Top Applications for Custom Wire Rope Assemblies in Rigging

In modern industrial and rigging applications, wire rope assemblies serve as critical engineered systems designed to perform under extreme stress, dynamic loads, and harsh environmental conditions. These customized solutions—comprising high-strength wire ropes paired with application-specific end terminations such as swaged sleeves, hooks, or shackles—deliver enhanced safety, durability, and load-bearing performance across diverse sectors including construction, marine, logistics, entertainment, and agriculture. Compliance with international standards such as EN, ASME, and DIN, coupled with rigorous inspection, maintenance, and discard protocols, ensures that these assemblies meet the highest levels of operational safety and reliability. By opting for custom-designed wire rope assemblies from trusted manufacturers, industries achieve optimized fit, function, and cost-efficiency, unlocking full potential in both routine and demanding lifting, securing, and tensioning tasks.

I. Introduction: Wire Rope Assemblies – From Basic Components to Engineering Lifelines

• In the steel jungle of today’s heavy industry, wire rope assemblies have long transcended their primitive definition as “simple lifting tools” to become the core of meticulously calculated and rigorously verified engineering systems. They are the tangible bridges of human industrial power against gravity, the silent arms bearing the weight of civilization. From the construction sites of skyscrapers piercing the heavens to the tempestuous waters of offshore drilling platforms; from high-speed automated production lines to the giant, light-transformed stages at the heart of theaters; from deep-forest logging operations to transcontinental logistics networks – wire rope assemblies are ubiquitous. Their performance directly determines the success of projects, the safety of assets, and the preservation of human life. The challenges they face are the pinnacle of the industrial domain: extreme static loads of hundreds of tons transforming into massive impact forces the instant lifting begins; cyclical fatigue stresses testing material endurance limits relentlessly over millions of cycles; harsh environments like high temperatures, extreme cold, salt spray, chemical corrosion, and abrasive grit acting as an unceasing erosive flood. A single lifting operation failure can lead to catastrophic consequences – from the destruction of invaluable equipment and indefinite project delays to disastrous accidents with incalculable costs.

• It is against this stringent backdrop that the strategic value of Custom Wire Rope Assemblies is elevated to unprecedented heights. They are far from simple stacks of standard parts; they are engineered solutions that systematically integrate high-strength wire rope – the “force carrier” – with deeply optimized end terminations and fittings – the “force transfer and interface system.” This customization process essentially translates abstract application scenarios (load characteristics, motion trajectories, environmental spectra, safety redundancy) into concrete choices of materials, structural design, manufacturing processes, and verification standards. Engineers must precisely calculate the Working Load Limit (WLL) and apply stringent safety factors (typically 5:1 or higher), analyze dynamic load spectra (e.g., impacts from acceleration, braking, wind-induced sway), predict wear and corrosion rates and patterns, and assess connection point compatibility and failure risks. For instance, customizing an assembly for a heavy crane on a deep-sea pipelay vessel necessitates selecting a special alloy stainless steel core rope structure to resist high-pressure seawater penetration and hydrogen sulfide corrosion, employing oversized deep-sea grade forged shackles paired with triple-sealed swaging processes, and subjecting the entire assembly to fatigue life testing simulating pressures at thousands of meters depth. This deep customization yields systemic benefits: safety leaps due to precise matching of operating conditions, eliminating risks of “overloading” or “under-design”; performance (e.g., flexibility, rotation resistance, abrasion resistance) is specifically optimized, significantly enhancing operational efficiency and precision; service life is multiplied in harsh environments, reducing total lifecycle costs; ultimately achieving optimal cost-effectiveness – avoiding massive losses from failures, reducing maintenance downtime, and maximizing equipment utilization. Therefore, choosing Custom Wire Rope Assemblies is the proactive response of industrial wisdom to complex challenges and the inevitable choice for the engineering field’s pursuit of “precision and reliability.”

II. Deconstructing Custom Wire Rope Assemblies: A Multidimensional Symphony of Engineering Precision

A Custom Wire Rope Assembly is essentially an integrated force transmission system born for a specific function. Its core lies in permanently or semi-permanently combining a length of wire rope – with precise dimensions, specific structure, and defined performance – with one or more meticulously designed and manufactured end terminations or hardware through a reliable termination process. This combination is far from a simple connection; it is the critical node enabling efficient, lossless, and safe power transmission from the source (crane, winch) to the load. Its customized nature manifests in every constituent dimension, ensuring the final assembly achieves seamless compatibility with the target application in physical, chemical, and environmental aspects.

1.Wire Rope Type: The Cornerstone of Material Science and Environmental Resistance

•  Galvanized Wire Rope: A model of balance between economy and protection, its core value lies in the sacrificial anode protection provided by the zinc coating. In non-extreme corrosive outdoor environments (e.g., general construction sites, inland logistics yards), a uniform and dense hot-dip galvanized layer effectively blocks oxygen and moisture, significantly delaying rust progression. However, its protective efficacy is significantly influenced by zinc coating thickness, environmental humidity, and pollutant concentration (e.g., acid rain, de-icing salts). In marine atmospheres or industrial pollution zones, higher zinc coating weight grades (e.g., Class A Zinc) are required, supplemented by more frequent inspection and maintenance. Its advantages lie in high cost-effectiveness, mature processes, and wide availability.

• Stainless Steel Wire Rope (Austenitic 304/316/L): The ultimate weapon against harsh corrosive environments. AISI 304 stainless steel performs excellently in general atmospheres and mild chemical media; while AISI 316/L stainless steel, with its added Molybdenum (Mo), exhibits exceptional resistance to pitting and crevice corrosion in chloride-ion environments (e.g., seawater, salt spray, chemical plants). Although its strength is slightly lower than carbon steel galvanized rope of the same specification, its near-maintenance-free nature and ultra-long service life make it irreplaceable in critical applications (e.g., permanent mooring on offshore platforms, reactor vessel lifting in chemical plants, food/pharmaceutical-grade equipment). Strict differentiation of material grades is essential during selection to avoid inferior substitutes.

• Plastic Coated Wire Rope (PVC, PU, Nylon):This polymer sheath imparts multiple protective and functional characteristics. Physical Protection: Effectively reduces internal wire-to-wire fretting wear and blocks the ingress of external abrasives (sand, stone, ore), significantly extending service life (especially in ore handling, towing applications). Chemical Protection: High-quality PVC or PU coatings resist oils, weak acids/alkalis, and various solvents, protecting internal wires from erosion. Functional Optimization: Colored coatings facilitate identification management; noise reduction (reducing metal-on-metal friction sounds); improved handling feel; in stage applications, black coatings achieve “invisible” effects. The core lies in coating material selection (abrasion resistance, weather resistance, chemical resistance) and coating process quality (uniformity, adhesion).

• Rotation-Resistant Wire Rope: The key design solution to the troublesome problem of load rotation during lifting. Its principle relies on a special core and strand layer structure (e.g., Independent Wire Rope Core (IWRC) + multiple layers of reverse-lay strands, or parallel compacted Warrington-Seale construction), causing rotational moments generated in inner and outer layers to cancel each other out. In deep shaft hoisting, precision lifting of heavy equipment (e.g., generator rotors, wind turbine nacelles), and applications using multi-leg slings or long travel, rotation-resistant design greatly enhances stability and safety, preventing uncontrolled load rotation, sling entanglement, and reducing additional torque on crane structures. Customization requires precise calculation of load, length, and suspension method effects on rotation characteristics.

2.Construction: The Code of Geometric Configuration and Performance

• 6×19 / 6×36 Class: The king of versatility. 6 strands laid around a Fiber Core (FC) or Independent Wire Rope Core (IWRC). 19 or 36 denotes the number of wires per strand. FC cores provide better flexibility and cushioning; IWRC cores significantly increase strength, crush resistance, and structural stability (especially suitable for multi-layer coiling on drums). This construction offers a good balance between strength, flexibility, abrasion resistance, and cost, widely used in cranes, excavators, elevators, and tow trucks. Variants (e.g., Seale, Warrington) allow fine-tuning of wear resistance and flexibility.

• 7×7 / 7×19 Class: Higher-grade multi-strand structures, with 7 strands (each having 7 or 19 wires) laid around a core. 7×7 offers excellent flexibility and bending fatigue resistance, commonly used for control cables, light lifting (e.g., stage flying systems), lashing, and securing. 7×19 retains good flexibility while offering higher breaking strength and abrasion resistance, suitable for applications requiring frequent bending and moderate loads, such as forklift chains, ship deck machinery, and construction machinery control cables.

• 1×19: Single strand construction, formed by laying 19 wires in one operation. Characterized by extreme rigidity, very low elongation, and a high strength-to-weight ratio. Almost non-rotating, with excellent dimensional stability. Primarily used in static or quasi-static tensioning systems: architectural structural cables (curtain wall tension rods, cable trusses), aerial ropeway carrier cables, bridge hangers, mast stays, power transmission earth wires. Its bending performance is poor; strictly prohibited for use on drums or sheave systems.

• Custom Constructions: For extreme operating conditions, custom constructions may be required. Examples:Compacted Strand Wire Rope (wires within strands are rolled/deformed, increasing contact area, boosting strength by 10-15%, greatly enhancing wear and crush resistance; used in mine hoisting, port heavy-duty grabs). Plastic Filled Wire Rope (interstitial spaces filled with plastic, blocking corrosive media ingress, enhancing structural stability; for corrosive environments or deep-sea). Multi-Strand Parallel Lay Non-Rotating Ropes (for ultra-deep shaft hoisting or very large cranes).

3.End Terminations: The Precise Interface and Functional Hub for Force Transfer

Terminations are the critical converters that safely, efficiently, and conveniently transfer the force from the wire rope to other components (hooks, shackles, equipment lugs, anchor points). Their selection must perfectly match the load type, connection method, space constraints, operational frequency, and safety requirements.

• Thimble: The core protective element embedded inside the rope eye. Its U-shaped or heart-shaped design provides a smooth, large-radius bearing surface for the wire rope, preventing eye deformation or cutting (especially when connecting to shackles or hooks). Material is typically forged carbon steel or stainless steel, strength-matched to the wire rope. Indispensable for forming a safe, durable rope eye.

• Hook: The most common gripping device. By Manufacturing Process:Forged hooks (highest strength, best reliability, preferred for heavy lifting); stamped hooks (lower cost, for light duty). By Safety Device: Safety hooks (with self-locking latch to prevent accidental sling/disengagement); plain hooks. By Shape: Clevis hook (deep throat design, anti-slip), C-hook, eye hook, etc. Selection requires considering throat opening, depth, material, WLL rating, and compliance with standards like ASME B30.10. Swivel hooks eliminate torsional loads.

• Eyebolt: A threaded fastener used to directly secure or connect a load to a lifting point. Straight Shank Type requires force direction along the axis, otherwise strength plummets; Shoulder Type/Side Pull Type allow a certain degree of side load. Material (alloy steel, stainless steel), thread specification (metric, imperial), WLL rating (DIN 580, ASME B18.15) must strictly match the application. Installation torque and load angle are critical for safety.

• Shackle: The king of connections. Bow Shackles offer larger internal space for accommodating multi-leg slings or large connectors; Dee Shackles have higher strength, better suited for straight-line pull. Material (carbon steel, alloy steel, stainless steel), pin type (screw pin – easy disassembly, bolt pin/cotter pin – higher reliability), size, and WLL (ASME B30.26, DIN EN 13889) are core selection factors. Safety pin shackles have locking mechanisms.

• Swage Sleeve/Fitting: One of the most mainstream, reliable permanent mechanical termination methods. Massive radial pressure (hydraulic or die-forged) compresses the sleeve (typically aluminum, copper alloy, stainless steel) tightly around the rope strands, forming a high-strength, low-profile, often gas-tight connection point. Performance depends on precise matching of sleeve material/size to the wire rope, and the accuracy/process control (pressure values, position marking) of the swaging equipment.

• Turnbuckle: A precision tool for length adjustment and tensioning. Consists of a body with left-hand and right-hand threads at each end, fitted with two ends featuring eyes or hooks. Rotating the body precisely adjusts the total assembly length for load equalization or structural tensioning. Widely used in rigging, structural bracing, equipment securing, and sling tension adjustment. Material (stainless steel for corrosion resistance), thread specification, adjustment range, and WLL are key parameters. Designs with lock nuts or wire holes prevent accidental loosening.

4.Termination Methods: Building the Inseparable Mechanical Union

This is the process of permanently or reliably joining the wire rope to the end termination. Its quality directly determines the assembly’s overall strength (typically required to be ≥90% of the wire rope’s minimum breaking force) and long-term reliability.

• Swaging: As described above, achieves connection via high-strength plastic deformation. Advantages:High strength (up to 95%+ of rope MBF), compact and smooth profile (runs smoothly over sheaves), good fatigue resistance, excellent corrosion sealing (especially with metal sleeves), extremely high reliability. Disadvantages:Requires specialized equipment and process control; usually permanent connection (non-detachable). The preferred choice for industrial lifting.

• Flemish Eye/Splice: The art and science of hand (or semi-automated) braiding. Strands from the rope end are intricately tucked back into the main rope body according to complex rules, forming a smooth, high-strength rope eye (typically fitted with a thimble). Its flexible connection point offers excellent bending fatigue resistance, often used where frequent passage over sheaves and shock sensitivity are concerns (e.g., marine rigging, crane boom hoist ropes). Strength can reach 80-90% of rope MBF, highly dependent on operator skill. Requires regular inspection of the splice area.

• Resin Socketing / Zinc Poured Socket: The rope end is splayed, cleaned, inserted into a tapered socket (steel or alloy), and molten metal (zinc-based alloy) or high-performance epoxy resin is poured in. Upon cooling/curing, a high-strength “anchorage” is formed. Advantages:Very high strength (approaching 100% MBF), good corrosion resistance (metal pour), detachable (resin type), suitable for very large diameters or special rope constructions. Commonly used for permanent anchors (e.g., cable-stayed bridge cables, elevator hoist rope terminals), mine shaft conveyance connections. Process control (cleanliness, pouring temperature, curing) is paramount.

• Wire Rope Clips / U-Bolt Clips: Use a U-bolt, saddle/base, and nuts to mechanically clamp the rope end to form an eye or connection. Advantages: Can be installed/disassembled onsite, low cost, simple. Disadvantages:Significant strength loss (only 80% of rope MBF with correct installation, lower if incorrect), stress concentration (U-bolt flattens wires), prone to loosening (requires periodic re-tightening), bulky profile (snag hazard). Typically only suitable for temporary, non-critical, or low-load applications (e.g., guardrail wires, temporary securing), and must follow the “Saddle on the live rope, U-bolt on the dead rope” installation rule with correct torque. Swaging or splicing is superior for important lifting.

The design process for a Custom Wire Rope Assembly involves countless iterative trade-offs and precise calculations across these four dimensions (Rope Type, Construction, Termination, Termination Method), based on a deep understanding of the application’s physical constraints, environmental spectrum, safety codes, and operational needs, ultimately arriving at the optimal engineering solution. Every custom assembly is a finely balanced entity of function, safety, longevity, and cost.

III. The Industrial Symphony of Custom Wire Rope Assemblies: Deep Dive into Application Scenarios & Technical Challenges

1. Construction & Heavy Lifting: The Power Backbone Beneath the Steel Sky

On the stage of modern mega-projects, cranes (tower, crawler, mobile), tower elevators, and heavy winches are the undisputed protagonists.Custom Wire Rope Assemblies are the core tendons and nerve endings driving these steel giants and directly grasping colossal burdens. They face peak engineering challenges: lifting hundreds of tons of precast concrete segments, giant steel trusses, precision electromechanical modules, or large construction machinery. This extreme duty demands near-imperative requirements.

• Ultimate Tensile Strength: The assembly’s Minimum Breaking Force (MBF) must be multiple times the maximum anticipated working load (considering dynamic factors, wind load, accidental impact), with safety factors often 5:1 or higher. This necessitates selecting the highest grade wire ropes (e.g., 1960MPa, 2160MPa) paired with forged high-strength alloy steel terminations (hooks, shackles). Calculations must precisely include load, rigging weight, and acceleration forces.

• Exceptional Fatigue Resistance: A main hoist rope on a large project may endure tens of thousands of hoist/lower, boom, and slew cycles. Bending fatigue (over sheaves/drums) and tensile fatigue are primary failure modes. Solutions include: Selecting IWRC construction 6×36 or compacted strand ropes for enhanced crush and fatigue resistance; Optimizing sheave/drum diameter ratio (D/d ratio ≥ 18-25); Special treatment of termination zones (swage, eye) (e.g., pre-forming, stress concentration relief); Employing swivel terminations to release torsional loads.

• Superior Flexibility & Rotation Stability: When lifting hundreds of meters, the rope needs sufficient flexibility to smoothly spool in multiple layers on giant drums, while being highly rotation-resistant to prevent the load (especially slender items like steel columns, wind turbine blades) from uncontrolled spinning mid-air, sling entanglement, or applying destructive torque to the crane structure. This invariably points to multi-strand rotation-resistant ropes (e.g., 34×7, 36×7 construction), whose complex reverse-lay layers effectively counteract rotational moments. Combined with swivel hooks or equalizer beams, this ensures stable, controlled load lifting.

• Environmental Suitability: Outdoor sites are harsh – abrasive dust, rain, UV. Galvanized rope (Class A or higher) is the economical choice; critical points or corrosive environments (seaside, near chemical plants) require stainless steel. Termination surface treatments (e.g., galvanizing, Dacromet) enhance corrosion resistance.

• Key Termination Configuration: Eye & Thimble + Forged Bow Shackle + Alloy Steel Safety Hook is the classic combination. The thimble protects the eye; the shackle provides a reliable, convenient connection hub; the safety hook has a self-locking latch to prevent accidental release. For super-heavy or uniquely shaped loads, custom spreader beams may be used, with multiple connection points for assemblies (e.g., with oversized WLL eyebolts).

2. Marine & Offshore Operations: Corrosion-Resistant Fortresses in Angry Seas

The ocean is Earth’s most demanding corrosive environment: high salt spray, 100% humidity, UV radiation, seawater immersion, temperature fluctuations, microbiological fouling. Wire rope assemblies on ships (cargo, cruise, naval), offshore platforms (drilling, production, wind), port machinery, and subsea equipment endure a combined assault of “corrosion-wear-fatigue.” Failure consequences are especially dire far from land.

• Material Choice: Stainless Steel Reigns Supreme:AISI 316/L stainless steel wire rope is the absolute mainstay. Its added Molybdenum (Mo) imparts exceptional resistance to chloride-induced pitting and crevice corrosion, far surpassing 304 stainless steel. For critical permanent moorings or deep-sea equipment, super duplex stainless steel or special high-nickel alloy ropes may even be used. Sacrificial anodes or impressed current systems can supplement lifespan.

• Structural Optimization: Seawater ingress is the primary cause of internal corrosion.All-stainless ropes (including core) are ideal. If galvanized rope is used for cost reasons,plastic-filled constructions are mandatory, using polyethylene etc. to fill interstices, creating a physical barrier.Compacted strand structures reduce surface area and ingress paths while enhancing abrasion and crush resistance.

• Termination & Hardware – Marine Grade Configuration:

1. Mooring & Anchoring: Oversized Eye-Eye Turnbuckle assemblies (316 stainless steel) are central for tension adjustment. Paired with high-grade forged shackles (with safety pins) and marine-grade fairleads/bollards. Assemblies must withstand massive, unpredictable shock loads.
2. Towing & Tugging: Tugs towing large vessels or structures subject assemblies to huge, fluctuating tension. Assemblies with forged triangular or pear-shaped links are common, connecting to high-strength synthetic hawsers or main towlines. Swivel terminations to eliminate torque are crucial.
3. Winch Ropes (Cargo, Anchor, Deep-Sea): Rotation-resistant multi-strand stainless rope is standard. Terminations typically use heavy-duty swage sleeves connected to winch drums or poured sockets for anchoring. Deep-sea research winch ropes may involve kilometers in length, ultra-high strength, and pressure resistance requirements.
4. Cargo Handling Systems (Ship Cranes, Deck Cranes): Similar to land cranes but with a more corrosive environment. Stainless steel rope or heavily galvanized rope + stainless or hot-dip galvanized heavy-duty shackles/hooks are standard. All moving parts need seawater-resistant lubrication design.

• Standards & Certification: Must strictly comply with Classification Society rules (e.g., ABS, DNV-GL, LR, CCS, NK) and relevant IMO requirements, covering materials, manufacturing, testing (break, fatigue, salt spray), and traceability. Certification is mandatory for maritime use.

3. Industrial Lifting & Manufacturing: The Invisible Skeleton on Precision Assembly Lines

Within factory floors, assembly lines, and warehouses,Wire Rope Assemblies play the role of precise, reliable, tireless movers and supporters, driven by automation and efficiency demands. Their applications are often “quieter” but equally critical, demanding high precision, reliability, and longevity.

• Overhead Cranes & Monorails: Main hoist, trolley traverse, bridge traverse all rely on custom ropes. Characteristics: High cycle count (hundreds/day), medium-high loads, need for precise positioning. Use high-strength, wear-resistant 6×36 IWRC or compacted strand galvanized rope. Terminations are typically swaged eyes + forged alloy steel shackles connecting to hook blocks or direct swaging to crane trolley wedge sockets. Rotation resistance aids precise positioning.

• Winches & Hoists: For vertical material/equipment movement or as production line lift units. Flexibility (for small drums) and wear resistance are key. 7×19 or 6×19 FC galvanized ropes are common. Terminations are swaged eyes connected to loads or direct poured/swaged attachment to drums. May include overload protection devices.

• Conveyor Belt Tensioning & Direction Change: Wire rope assemblies (often 1×19 or 7×7 stainless/galvanized) are used in gravity tensioners or support/adjustment for heavy conveyor belt idler rollers. Require high rigidity and environmental resistance (dust, oil). Terminations often use turnbuckles for precise tension adjustment.

• Load Stabilizers & Fall Arrest Systems: For equipment maintenance and aerial work platforms, wire rope (often flexible 7×7 or 7×19 stainless) serves as fall arrest lifelines or equipment stabilization guys. Terminations connect to self-retracting lifelines (SRLs), safety hooks, high-strength eyebolts. Reliability is paramount; mandatory periodic replacement is common.

• Custom Connection Fittings Rule: Industrial environments have compact spaces and diverse connection points.Clevis End Assemblies facilitate pin insertion; Jaw End Assemblies connect easily to shoulder eyebolts; Threaded Rod End Assemblies screw directly into equipment bases;Wedge Socket Anchor Assemblies provide simple, efficient rope end fixing. Engineers must precisely design end forms based on equipment interfaces.

4. Entertainment & Stage Rigging: Wings of Safety in the Realm of Light & Shadow

In theaters, concerts, TV studios, theme parks, behind breathtaking aerial performances, rapidly changing stage scenery, and stunning lighting/sound arrays, lie invisible Custom Wire Rope Assemblies balancing art and safety. Here, safety is the absolute red line, and aesthetics are a hard requirement.

• Invisible Aesthetics: Black PVC or Nylon coated wire rope is absolutely standard. The coating provides matte black (blending into dark backgrounds), reduces operational noise (metal-on-metal sounds), prevents snagging props/costumes, and offers extra corrosion/abrasion protection. Terminations (shackles, links) are often black oxide treated or painted.

• Extreme Safety Redundancy: Suspending personnel (aerialists, wire work), expensive equipment (LED walls, lasers, audio), heavy scenery demand safety factors far exceeding industrial norms (often ≥10:1). Use high-grade rope (e.g., 316 stainless core + coating), heavy forged stainless shackles, and swivel hooks. Double or even triple redundancy (e.g., primary point + secondary safety rope) is common.

• Precision Control & Low Elongation: Stage scenery movement requires pinpoint positioning. Assemblies need low elongation (to prevent load creep) and good dimensional stability. Rotation-resistant rope prevents scenery rotation. Compact swage terminations are preferred, ensuring smooth passage through pulley systems.

• Dynamic Loads & Fatigue: Wire work involves high speeds, sudden stops, direction changes. Assemblies endure complex dynamic shock loads and bending fatigue. Requires specialized design: high-toughness, high-fatigue strength stainless rope (e.g., special 7×19 construction), termination zone reinforcement, rigorous dynamic load testing.

• Standards & Regulations: Strict adherence to entertainment industry standards like ESTA’s ANSI E1.43 (for personnel lifting) and BS 7905-1 (UK stage rigging). Regular professional inspections (LOLER) and load testing certificates are indispensable.

5. Agriculture & Forestry: The Tough Sinews Across Fields and Forests

Vast farmlands and rugged mountains are battlefields where Wire Rope Assemblies endure rough use, complex terrain, and harsh weather. They need unpretentious strength, reliability, and ease of use.

• Abrasion Resistance: Dragging over rough ground (logs, rocks, equipment), friction with dirt/gravel is routine. Heavy galvanizing is basic protection. Plastic coating (especially abrasion-resistant PU) provides superior protection, reducing internal wear, extending life manifold. Compacted strand construction enhances surface hardness.

• Flexibility & Impact Resistance: Needs to wrap around trees, posts, tractor hitches; withstand violent jerks and impacts during felling and skidding. 6×19 or 6×37 FC construction provides good flexibility and impact resistance. The FC core’s cushioning is vital under dynamic loads.

• Practical & Reliable Terminations: Quick connection is key.

1. Wire Rope Clips: Though strength-limited and needing maintenance, remain widely used on farms for temporary, low-load connections (fence tightening, equipment towing) due to simplicity and low cost. Must be installed correctly and checked/tightened regularly.
2.  Turnbuckle with Jaw End: Widely used for fence tensioning. Jaw fits over fence post bolt; turnbuckle adjusts tension. Material must be rust-resistant (hot-dip galvanized).
3. Clevis End: Extremely robust and reliable, connects via pin. The preferred end type for forestry machinery (skidders, winches) for heavy towing and lifting assemblies. Paired with forged clevises and heavy pins.

• Resistance to Environmental Degradation: Long-term exposure to sun, rain, fertilizer, pesticides. Hot-dip galvanizing is the minimum requirement. For critical or high-value equipment (e.g., large combine harvester lift ropes), stainless rope or plastic-coated rope are better choices.

6. Transportation & Logistics: The Securing Bonds in the Moving World

Within the vast network of global goods movement,Wire Rope Assemblies are the “invisible guardians” ensuring cargo stays firmly in place, undamaged, during road, rail, and sea transport, especially for high-value, hazardous, or heavy equipment.

• Lashing & Load Securing: For securing containers, large machinery, pipes, timber. Assemblies are often flexible, moderate-strength 7×19 or 6×19 galvanized/coated rope. Termination configuration is core:

1. Lever Hook/Snap Hook: Spring-loaded latch allows one-handed quick connect/disconnect, hooks onto D-rings on trailers/containers. Operational ease is paramount.
2. Quick Link: Like a large threaded carabiner, unscrews for fast connection/disconnection, more compact than a shackle. Must be tightened securely.
3. Forged Eye: Provides an extremely robust connection point, typically used with turnbuckles or ratchet binders for powerful tightening.
4. Vehicle Tow Cables: For recovery, towing disabled vehicles. Require high breaking strength and good impact resistance. Often use galvanized wire rope with swaged eyes or poured sockets, terminated with heavy-duty tow hooks or D-rings. Assemblies with elastic buffers absorb shock.
5. Container Locks & Twistlocks: Secure containers on ship cells, rail cars, or trailers. While the main body is steel, operating handles and linkage mechanisms often use flexible 7×7 stainless or synthetic rope. Require corrosion resistance, smooth operation, reliability.

• Core Requirements: Regulatory Compliance, Matched Strength, Operational Ease:Must meet national transport safety regulations (e.g., North American DOT, WSTDA standards). Assembly WLL must be clearly marked and match tensioners/vehicle anchor points. Ease of quick operation and inspection is crucial for logistics efficiency.

7. Architectural & Structural Support: Aerial Poems of Strength and Beauty

In modern architectural aesthetics, wire rope has moved from behind the scenes to center stage, acting as both load-bearing backbone and design language. They make structures lighter, more transparent, and dynamic.

• Suspension Bridge Main Cables & Hangers: The pinnacle of wire rope application. Parallel Wire Strand (PWS) or Spiral Strand is standard. Main cables bear most of the bridge’s dead and live loads, requiring ultra-high strength (1770MPa+), very low relaxation, excellent fatigue and corrosion resistance. Protected by extruded HDPE sheathing + internal dehumidification systems. Hangers (often high-strength 1×19 or 1×37 round strand rope or strand) connect main cables to the deck, terminated with special alloy steel hot-poured sockets. NDT (Magnetic Rope Testing – MRT, Ultrasonic Testing – UT) is key for maintenance.

• Tensile Structures & Canopy Systems: Provide prestress for large stadium roofs, station canopies, tensile membrane structures. 1×19 stainless rope is preferred (strength, low creep, aesthetics). Tension applied precisely via turnbuckles or hydraulic tensioners. Swaged end sleeves provide efficient connection. Assemblies require precise length calculation, considering thermal expansion.

• Glass Curtain Wall Tension Rod Systems: Create frameless, maximally transparent views. Small diameter (Φ8-Φ24mm) 1×19 stainless rope is the only choice. High precision (length tolerance ±1-2mm) is critical to ensure uniform glass panel loading. Custom swaged terminations (often threaded adjusters) connect to the building structure and glass fittings. Pre-tension eliminates system deflection. 100% corrosion resistance and aesthetics are non-negotiable.

• Handrail & Balustrade Support Cables: Combine safety and aesthetics. Φ3-Φ8mm 1×19 or 7×7 stainless ropes tensioned horizontally as guardrails. Require sufficient tension to prevent excessive sway, smooth surface (often mirror or satin finish). Decorative swaged end fittings (e.g., spherical, cylindrical) add finishing touches. Must comply with building code load requirements.

• Stainless Steel & Swaging Dominate: In this domain, AISI 316 stainless steel is almost the exclusive choice due to its superb weather resistance, lasting bright appearance, and adequate strength. Swaging technology, with its high connection strength, compact smooth profile, and minimal visual intrusion, is the predominant termination method, perfectly aligning with the refined aesthetic pursuits of modern architecture. Structural calculations (form-finding, pre-tension setting, node design) and construction precision are critical to success.

IV. The Key to Lifting Success: The Precision Engineering of Custom Wire Rope Assembly Selection

Choosing the right Custom Wire Rope Assembly is not a simple product purchase; it’s a technical decision process demanding rigorous engineering thinking, systematic risk analysis, and precise parameter calculation. This directly determines the safety, efficiency, cost, and long-term reliability of the lifting operation. Below are the key dimensions and decision trees for selection:

1. Load Requirements: Calculating the Safety Margin

• Working Load Limit (WLL): The maximum static load the assembly is rated to safely lift under specific, defined conditions. WLL ≠ Breaking Strength! WLL = Minimum Breaking Force (MBF) / Design Factor (DF).

• Design Factor (DF) Selection is Core: Reflects tolerance for potential risks. DF values are significantly >1, typical ranges:

1. General Industrial Lifting: DF = 5:1
2. Involving Personnel, Valuable Items, Frequent Use, Harsh Environments: DF = 6:1 to 8:1
3. Entertainment Industry Personnel Suspension: DF ≥ 10:1
4. Architectural Structural Support (e.g., tension cables): Per code (often using load/material partial factors, equivalent DF may be higher). 

• Calculation Steps:

1. Determine Maximum Anticipated Static Load (including lifted item and rigging weight).
2. Consider Dynamic Amplification Factor: Acceleration/Deceleration forces, braking, wind-induced sway, accidental impact. This factor is often 1.1 – 2.0+, must be assessed based on the operation.
3. Total Calculated Load = Maximum Static Load x Dynamic Amplification Factor.
4. Select DF based on application risk level.
5. Required Assembly Minimum MBF = Total Calculated Load x DF.

• Key Point: The WLL is a value assigned by the manufacturer under specific conditions (straight pull, new rope, correct installation). Any deviation (e.g., side-loading a hook, multi-leg sling angles, wear/corrosion) significantly reduces the actual safety margin. Always refer to manufacturer charts for angle derating.

2. Environmental Exposure: The Decisive Battlefield for Material & Protection – Environment is the ultimate judge of assembly lifespan.

•   Corrosion:

1. General Outdoor Atmosphere (mild damp/pollution): Heavy Galvanized Wire Rope (Class A or B), galvanized terminations.
2. Marine Environment/Chemical Plants/De-icing Salt Areas: AISI 316/L Stainless Steel Wire Rope + Stainless Terminations are the only reliable choice. Consider Super Duplex Stainless for extreme environments.
3. High Temp Humidity/Acid/Alkali: Assess specific chemical concentrations. Stainless (316L) usually has good tolerance. Special chemicals may require plastic coating (e.g., acid-resistant PU) or special alloy ropes.
4. Internal Corrosion Risk (deep shafts, underwater): Plastic Filled Wire Rope or All-Stainless Rope.

• Abrasion:

1. Abrasive Environment (ore, sand, concrete): Compacted Strand Wire Rope preferred. Add abrasion-resistant plastic coating (e.g., Polyurethane PU) for dual protection.
2. Frequent Bending over Small Sheaves/Drums: Ensure D/d Ratio (Sheave Diameter / Rope Nominal Diameter) ≥ Recommended Value (e.g., 18-25). Use bending fatigue resistant constructions (e.g., 6×36 IWRC).

•  Temperature:

1. Sustained High Temp (>100°C): Standard plastic coatings and resin cores fail. Require special high-temp synthetic core ropes (e.g., SC) and high-temp plastic coatings or bare rope. Termination materials must also be heat-resistant.
2. Extreme Cold (< -30°C): Avoid standard plastic coatings (become brittle), use cold-resistant coatings or uncoated stainless rope. Material impact toughness must be verified.

• UV Radiation: Long-term exposure accelerates coating degradation. Choose plastic coatings with UV-resistant formulations.

3. Length & Flexibility: Constraints of Motion Geometry

• Length Precision:

1. Architectural Structural Cables: Tolerances often required ±1mm to ±5mm, need precision customization.
2. Crane/Winch Ropes: Length must ensure sufficient dead wraps remain on the drum (typically ≥2 wraps), including the fixed end length.
3. General Slings: Tolerances relatively relaxed, but requirements must be specified.

•  Flexibility vs. Rigidity Needs:

1. Frequent Bending, Multi-layer Spooling: Require high flexibility constructions (e.g., 6×19 FC, 7×19). Avoid rigid ropes (e.g., 1×19).
2. Static Tensioning, Minimal Deformation Required: High rigidity, low elongation is mandatory (e.g., 1×19, 1×37).
3. Rotation Resistance: Long travel, multi-leg slings, precision loads: Multi-strand rotation-resistant constructions (e.g., 34×7) are the only solution.

•  Installation Space Constraints: Compact spaces demand small-sized terminations (e.g., compact swage sleeves) or specific termination orientation.

4. End Termination Type: The Interface Protocol for System Compatibility – Terminations are the “plugs” integrating the assembly into the entire lifting system.

•  Matching the Connection Point:

1. Connecting to Crane Hook –> Eye & Thimble + Shackle or Swaged Hook.
2. Connecting to Equipment Lug –> Jaw End or Clevis End + Pin.
3. Connecting to Anchor Point –> Eyebolt or Eye & Thimble + Shackle.
4. Need Length Adjustment/Tension Control –> Turnbuckle.
5. Need Frequent Connect/Disconnect –> Snap Hook, Safety Hook, Quick Link.

• Load Direction: Ensure termination design matches force direction (axial tension? side load? combined?). E.g., standard eyebolts only for axial tension.

• Space & Interference: Consider if terminations might collide with surroundings; if swivel function is needed (swivel hook/shackle).

• Safety Requirements: Anti-release designs (safety hook latch, safety pin shackle) are crucial when personnel or valuables are involved.

• Successful Selection = Load Calculation (Safety) x Environment Match (Longevity) x Geometry Compatibility (Function) x Interface Fit (Reliability). Deep technical communication with an experienced custom manufacturer, providing as much detailed operating condition information as possible, is the foundation for obtaining the perfect solution. Never underestimate the impact of environment or usage on assembly lifespan – a wrong choice can lead to catastrophic consequences or high hidden costs (frequent replacement, downtime).

V. Compliance & Safety: The Lifeline of Custom Wire Rope Assemblies

In the lifting field, safety is not a slogan; it is the gene infused into the product’s blood and the iron law that must be followed. For Custom Wire Rope Assemblies as the load-bearing core, compliance and safety permeate the entire lifecycle – from design and manufacturing, through use and inspection, to disposal. A single failure not only means property loss and schedule delays but can also lead to irreparable human tragedy. Therefore, understanding and executing stringent safety codes and proactive risk management are absolute prerequisites for applying custom assemblies.

1. Adherence to Global Authoritative Standards: The Cornerstone of Quality & Safety

The design, manufacture, testing, and use of custom wire rope assemblies must strictly comply with international, national, and industry-specific standard systems. These standards, crystallized from countless engineering experiences and accident lessons, represent the “minimum threshold” for safety assurance.

• Europe (EN Standards): Comprehensive system, highly influential.

1. EN 12385 Series:Core wire rope standards, covering terms, safety, use information, delivery conditions, specific requirements for various rope types (mines, cranes, lifts, general purpose). E.g., EN 12385-5 specifies delivery technical requirements for general purpose ropes.
2. EN 13411 Series: Specifically regulates wire rope terminations (swage sleeves, resin sockets, zinc poured sockets) for requirements, testing, and marking. EN 13411-3 and EN 13411-4 detail specifications for swaged and resin socketed terminations respectively.
3. EN 13889: Safety requirements for forged steel shackles.
4. EN 1677 Series: Requirements for lifting accessories like hooks and eyebolts.
5. LOLER (Lifting Operations and Lifting Equipment Regulations 1998): UK regulation, though not an EN standard, is widely applied in Europe, mandating periodic thorough examinations and load testing for lifting equipment (including wire rope assemblies).

• North America (ASME Standards):

1. ASME B30 Series: The bible of crane safety. B30.9 (Slings), B30.10 (Hooks), B30.26 (Rigging Hardware – covering shackles, eyebolts etc.) impose mandatory requirements for the design, manufacture, marking, inspection, use, and maintenance of wire rope slings and their accessories. B30.30 (Personnel Lifting Systems) sets even stricter standards for personnel lifting components.
2. WSTDA (Web Sling & Tie Down Association) Standards: While not official codes, are widely accepted and referenced in North America for cargo securement, providing recommended practices for wire rope lashing assemblies.

• Germany (DIN Standards):

1. DIN EN Equivalent Standards: Germany widely adopts EN standards (e.g., DIN EN 12385, DIN EN 13411).
2. DIN 3055: Wire rope slings (safety requirements for wire rope slings for lifting purposes).
3. DIN 3093: Swaged connections (swaged connections for wire ropes).
4. DIN 580: Eyebolts.
5. DIN 6899: Resin socketing for wire ropes.

• International (ISO Standards):

1. ISO 2408: Steel wire ropes for general purposes – Foundational standard covering terms, constructions, dimensions, materials, mechanical properties (breaking force, fatigue), test methods, globally significant.
2. ISO 4309: Cranes – Wire ropes – Care, maintenance, installation, examination and discard – Provides the core guidance for lifecycle management of wire ropes on cranes, the key reference for inspection and discard.
3. ISO 7531: Wire rope slings – Safety – For general purpose synthetic fibre and wire rope slings – Specifies safety requirements for sling use.
4. ISO 10425: Steel wire ropes for the petroleum and natural gas industries – Special requirements for harsh environments in oil/gas exploration, drilling, production.

• Maritime (Classification Society Rules):

1. ABS (American Bureau of Shipping), DNV-GL (Det Norske Veritas – Germanischer Lloyd), LR (Lloyd’s Register), CCS (China Classification Society), NK (Nippon Kaiji Kyokai), etc.: Have specialized, extremely stringent rules for wire rope assemblies used in ship mooring, cargo gear, offshore platform mooring, towing, etc. Covering materials, manufacture, testing (break, fatigue, salt spray, low-temperature impact), certification, and traceability. Compliance with specific Class rules and obtaining their certification is the passport to the maritime market.

2. Compliance Control in Design & Manufacture: Fortifying Safety from the Source

Customization does not mean arbitrariness. Compliance begins at the design and manufacturing stages:

• Design Verification: Assembly design must be based on strength and suitability calculations per selected standards (e.g., ASME B30.9, DIN 3055). Critical applications require Finite Element Analysis (FEA) to verify stress distribution and potential weak points, especially termination zones. Safety factors must be explicit and comply with standards.

• Material Certification: Wire rope, sleeve materials (Al, Cu alloy, SS), forged termination materials (alloy steel, SS) etc., must have Material Test Certificates (MTC). Chemical composition and mechanical property retesting may be necessary to ensure compliance (e.g., EN 10204 3.1/3.2).

• Process Qualification: Core processes (especially swaging, socketing) must have validated Process Specifications (WPS/PQR). Operators must be certified. Swaging equipment requires regular calibration for pressure and dimensional accuracy. Socketing requires strict control of temperature, cleanliness, and curing.

• Destructive Testing: Manufacturers must perform destructive tests on representative batches per standards (e.g., EN 13411-3/4, ASME B30.9) (typically per batch or heat lot). Tests usually include:

1. Breaking Force Test: Verifies the assembly’s overall (rope + termination) minimum breaking force meets design requirements (typically ≥90% of rope MBF or higher).
2. Cyclic Bending Fatigue Test (e.g., EN 12385-10): Evaluates the assembly’s life under repeated bending (especially rope sections passing over sheaves and termination transition zones), key for predicting in-service performance.
3. Salt Spray Test (e.g., ISO 9227): Evaluates corrosion resistance, especially for marine applications requiring specific durations (e.g., 4000 hours).

• Non-Destructive Testing (NDT): Applied during or after manufacturing to detect internal and surface flaws:

1. Magnetic Particle Testing (MT) / Liquid Penetrant Testing (PT): Detects surface cracks, seams, laps in forged/cast terminations.
2. Ultrasonic Testing (UT): Detects internal voids, inclusions in large poured sockets/sleeves.
3. Radiographic Testing (RT – X-ray): Primarily used to examine internal soundness, porosity, and wire arrangement in poured sockets.

• Clear, Permanent Marking: Each assembly or termination must be permanently and legibly marked (typically stamped, laser engraved) with:

1. Manufacturer’s name or trademark
2. Working Load Limit (WLL) or Minimum Breaking Force (MBF)
3. Design Factor (DF) – sometimes implied in WLL
4. Assembly Identification Number (for traceability)
5. Date of manufacture or batch/lot number
6. Compliant Standard (e.g., EN 13411-3, ASME B30.10)
7. Size/Specification

3. Safety Risk Management During Service: The Shield of Active Defense

Once in service, strict management and inspection are the final and most critical lines of defense for safety:

• Professional Inspection: Must be performed by trained, qualified personnel following established procedures and standards (core is ISO 4309).

1. Pre-use Inspection: Confirm assembly type, WLL marking, certificates present; visual check for obvious damage.
2. Daily/Pre-shift Inspection: Operator quick visual check before use, focusing on obvious damage, deformation, wear, or corrosion.
3. Periodic Thorough Inspection: Detailed examination by a competent inspector, frequency determined by risk level (e.g., monthly, quarterly, annually). Covers:
   (1) Wire Rope:
   ① Number, distribution, and nature of broken wires (single, cluster in one strand, valley break).
   ② Degree of wear (reduction in diameter).
   ③ Corrosion (external rust, pitting, internal corrosion signs like reddish-brown powder between strands).
   ④ Distortion (flattening, kinking, birdcaging, core protrusion).
   ⑤ Evidence of heat damage/electric arc burns.
   ⑥ Condition of end fixing (swage sleeve loose/cracked/corroded, socket cracked/wire slippage).
   (2) End Terminations/Hardware:
   ① Cracks (especially bend areas of forged hooks/shackles, thread roots of eyebolts).
   ② Deformation (hook opening increased, shackle bow bent).
   ③ Excessive wear (hook throat, shackle pin).
   ④ Corrosion (especially threaded parts).
   ⑤ Free movement of rotating parts (swivel hooks, turnbuckle threads), lubrication adequacy.
   ⑥ Integrity of safety devices (hook latch, shackle safety pin).
4. Exceptional Event Inspection: Mandatory immediately after abnormal events (overload, severe shock, exposure to fire/chemicals), even if superficially intact.

• Advanced Inspection Technology Application:

1. Electromagnetic Inspection (EMI):
   (1) Leakage Flux (LF): Most common, quantitatively detects metallic cross-section loss (from wear, broken wires, corrosion) and locates local faults (breaks, holes). Modern devices plot rope length vs. damage.
   (2) Residual Field (RF): Sensitive to severe local damage (e.g., fracture).
   (3) Transverse Field Inspection (TFI): Good capability for detecting internal damage (e.g., core failure) and external wear.
   (4) Ultrasonic Thickness/Diameter Gauging: Precisely measures rope diameter and sleeve wall thickness to assess wear and corrosion loss.
   (5) LiDAR/HD Camera Drones: Enable efficient, safe macroscopic condition assessment and diameter measurement for high, long, or hard-to-access ropes (e.g., bridge cables, large crane boom ropes).
   (6)Fiber Optic Sensing: Embedding sensors into rope or terminations allows real-time strain, temperature, vibration monitoring for condition-based monitoring and early warning (especially for critical permanent structures).

• Maintenance & Care:

1. Cleaning: Regularly remove accumulated dirt and abrasive particles (accelerate internal wear).
2. Lubrication: Apply suitable wire rope lubricant per manufacturer’s recommendation to lubricate internal wires, reducing friction and preventing rust. Note: Plastic coated ropes usually don’t need extra lubrication.
3. Correct Storage: Avoid damp, corrosive environments or ground contact. Coil diameter should be sufficiently large to avoid kinks.
4. Correct Use: Avoid dragging, crushing, knotting, small bend radii, side-loading

4. Discard Criteria: The Lifeline for Decisive Loss-Cutting

Timely identification and discard of assemblies reaching end-of-life or showing severe damage is the final barrier against failure. ISO 4309 provides detailed discard guidelines, core principles include:

• Excessive Broken Wires: The most common, visual discard indicator. Permissible broken wire count depends on:

1. Rope construction (6-strand, 8-strand, rotation-resistant)
2. Location (within one lay length, near terminations, over sheave contact zone)
3. Nature of breaks (single, cluster, whole strand break)
4. Safety level of application (general, personnel, critical equipment)

        E.g., for a 6-strand rope, a certain number (e.g., >10% of outer wires) of visible breaks within one lay length usually warrants discard. Cluster breaks or whole strand breaks signal immediate discard.

• Significant Diameter Reduction from Wear: Measure under no load, away from ends and anomalies. Discard when nominal diameter reduction reaches a specified value (typically 7%-10%, depending on standard/risk level). Uniform wear is less critical than severe localized wear.

• Severe Corrosion: Heavy external rusting (especially in valleys), pitting corrosion, or internal corrosion causing significant reddish-brown powder (rust) between strands accompanied by marked loss of toughness. Corrosion drastically reduces effective wire cross-section and fatigue strength.

• Distortion: Includes crushing/flattening (oval cross-section), kinking (permanent helical deformation), birdcaging (strand/wire protrusion), core protrusion, loop formation (rope knotting). These distortions compromise structural integrity, causing uneven stress distribution and rapid failure.

• Heat Damage/Electric Arc Burns: Wires annealed by heat (color change: blue/straw), strength severely reduced. Arc burns create localized hard/brittle points, initiating fatigue cracks.

• End Termination Failure Signs: Loose, cracked, or severely corroded swage sleeve; cracked socket or visible wire slippage; severe wear or looseness at splice; loose U-bolt clips or severely flattened/crushed wires.

• Termination/Hardware Damage: Hook opening increased >10%, or severe wear/deformation/cracks; shackle bow deformed, pin bent/worn/cracked; eyebolt threads damaged, shank bent/cracked; turnbuckle threads damaged, body bent. Any damage affecting strength means discard.

• Core Principle: When in doubt or damage exceeds standard limits, follow “If in doubt, throw it out.” Never risk using a defective assembly.

5. Personnel Qualification & Document Traceability: The Closed Loop of Responsibility

• Personnel Qualification: Personnel involved in design, manufacturing (especially critical processes), inspection, and operation of lifting equipment must be professionally trained and qualified. E.g., NDT personnel need ASNT/PCN etc. certification; crane operators and signalers need licenses; competent inspectors need extensive experience and knowledge.

• Document Traceability: A complete traceability document chain is fundamental for quality assurance and safety accountability. This includes:

1. Material Certificates (MTC)
2. Manufacturing Process Records (e.g., swaging pressures, socketing temperature curves)
3. Test Reports (Break Test, Fatigue Test, NDT Reports)
4. Final Inspection Report
5. Certificate of Conformity (CoC)
6. Usage & Maintenance Logs
7. Periodic Inspection Reports
8. Discard Records

  These documents must be securely stored, ensuring traceability of origin, status, and compliance evidence throughout the assembly’s entire lifecycle. Modern digital technologies (e.g., QR code marking, blockchain) are enhancing traceability efficiency and reliability.

• Compliance and Safety are the fundamental guarantees for realizing the value of Custom Wire Rope Assemblies. They require manufacturers, suppliers, inspection bodies, and users to jointly bear a strict chain of responsibility, integrating standards into every step, embedding risk awareness into every operation, and solidifying inspection and maintenance as daily habits. Only then can the high-performance advantages brought by customization truly translate into safe and efficient lifting outcomes.

You can feel free to contact SICH Manufacturer in China for purchasing wire ropes and get the Crane Wire Rope Catalog: Email: info@sichwirerope.com