Dozers, commonly known as bulldozers, are powerful construction machines produced either on tracks or wheels, primarily used for pushing materials, land preparation, trenching, and rock breaking.

Historical Development

The origins of the bulldozer date back to the early 20th century. The first version was designed and patented by James Cummings and J. Earl McLeod in 1923. It consisted of a straight blade mounted in front of a tractor. Over time, with the development of hydraulic controls, the blade’s movement capabilities were enhanced, laying the foundation for modern bulldozers. During World War II, the widespread military use of bulldozers accelerated their global adoption. Today, bulldozers are produced in a wide variety of models equipped with advanced hydraulic, electronic, and automation systems.

Technical Structure

Modern bulldozers consist of the following main components:

• Track or wheeled undercarriage,
• Engine and power transmission components,
• Front blade,
• Ripper (rear-mounted rock breaker),
• Operator cabin and control systems.

Dozers are classified into three main types:

• Bulldozer: With a straight blade, used for pushing materials.
• Tiltdozer: With a blade that can be adjusted horizontally and vertically, suitable for excavation, spreading, and grading.
• Angledozer: With an angled blade, used especially for directing materials to the right or left while spreading.

In addition, there are two main undercarriage systems:

• Track-type dozers: Suitable for heavy-duty tasks, providing high maneuverability in confined spaces.
• Wheeled dozers: Faster and more mobile, typically used for spreading and pushing tasks.

Engine power ranges between 40-700 HP, and operating weight ranges between 4-80 tons

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Areas of Use

Dozers have a very wide range of applications:

• Land clearing and road building,
• Material spreading and grading,
• Backfilling trenches and loosening soil,
• Rock breaking and tree root removal,
• Dam construction and mining,
• Forestry and creating firebreaks.

Operator Training

In Türkiye, dozer operator training is provided under the Directive on Construction Equipment Driver Training Courses issued by the Ministry of National Education.

To become a dozer operator, the following training stages are required:

• Theoretical training: Structure of the dozer, safety rules, maintenance, and inspection.
• Practical training: Hands-on use on actual machines.
• Practical exam: Includes operations such as stripping 10 cm deep, 10 m long, and 1.5 blade widths, properly spreading and grading materials.

Successful candidates receive the Construction Equipment Operator Authorization Certificate.