Page 41 - Built Expressions - Online Construction Magazine - November 2014 Issue

Cover Feature instrument from a distance via 2. Earth Excavators remote control. This eliminates the Excavators fall under heavy equipment need for an assistant staff member as category and consist of a boom, bucket the operator holds the refector and and control cab on a rotating platform. controls the total station from the The cab which sits on top of an observed point. under carriage with tracks or wheels, controls all movement and functions • Automatic level - It is an instrument of the excavator and are accomplished to take levels of any surface. through the use of hydraulic fuid, be Good level instrument shall have it with rams or motors. Excavators property of automatic horizontal are used in many ways and for many adjustment of the line of sight, an purposes by changing the attachments. erect fgure and a horizontal circle • Digging of trenches, holes and of 0 - 360° and large ribbed control foundations buttons to simplify the adjustment • Material handling of the instrument. The compensator • Brush cutting with hydraulic shall be magnet damped, so that after attachments icdn.tonzof.com the instrument has been set almost • Forestry work horizontal, the line of sight can be • Demolition carefully levelled using the automatic • General grading/landscaping compensation mechanism. • Heavy lift, e.g. lifting and placing of pipes • Abney Levels - A Topographic • Mining, especially, but not only Abney Level is an instrument used open-pit mining in surveying which consists of • River dredging a fxed sighting tube, a movable • Driving piles, in conjunction with a spirit level that is connected to a Pile Driver pointing arm and a protractor scale. Types of Excavators can be listed as The Topographic Abney Level is below: used to measure degrees, percent • Compact Excavator of grade, topographic elevation • Crawler Excavator images.tigersupplies.com and chainage correction. By • Wheeled Excavators using trigonometry the user of • Backhoe Loader a Topographic Abney Level can • Dragline Excavator determine height, volume and grade. • Bucket Wheel Excavator The Topographic Abney Level is used • Long Reach Excavator at the eye height of the surveyor and • Power Shovel is best employed when teamed with • Suction Excavator a second surveyor of the same eye Descriptions and other parameters height. This allows for easy sighting related to Excavators are since of the level and greater accuracy. available in plenty, these are not dealt in detail in this section. • Clinometers - Clinometers is an instrument for measuring angles 3. Dozers of slope (or tilt), elevation or Powerful machine for pushing earth or inclination of an object with rocks, used in road building, farming, respect to gravity. It is also known construction and wrecking; it consists as a tilt meter, tilt indicator, slope of a heavy, broad steel blade or plate alert, slope gauge, gradient meter, mounted on the front of a tractor. gradiometer, level gauge, level Sometimes it uses a four-wheel-drive meter, declinometer and pitch & roll tractor, but usually a track or crawler upload.wikimedia.org indicator. Clinometers measure type, mounted on continuous metal both inclines and declines. treads, is employed. The blade may be Vol: 3 Issue: 11 November 2014 Built Expressions PG 41