CM 2113 FINAL EXAM 2025

CM 2113 FINAL EXAM 2025 Dozer is good for applications of less than 300ft short haul, and scraper is good for applications of up to 3,000ft medium haul. - correct answer-true An advantage of a crawler dozer as compared with a wheel-type dozer is higher speed. - correct answer-false Which of the following work tasks can be performed by a dozer? - correct answer- spreading -striping -backfilling The ________________ is very effective for side-casting material, particularly for backfilling or making sidehill cuts. - correct answer-angle blade ______________ is a technique whereby the blade end spillage from the first pass or the sidewalls from previous cuts are used to hold the material in front of the dozer blade on subsequent passes. - correct answer-slot dozing Which of the following factors need to be considered when selecting a proper scraper for your project? - correct answer--scraper configuration -volume of material -job size Articulated trucks consist of two individual frames joined by pin, and can be easily operated over soft ground. - correct answer-true Buckets of loaders are rated in both heaped and struck capacities. _________________ is based on the sae standard of a 2:1 material repose angle. - correct answer-heaped capacity Which of the following is a job condition that could affect the operator's job efficiency? - correct answer-surface and weather conditions Fill factor is the ratio of the actual loose volume of material in the bucket compared to the bucket's rated-heaped capacity. It varies based on the type of material being handled and the type of excavator. - correct answer-true Which of the following is not a disadvantage of a crawler crane? - correct answer-limited capacity CM 2113 CM 2113 Straight blades - correct answer-shh hi pet and medium distance passes, such as backfilling, grading, and spreading full material Universal blades - correct answer-working stockpiles and drifting loose or no cohesive materials Semi-u blade - correct answer-combination of the s and u blade designs Cushion blades - correct answer-mounted on large dozers that are used primarily for push-loading scrapers. Limited utility in pushing material and should not be used for production dozing. Cannot be tilted, pitched or angled. Side-to-side - correct answer-blade-to-blade dozing. Two machines maneuver so that their blades are next to each other during the pushing phase of the production cycle. What factors affect dozer real production rates? - correct answer-1. Blade type 2. Type and condition of material 3. Cycle time Scrapers - correct answer-excavating, loading, hauling and dumping material over medium to long haul distances Scrapers production cycle - correct answer-1. Loading 2. Haul travel 3. Dumping and spreading 4. Turn 5. Return travel 6. Turn getting next load 2-axle scraper - correct answer-towed by a tractor, effective in short hauls Single powered scraper - correct answer-one engine Tandem powered scraper - correct answer-dual engines, greater tractive effort, 25% initially more expensive then conventional scrapers. For that reason, they commonly considered a specialized machine, open up a job, work on extremely adverse grades and on soft ground conditions Elevating scrapers - correct answer-not designed to be push loaders, use a ladder to lift material into the bowl. However the ladder is dead weight during the haul cycle. Used for utility work, good in small quantity situations. No pusher is required. They cannot handle rocky materia CM 2113 CM 2113 Auger scraper - correct answer-self loading scrapers that use a rotating auger to lift material into the bowl. Available in single and tandem configurations. More costly to own and operate. Push-loaded wheel scraper - correct answer-has potential for high travel speeds on favorable roads Push-pull tandem powered scrapers - correct answer-all wheel drive scrapers equipped with coupling devices that enable 2 scrapers to assist eachother in loading Loading - correct answer-tandem powered scrapers sometimes require help Single powered axle pusher-loader wheel-tractor scrapers - correct answer-suited for jobs where the haul-road rolling resistance is low and grades are minimal. They become uneconomical when haul grades are greater than 5% and return grades are greater than 12% Self-loading scrapers - correct answer-heavier and more costly than conventional scrapers, can be economical in isolated work and for stripping materials The capacity of a scraper - correct answer-expressed in bank cubic yards, approximated by multiplying the loose volume in the bowl by an appropriate swell factor Backtrack loading - correct answer-most common. It permits all scrapers to load in the same area. However, the slowest bc of the addition pusher travel distance Scraper fixed cycle time - correct answer-1. Spot time 2. Load time 3. Maneuver and dump time Crawler dozer - correct answer--good for short distance -can handle tight soil -can push large blade loads -exerts low ground bearing pressure -works on almost any terrain -can work on soft ground and mud slick surfaces Crawler dozer - correct answer-(tracklaying) - the work horses of the construction industry How to classify trucks - correct answer- 1. Size and engine type (gas, diesel) 2. Number of gears 3. Drive type (2 wheel, 4 wheel) 4. Number of wheels and axles CM 2113 CM 2113 5. Method of dumping 6. Material being hauled 7. Holding capacity Trucks - correct answer-distance is a major factor in selecting haul units Dozers - correct answer-they are designed to provide high drawbar pull and tractive effort. Crawler dozer - correct answer-exerts low ground-bearing pressure adding to its versaility Dozers - correct answer-equipped with a blade are standard equipment for excavating Dozers - correct answer-equipped with special clearing blades are used for land clearing Dozers - correct answer-equipped with push blades or blocms are used for assisting scrapers to load Dozer - correct answer-can have a rear mounted ripper for loosing and breaking up rock Fill factor - correct answer-adjusts heaped capacity in lcy based on the type of material being handled Excavators job efficiency - correct answer-management conditions: - skill, training, and motivation of workers - planning, job layout, supervision, and coordination of work Job conditions: - topography and work dimensions - surface and weather conditions Cranes - correct answer-mobile cranes and tower cranes are the primary machine used for the vertical movement of construction materials Crawler cranes - correct answer-mounted on a pair of parallel crawler tracks, which provide the crane with good travel capability around the job site Telescoping boom truck mounted cranes - correct answer--travel on highways, can change boom length, have outriggers for stability. -outriggers on large steel mats to reduce ground pressure and prevent damage to pavement -crane positioned on hollow-core precast concrete panel slab CM 2113 CM 2113 Lattice-boom truck mounted cranes - correct answer-the lattice-boom structure is lightweight. This reduction in boom weight means additional lift capacity, as the machine predominately handles hoist load and less weight of boom Rough-terrain cranes - correct answer-these units are equipped with unusually large wheels and closely spaced axles to improve maneuverability at the job site. They earn the right to their name by their high ground clearance, as well as the ability to move on steep slopes All-terrain cranes - correct answer-they have an undercarriage capable of long-distance highway travel. Yet the carrier has all-axle drive and all-wheel steering, crab steering, large tires, and high ground clearance. Crawler cranes for heavy-lifting - correct answer-additional counterweight mounted on a wheeled platform to increase lifting capacity. Ring system, "ringer," a heavy counterweight system supported on a large circular turntable ring Pros and cons of different types of cranes - correct answer- Rough terrain crane "pickers" -pros= off road applications, set up quickly, very maneuverability. -cons= limitation of capacity and cost of freight *all terrain crane -pros= travel on highway and rough terrains -cons= limitation of capacity, set up time, maneuverability and foot print. *crawler -pros= don't require outriggers, very high lifting capacity, any site even soft soils, travel with load -cons= expensive, set up time, large foot print, lot of matting, larger number of fall off loads Top slewing cranes - correct answer-cranes can increase their height Tower cranes - correct answer-the flexibility of its freely suspended hook moving in three planes provides a tremendous advantage in terms of load pick-up and positioning. Advantage of having both the operator and jib above the construction site. Crane selection factors - correct answer- Hoisting - correct answer-the hoist cable runs from the hoist drum located on the crane's counter jib, through the jib and then to the trolley and down to the hook Trolleying - correct answer-the horizontal movement of the trolley along the jib; this allows adjustment of the operating radius. Slewing - correct answer-when the job rotates around t