UNIT 2: EATHWORK EQUIPMENTThe equipment which involves the moving or processing of parts of the earth's surface. Much of earthworks involve machine excavation and fill or backfill. ENGINEERING FUNDAMENTALS OF MOVING EARTH:On heavy construction projects the major portion of the work consists of handling and processing bulk materials. The constructor must select the proper equipment to relocate and/or process these materials economically. The decision process for matching the best possible machine to the project task requires that the estimator take into account both the properties of the material to be handled and the mechanical capabilities of the machine.Larger units generally have lower unit-production cost, but there is a trade-off in higher mobilization and fixed costs. The size of the individual material pieces will affect the choice of the machine size. A loader used equally to move shot rock must be able to handle the largest rock sizes produced.VOLUMETRIC MEASUREFor bulk materials volumetric measure varies with the materials position in the construction process. The same weight of a material will occupy different volumes as the material is handled on the project.Soil volume can be measured as bank cubic yard, loose cubic yard, compacted cubic yard.The shrinkage factor is the ratio of the compacted dry weight per unit volume to the bank dry weight per unit volume.The swell factor is the ratio of the loose dry weight per unit volume to the bank dry weight per unit volume.ROLLING RESISTANCERolling resistance is the resistance of a level surface to constant-velocity motion across it. This is sometimes referred to as wheel resistance or track resistance, which results from friction or the flexing of the driving mechanism plus the force required to shear through or ride over the supporting surface.This resistance varies considerably with the type and condition of the surface over which a vehicle moves. Soft earth offers a higher resistance than hard-surfaced roads such as concrete pavement. For vehicles which move on rubber tires the rolling resistance varies with the size of, pressure on, and tread design of the tires. For equipment which moves on crawler tracks, such as tractors, the resistance varies primarily with the type and condition of the road surface.A narrow-tread, high-pressure tire gives lower rolling resistance than a broad-tread, low-pressure tire on a hard-surfaced road. This is the result of the small area of contact between the tire and the road surface. However, if the road surface is soft and the tire tends to sink into the earth, a broad-tread, low-pressure tire will offer a lower rolling resistance than a narrow-tread, high-pressure tire. The reason for this condition is that the narrow tire sinks into the earth more deeply than the broad tire and thus always has to climb out of a deeper hole, which is equivalent to climbing a steeper grade.The rolling resistance of an earth-haul road probably will not remain constant under varying climatic conditions or for varying types of soil which exist along the road. If the earth is stable, highly compacted, and well maintained by a grader, and if the moisture content is kept near optimum, it is possible to provide a surface with a rolling resistance about as low as that for concrete or asphalt. Moisture can be added, but following an extended period of rain it may be difficult to remove the excess moisture and the haul road will become muddy, thus increasing the roiling resistance. Providing good Surface drainage will speed the removal of the water and should permit the road to be reconditioned quickly.TYPES OF EARTH WORK EQUIPMENT: Loaders Backhoes Excavators Scrapers Motor graders Rollers Dump trucks TRACTORS: A tractor is an engineering vehicle whose applications are land clearing, bull dozing, ripping and towing other pieces of construction equipment. Tractors can be fitted with engineering tools such as dozer blades, buckets, hoes, rippers, etc. The most common attachments for the front of a tractor are dozer blades or buckets. A bulldozer is a track-type tractor with a blade attached in the front and a rope-winch behind. Bulldozers are very powerful tractors and have excellent ground-hold, as their main tasks are to push or drag. Loader tractors were created by removing the blade and substituting a large volume bucket and hydraulic arms which can raise and lower the bucket, thus making it useful for scooping up earth, rock and similar loose material to load it into trucks. A tractor is an engineering vehicle whose applications are land clearing, bull dozing, ripping and towing other pieces of construction equipment. Tractors can be fitted with engineering tools such as dozer blades, buckets, hoes, rippers, etc. The most common attachments for the front of a tractor are dozer blades or buckets.Bulldozer: The bulldozer is a very powerful crawler that is equipped with a blade. The term bulldozer is often used to mean any type of heavy machinery, although the term actually refers to a tractor that is fitted with a dozer blade. Often times, bulldozers are large and extremely powerful tracked vehicles. The tracks give them amazing ground mobility and hold through very rough terrain. Wide tracks on the other hand, help to distribute the weight of the dozer over large areas, therefore preventing it from sinking into sandy or muddy ground. Bulldozers have great ground hold and a torque divider thats designed to convert the power of the engine into dragging ability, which allows it to use its own weight to push heavy objects and even remove things from the ground.TYPES OF BLADES:The blade on a bulldozer is the heavy piece of metal plate that is installed on the front. Theblade pushes things around. Normally, the blade comes in 4 varieties:1. Straight Blade (S) is most commonly used for general dozing since it has high of cutting edge; and high penetration. Productivity and utility of the dozer increases, if blade can be tilted. However, as compared to "U" blade, straight blade has higher frictional drag, which prevents movement of soil, thereby reducing output.2. On the other hand, with U blade/bowl excavated soil which is in front of the blade keeps on rolling, thereby reducing frictional drag and increasing output. U blade is longer and due to side wings soli carrying capacity is more than "S" blade. U blade is more suitable for handling large volumes of light loads. 3. Angling blade (A) is slightly curved and is fitted with sharp cutting edge, shape of which is similar to letter (A) at the both ends, which may flare at an angle up to 25. This blade is quite useful in cutting roads in hills, back tilling cutting ditches. 4. "C" blade - This blade is used while pushing scrapers. Straight blade "S" being longer if used for pushing is likely to damage costly tyres of scraper while turning. "C" blade is shorter than normal blade and acts like cushion. It is also called as cushion blade. CLASSIFICATION OF TRACTORS Tractors can be classified into three classes on the basis of structural design 1. Wheel tractor 2. crawler tractor

WHEEL TRACTOR Tractors having three or four pneumatic wheels are called wheel tractors. Four wheel tractors are popular everywhere CRAWLER TRACTOR A crawler tractor (also called: track-type tractor, tractor crawler, or track-laying vehicle) is a vehicle that runs on continuous tracks instead of wheels. In agriculture they are used for land clearing and land leveling works. The principal advantages of crawler tractor over wheeled tractors are that they are in contact with a larger surface area than the wheeled tractor, and as a result exert a much lower force per unit area on the ground than a conventional wheeled tractor of the same weight. This makes them suitable for use on soft, low friction and uneven ground such as mud, ice and snow. The principal disadvantage is that tracks are a more complex mechanism than a wheel, and relatively prone to failure modes such as snapped or derailed tracks. Crawler tractor or chain type tractor has the following characterizes 1. It is designed to secure good adhesion and transmit high drawbar pull in difficult field conditions, where wheel tractors fail to secure adequate grip on the soil. 2. It provides large area of contact with the ground 3. It is useful at places where adhesion is difficult and rolling resistance is high 4. It is most suited for heavy work, specially earth moving work and reclamation work 5. It is used for all types of agricultural works with heavy implements Difference between wheel and crawlers tractorsWheel tractorCrawler tractor

1. Can travel fast.2. Not more powerful and hence used for light duty jobs.3. Less costly4. Less operation and maintenance cost5. Required less skill for their operation because of wheels.6. Can used for roads or pavements.7. Self driven for longer distance hence transportation is easy.8. Does not have better stability during working

1. Travel slowly2. Very powerful and hence used for powerful jobs.3. Costly due to use of chains4. More operation and maintenance cost.5. Requires more skill for their operation.6. Used for rough ground conditions.7. Transportation for longer distance required with trailers.8. Does have better stability during working.

Application:WHEEL TYPECRAWLER TYPE

Good on firm soil, concrete and abrasive soil which have no sharp edged piecesCan work on a variety of soil

Best on level and downhill workCan work almost any terrain

Wet weather, causing soft and slick surfaces will stop operationCan work on soft ground and over mud slick surfaces; will exert low ground pressures with special wide tracks and floatation track shoes

The concentrated wheel load will provide compaction and kneading action

Good for long travel distancesGood for short work distances

Best in loose soilCan handle tight soils

Has fast return speeds, 8 20 mphSlow return speeds, 5- 7 mph

Can only handle moderate blade loadsCan push large blade loads

LOADER: A loader (also known as: bucket/ frontend/pay/scoop/skip/wheel loader and or shovel.) is a type of tractor, usually wheeled, sometimes on tracks, that has a front mounted square wide bucket connected to the end of two booms (arms) to scoop up loose material from the ground, such as dirt, sand or gravel, and move it from one place to another without pushing the material across the ground.Tractor-pulled scrapers have established an important position in the earthmoving field. As they are self-operating to the extent that they can load, haul, and discharge material, they are not depends on other equipment. If one of them experiences a temporary breakdown, it is necessary to stop the job, as would be the case for machine which is used exclusively for loading earth into hauling units, for if the loader breaks down, the entire job must stop until repairs can be made. The self-loading scrapers are available with capacities up to 50 cu yd or more.These machines are the result of a compromise between the best loading and the best hauling machines, and, as must be expected of any composite machine, they are not superior to other equipment in both loading and hauling Power shovels, draglines, and belt loaders usually will surpass them in hauling only, especially when long, well-maintained haul roads are used. However, their ability to load and haul gives them a definite advantage on many projects. The development of high-speed wheel-type tractors has increased the economic haul distance for this type equipment up to a mile or more on many projects.The ability of these machines to deposit their loads in uniformly thick layers will facilitate the succeeding spreading operations. On the return trips to borrow pits the cutting blades of scrapers may be lowered enough to remove high spots, thereby assisting in maintaining the haul roads.Earth frequently is found in stratified layers, which must be blended by mixing the materials from several layers. The limited depth of cut will not permit scrapers to mix the layers satisfactorily. For this reason shovels and trucks sometimes are used, even though scrapers will handle the earth more economically.Applications:Loaders with its general purpose bucket and with additional attachments can be used for:1. Loading the dump trucks in queries, mines and industries.2. Loading the waste materials, clearing debris.3. To move bulky objects.4. Removing snow.5. Clearing the areas.6. For fork lifting.7. For dodging, trenching, ripping etc. with the help of suitable attachments.Thus the loaders are very useful equipment and are used in mining, quarrying, industrial work in addition to the construction engineering works. Operations:Loaders are used to carry out following main operation:1. Loading :Loading operation is the main operation performed by the loaders. Loading consists of scooping, lifting, turning and dumping materials such as sand, gravel and crushed materials from stockpiles, bank or construction site into the hauling units. For better out put the bucket should be filled full and the number of hauling units deployed for the work should be such that there is no waiting time for the loader and there should not be more than one hauling unit in the queue.2. Hauling :Wheel loaders are excellent for moving loose materials over short distances to dump into hauling units, hoppers, conveyors, bins or any other place of work in the construction sites.3. Excavating :Crawler loaders and heavy duty wheel loaders are excellent for many excavation jobs, like basement digging etc.With excavator attachment it can also handle several other types of excavator works. These loaders can excavate as well as lift the excavated material and dump it into trucks or on the stock piles.4. Clearing:Loaders can scoop up and load the debris of demolition buildings into hauling units. They also knock down small and temporary buildings. Loaders are also used for clean up the areas after snow storms, tornadoes, floods etc. A grubber blade attachment is used in place of bucket for large scale clearing works. Thus the loaders are the first equipment preferred for the construction site and for the building works.Attachments:Following are the main attachments which can be fitted to a wheel loader:a. Back filling attachments.b. Fork lifting attachment.c. Side bucket attachment.d. Sweeping attachment.e. Multipurpose attachment.f. Ripper attachment.g. Miscellaneous other attachments.h. Snow removal attachment.i. Protective chains.BACK HOES: The backhoe attachment is used to dig up hard material and is often used to dig trenches. The bucket is extended away from the tractor, lowered, and filled by draggingtowardthe tractor -- then raised and moved to the side before being dumped. Extending and raising a backhoe reduces overall stability, so before the backhoe is used outriggers are extended for safety.SCRAPERS: In engineering, machine for moving earth over short distances (up to about two miles) over relatively smooth areas. Either self-propelled or towed, it consists of awagonwith a gate having a bladed bottom. The blade scrapes up earth as thewagonpushes forward and forces the excavated material into the wagon. When the wagon is filled, the gate is closed, and the material is carried to the place of disposal. Thescraperis the dominant tool in highway construction.Tractor-pulled scrapers have established an important position in the earthmoving field. As they are self-operating to the extent that they can load, haul, and discharge material, they are not depends on other equipment. If one of them experiences a temporary breakdown, it is necessary to stop the job, as would be the case for machine which is used exclusively for loading earth into hauling units, for if the loader breaks down, the entire job must stop until repairs can be made. The self-loading scrapers are available with capacities up to 50 cu yd or more.These machines are the result of a compromise between the best loading and the best hauling machines, and, as must be expected of any composite machine, they are not superior to other equipment in both loading and hauling Power shovels, draglines, and belt loaders usually will surpass them in hauling only, especially when long, well-maintained haul roads are used. However, their ability to load and haul gives them a definite advantage on many projects. The development of high-speed wheel-type tractors has increased the economic haul distance for this type equipment up to a mile or more on many projects.The ability of these machines to deposit their loads in uniformly thick layers will facilitate the succeeding spreading operations. On the return trips to borrow pits the cutting blades of scrapers may be lowered enough to remove high spots, thereby assisting in maintaining the haul roads.Earth frequently is found in stratified layers, which must be blended by mixing the materials from several layers. The limited depth of cut will not permit scrapers to mix the layers satisfactorily. For this reason shovels and trucks sometimes are used, even though scrapers will handle the earth more economically.SCRAPER TYPESThere are several types of scrapers, primarily classified according to the number of powered axles or by method of loading. These are all wheel-tractor-pulled machines. In the past crawler-tractor towed two-axle scraper bowls were manufactured. They proved effective in short-haul situations, less than 600 ft one-way. Another machine of the past is the two-axle pulling tractor which can now be found only in much older spreads. Machines currently available include:1. Push-loadeda. Single-powered axleb. Tandem-powered axles2. Push-pull, tandem-powered axles3. ElevatingPUSH-LOADED SCRAPERSThe wheel-type tractor scraper has the potential for high travel speeds on favourable haul roads. Many models can achieve speeds up to 30 mph when fully loaded. This extends the economic haul distance of the units. However, these units are at a disadvantage when it comes to individually providing the high attractive effort required for economical loading. For the single-powered axle scraper only a portion, on the order of 50-50% of the total loaded weight, bears on the drive wheels.Additionally, in most materials the coefficient of traction for rubber tires is less than for tracks. Therefore, it is necessary to supplement the loading power of these scrapers. The external source of loading power is usually a crawler- tractor pusher.PUSH-PULL SCRAPERThese are basically tandem-axle-powered units having a cushioned push block and bail mounted on the front and a hook on the rear above the usual push block. These features allow two scrapers to assist one another during loading by hooking together. The trailing scraper pushes the lead scraper as it loads. Then the lead scraper pulls the trailing scraper to assist it in loading. This feature allows two scrapers to work without assistance from a push tractor.ELEVATING SCRAPERSThis is a completely self-contained loading and hauling scraper. A chain elevator serves as the loading mechanism. The disadvantage of this machine is that the weight of the elevator-loading assembly is deadweight during the haul cycle. Such scrapers are economical in short-haul situations where the ratio of haul time remains low. Elevating scrapers are also used for utility work dressing-up behind high production spreads or shifting material during fine-grading operations. They are very good in small quantity situations. No pusher is required, so there is never a mismatch between the pusher and the number of scrapers. Because of the elevator mechanism, they cannot handle rock or material containing rocks.THE SIZE OF A SCRAPERThe size of a scraper may be specified as the struck, or heaped, capacity of the bowl, expressed in cubic yards. The struck capacity is the volume of the material that a scraper will hold when the top of the material is struck off even with the top of the bowl. In specifying the heaped capacity of a scraper some manufacturers specify the slope of the material above the sides of the bowl with the designation SAE. The SAE (Society of Automotive Engineers) specifies a slope of 2:1, measured horizontally and vertically, respectively. Because the slope will vary with the class of material being hauled, the heaped capacity is only an approximate value. BASIC OPERATING PARTS OF A SCRAPERBowl:The bowl is the loading and carrying component. It has a cutting edge, which extends across the front bottom edge. Lower the bowl until the cutting edge enters the ground for loading, raise it for carrying, and lower it to the desired lift thickness for dumping and spreading.Apron:The apron is the front wall of the bowl. It is independent of the bowl and, when raised, it provides an opening for loading and spreading. Lower the apron during hauling to prevent spillage.Ejector:The ejector is the rear wall of the bowl. Keep the ejector in the rear position when loading and hauling materials. Activate the ejector to move forward during spreading to provide positive discharge of materials. OPERATING A SCRAPERA scraper is loaded by lowering the front end of the bowl until the cutting edge, which is attached to and extends across the width of the bowl, enters the ground and, at the same time, raising the front apron to provide an open slot through which the earth is forced into the bowl. This operation is continued until the bowl is filled or until no more earth may be forced in. The cutting edge is raised and the apron is lowered to prevent spillage during the haul trip.The dumping operation consists of lowering the cutting edge to the desired height above the fill, raising the apron, and forcing the earth out between the blade and the apron by means of a movable ejector mounted at the rear of the bowl.EXCAVATORS: Excavators are machines with multiple uses. They are primarily used for digging, demolition, forestry work, grading, landscaping, heavy lifting, and brush cutting. The important features on these heavy pieces of equipment are hydraulic powered motors or rams, sealed cab on rotating platform, head attachments (such as a bucket), which are used for different purposes. These attachments can change the functionality of the machine instantly from a trench digger to a logger.The rotating platform adds convenience for other machinery. For example a dump truck can be located directly behind the excavator and it can still easily deposit material by swinging around on a 180 degree pivot.MOTOR GRADER: Motor graders are used for levelling and smoothening the earthwork, spreading and levelling the base courses in the construction of roads and airfields. It can also be used for land reclamation, snow clearance, gravel road repairing, mixing and stabilising materials such as asphalt, cement and lime. It can also undertake large scale ditching and trenching work in irrigation schemes.Motor graders may be towed or motorized. Towed grader is drawn with a tractor and is of smaller sizes. Generally motor graders are self propulsive.ADJUSTING THE BLADEThe is the main tool of the grader. It is carried by a rotating circle and is easily manoeuvrable to a wide range of cutting positions with the help of hydraulic controls. The blade and the circle are mounted on a frame and are supported at the front of the machine by a ball joint. The blade can be adjusted to any position with the help of lever1. Side shift: the blade has blade side shaft ram which is operated by a lever in the operators cabin this lever when operated in one direction shifts the blade to one side with the help of blade side shift ram.2. Lifting the blade: the blade can be lifted or lowered by levers operating the two rams. With the help of these rams operated separately the blade can be kept either horizontally or raised or lowered towards left or right hand side to keep it in inclined position.3. Rotating the circle: a hydraulic motor is provided to rotate the circle and blade. Blade can be rotated either in clockwise or anti clockwise direction by operating the lever 4. Adjusting blade cutting angle (blade pitch): the vertical angle of the blade can be adjusted. For adjustments some motor graders provide a hydraulic tilt ram whereas in some others the adjustments can be done manually. The cutting angles are generally adjustable between 30 degree to 60 degree.Various operations by motor graders1. Grading: grading in road construction means flattening and smoothening the road surface and others by the scraping action of the blade, and includes working operation like, surface skimming, light duty bull dozing, leveling, spreading and crowning. A cutting depth of 2-3cm is considered to be the best for optimum efficiency. Under no circumstances it should be greater than 5cm. for fining cuts, depth of the cut is kept within 1cm. before applying the second cut, entire portion of the road surface being graded is transverse. In subsequent cuts also speed is determined by the depth of cut and nature of surface to be cut. For normal grading operations including cutting, leveling, spreading etc. blade should be adjusted as follows: a. Move the blade and angle it by rotating the circle until rear end is just outside the rear wheels. The angle should be just sharp enough to let material roll freely off the end of the blade.b. At the start of a pass, rest the front and rear ends of the blade equally on the ground. c. Note action of the earth and try slight alteration of blade angle and speed until earth rolls along the blade and forms a windrow.d. To counteract the side draft, lean the front wheels to the right properly to keep the grade on its straight head cores.2. Spreading: gravel together with the binding material is spread by the motor grader. The blade is kept in level and square to the windrow. For spreading, the cutting angle is set at 60 degree nearly. Cutting edge of the blade is set above the ground at a distance equal to the depth to which material is to be spreaded.3. Finishing and leveling: in final finishing and leveling, surface has to be finished in fine limits. In such cases make the finishing pass with the blade only slightly angle and set to skim the surface.4. Ditch digging: the front end of the blade is tilted down and a rear end is tilted up above the road surface. This is used to dig drainage ditches and road side ditches. 5. Cutting: for the purpose of cutting in soft drift, set the blade to an angle between 40-55 degree, while for cutting in hard dirt and an angle of 30-45degree. To grade by cutting, motor grader should be driven at a speed of 4-6kmph. 6. Bank Cutting: In this operation, the position of the blade is for scraping or cutting the bank wall. Blade position is set by rotating the circle and tilt the blade forward with its rear end staying on the outside of the rear wheels. Blade lift lever is operated to align the blade along the sloped surface of the bank. Using first gear work of bank cutting can be proceeded.7. Earthen Road Maintenance: Maintenance of earthen road does not require moving of large amounts of material. The blade is circled and side shifted to make windows outside or between rear wheels. The blade cuts high areas and fill low areas. First or Second gear may be used depending on the nature of ground and depth of cut. If the earthen road is wide enough, first work along one side and then back along other side.8. Earthen road Construction: a) Turf is stripped off by setting blade square to motor grader with cutting edge level, and by lowering the blade just sufficient to roll up turf as grader moves forward in the first gear. b) Surface is then levelled by filling hollows and holes left by trees etc. c) Ditch is then made d) If the camber to the earthen road is required, set the blade square to the machine and angled to give the required camber.ROLLERS: Rollers are machines used in the compaction of soils after grading. Compaction reduces the volume of air space in the soil. This compaction increases the dry unit weight and strength of the soil to better support structures. This is a very important step, and there are various tools to complete this task. Rollers complete compaction using various methods: Pressure, Impact, Vibration, and Manipulation.Sheep foot roller:A sheep foot roller has almost hoof like structures protruding from a roller to offer pinpoint pressure as in a herd of sheep was walking across the field. Vibratory roller :A Vibratory roller is a heavy machine similar to a sheep foot or tamping roller but adds vibration. It utilizes eccentric (alternating) weights and other methods to produce a vibration as it drops them against the soil with a typical frequency of 1000-3500 cycles, vibrating the soil to compaction. Vibration is usually more effective in sandy and gravelly soils. Can be effective up to 2m.DUMP TRUCKS: Dump Trucks - used instead of scrapers when the soil is being excavated by loaders. Most can travel over public highways, and move faster than scrapers.CAPACITY CALCULATIONSThe next phase of planning is to decide the equipment on the basis of its output and capability. The equipment must be capable to handle the work efficiently on which it is to be engaged. The output of the equipment so decided should be determined on the basis of past experiences on similar works. As we have discussed earlier that the same equipment gives different output in different conditions or work, therefore it is very essential to use the past output data of similar works handled by the equipment in similar conditions.Output of the equipment varies with various conditions. Following are some of them:(i) Different type of soil needs different amount of effort and hence equipment engaged on them gives different output.(ii) Reduction of horse power of engine due to altitude.(iii) Time spent on servicing and inspection varies with the working condition.(iv) Output of the equipment also depends upon the operators efficiency.(v) Output of dumper etc. depends on the condition of haul road.(vi) Time spent on the unproductive works.(vii) Changing weather conditions are also responsible for variation in output.(viii) Capacities of the matching machineries working in the same group.While selecting an equipment care must be taken that the equipment should neither be neither of too big size nor of too small size than required for work. It should be able to complete the work economically in completion period. Since too big size equipment will complete the work before time and its residual value (initial cost minus depreciation) will be high, which may not be gainfully used after completion of the job. Similarly with too small size of equipment, more number of equipment will be required for completing the quantity of work involved, which means un-economical proposition. Therefore most economical planning is to select an equipment which can be fully depreciated by the time project is completed. It means the equipment must complete its economical life as soon as the project is completed.

TWO MARKS:1) Suggest suitable measures to increase scraper production. (NOV 2011)2) What are the factors to be considered in dozer selection? (NOV 2013)3) Mention the different types of scrapers with their use. (NOV 2013)4) List the earth moving equipments used in roadwork. (JUNE 2013)5) Mention the advantages of tractors and scrapers in earthwork. (JUNE 2013)6) What are the factors affecting the selection of a tractor? (NOV 2012)7) Write the formula to calculate the output of ripper. (NOV 2012)8) Explain the characteristics of crawler mounted excavator. (MAY 2012)9) Write the output of loader. (MAY 2012)10) Mention the various operations involved in grading? (MAY 2014)11) List the factors influencing the output of bull dozers. (DEC 2013)12) List the applications of front end loaders. (MAY 2012)13) What are all the major earth moving operations? (MAY 2014)14) Define scrapers. (MAY 2014)16 MARKS:15) Describe the main operations of loaders. (NOV 2011)16) List and explain the factors affecting the output of a power shovel. (NOV 2011)17) What are the different applications of dozer? (NOV 2013)18) What are scrappers? Explain the different types of scrappers in use. Mention the important specifications of scrappers. (NOV 2013)19) What are the various pile driving equipment used in construction projects? (NOV 2013)20) List the types of earthwork equipment and discuss on earthwork equipment and discuss on earthmoving operations. (JUNE 2013)21) Discuss in detail on advantages and disadvantages in the uses of tractors and scrapers in the project. (JUNE 2013)22) Explain the working procedure of scraper with a neat sketch. (NOV 2012)23) Explain in detail about the types of loaders with a neat sketch. (NOV 2012)24) Write a neat sketch; explain the different types of blades can be attached with dozer. (MAY 2012)25) Explain the functions and operations of scraper with a neat sketch. (MAY 2012)26) Explain in detail, about the various types of scrapers? (MAY 2014)27) Describe in detail about the earth moving operations. (MAY 2014)28) Explain the operations of an elevating scraper. Also give your suggestions for improving scraper productions. (DEC 2013)29) Describe about the components of a hydraulic excavator with a sketch. (DEC 2013)30) With a neat sketch explain the components of a power shovel. Also give its applications. (MAY 2012)31) List and explain the main attachments fitted to a loader. (MAY 2012)32) Discuss the role of tractors in earth moving. What considerations govern section of wheel type or crawler type tractor on a job? Compare the application of two types of tractors. (MAY 2014)33) Explain the functions and operations of scraper with a neat sketch. (MAY 2014)