Crane rope, or crane cable, typically crafted from high-quality steel, is indispensable for the lifting and hoisting operations of crawler crane. Without a suitable crane rope, the full potential of a crawler crane in construction remains untapped. With numerous crane wire rope options available in the market, selecting the right rope for crawler crane can be challenging for crane owners. This blog serves as a helpful guide to choosing the perfect wire rope. Follow Value Crane, a reputable supplier of crane parts, to discover the ideal crane rope for your needs.
components of crane rope
The crane rope comprises three crucial components that contribute to its design. Firstly, there are individual metal wires that are twisted together to form a single strand. Multi-wire strands are then helically laid around a core, providing strength, flexibility, and durability. The core, which can be made of either fiber or steel, adds support and stability to the wire strands. These components work in harmony, enabling the crane wire rope to handle the demanding lifting and hoisting operations with reliability and efficiency.
Wire - Building Blocks of the crane rope
The wire is the smallest component of a crane wire rope, forming the individual strands that make up the rope. Wires are typically made from various metals such as steel, iron, stainless steel, monel, or bronze. Different grades of wires offer varying properties related to strength, wear resistance, fatigue resistance, corrosion resistance, and flexibility. Coatings may be applied to wires, although they are commonly available in an uncoated or “bright” finish.
strand - Twisted Strength and Flexibility
Strands are formed by arranging and twisting two or more wires together in a specific pattern. These individual strands are then helically laid around the core of the crane cable. Strands with larger diameter wires are more resistant to abrasion, while strands with smaller diameter wires provide greater flexibility.
core - Central Support for Stability and Performance
At the center of a crane cable lies the core, which plays a crucial role in providing support to the strands and ensuring their stability during loading and bending. Cores can be crafted from a range of materials, including natural or synthetic fibers, as well as steel. The core’s function is essential in maintaining the integrity and performance of the crane wire rope in various operational conditions.
Types of crane cable core
Fiber Core (FC)
A fiber core is composed of natural or synthetic polypropylene fibers. It provides increased elasticity but is not recommended for high-heat environments due to its susceptibility to crushing.
Independent Wire Rope Core (IWRC)
An IWRC consists of a separate wire rope within the main wire rope. This steel core offers enhanced strength and durability, making it suitable for applications where a fiber core may not provide sufficient support.
Wire Strand Core (WSC)
A WSC refers to an individual strand serving as the core of the wire rope. Similar to IWRC, it provides robust support and is preferable in environments where temperatures may exceed 180°F.
Crane rope construction
Crane rope construction involves considering seven key factors: length, size, preformed or non-preformed, direction and type of lay, finish of wires, grade of rope, and type of core. Each of these factors plays a crucial role in determining the suitability and performance of the rope for lifting and hoisting operations.
Strand Patterns of crane cable
- Filler Wire: In this pattern, two layers of uniform-size wires encircle a center wire. The inner layer has half the number of wires compared to the outer layer, and small filler wires are placed in the valleys of the inner layer.
- Seale: In the Seale construction pattern, there are two layers of wires encircling a center wire. Both layers have an equal number of wires, and all wires within each layer have the same diameter. The larger outer wires are positioned in the valleys, which are the spaces between the smaller inner wires.
- Warrington: The Warrington construction pattern involves two layers of wires surrounding a center wire. The inner layer consists of wires with a single diameter, while the outer layer alternates between larger and smaller wire diameters. The larger outer-layer wires rest in the valleys between the crowns of the inner layer, where the smaller wires are located.
Single Layer
This pattern consists of a center wire surrounded by six wires of the same diameter, forming a 7-wire strand.
Combination
A combination strand incorporates any combination of two or more of the aforementioned patterns.
Preformed or Non-Preformed crane cable
Preformed or Non-Preformed wire rope refers to the manufacturing process and resulting characteristics of the crane cable. In a preformed wire rope, the strands and wires are shaped into their helical form during manufacturing, ensuring they maintain a predetermined shape. This offers advantages such as uniform spooling on a drum, increased flexibility, and enhanced fatigue resistance during bending. On the other hand, non-preformed wire rope is not shaped during manufacturing and takes its form naturally under tension. Non-preformed ropes are more flexible, adaptable to various applications, and well-suited for situations requiring frequent bending and movement. They offer efficient load distribution and ease of handling, making them popular in lifting and rigging operations.
Type of Lay and Direction
Regular Lay
In a regular lay configuration, the wires of the rope align with its axis, while the wire lay within the strand runs in the opposite direction to the strand lay. Regular lay ropes offer resistance to crushing forces, natural rotation resistance, and efficient spooling on a drum compared to lang lay ropes.
Lang Lay
Lang lay crane ropes have wires that form an angle with the axis of the crane rope. Both the wire lay and strand lay around the core follow the same direction. Lang lay ropes provide greater fatigue resistance and increased resistance to abrasion.
Alternate Lay
The alternate lay crane rope consists of strands with alternating regular lay and lang lay configurations. This type of rope is primarily used for specialized applications that require specific performance characteristics.
crane rope grade
The strength of crane cable used in cranes is categorized into different grades, which include:
Improved Plow Steel (IPS): This is a standard grade of wire rope commonly used in various applications, including cranes.
Extra Improved Plow Steel (EIPS): EIPS wire rope offers approximately 15% higher strength compared to IPS. It provides improved performance and increased load capacity, making it suitable for demanding crane operations.
Extra Extra Improved Plow Steel (EEIPS): EEIPS wire rope offers approximately 10% higher strength compared to EIPS. It is the highest grade among the three, providing exceptional strength and load-bearing capabilities for critical crane applications.
The model type of crane rope
Use 2″ 6*19 FW EFIP RRL IWRC as an example:
- Diameter = 2″
- Number of Strands = 6
- Number of Wires Per Strand = 19
- Strand Pattern = Filler wire
- Grade = Extra Improved Plow Steel
- Direction and Lay = Right Regular Lay
- Core Type = Independent Wire Rope Core
How to choose crane rope for your crawler crane?
Crane machinery is commonly used across various industries and sectors. When selecting wire rope for cranes, considerations should be given to the specific lifting conditions and requirements. This includes factors such as load capacity, operating environment, and the need for flexibility and fatigue resistance.
Moderate Load Capacity
Crane machinery typically operates with a moderate load capacity compared to mining hoisting. However, due to the compact arrangement of crane components, the wire rope needs to pass through multiple sheaves, and the drum and sheave diameters are smaller. This imposes limitations on the drum-to-rope diameter ratio (D/d).
Emphasis on Bending Fatigue Resistance
Given the compact layout and higher number of sheaves, crane wire rope selection should prioritize excellent bending fatigue resistance. It is advisable to choose wire rope with smaller wire diameters, uniform thickness, and good flexibility. Six-strand and eight-strand ropes are often preferred options.
Customized Selection for Specific Crane Types
Different types of cranes, such as crawler cranes and belt cranes, have unique requirements for crane wire rope selection. For main and auxiliary lifting ropes, flexibility and appropriate wire diameters are crucial. Multiple layers of wire rope winding on the drum call for a metal core to resist compression. Free-suspension lifting of loads requires wire rope with anti-twisting and impact resistance properties.
Recommended Wire Rope for Crawler Crane
- Small-Sized Cranes: 6x29F+IWR, 18×7+IWS
- Medium-Sized Cranes: 4Vx39S+5FC, K4xK39S, 35Wx7
- Large-Sized Cranes: 4Vx48S+5FC, K4xK36WS, 35(W)xK7
The model type meaning of crane rope
K4xK36WS
- “K4”: Represents a compacted strand construction, where the wires are compacted together to increase the rope’s strength and resistance to crushing.
- “K36”: Represents 36 wires in total, distributed among the strands.
- “WS”: Stands for “Warrington-Seale” construction, which is a specific type of wire rope construction where the inner layers of wires are smaller in diameter, and the outer layers are larger.
4Vx48S+5FC
- “4V”: Indicates a wire rope construction with four strands.
- “48S”: Represents 48 wires per strand.
- “+5FC”: Signifies the presence of five filler wires in the core of the crane cable.
35(W)xK7
- “35”: Represents a total of 35 wires in the wire rope.
- “(W)”: Indicates the presence of a fiber core, where natural or synthetic fibers are used as the core material.
- “K7”: Signifies a standard lay construction with seven wires per strand.
Wire rope for sale at Value Crane
Explore our extensive range of high-quality wire ropes for sale at Value Crane. Designed for a variety of lifting applications, our crane ropes undergo rigorous testing to ensure durability and safety. With different configurations available, including varying diameters, constructions, and core types, we can provide the perfect wire rope solution for your specific needs. Count on our competitive pricing, excellent customer service, and prompt delivery to meet your project deadlines. Visit our website today to browse our selection of wire ropes. For further assistance or to make a purchase, please don’t hesitate to contact us.
