Wire ropes are essential slinging and safety devices on construction sites and in extraction as well as deconstruction. In combination with tools and equipment from Darda GmbH—such as concrete demolition shear, hydraulic rock and concrete splitters, compact hydraulic power units, combination shears, rock splitting cylinders, Multi Cutters, steel shears, and tank cutters—they enable controlled guiding, securing, moving, and lowering of structural elements made of concrete, reinforced concrete, and natural stone. They combine rugged load capacity with flexibility and are used in fields such as concrete demolition and special demolition, building gutting and cutting, rock breakout and tunnel construction, natural stone extraction, and special operations.
Definition: What is meant by wire rope
A wire rope is a flexible load-bearing element made of multiple steel wires. Individual wires are stranded into strands; several strands surround a core and form the rope. Typical designations refer to construction and wire count (e.g., 6×19, 6×36, 8×K36), lay type (ordinary/long lay), lay direction (right/left), and the core (steel core/fiber core). Key parameters include rope diameter, minimum breaking force, and permissible working load considering an appropriate safety factor. Standards and accepted engineering rules (e.g., for construction, termination types, and discard criteria) must be observed; company procedures and national regulations take precedence.
Design and construction features of wire ropes
The construction determines load capacity, bending resistance, and wear behavior. Multi-wire strands enclose a core; material grade, wire arrangement, and lubrication influence service life during reeving, pulling, and lifting. For deconstruction and extraction applications, galvanized, rotation-resistant constructions with sufficient lateral and crush resistance are commonly used, while also ensuring compatible interaction with sheaves, winches, and slings.
Wire ropes in concrete demolition and special demolition
In controlled deconstruction, wire ropes serve as slings, taglines (guiding ropes), and pulling and lowering ropes. In combination with concrete demolition shear, concrete components are first released, then guided, secured, or lowered using ropes. Rock and concrete splitters separate components by splitting forces; wire ropes stabilize the work area, hold sections in position, or pull released elements out of the danger zone. Hydraulic power packs and accessories can be moved or secured by rope when access is difficult.
Typical applications in deconstruction
- Attaching loads to slabs, beams, and wall panels prior to separation with concrete demolition shear
- Guiding ropes (taglines) to prevent uncontrolled rotation during lowering
- Pulling ropes to fine-position components during cutting, splitting, or separation
- Temporary guying and securing of component edges and edge zones
- Position securing of hydraulic power packs on inclined planes
Use in rock breakout and tunnel construction
In rock extraction and underground works, wire ropes are used for pulling and securing tasks: recovering blasted or split boulders, guying, as helper ropes when positioning tools such as rock splitting cylinders or combination shears, and for guiding heavy components in confined spaces. In heading areas, rotation-resistant ropes with robust end terminations are used to damp vibrations and limit torsion. These practices are standard in rock demolition and tunnel construction.
Natural stone extraction
- Guiding and securing raw blocks when breaking them out of the deposit
- Pulling sections over short distances with rope pullers or winches
- Temporary attachment points on drilling frames and bracing
Selection criteria and sizing
Rope selection is based on load, geometry, wrap angle, reeving, and environmental influences. Besides diameter, minimum breaking force, bending fatigue resistance, surface protection (galvanized/bright), lubrication, and compatibility with fittings are decisive. Rotation-resistant or non-rotating ropes prevent component rotation during lowering. For edge contact, sheath protection, suitable edge protectors, and, if necessary, inserts with higher abrasion resistance are crucial.
Practical procedure
- Determine the load (self-weight, adhering reinforcement, allowances for dynamics and side pull)
- Define the safety factor; observe company procedures
- Select the rope construction (bending over sheaves, drum winding, rotational behavior)
- Specify the end termination (swaged ferrule with thimble, splice, defined termination systems)
- Match accessories (shackles, swivels, turnbuckle, sheave) — check load capacity and fit
- Verify compatibility (bend radius ≥ recommended multiple of rope diameter, sufficient sheave diameter)
Slings and end terminations
The performance of a wire rope is largely determined by its end termination. Proven solutions include swaged thimble eyes, spliced loops, or defined termination systems. Improvised connections must be avoided. Wire rope clips are installed per specification; quantity, orientation, and tightening torques are critical. Swivels reduce torsion when components tend to rotate.
Typical components
- Shackles with suitable grade and jaw opening
- Thimbles to increase radius and protect against edge contact
- Swivels to limit torsion on suspended loads
- Turnbuckles for sensitive guying
- Sheaves with suitable groove diameter and profile
Construction, lay type, and surface
Ordinary-lay ropes offer high rotation resistance and good shape stability; long-lay ropes are flexible and wear-resistant under longitudinal sliding. A steel core (IWRC) increases crush resistance; a fiber core improves lubricant retention and bending fatigue resistance. Galvanized ropes protect against corrosion; bright ropes offer higher friction values but require consistent care.
Inspection, care, and discard criteria
Regular inspections ensure fitness for service. Discard criteria and inspection intervals follow standards, manufacturer specifications, and company procedures. Visual inspections detect damage early and prevent failure in use with concrete demolition shear, rock and concrete splitters, and other tools.
Damage patterns
- Single wire breaks, strand breaks, wire protrusion
- Corrosion, rust scarring, pitting
- Crushing, flattening, kinks, “birdcaging”
- Nicks and notch effects from sharp edges
- Heat exposure and loss of lubricant
Care
- Remove dust, cement slurry/laitance, and splinters
- Re-lubricate as specified; use compatible lubricants
- Store dry and ventilated; protect from chemicals
- Document inspections and deployments
Safety and handling on site
Safe work with wire ropes requires careful slinging, defined sling angles, and protection from sharp edges. When guiding and lowering components—e.g., after separation with concrete demolition shear or splitting with rock and concrete splitters—team communication is essential. Personal protective equipment and keeping the danger zone clear are binding fundamentals.
Good practice
- Use edge protection, plan reeving, avoid kinks
- Control sag, damp oscillations, use taglines
- Never overload; consider load sharing in multi-leg slings
- No knots in the wire rope—use approved end terminations only
- Take the load and secure it before cutting or splitting
Comparison with chain and textile slings
Wire ropes are abrasion-resistant and tolerant to temperature and are better suited to edge contact than textile slings, but still require careful edge protection. Chains are robust against point loads and heat but are heavier and less flexible in bending. Textile round slings offer low weight and gentle handling of sensitive surfaces but are susceptible to cutting and heat. In concrete demolition and rock work, the choice depends on environmental conditions, edge exposure, handling, and required flexibility.
Typical sources of error and how to avoid them
- Insufficient bend radius over too-small sheaves—causes premature wire breaks
- Side pull without calculating the resulting leg forces
- Inadequate edge protection on sharp concrete edges or rebar ends
- Incorrect clip installation or undocumented swaged terminations
- Continued use despite visible damage or exceeded service life
Example procedure: Separate a component with a concrete demolition shear and lower it in a controlled manner
A practical, simplified sequence illustrates the interplay of rope work and separation technology. The specific approach always depends on planning, structural analysis, surroundings, and company procedures.
- Assess the component: weight, center of gravity, edge situation, reinforcement layout
- Select rope and slings: rotation-resistant wire rope, suitable shackles and thimbles, defined safety factor
- Create or verify attachment points; apply edge protection
- Sling the rope, consider sling angles, apply pre-tension
- Position the concrete demolition shear; start the cut under rope control
- Release the component in a controlled manner; limit rotation with taglines
- Lower via winch or crane; keep the area clear; ensure communication
- Set down the component, slacken the rope, remove and inspect slings
Cutting, disposal, and specifics in special operations
Damaged or to-be-discarded wire ropes are cut and disposed of properly. Cutting is performed only with suitable tools, e.g., with steel shears or Multi Cutters, considering the energy stored in the rope. In special demolition—such as in contaminated sites or ATEX zone areas—environment, media, and temperature influence rope selection and permissible accessories; the relevant company rulebooks are authoritative.