Scraper (Download)
Scrapers Caterpillar 613C Scraper 1 Scrapers are a type of heavy machinery used for earthmoving Scrapers are capable of excavating, hauling, and dumping material over medium-to long haul distances. Scrapers are useful construction equipment when hauling distances range between 500 to 3000 feet. Source: Caterpillar Performance Handbook : Edition 24, 8-1 to 8-5 S. W. Nunnally , Construction methods and management, 7th edition, 2007 What is scraper? 2 Loading and transporting earth over short and medium distances. Source: www .terex.com/main.php?obj =prod&action=VIEW&id=21&nav=prod&cid=e3959eefdc65adcc4e0e616b833694b1 Standard usage 3 Self-propelled scrapers were invented in the 1930s by R.G. LeTourneau Source: Dr . John H. Niemela , “A History of R.G. LeTourneau’s Earliest Scrapers,” Ver. 1.1B 10–31–07, MoL © History of scraper 4 Source: United States Army Training Support Center Components of scraper 5 The scraper excavates (cuts) by lowering the front edge of its bowl into the soil. The bowl front if equipped with replaceable blades, which may be straight, curved, or extended at the center. Source: S . W. Nunnally , Construction methods and management, 7th edition, 2007 How it works? 6 Hopper (the rear part of the machine ) is lowered or raised to cut into the ground collecting the dirt The collected earth can be moved and dumped accordingly as this process is repeated Some scrapers work in tandem with a bulldozer Source: S . W. Nunnally , Construction methods and management, 7th edition, 2007 How it works? 7 Features of Caterpillar Scrapers include: Standard cubic yard capacities range from 14 yd 3 to 66 yd 3 Weight of machinery can be 67,195 lb up to 146,770 lb Source: Caterpillar Performance Handbook : Edition 24, 8-1 to 8-5 Some features 8 Each type has different characteristics of rolling resistance, maneuverability, stability, and speed in operation. Although there are a number of different types of scrapers, principal types are as follows: types of scrapers 9 Single engine overhung (two or three axle) scrapers Major types of scrapers 10 Twin-engine all-wheel-drive scrapers Cat 627 Twin Engined Scraper Major types of scrapers 11 Towed scrapers Major types of scrapers 12 Towed Scrapers Capacity (heaped) – 18.8 yd 3 to 23.5 yd 3 Capacity (struck) – 13 yd 3 to 17 yd 3 Least expensive Source: http://www.cat.com/cda/layout?m=111776&x=7 13 Elevating scrapers (also known as Paddle Wheel or Self-loading scrapers) Caterpillar 615C elevating scraper Caterpillar 633 elevating scraper Caterpillar 633D elevating scraper Michigan scraper Major types of scrapers 14 Elevating Scrapers Capacity(heaped) – 11 yd 3 to 23 yd 3 Max. Speed – 24.4 mph to 32 mph Ability to homogenize and condition soil while loading Source: http://www.cat.com/cda/layout?m=111776&x=7 15 Auger Scrapers Caterpillar 627G Auger Scraper Major types of scrapers 16 Push-pull (twin-hitch) scrapers Caterpillar 637E tandem push-pull scraper 657G Push Pull Scraper Major types of scrapers 17 18 19 Open-bowl scrapers (Capable of being loaded by front-end loaders or hydraulic excavators) Caterpillar 621 open bowl scraper Caterpillar 627F tandem open bowl scraper Caterpillar 631E open bowl scraper Caterpillar 651 open bowl scraper Major types of scrapers 20 Open Bowl Scrapers Capacity (heaped) – 22 yd 3 to 44 yd 3 Max. Speed – 32 mph to 36 mph Often have push/pull ability Source: http://www.cat.com/cda/layout?m=111776&x=7 21 Coal Bowl Scrapers Capacity (heaped) – 50 yd 3 to 73 yd 3 Max. speed – 31.1 mph to 34.1 mph Often powered by twin engines Most Expensive Source: http://www.cat.com/cda/layout?m=111776&x=7 22 Rolling over on uneven ground and during turns, especially with full loads Failure of brakes or other machinery components Low visibility behind and around the machine Crushing and wedging in between other objects Scraper hazards 23 Failure of safety measures such as ROPS, backup alarms, safety belts Poor communication among workers and operators Hazardous road conditions Dangerous maintenance situations Some concerns 24 Scraper Fatality Statistics From 1990 thru 2009 OSHA investigated 52 incidents involving scrapers 25 Type of Scraper Movement 26 An operator was pulling a pan scraper with a tractor The operator was driving along a ditch The slope caused a rollover The man was crushed because of a lack of rollover protection Source: Extracted from OSHA Accident Investigation Data 1990- 2009 Fatality Example 1 27 Operator was working with a surveyor The surveyor knelt down to place a grade stick The backup alarm was not working and the operator backed over the surveyor with a scraper There was no third observer to communicate between the two men Source: Extracted from OSHA Accident Investigation Data 1990- 2009 Fatality Example 2 28 An employee just finished dumping a full pan load As he made another pass he fell off of the machine He was run over by the front left tire Source: Extracted from OSHA Accident Investigation Data 1990- 2009 Fatality Example 3 29 The owner/operator of an E200 International was completing a sharp left turn down a slope The right rear wheel lifted off the ground and the scraper tilted down the hill The machine rolled over and crushed the operator Source: Extracted from OSHA Accident Investigation Data 1990- 2009 Fatality Example 4 30 An employee was standing next to a scraper with his back facing another scraper To move out of the way, the operator shifted the front scraper in reverse The employee on the ground was crushed between the two machines Source: Extracted from OSHA Accident Investigation Data 1990- 2009 Fatality Example 5 31 A scraper was parked on a downhill incline The scraper rolled forward and pinned an employee between the scraper and a service truck. Source: Extracted from OSHA Accident Investigation Data 2007-2009 Fatality Example 6 32 A worker noticed a piece of wood lodged in the cables under the scraper He told the operator to wait a minute but the message was missed due to the operator talking on his mobile telephone The employee was crushed by the rear tire when the operator proceeded to drive the scraper Source: Extracted from OSHA Accident Investigation Data 2007-2009 Fatality Example 7 33 Subpart O- Motor Vehicles, Mechanized Equipment, and Marine Operations 1926.602 Material Handling Equipment 9. Audible alarms. (I) All bidirectional machines, such as {…} [scrapers] shall be equipped with a horn, distinguishable from the surrounding noise level, which shall be operated as needed when the machine is moving in either direction. The horn shall be maintained in an operative condition. Source: OSHA 29 CFR 1926 Construction Industry Regulations OSHA regulations 34 Subpart W: 1926.1000(c)(2) Rollover protective structures (ROPS) and supporting attachment shall [be] {…} installed in a manner which will support, based on the ultimate strength of the metal, at least two times the weight of the prime mover applied at the point of impact. Source: OSHA 29 CFR 1926 Construction Industry Regulations OSHA regulations 35 1926.1000(c)(2)( i ) The design objective shall be to minimize the likelihood of a complete overturn and thereby minimize the possibility of the operator being crushed as a result of a rollover or upset. Source: OSHA 29 CFR 1926 Construction Industry Regulations OSHA regulations 36 1926.600(a)(3)( i ) scraper blades {…} shall be either fully lowered or blocked when being repaired or when not in use. All controls shall be in a neutral position, with the motors stopped and brakes set, unless work being performed requires otherwise. Source: OSHA 29 CFR 1926 Construction Industry Regulations OSHA regulations 37 1926.602(a)(2)( i ) Seat belts shall be provided on all [scrapers]. and shall meet the requirements of the Society of Automotive Engineers, J386-1969, Seat Belts for Construction Equipment. Source: OSHA 29 CFR 1926 Construction Industry Regulations OSHA regulations 38 1926.602(a)(4) All earthmoving equipment [including scrapers] shall have a service braking system capable of stopping and holding the equipment fully loaded, as specified in Society of Automotive Engineers SAE-J237. Brake systems for self-propelled rubber-tired off-highway equipment manufactured after January 1, 1972 shall meet the applicable minimum performance criteria set forth in the following Society of Automotive Engineers Recommended Practices: Self-Propelled Scrapers; SAE J319b-1971. Source: OSHA 29 CFR 1926 Construction Industry Regulations OSHA regulations 39 1926.602(a)(5) Pneumatic-tired earth-moving haulage equipment [ such as scrapers] whose maximum speed exceeds 15 miles per hour, shall be equipped with fenders on all wheels to meet the requirements of Society of Automotive Engineers SAE J321a-1970, Fenders for Pneumatic-Tired Earthmoving Haulage Equipment. An employer may, of course, at any time seek to show under 1926.2, that the uncovered wheels present no hazard to personnel from flying materials. Source: OSHA 29 CFR 1926 Construction Industry Regulations OSHA regulations 40 1926.1000(c)(2)(ii) The design shall provide a vertical clearance of at least 52 inches from the work deck to the ROPS at the point of ingress or egress. 1926.1000(d) Remounting. ROPS removed for any reason, shall be remounted with equal quality, or better, bolts or welding as required for the original mounting. 1926.1000(e) Labeling. Each ROPS shall have the following information permanently affixed to the structure: Manufacturer or fabricator’s name and address; ROPS model number, if any; Machine make, model, or series number that the structure is designed to fit. Source: OSHA 29 CFR 1926 Construction Industry Regulations OSHA regulations 41 Proper operation and maintenance of the scraper prevents accidents ! 42 DRESS RIGHT FOR THE JOB: Safety hat Safety Shoes Safety Glasses / Goggles Heavy Gloves Hearing Protection Reflective Vest Respirator(when needed) Source: Construction Industry Manufacturers Association, Scraper safety manual for operating and maintenance personnel, 1980 Safe work practices – PPE 43 Think ahead! Become familiar with all conditions in the area, such as: Condition of haul roads. Holes, obstructions, mud and ice. Traffic routes and rules. Dust, smoke or fog. Underground utilities Know the working area Source: Construction Industry Manufacturers Association, Scraper safety manual for operating and maintenance personnel, 1980 44 Read the manufacturer’s operating manual. Know the capabilities of the equipment; and its limitations. Become thoroughly familiar with all controls, gauges and instruments. Work slowly and carefully until accustomed with the equipment. Know the protective devices on the scraper. For example: Guards, Canopies / Roll-over Protective Structures, Shields, Backup Alarms, Seat Belts. Pre-operation instructions Source: Construction Industry Manufacturers Association, Scraper safety manual for operating and maintenance personnel, 1980 45 Walk-Around the scraper at the start of each shift; and inspect: Check to be sure there is nobody working on it, under or nearby. Check the area to be sure it is clear of obstructions and/ or people. Machine and engine compartments / instruments Check utility / pressurized lines Safety devices Pre-operation walk-around check Source: Construction Industry Manufacturers Association, Scraper safety manual for operating and maintenance personnel, 1980 46 Brake systems Headlights and warnings Dirt or trash buildup Oil or coolant leaks Structural maladjustments/ Looseness/ cracks Wear or damage to moving parts The scraper operator is responsible for operations and has the authority to stop work when conditions are unsafe. Pre-operation walk-around check continued Source: Construction Industry Manufacturers Association, Scraper safety manual for operating and maintenance personnel, 1980 47 Sound horn before starting Observe all signs and signals Mount and dismount carefully (Never forget three-point contact!) Check warning devices Obey traffic rules Maintain control of scraper at all times Be sure that communication between ground employees is clear and evident Safe work practices – DO s 48 Don’t overspeed especially with full pans Don’t carry passengers Don’t service a machine in motion Don’t operate an unsafe machine Don’t engage in horseplay Don’t forget safety belt. Uneven terrains may cause a scraper to tilt Safe work practices – DON’T s 49 Be aware of overhangs / electrical wires, slide areas, or other dangerous conditions Cross ditches, sidehills and ridges slowly, usually at an angle Do not coast in neutral Make sure clearance flags and other required warnings are on machine when roading Watch for flagman or other personnel Always apply retarder / brakes to reduce speed before entering sharp turns Always anticipate grade; and select proper gearing range accordingly. Operating scraper – safely Source: Construction Industry Manufacturers Association, Scraper safety manual for operating and maintenance personnel, 1980 50 Attach appropriate warning tags to the steering wheel to prevent accidents. Read and understand maintenance, lubrications, and engine manuals. Keep hands and clothing away from moving parts. Lower all raised equipment before servicing. Always block the apron and ejector securely. Do not use gasoline or diesel fuel to clean parts. Pressurized systems / Electrical systems can cause burns or serious injuries if not handled properly. Service and repair scraper – safely Source: Construction Industry Manufacturers Association, Scraper safety manual for operating and maintenance personnel, 1980 51 Think safety Work safely 52