hour for each scraper.
Wagons. Over ordinary earth roads a team and wagon will carry an average load of. x cubic yard; on good hard earth roads 11 yards may be taken. In loading ordinary soil which has been loosened by plows, men may be expected to average from I I- to 2 cubic yards per hour. When the work is fairly well organized and as many men are employed in loading as can con veniently work about a wagon (usually about 7 or 8) the loss of time of each team in loading, unloading, etc. may average about 5 to 7 minutes for loads of one cubic yard, while the time occupied in hauling will average about one minute foreach Ioo feet of lead. When dump wagons are used, about one minute would be saved on each trip.
In estimating the cost of earthwork, about 20 to 25 per cent should be added to the labor cost for con tractor's profit, contingencies, etc. The skill with which earthwork is managed has much to do with the cost. Failure to properly organize and systematize the work may easily increase the labor cost 50 per cent. It is not uncommon to find that two pieces of work identical in character, and 'conducted under the same conditions, differ 25 per cent in cost, because of the difference in the foremen handling the work.