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Mobile heavy equipment is indispensable to construction, logging, surface mining, and other industrial activities. Mobile heavy equipment mechanics service and repair the engines, transmissions, hydraulics, electrical systems, and other components of equipment such as motor graders, trenchers and backhoes, crawler-loaders, and stripping and loading shovels. (Mechanics who specialize in servicing only diesel engines are discussed in the section on diesel mechanics elsewhere in the Handbook.)Mobile heavy equipment mechanics perform routine maintenance on the diesel engines that power most heavy equipment, and, if an operator reports a malfunction, they search for its cause. First, they inspect and operate the equipment to diagnose the nature of the repairs required. If necessary, they may partially dismantle the engine, examining parts for damage or excessive wear. Then they repair, replace, clean, and lubricate the parts as necessary, and reassemble and test the engine for operating efficiency. If repairs to the drive train are needed, mechanics remove and repair the transmission or differential.
Many types of mobile heavy equipment use hydraulics to raise and lower movable parts such as scoops, shovels, log forks, or scraper blades. Repairing malfunctioning hydraulic components is an important responsibility of mobile heavy equipment mechanics. When hydraulics loses power, mechanics examine them for hydraulic fluid leaks and replace ruptured hoses or worn gaskets on fluid reservoirs. Occasionally, more extensive repairs are required, such as replacing a defective hydraulic pump.
Mobile heavy equipment mechanics perform a variety of other types of repairs. They diagnose and correct electrical problems and replace defective electronic components. They also disassemble and repair crawler undercarriages and track assemblies. Occasionally, mechanics weld broken body and structural parts, using electric or gas welders.
Many mechanics work in small repair shops of construction contractors, logging and mining companies, and local government road maintenance departments. They typically perform routine maintenance and minor repairs necessary to keep the equipment in operation. Mechanics in larger repair shopsparticularly those of mobile heavy equipment dealers and the Federal Governmentperform more difficult repairs, such as rebuilding or replacing engines, repairing hydraulic fluid pumps, or correcting electrical problems. Mechanics in some large shops specialize in one or two types of work, such as hydraulics or electrical systems.
Mobile heavy equipment mechanics use a variety of tools in their work, including common handtools such as pliers, wrenches, and screwdrivers and power tools such as pneumatic wrenches. They use micrometers and gauges to measure wear on parts, and a variety of testing equipment. For example, they use tachometers and dynamometers to locate engine malfunctions; when working on electrical systems, they use ohmmeters, ammeters, and voltmeters.
Most mobile heavy equipment repair shops are well ventilated, lighted, and heated. Many mechanics work indoors in shops, but others work as field service mechanics and spend much of their time away from the shop working outdoors. When mobile heavy equipment breaks down at a construction site, it may be too difficult or expensive to bring it into a repair shop, so a field service mechanic is sent to the job site to make repairs. Generally, the more experienced mobile heavy equipment mechanics specialize in field service; they usually drive specially equipped trucks and sometimes must travel many miles to reach disabled machinery. For many mechanics, the independence and challenge of field work outweigh the occasional long hours or bad weather, but other mechanics are more comfortable with the routine of shop work and the opportunity to work as part of a team.Mechanics handle greasy and dirty parts and often work in awkward or cramped positions. They sometimes must lift heavy tools and parts, and must be careful to avoid burns, bruises, and cuts from hot engine parts and sharp edges of machinery. However, serious accidents may be prevented when the shop is kept clean and orderly and safety practices are observed.
Mobile heavy equipment mechanics held about 101,000 jobs in 1994. Over half worked for mobile heavy equipment dealers and construction contractors. About one-fifth were employed by Federal, State, and local governments; the Department of Defense is the primary Federal employer. Other mobile heavy equipment mechanics worked for surface mine operators, public utility companies, logging camps and contractors, and heavy equipment rental and leasing companies. Still others repaired equipment for machinery manufacturers, airlines, railroads, steel mills, and oil and gas field companies. About 1 out of 20 mobile heavy equipment mechanics was self-employed.Mobile heavy equipment mechanics are employed in every section of the country, but most work near cities and towns, where most construction takes place.
For trainee jobs, employers hire persons with mechanical aptitude who are high school graduates and at least 18 years of age. They seek persons knowledgeable about the fundamentals of diesel engines, transmissions, electrical systems, and hydraulics. Although some persons are able to acquire these skills on their own or by working as helpers to experienced mechanics, most employers prefer to hire graduates of formal training programs in diesel or heavy equipment mechanics.Training programs in diesel and heavy equipment mechanics are given by vocational and technical schools and community and junior colleges. Training in the fundamentals of electronics is also essential because new mobile heavy equipment increasingly features electronic controls and sensing devices. Some 1- to 2-year programs lead to a certificate of completion; others lead to an associate degree if they are supplemented with additional academic courses. These programs provide a foundation in the basics of diesel and heavy equipment technology, including hydraulics, and enable trainee mechanics to advance more rapidly to the journey, or experienced worker, level.
Through a combination of formal and on-the-job training, trainee mechanics acquire the knowledge and skills to efficiently service and repair the particular types of equipment handled by the shop. Beginners are assigned relatively simple service and repair tasks. As they gain experience and become more familiar with the equipment, they are assigned increasingly difficult jobs, and are exposed to a greater variety of equipment.
Many employers send trainee mechanics to training sessions conducted by heavy equipment manufacturers. These sessions, which typically last up to 1 week, provide intensive instruction in the repair of a manufacturer's equipment. Some sessions focus on particular components found in all of the manufacturer's equipment, such as diesel engines, transmissions, axles, and electrical systems. Other sessions focus on particular types of equipment, such as crawler-loaders and crawler-dozers. As they progress, trainees may periodically attend additional training sessions. Experienced mechanics also occasionally attend training sessions to gain familiarity with new technology or with types of equipment they may never have repaired.
High school courses in automobile mechanics, physics, chemistry, and mathematics provide an essential foundation for a career as a mechanic. Good reading and basic mathematics skills and a basic understanding of scientific principles are needed to help a mechanic learn important job skills and to keep abreast of new technology through the study of technical manuals. Experience working on diesel engines and heavy equipment acquired in the Armed Forces also is valuable.
Mobile heavy equipment mechanics usually must buy their own handtools, although employers furnish power tools and test equipment. Trainee mechanics are expected to accumulate their own tools as they gain experience. Many experienced mechanics have thousands of dollars invested in tools.
Experienced mechanics may advance to field service jobs, where they have greater opportunity to tackle problems independently and earn overtime pay. Mechanics who have leadership ability may become shop supervisors or service managers. Some mechanics open their own repair shops.
Opportunities should generally be good for persons who have completed formal training programs in diesel or heavy equipment mechanics. Persons without formal training are expected to encounter growing difficulty entering this occupation.Employment of mobile heavy equipment mechanics is expected to grow more slowly than the average for all occupations through the year 2005. Increasing numbers of mechanics will be required in repair shops of equipment dealers and rental and leasing companies as the growing complexity of mobile heavy equipment necessitates more repairs being done by professionals. More mechanics also will be needed by all levels of government to service construction equipment that repairs and maintains the country's system of highways and bridges. But employment of mechanics will increase more slowly at the Federal level as defense-related spending is trimmed. Employment of mechanics by construction contractors will increase more slowly as more of the equipment in use is rented or leased.
As the economy expands, growth of construction activity should result in the use of more mobile heavy equipment, which would increase the necessity for periodic service and repair. Various kinds of equipment will be needed in increasing numbers to grade construction sites, excavate basements, lay water and sewer lines, and put in streets. In addition, construction of new highways and bridges and repair or rebuilding of existing ones will also require more mechanics for servicing the equipment.
Since construction and mining are sensitive to changes in the level of economic activity, mobile heavy equipment may be idled during downturns. In addition, winter is traditionally the slack season for construction activity, particularly in colder regions. Fewer mechanics may be needed during periods when equipment is used less intensively, but employers usually try to retain experienced workers. However, employers may be reluctant to hire inexperienced workers during slack periods.
Median weekly earnings of mobile heavy equipment mechanics were about $554 in 1994. The middle 50 percent earned from around $409 to $684 a week; the lowest 10 percent earned less than $322 a week, and the top 10 percent earned over $864 a week in 1994.Some mobile heavy equipment mechanics are members of unions. The unions include the International Association of Machinists and Aerospace Workers; the International Union of Operating Engineers; and the International Brotherhood of Teamsters.
Workers in other occupations who repair and service diesel-powered vehicles and heavy equipment include rail car repairers and diesel, farm equipment, and mine machinery mechanics.
More details about work opportunities for mobile heavy equipment mechanics may be obtained from local mobile heavy equipment dealers, construction contractors, surface mining companies, and government agencies. Local offices of the State employment service may also have information on work opportunities and training programs.
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