Building Construction Handbook, Eighth Edition

Scrapers ~ these machines consist of a scraper bowl which is

lowered to cut and collect soil where site stripping and levelling

operations are required involving large volume of earth. When the

scraper bowl is full the apron at the cutting edge is closed to

retain the earth and the bowl is raised for travelling to the

disposal area. On arrival the bowl is lowered, the apron opened

and the spoil pushed out by the tailgate as the machine moves

forwards. Scrapers are available in three basic formats:-

1. Towed Scrapers † these consist of a four wheeled scraper bowl

which is towed behind a power unit such as a crawler tractor.

They tend to be slower than other forms of scraper but are

useful for small capacities with haul distances up to 30000.

2. Two Axle Scrapers † these have a two wheeled scraper bowl
   with an attached two wheeled power unit. They are very
   manoeuvrable with a low rolling resistance and very good
   traction.


3. Three Axle Scrapers † these consist of a two wheeled scraper
   bowl which may have a rear engine to assist the four
   wheeled traction engine which makes up the complement.
   Generally these machines have a greater capacity potential
   than their counterparts, are easier to control and have a
   faster cycle time.

To obtain maximum efficiency scrapers should operate downhill if

possible, have smooth haul roads, hard surfaces broken up before

scraping and be assisted over the last few metres by a pushing

vehicle such as a bulldozer.

Note: Protective cab/roll bar to be fitted before use.

Scrapers