Crawler excavators are key carrier machines in modern demolition, in rock and tunnel construction, and in natural stone extraction. Thanks to their crawler undercarriage, they combine high stability, precise movements, and traction on difficult ground. In combination with hydraulic excavator attachments—such as concrete demolition shears, hydraulic rock and concrete splitters, combination shears, Multi Cutters, steel shears, or tank cutters—structures can be dismantled in a controlled manner, rock formations can be opened, or natural stone blocks can be gently released. Darda GmbH develops attachments and hydraulic power packs that, together with the crawler excavator, support a low-vibration, controlled, and safe working method.
Definition: What is a crawler excavator
A crawler excavator is a hydraulically driven earthmoving and demolition machine with a crawler undercarriage. The undercarriage distributes the machine mass over a large contact area and enables work on soft or uneven ground. The upper carriage with boom and stick carries the attachment; slew drive and hydraulics allow sensitive yet powerful movements. Compared to wheeled excavators, crawler excavators score with higher stability and tractive force; they are therefore the preferred carrier machines in concrete demolition and special demolition, in strip-out and cutting, in rock excavation and tunnel construction, in natural stone extraction, and in special operations.
Design and functioning of a crawler excavator
A crawler excavator consists of the undercarriage (crawler undercarriage), upper carriage (engine, hydraulics, cab), and the equipment set (boom, stick, quick coupler/adapter plate). The auxiliary hydraulics provide the attachment with oil flow and pressure. Selecting and correctly parameterizing the hydraulics is critical so that attachments such as concrete demolition shears or rock and concrete splitting devices reach their nominal forces and thermal loads remain under control.
Crawler undercarriage and stability
Stability results from track gauge, track length, and machine mass. Wide track shoes reduce ground pressure and improve bearing capacity on soft ground, while narrow, toothed shoes provide more traction on rocky terrain. Working on slopes requires adapted working angles and forward-looking positioning of upper carriage and boom to avoid crossing the tipping line.
Hydraulics and auxiliary circuits
Key parameters are maximum system pressure, flow rate (L/min), return line and, if applicable, case drain connection. For high-performance concrete demolition shears, combination shears, and steel shears, a high-throughput, pressure-stable auxiliary circuit with sufficient tank capacity and cooling is important. Rock and concrete splitting devices, especially stone splitting cylinders, can, depending on configuration, be operated via the excavator hydraulics or via separate Darda hydraulic power units, which offloads thermal load from the carrier machine and offers advantages indoors.
Crawler excavator as carrier machine in concrete demolition and special demolition
In deconstruction, crawler excavators take on the core tasks: positioning, separating, removing, and sorting. With concrete demolition shears, reinforced concrete can be mechanically crushed in primary and secondary demolition, with reinforcement exposed in the process. Combination shears and Multi Cutters cover mixed materials; steel shears cut structural steel, reinforcement, or beams. Tank cutters enable cold cutting where spark-free requirements apply.
Concrete demolition shears: controlled breaking of reinforced concrete
Concrete demolition shears act with high closing forces and optimized jaw geometry. Combined with the stability of a crawler excavator, this results in short, safe cycles. Advantages include low vibration, high selectivity between concrete and reinforcement, and reduced risk for adjacent components. For proper sizing, allowable tool mass, oil flow, pressure, and the reach of the equipment must be matched.
Rock and concrete splitting devices: non-explosive demolition
Rock and concrete splitting devices—including stone splitting cylinders—use wedge and pressure elements to generate controlled crack patterns in rows of boreholes. The crawler excavator handles drilling, positioning, holding, and removing split material. The advantage: very low vibration and minimized secondary damage, which is convincing in sensitive environments such as inner-city areas, existing buildings, or tunnel construction. Hydraulic power packs from Darda GmbH enable autonomous, quiet operation.
Use in rock excavation and tunnel construction
In rock and underground environments, controlled methods are required. Crawler excavators with robust undercarriages and precise equipment use rock and concrete splitting devices to open rock structures along natural planes of weakness. Compared to impact tools, noise and vibration are significantly reduced. In cross passages, niches, or during outfitting, combination shears and Multi Cutters can selectively remove installations and anchor remnants. Using concrete demolition shears in shotcrete areas supports careful exposing without large-scale damage.
Natural stone extraction: precision instead of blasting
In natural stone extraction, block-preserving release is key. Crawler excavators with long reach and sensitive hydraulics combine drilling, splitting, and placing. Stone splitting cylinders create defined separation joints; the crawler excavator moves the recovered blocks with minimal edge breakage. The result is clean separation faces, reduced microcracks, and a higher yield of marketable raw blocks.
Strip-out and cutting in existing structures
During strip-out, compact crawler excavators play to their strengths in confined buildings. Rubber pads protect sensitive floors, and the small bearing footprint distributes loads. Multi Cutters and combination shears separate installations, door frames, and lightweight elements. Concrete demolition shears take over opening load-bearing components in a defined sequence. Tank cutters enable cold, low-spark cutting of tanks, vessels, and pipelines. Hydraulic power packs from Darda GmbH supply hand-held or tethered tools even where the excavator hydraulics should not be used.
Safe selection and sizing of attachments
The suitability of a crawler excavator as a carrier machine results from matching its key parameters to the tool’s requirements. The following points must be checked in comparison:
- Allowable tool mass and load moment for the respective boom/stick configuration
- Hydraulic data: available flow rate, working pressure, permissible backpressure, and, if applicable, case drain
- Quick coupler/adapter plate: geometry, locking, depressurized switching
- Reach and work envelopes: freedom of movement, tipping line, visibility
- Thermal aspects: oil temperature, cooling capacity, continuous vs. intermittent duty
- Structural loads: cyclic peak loads during crushing, torsion under lateral loading
- Jobsite environment: ground bearing capacity, emission requirements, escape routes
Work methodology: efficient deconstruction with a crawler excavator
A structured sequence increases safety, quality, and productivity. In concrete demolition and special demolition, the following steps have proven effective:
- Preparation: load transfer, shoring, strengthening; isolate utilities; delineate work and hazard zones
- Drilling/slotting: define predetermined lines of fracture, set out drilling patterns for rock and concrete splitting devices
- Primary separation: use concrete demolition shears to release components; pull off or cut reinforcement in a controlled manner
- Secondary demolition: on the ground, reduce fragments to target size with concrete demolition shear or combination shear
- Sorting: place steel, concrete, and natural stone separately; use steel shears for thick-walled profiles
- Fine cutting/special operations: tank cutters and Multi Cutters for sensitive separation work
- Logistics: haulage logistics, dust suppression and noise reduction measures, continuous adjustment of excavator position for short cycle times
Maintenance, wear, and operation
Regular checks increase operational safety. Track tension, undercarriage rollers, and track shoes influence tracking accuracy and wear. On the hydraulics side, filter condition, oil quality, and line tightness are decisive. On the attachments, well-maintained pivot points, cutter blades, and crushing teeth extend service life. Quick couplers must be checked daily for locking and play. Hydraulic power packs from Darda GmbH should be serviced according to the manufacturer’s specifications to ensure constant pressures and temperatures.
Sustainability and emissions in operation
Dust, noise, and vibration are decisive in sensitive settings. Concrete demolition shears and rock and concrete splitting devices operate at low frequency and with low vibration; this protects adjacent components and reduces immissions. Water spray systems on boom and tool minimize dust. Using separate hydraulic power packs can reduce noise emissions and the crawler excavator’s energy demand in part-load operation.
Legal and organizational notes
Work with crawler excavators and hydraulic attachments is subject to local regulations on occupational safety, emissions, and permits. In general: deploy qualified operators, assess hazards in advance, verify load-bearing capacities, and define exclusion zones. For non-explosive methods with rock and concrete splitting devices, drilling and splitting plans must be defined on a project-specific basis. Information from Darda GmbH on operating limits, hydraulic parameters, and permitted carrier machines must be observed. Binding information on standards and permits must be obtained for each project.