One carrier, many tools
Most demolition tools are hydraulic attachments mounted on an excavator, so a single machine can change its role in a few minutes. With a quick coupler, the operator can swap a breaker for a shear, or a shear for a grapple, as the job moves from one stage to the next. The tool decides what the machine can do to the material. The carrier decides how much reach, weight and hydraulic power is available.
This review looks at the common tools and what each one does. The choice of the excavator itself, including long-reach arms and stability, is a separate question covered in the companion review of demolition excavators.
Hydraulic breakers
A hydraulic breaker, often called a hammer, delivers repeated blows through a steel tool point. It breaks material by impact. Breakers are widely used on concrete slabs, footings, rock and pavement, and for breaking oversized pieces into smaller ones.
Strengths and limits to know about:
- They are versatile and can work in tight spots, but they are noisy and produce vibration.
- Impact does not cut rebar. Reinforcing steel stays in place and has to be cut or pulled out afterward.
- Using one when the tool is not firmly seated, or pushing it sideways, can damage the tool and carrier. Training matters.
Because of the sound they produce, a breaker is a case where workplace noise exposure needs attention, both for the operator and for anyone nearby.
Concrete crushers and pulverizers
A concrete crusher grips the material between two jaws and squeezes it until it cracks. A pulverizer is a similar tool with teeth, designed to break concrete into smaller pieces and often to separate the reinforcing steel from it as it works.
Compared with a breaker, crushing by pressure is typically quieter and produces less vibration, which can matter near occupied buildings. The jaws can also help expose rebar, so it can be cut in the same operation. On the other hand, crushers need the concrete to be reachable and thin enough to grip, so very thick sections may be pre-broken first.
Shears
Shears cut through steel the way very powerful scissors would, using hydraulic force on a moving jaw. They are used on structural steel, pipes, tanks, rebar and other metal. Different shears exist for different jobs, such as cutting beams in a framed structure or processing scrap into sizes that can be handled.
Shears are the main tool where a building has a steel frame. They also make scrap handling more efficient because the metal can be cut to lengths that fit trucks and processing. Cutting force and jaw opening limit what a particular shear can cut, so it should be matched to the steel section. The manufacturer’s data plate and manual provide those limits.
Multi-processors
A multi-processor is a tool with interchangeable jaws, often one set for concrete crushing and another for cutting steel. It is a compromise that trades some peak performance for flexibility. On a job with varied materials and limited space, one tool that does several things can save time that would otherwise go into swaps.
Grapples and sorting tools
Not every demolition tool breaks things. Grapples pick up and place debris, and sorting grapples let the operator separate material into piles. A grapple with rotating capability turns to pick up awkward pieces. Magnets lift scrap steel out of mixed rubble. Where rubble must be sorted by type, tools like these reduce hand labor. The devices used here are related to the load handling attachments that appear in other material-handling jobs, though the demolition versions are built heavier.
Sorting often feeds a crushing stage. Crushed concrete can sometimes be reused as fill or base material after processing. Mobile crushers and screens do this work on site, and magnetic separators pull steel out of the stream. The principles are the same as those described under size reduction.
Matching tool to carrier
A tool and carrier have to suit each other:
- Weight. The attachment’s weight reduces how much the carrier can lift and reach. A heavy tool at full extension may exceed the machine’s chart.
- Hydraulic flow and pressure. The tool needs a certain flow and pressure to perform as designed. Auxiliary circuits are set up for the tool.
- Coupler and mounting. The tool must be compatible with the coupler and pins, and locked correctly before use.
- Size of the work. Large tools on a small machine are unsafe, and small tools on a large machine may waste its capability.
Care and safety
Attachments take a pounding, so inspection is routine work. Tool points, jaw tips, pins, bushings, hoses and couplings wear, and cracks can form in highly stressed parts. Under a preventive maintenance plan, they are checked before use and greased on schedule. Before anyone works on an attachment, the machine should be shut down and isolated using lockout and tagout style procedures, because stored hydraulic pressure can remain in the lines.
General rules also apply during demolition itself: trained and certified operators, a clear exclusion zone, guarding against flying fragments, dust control and respect for local regulations. Specific procedures come from the manufacturer’s manual and the site plan. This is general information and not engineering advice.