Machine Types
What the exam tests
Machine Types checks that you can identify common heavy machines and match them to the task, ground conditions and site constraints. Expect questions on excavators, wheel loaders, backhoe loaders, bulldozers, graders, rollers, telehandlers, mobile cranes and dump trucks.
Core rules
- An excavator digs and loads within its reach; it is not a long-haul truck. Tracked machines suit soft or uneven ground; wheeled machines suit firm surfaces and travel.
- A wheel loader stockpiles, loads trucks and handles short carry distances. Its bucket is not a personnel platform.
- A bulldozer pushes and grades; it does not lift. A grader finishes grade; a roller compacts in layers.
- A telehandler lifts with a load chart that changes with boom extension and attachment. A mobile crane lifts on outriggers or tyres according to its chart.
- Attachment changes alter capacity, stability and risk. Confirm the machine is rated for the attachment and the load.
Worked example
A contractor must move 20 mm aggregate from a stockpile to highway trucks parked 30 m away. A wheel loader with a 3.1 m3 bucket is selected because the carry is short, the ground is firm and the bucket matches loose aggregate. An excavator could load trucks but would swing repeatedly and may not travel well; a dump truck would need another machine to load it.
Traps
Do not call every lifting machine a crane. Do not use a loader bucket as a work platform. Do not assume a telehandler can lift its rated capacity at full reach. Do not select a machine by size alone; check access width, ground bearing and overhead clearance.
Key points
- Match machine to task, ground and access.
- Excavators dig and load; loaders carry and stockpile.
- Attachments can reduce rated capacity.
- Never use buckets as personnel platforms.