Know your `Wellworth Rope
Steel Ropes is a technical product and knowing the broad parameters can only be useful
The diameter of rope is the diameter of its circumference, circumscribed to its normal section. This diameter is given in millimeters. Determining the Practical Diameter:-
- Measurements are taken at two points at least one meter apart.
- Diameters are measured at 90° one from the other.
- The average of the four values thus obtained is the practical diameter.
- Usually the practical diameter is taken from a sample of straight rope not subjected to traction.
- In special cases when the tolerance is less than 5% of the minimum guaranteed breaking strength.
- The correct diameter is the greatest diameter of the rope or strand.
The strand is the simplest construction. It consists of one or more layers of superimposed wires laid spirally around one or more centre wires or around a fibrous core. The construction of the strand is identified by the number of wires in the individual layers, starting from the outer one (e.g. 12+6+1 or 15+9+FC). FC indicates a fibrous core. Distinction is made between strands with cross laid and equal laid wires.
- Strands with Cross Laid Wires All the wires in this type of strand are of equal diameter and for geometrical reasons the number of wires decreases in each layer, starting from the outermost one, according to an arithmetical progression based on number (18 + 12 + 6 + 1 or 12 + 6+1). In cross laid constructions each layer of wire is laid up a separate operation with a different length of lay, the result being the crossing of the various layers of wires.
- Strands With Equal Laid Wires In these constructions the
pitches of the various layers of wires are identical as stranding is
carried out in a single operation; therefore, the contacts between wires
are linear. Seale, Warrington and Filler strands belong to this
construction. Wires of different diameters are required for these
constructions. As for example:
Seale: 9 + 9 + 1
Warrington: 6/6 + 6 + 1
Filler: 12 + 6F + 6 + 1.
- Single Strand Ropes are commonly called strands.
- Round Stranded Ropes These have both the strands and the wires in the strands laid helically. It consists of a number of strands either laid around a fiber core or metallic strand or an independent wire rope core. They can be identified by the number to each strand. A rope with 6 strands, each having 9+9+1wires laid around a central fibre core is designated as; 6 x (9 + 9 +1} + FC or more concisely 6 x 19 Seale + FC. If this same rope has an independent wire rope core, the designation will be: 6(9 + 9+1) + IWRC. Should the strands also contain a fibre core then the rope will be known for example as 6x (12 + FC)+FC or 6x 12 + 7FC. Lastly if the rope is formed of two or more layers of strands superimposed around a FC, then it will be known as: 12 x (6 +1} + 6 x (6 +1) + FC or 18 x 7 + FC.
This can be Steel Core, IWRC (Independent wire Rope Core) of a Fibrous core. Wherein Steel Core just refers to another Single Strand serving as the central core, the IWRC is a metallic rope having for example a construction designated by 7 x (6 +1) or 7 x 7.
The Core is said to be Fibrous or FC when we use a fibrous material like jute, cotton, nylon, polypropylene etc in the centre of the rope. This is primarily used to attain additional flexibility in the rope.
Type of Lay
We offer RH, LH & Langs lay ropes in our range. The lay of the outer wires in the strands be in the same direction or in the opposite direction to that of the strands in the rope, the result will be respectively a Lang's Lay rope or an ordinary (regular) Lay rope, having a right hand lay or left hand lay according to the lay of the strands. Right hand and left hand lays are designated respectively Z and S.
Wire ropes are lubricated as a protection against oxidization and to reduce friction between wires and strands. Fiber cores are impregnated for preservation purposes. During the stranding and roping operations, all wires forming the strand and all strands forming the rope are lubricated. The type of lubrication varies according to the application for the rope and the type of plant for which it is intended. During the working life of the rope, lubrication should be carried out periodically with good quality products compatible with those used during manufacture and which we shall be pleased to indicate upon request.
Lubricants used during manufacture shall be free from solvents, moisture, aromatic compounds, alkaline soaps and acidity both organic and inorganic. For protection of wire ropes against corrosion and frictional wear, elephant wire ropes have various kinds of lubrications.