Cargo crane

Cargo cranes are central lifting devices on construction sites, in factory halls, and in deconstruction. They move heavy components, position equipment, and secure dismantled elements. In concrete demolition, during strip-out, or in natural stone extraction, particular value is created when a cargo crane works in tandem with hydraulic tools. For example, components can be separated with a concrete demolition shear and simultaneously lowered in a controlled manner under the hook. Hydraulic rock and concrete splitters can also be brought to level, held, or precisely repositioned for special operations. This article explains the term with technical precision and provides practical guidance for planning, operation, and safety. Coordinated interaction between crane and tool reduces rework, limits collateral damage to adjacent structures, and supports low-noise, low-vibration methods in sensitive environments. Robust planning of crane logistics shortens cycle times and strengthens regulatory compliance across project phases.

Definition: What is a cargo crane?

A cargo crane is a mechanical lifting and transport device for lifting, lowering, and moving loads in space. It typically consists of a load-bearing structure (e.g., jib, runway, bridge, or gantry), drives, hoist with rope or chain, and a control system. The spectrum ranges from tower cranes to mobile and loader cranes through to bridge and gantry cranes. Key parameters are load capacity, load moment, working radius, lifting height, and outreach. Cargo cranes serve material flow in construction, refurbishment, dismantling, and industrial maintenance-they are not intended for lifting persons. Safety devices such as overload protection and end limit switches must not be bypassed, and the lifting of people with cargo cranes is prohibited.

Core components and functionality

The functionality of a cargo crane follows the principle of safely transmitting force from the drive to the load pickup. The hoist generates the lifting force, while the load-bearing structure channels forces and moments into the ground or building structure. Lifting accessories connect the load positively or friction-locked to the hook. Modern systems often work with fine hoisting, load moment limiting, and radio remote control to position loads precisely. In deconstruction and demolition projects, cranes hold components in position during cutting and splitting operations and prevent uncontrolled movements – such as when using a concrete demolition shear or stone and concrete splitters.

Depending on the crane type, slewing drives, trolley travel, and gantry or bridge travel enable horizontal repositioning. Typical control and safety features include rated capacity limiters, anti-collision systems, and emergency stop circuits. Clear hook visibility and adequate headroom are essential to avoid snagging during precision placement.

Types and designs of cargo cranes

The choice of design determines reach, maneuverability, and suitability in confined spaces. For concrete demolition and specialized deconstruction, the following variants are defining:

Mobile crane

Mobile cranes are flexible, quick to relocate, and reach great lifting heights with variable working radius. They are suitable for picking up concrete elements after separation by concrete demolition shears, repositioning façade panels, or removing fit-out elements from upper floors. Set-up area, outrigger loads, and subbase must be planned early. For urban projects, traffic management and short rigging times often drive the economic choice.

Tower crane

Tower cranes offer high reach over the construction site and are suitable in high-rise deconstruction for serial lifting of small and medium loads. Hydraulic power packs and tool sets – such as for stone and concrete splitters or combination shears – can be quickly moved between work areas. Their fixed position enables predictable logistics with minimal ground occupation.

Loader crane (truck-mounted crane on a truck)

Loader cranes are compact and ideal for inner-city strip-out work. They take care of inserting concrete demolition shears, multi cutters, or steel shears into courtyards, roofs, and intermediate floors where large machines cannot reach. Short setup and integrated transport capability reduce interfaces on tight schedules.

Bridge and gantry crane

In industrial buildings or factory halls, bridge and gantry cranes move plant components precisely under roof. When using a tank cutter, they ensure safe handling of sheet panels or shell segments that are lifted out after the cut. Stable, rail-bound travel and repeatable positioning benefit delicate separation sequences.

Mini crawler crane (spider crane)

Mini crawler cranes operate in confined interiors, on slabs with limited load capacity, or in courtyards with narrow access. Their low ground pressure, compact outrigger footprint, and fine hoisting control suit precision picks of separated elements and the positioning of hydraulic power packs.

Understanding load capacity, load moment, and working radius

The permissible load of a crane depends on the radius, jib configuration, and setup. Load charts define the maximum loads per radius. The governing factor is the load moment: the larger the lever arm, the lower the load capacity. In addition, lifting accessories, wind loads, and dynamic effects influence the actual lifting capability. For practical planning, consider that load moment equals the product of load and radius; small increases in radius can significantly reduce permissible load.

• Derate for wind-exposed loads with large sail area and for gusty conditions
• Account for reeving and hook block weight within the rated capacity
• Include sling angles and possible shock loads from starting and stopping
• On uneven or sloped ground, apply additional safety factors or reconfigure the setup

Lifting accessories and attachment points

The correct choice of lifting accessories is crucial so that load capacity and stability are not undermined:

• Slings and chains with sufficient rated capacity considering sling angle
• Shackles, rings, and spreader beam systems (spreading attachment points for load distribution)
• Grabs, shears, or specialized lifters for concrete elements and steel segments
• Taglines (guide ropes) to control swinging components
• Edge protection and corner saddles to prevent sling damage and capacity loss
• Documented inspections with valid identification tags and traceable certificates
• Choose hitch type deliberately: straight, choke, or basket, and verify angle effects

For components separated with concrete demolition shears, the center of gravity must be determined. Drilled lifting points or cast-in building inserts may only be used if they are suitable for the load. For elongated components, a spreader beam increases stability by reducing tipping moments. Where the center of gravity is uncertain, use two-point suspension with adjustable slings and perform a controlled trial lift close to the ground.

Interfaces with demolition technology and hydraulic tools

In projects where tools from Darda GmbH are used, the cargo crane often acts as a precise partner: It positions equipment, holds components in place, and enables controlled lowering. This reduces secondary damage and increases process safety in concrete demolition, strip-out, and special applications.

Concrete demolition shear under the hook

Concrete demolition shears cut reinforced concrete. The crane typically takes over:

• Preloading the load before the shear closes – minimizes uncontrolled cracking
• Picking up the separated element with a defined center of gravity
• Controlled placement or direct removal

Ensure sufficient clearance for the shear to open and maintain clear communication between rigger, crane operator, and the operator of the hydraulic power packs. Balanced attachment via two lifting points reduces torsion on the shear body and prevents residual binding at rebar.

Stone and concrete splitters in lifting operations

Stone and concrete splitters generate separating forces without impact or vibration. The crane brings cylinders, wedges, and hydraulic power packs to working height, holds components during splitting, and lifts segments out after the split. In tight shafts or for ceiling openings, this is a low-emission, low-vibration method. Rows of wedges can be set systematically so the crane can support and remove segments in a planned sequence.

Steel deconstruction with steel shears, multi cutters, and tank cutter

When cutting steel sections or vessel shells, cranes hold the freed segments in a load-appropriate and position-stable manner. Using steel shears or a tank cutter requires adequately sized attachment points, spark and drip protection, and a clear lowering strategy. For vessels and tanks, ensure gas-free condition, implement hot-work permits, and define a stepwise cut pattern that keeps segments within crane control at all times.

Planning and logistics on the construction site

Crane logistics start with site selection and extend to the pacing of lifting tasks. Good planning reduces downtime and increases safety.

Set-up area, outrigger support, and ground

• Check ground bearing capacity, provide load distribution mats
• Derive outrigger pressures from crane planning
• Cordon off or bridge hazard zones (trenches, shafts, utilities)
• Verify underground voids, basements, and backfills with current survey data
• Monitor settlement and recheck outrigger levels during lifting operations

Crane configuration and setup times

• Jib length, counterweights, and attachments to suit the load spectrum
• Integrate setup and dismantling times into the construction schedule
• Coordinate access routes for mobile cranes and transport vehicles
• Consider reeving, required parts of line, and hook block clearance at all radii

Lifting paths and material flow

• Define short, conflict-free flight paths
• Provide laydown areas for separated components
• Position hydraulic power packs for shears and splitters so hose runs are short and protected
• Plan intermediate staging and drop zones to decouple trades and reduce wait times

Safety and organization for lifting

Safe crane work requires clear responsibilities, inspected equipment, and unambiguous communication. In general: people must not remain under suspended loads, and loads must be secured against swinging.

• Define roles: crane operator, signaler/rigger, equipment operator
• Specify communication means: hand signals or radio with call discipline
• Observe wind and weather limits, ensure visibility
• Mark exclusion zones and escape routes
• Before each lift: visual inspection of lifting accessories, hook, and latches

Legal requirements and recognized rules of technology may vary by region. It is generally advisable to consider current regulations as well as manufacturers’ operating manuals and to use only qualified personnel. For critical lifts with high load share, limited clearance, or complex geometry, prepare a written lift plan and conduct a pre-task briefing.

Weather and ambient conditions

Wind acts over the area of the load and the jib length. Large façade panels, sheets, or debris pieces have significant sail area. In gusts, choose lifting loads conservatively, plan taglines, and postpone lifts if necessary. Temperature, precipitation, and lighting conditions can affect footing, visibility, and hose flexibility for hydraulic tools, requiring adjustments in pacing and rigging.

Visibility, signals, and radio

If the crane operator has no direct line of sight, a designated, trained rigger with unambiguous signals is required. Radio can increase safety but does not replace a clear command structure. Agree on a single emergency stop word and ensure all parties acknowledge commands before execution.

Special applications in demolition, tunneling, and extraction

Cargo cranes are versatile and support a wide range of uses – from concrete demolition and specialized deconstruction to strip-out and cutting, through to rock removal, tunneling, and natural stone extraction.

High-rise deconstruction and strip-out

Tower cranes lift concrete demolition shears, hydraulic power packs, and waste containers to upper floors. Separated elements are secured and lowered in small units. Stone and concrete splitters allow low-vibration opening of slabs while the crane holds the segment. Coordination with debris chutes, floor openings, and dust control shortens cycles and enhances safety.

Tunneling and rock removal

In low cavities, gantry cranes or traveling girders handle heavy tools. Rock blocks released by splitting cylinders can be moved and loaded in a controlled manner. Constrained access and ventilation requirements make precise lifting paths and compact rigging essential.

Industrial and plant deconstruction

When dismantling tanks, silos, and pipe bridges, the crane fixes cut lines, picks up shell segments, and lowers them after separation with tank cutter, steel shear, or multi cutter. Interface management with isolation, cleaning, and hot-work control is part of safe sequencing.

Work preparation: load calculation and selecting lifting gear

Reliable load estimation is the basis of every lift briefing. For concrete, steel, and natural stone, simple approximations can help.

1. Determine geometry: length, width, thickness – calculate volume
2. Assume material density: steel approx. 7.85 t/m³, reinforced concrete often approx. 2.4-2.5 t/m³, natural stone depending on type
3. Consider reinforcement content and embedded items
4. Provide safety allowance and dynamic factors
5. Define the center of gravity and plan attachment points (spreader beam if necessary)
6. Select lifting accessories by required rated capacity and angle
7. Check crane reach and load chart; weigh alternatives

When cutting with concrete demolition shears, residual connections or restrained reinforcement often remain. A short trial lift under observation can help assess the behavior of the load before final separation. For natural stone, moisture content and fissures may change mass and balance; conservative allowances are recommended.

Documentation, inspections, and maintenance

Cranes and lifting accessories must be inspected regularly. Inspection intervals and scope depend on operating conditions and applicable rules. Complete documentation of inspections, commissioning, and briefings supports operational safety. Hydraulic power packs and tools – such as combination shears or stone splitting cylinders – must be checked for tightness, hose condition, and couplings before being moved with the cargo crane.

• Maintain inspection records for crane, rigging, and lifting points
• Verify current calibration and functionality of safety systems
• Record lift plans and post-lift reviews for critical operations

Selection criteria for the right cargo crane

• Load spectrum: weight, geometry, center of gravity, surfaces (sail area)
• Reach and lifting height: building edges, obstacles, access openings
• Setup conditions: ground, outriggers, space requirements, access
• Cycle rate: number of lifts per day and setup times
• Cooperation with tools: concrete demolition shears, stone and concrete splitters, steel shears, tank cutter, multi cutters
• Environmental aspects: noise, vibration, emissions, protective measures
• External constraints: power lines, permits, working hours, neighborhood sensitivities
• Availability and mobilization time in relation to project schedule

Term distinction and classification

Cargo cranes are to be distinguished from handling equipment such as forklifts or winches: cranes move loads freely in space, often with rotating jibs and great lifting height. Hoists such as winches or chain hoists operate locally. In combination with the demolition technology of Darda GmbH, cranes excel wherever controlled cutting, holding, and lowering are required – be it in building construction, tunnels, or industrial deconstruction.