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Proper Rope Selection

Storage

Wire ropes should always be stored in a dry place. As far as possible, the place should be free from moisture, dust or fumes.

The reels, on which ropes supplied by Usha Martin are packed, are sufficiently large to ensure that the ropes will not come into contact with the ground, provided that the floor is level and hard. It is advantageous, however, to keep the reels clear of the ground.

On no account, should the reels be stored on a cinder or ash floor, or in proximity to sulphur or acid fumes.

If ropes are stored for any length of time, it is advisable to apply an occasional dressing of lubricant to the top layer of rope on the drum to protect the same from corrosion because, once started, corrosion, may develop and render the rope unsuitable for use.

Turning the reel occasionally, about half a turn, helps prevent migration of the rope lubricant.

To protect the wooden reels from the attack of termites, the floor should be cemented. In no case, should the reels be put on ground on uncemented floor.

Neglect of these precautions may cause a rope to corrode or otherwise deteriorate.

Handling

Adequate arrangements for loading and unloading the reels containing rope, without damaging the wooden reels should be provided at the storage shed and installation.

A spindle should be put through the reel and its end should be jacked up to allow free rotation of the reel when the rope end is pulled. It is necessary to provide a simple braking mechanism to the reel to maintain constant tension during haul off. A timber plank held against the reel flange is a simple means of braking. This prevents turns being put in or lost from the rope and also prevents crossing of rope laps on the reel and avoids possible kinking.

If the ropes have to be diverted to any degree to facilitate installation, then a jockey pulley for guiding the rope should be fitted, not less than 36 times of the rope diameter in size.

During the paying off the rope, it is advisable to avoid dragging of the rope on the ground by means of short timber chocks suitably spaced.

Care should be taken so that in anticipation of cutting, end of the rope is neither carelessly and inadequately seized nor cut through the seizing.

Proper seizing and cutting operations are not difficult to perform, and they ensure that the wire rope will later do its job. The strands loosen back within the rope, as the ends become distorted and flattened if these are not cut properly.Later when the rope is put to work, the load is unevenly distributed to the strands And the life of the rope is significantly shortened. A short annealed wire should be used in seizing. For galvanised ropes, the use of soft, zinc coated wire is recommended for seizing. In any case, the length of the seize on a non performed rope should never be less than the diameter of the rope.Two seizings are recommended for ropes not preformed, the second seizing being applied at 6 times the rope diameter from the cut, or end, of the rope. Preformed ropes require only one seizing.

Ropes should be paid off in the correct manner to ensure that turn is neither put in nor taken out.

A coil of small length, say upto 100 meters , may be unrolled along the ground but should always be kept under control.

Never pull a rope away from a stationery coil.

Ropes in larger sizes or longer lengths should always be purchased on reels and transferring these ropes to coils should be avoided.

A long length of rope on a reel has a high inertia. Proper braking arrangements must be made to prevent over run which may lead to loop formation. A simple braking mechanism consists of a wooden plank acting against the reel flange.

If for any reason, a loop does form, ensure this does not tighten to cause a kink which may lead to distortion of the rope requiring its immediate discard.

Maintenance

Before installation please be sure that the rope was stored in proper condition and is free from any damage in transit or delivery.

A rope already deteriorated during storage is bound to give unsatisfactory service. The rope should be regularly lubricated at fixed interval with suitable lubricant to protect against atmospheric corrosive conditions.

Ensure that the new rope is correct for the pulleys and anchorages. All pulleys should be checked to ensure that they have worn out with the old rope and become unsuitable for the new rope.

Ensure that regular inspection of wedge socket, if used, is carried out with the rope being pulled through to sift the area of contact.

It is a common practice to leave a crane idle from one day to another or over a week end, with the rope at one position, e.g. with the out board end close to the jib sheaf, or else at ground level, or at position, between the two. This practice should be varied; otherwise the same part of the rope is constantly left on a bend.

Regular external inspection and internal inspection of the rope for the deterioration due to fatigue, wear and corrosion is very essential.

The ideal wire rope dressing is one that is at all times pliable, waterproof, water, acid and gas proof and free from any destructive acids, or any excess of sulphur within itself. It should be such that it cannot be easily wiped off or flung off by centrifugal force, and it must not decompose.

The use of relatively fluid dressings is sometimes preferred, which can easily penetrate between the outer wires of the rope, and displace any water, which may have entered.

When ropes are to be stored for prolonged periods, the heavier bituminastic type of dressing is preferable to low viscosity dressings, which tend to drain off the rope, thus exposing it to corrosion.

Installation

It is important to maintain the manufactured condition of the rope. Do not set a swivel and if replacing with the aid of an old rope, use of a fibre rope between the old and new rope.

Preferably, install with a fibre rope as a pilot rope.

Take care to prevent turn being put in or taken out of the rope. If turn is put inadvertently put in, core protusion is likely whereas if turns are taken out, bird caging of outer wires may occur. Slight manifestation caused by such lay disturbance is likely to occur in early stages of working.

When anchoring a plain end on a drum or winch barrel, it is essential that this end be securely and efficiently anchored so that the entire cross section of the rope is held solid. Otherwise the core may draw from the attachment end leaving only the outer strands anchored in position.

The winding of the rope in the drum is of prime importance and and as much tension as possible should be applied particularly on the first layer to ensure tight and even coiling.

If this procedure is not followed, the subsequent layers on the drum may pull in between the slack lower layers leading to knifing.

Poor coiling in a drum can result in jerking of the load as it is lowered with the consequent danger to personnel.

Inspection

The factor of safety normally used for ropes, takes care of not only the dynamic and static stresses, but also a reasonable degree of deterioration in service. It is nevertheless essential that all running ropes be inspected at regular intervals so that the rope is discarded before deterioration becomes dangerous. For many applications, the inspection requirements are laid down in various regulation guidelines.

a. Records
Regular details regarding the following rope parameters should be note and kept for future records:

	Rope Diameter
	Construction
	Tensile grade of the wirs
	Finish (galvanised or ungalvanised), length, details of loading, factors of safety as well as the coil number of the ropes.

b. Frequency
It can be either be cursory or detailed examination.

c. Measuring rope length and lay length
To find the correct diameter, at a point in a rope, the callipers must be placed over each pair of opposite strands, i.e. three separate readings for a six strand rope. The readings are then averaged. To define the rope lay length, a strand is marked by means of chalk at the point of the rope, then the strand is followed until it reappears at the opposite point on the rope periphery exactly inline with the first chalk mark. The rope lay length is the distance between the two chalk marks.

Assessment of rope condition

a. Plastic Flow and Wear at crossover points
When more than single layer of rope is coiled on to the drum, the rope will tend to develop points of what appear to be heavy wear where the rope is forced against the drum flange in climbing onto the succeeding layer.

b. Plastic Flow over rope length
When the rope is able to rotate freely as it works, wear will occur around the whole periphery of the section, which passes over the sheaves. If the sheaves have been consistently undersized since rope installation, plastic flow will become evident, and will eventually develop into wires broken into fatigue.

c. Wear
Generally, wear of outer wires will not seriously affect the ropes breaking strength unless accompanied by broken wires.

d. Mechanical Damage
Irregularities caused by kinks, bends, or accident talk damages, can reduce the ripe strength considerably. Such sections are likely to cause stress raisers, hastening the onset of fatigue and broken wires.

e. Broken Wires
Square ended fractures of outer wires indicate the onset of fatigue with serious weakening of the rope if many broken wires are concentrated in one place. It is important to remove broken wires as soon as they are discovered in order to prevent damage to neigbouring wires.

f. Corrosion
Where a localised reduction in rope diameter and a change in lay length is found together with the signs of external corrosion, internal corrosion is likely to be present. The load should be removed from the rope and the inner wires inspected with the help of spikes.

Problem Solving

Rope Trouble

Possible Cause

Solution

Snapping of Rope (Breakage)

Application of Load exceeding the breaking load of the rope may be due to :
i.	Severe impact / jerk / shockload.
ii.	Formation of kink during installation.
iii.	Localised wear weakening of one or more strands.
iv.	Severe rusting / corrosion and loss of elasticity.
v.	Loss of metallic area due to Wire breakages caused by severe bending or mechanical damage

i.	Avoid Overloading and Shock / Jerk loads.
ii.	Avoid formation of kink during installation / handling.
iii.	Remove any objects causing localised wear.
iv.	Proper storage of rope and regular application of lubrication.
v.	If possible remove the portion of the rope suffered by severe bending / mechanical damage or replace the rope

Breakage of one or more strands

i.	Overload
ii.	Kink
iii.	Excessive speed & Slipping or running too loosely.
iv.	Concentration of vibration at dead sheave or dead end divider.
v.	Interference by divider.
vi.	Rusting / corrosion & fatigue.

i.	Avoid loading beyond capacity / SWL of the rope.
ii.	Prevent kinking of rope through proper method of uncoiling / unreeling, handling at site.
iii.	Avoid loose running / slippage.
iv.	Find cause of vibration and rectify the same.
v.	Avoid interference at divider
vi.	Prevent rusting / corrosion through proper storage and lubrication during use.

Damage or failure on a fishing job

Rope improperly used on a fishing job, resulting in damage

Avoid damage / improper use - Dry fishing job.

Increase in lay length and reduction in diameter.

i.	Overloading.
ii.	Collapse of fibre core due to excessive concentration of pulsating / surging forces.

i.	Avoid overloading by keeping load as per capacity / SWL. Avoid jerk / shock loads.
ii.	Shift stress points by cropping the end attachment portion / end to end change, if possible ( incase of drag ropes in draglines).

Premature wire breakage.

i.	Excessive abrasion wear.
ii.	Frictional heat caused by pressure and slippage.
iii.	Mechanical damage.
iv.	Corrosion.

i.	Rectify worn-out pulley grooves by matching to suit ropes.
ii.	Lubricate during use.
iii.	Prevent external damage during use.
iv.	Apply service lubricant at regular intervals.

Localised excessive wear.

i.	Kinks / bends due to improper handling during installation.
ii.	Divider interference.
iii.	Rubbing against casing / other hard objects.

i.	Follow proper methods of rope handling.
ii.	Lubricate during use.
iii.	Avoid external damage during use.
iv.	Apply service lubricant a regular intervals.

Abrasion wire breakage in straight line.

Rope slippage through clamps

Use proper clamps an retighten the same periodically.

Distortion of rope.

Damage due to improperly attached clamps / clips.

Fix clamps / clips in correct manner.

Protrusion of strand.

i.	Slippage through clamps.
ii.	Inadequate seizing.
iii.	Improper Socketing / Splicing.
iv.	Kinks / Bends / Core Propping.

i.	Avoid loose clamps and improper fixing of clamps.
ii.	Apply longer seizing / servicing.
iii.	Follow correct methods of Socketing / splicing.
iv.	Avoid Kinks / bends during installation / use.

Abrasion wear.

i.	Worn out sheaves & grooves.
ii.	Rubbing against stationary objects.
iii.	Mis-alignment.
iv.	Lack of lubrication.

i.	Rectify or replace worn-out sheaves & grooves.
ii.	Remove unwanted materials in the rope travel path or guided rollers.
iii.	Correct the alignment.
iv.	Apply regular lubrication during use.

Wire breakage due to fatigue.

i.	Undersized sheaves or grooves.
ii.	Excessive & concentration of vibration due to poor drilling condition.
iii.	Insufficient cutting off to shift stress points.
iv.	Improper selection of rope construction.

i.	Use bigger sheaves and maintain groove dia. betwen 6 to 10% more than the nominal rope diameter in case of standard rope.
ii.	Shift stress points periodically.
iii.	Keep sufficient idle turns to allow longer cutoffs to shift stress points.
iv.	Always use rope of specification recommended by OEM or rope manufacturer.

Spiralling.

i.	Allowing rope to drag over objects during installation / operation.
ii.	Wrong method of handling / pay-off from reel.

i.	Remove external objects in rope path during installation / use.
ii.	Follow the recommended method of handling / pay-off from reel. It is recommended that a block with a sheave diameter 16 times the nominal rope diameter or larger is used during installation.

Whipping of a rope.

Running too loose / slack.

Always keep rope under tension.

Excessive flattening or crushing.

i.	Overload
ii.	Loose / Cross winding on drum.

i.	Prevent overloading beyond capacity.
ii.	Follow proper coiling on the drum and avoid cross winding whenever possible.

Bird-caging or core popping.

i.	Sudden release of load.
ii.	Shock / Jerk load.
iii.	Use of sheaves of too small diameter.

i.	Sudden release of load.
ii.	Shock / Jerk load.
iii.	Use of sheaves of too small diameter.

Proper Ordering Criteria

How to Order for a UMI Steel Wire Rope

When you are sending an enquiry or an order to purchase a steel wire rope, we reqest you to kindly furnish the following information so that you get the exact rope as per your requirements.

The specifications required while enquiring for a Usha Wire Rope.

1. Length of the rope required
Specify the correct length as per your requirement. Too long a rope will negatively influence coiling and will result in premature rope failure and subsequent wastage. A too short rope will not be able to last its full life.

2. Diameter
Try to maintain the same nomenclature as per the pertaining standards, e.g. if you require a rope as per IS, do specify the rope diameter in mm. Alternatively, for example, if you require a API rope, you require to specify the rope diameter in inches, in conformance to the API standards. The nominal diameter usually varies from the actual diameter of a rope. UMI supplies with a rope with an actual diameter -1% to 4 % of the nominal diameter of the rope.

3. Coating/ Finish
A rope can either be ungalvanised or galvanised. In rope nomenclature, we often specify an ungalvanised rope as black.

4. Tensile Grade of steel
This property signifies the strength/ load bearing capacity of the wire rope. Usually, if you procure a rope as per IS specifications, the usual designations are 1770 N/mm2, 1960 N/mm2, or 2160 N/mm2. The other less frequently used tensile designations are 1420 and 1570 N/ mm2. Alternatively, in place of N/mm2, we can use 160 Kgf/mm2, 180 Kgf/mm2, and 200 Kgf/mm2.

5. Construction
A rope is generally made up of number of strands twisted around a core. The strands are themselves formed from a number of wires twisted in a helical fashion. A description of a commonly used crane rope is as follows: 6X 36 (14/7/+ 7/7/1) Irwin This description means that there are 6 strands in the rope, each consisting of 36 wires. The number in the brackets indicate the make up of the strands, starting from the outer wire layer, There are 3 wire layers (separated by "/" sign. the first layer (outer consists of 14 wires, the second layer consists of 7 wires, and 7 small wires and the third layer has 7 wires over a core wire.

6. Core Types
The core of a steel wire rope can be either fibre or steel. The fibre core can further sub divided into natural fibre or artificial fibre (Sisal). In case of steel core, the alternatives can be Independent Wire Rope Core (IWRC) or Wire Strand Core (WSC). The IWRC is preferred as a core where resistance to crushing or heat is required.

7. Lay
There are two different methods of laying up of wire ropes, namely ORDINARY ( REGULAR ) LAY and LANGS LAY. In the ordinary lay rope the wires of the strands are laid in one direction and the strands are laid in the rope in the opposite direction. Ropes laid in this manner are suitable for all general work. In the langs lay rope, the direction of the both the wires in the strands as well as the strands in the rope are in the same direction. Ropes made up of langs lay tend to wear more evenly than ordinary lay rope, owing to the rotational movement of the rope when at work and since the wear is carried over a longer length of wire, the rope does not fatigue. When it becomes worn, langs lay rope are slightly more flexible than ordinary lay rope of similar size and construction and their resistance to bending fatigue is better. They are extensively used for winding and haulage duty, and their usage is limited as compared to Ordinary lay ropes. Hand of lay: This term refers to the direction in which the strands are laid up in the rope, as distinct from the direction of wires. Right hand lay is the usual standard adopted by rope manufacturers and all ropes are supplied with this lay unless otherwise specified. The use of left hand lay is usually confined to ropes used for drilling purposes, to prevent unscrewing of rods, or in connection with right hand lay ropes in on cranes and elevators to counteract the spin. Usually, a Left-hand lay rope is used in combination with a right Hand lay rope.

8. Minimum Breaking Load
If possible, the same should also be furnished, as it aids in checking on the specifications of the offered rope.

9. Preformed or Non Preformed
A rope can be pre-formed or non pre-formed. Usually, a general engineering rope is pre-formed, whereas an elevator rope is Non pre-formed.

10. Specification
Every rope is manufactured in conformance to specific quality conformation standards. The same may be either IS or Indian standards, DIN, BS, JIS, API or any other standard as specified by the customer.

11. Fittings/ End terminations
In certain applications, you may need to attach additional fittings, such as sockets, thimbles, sockets (spelter/ swaged), rings, loops ( plain/ bucket) which can be supplied by UMI as per customers' requirements.

12. Packing
Usually, a steel wire rope can be packed either in wooden or steel Reels or coils. In case of shorter lengths.

13. Area of Application
In addition to the above specification, we usually ask for the area of application of a rope, so that we can ourselves judge whether the specific rope that is being offered is the suitable one or not. It aids as an additional check for us so that we can ensure that only the rope with the best possible combination of properties is reaching you.

14. Lubrication
We usually deduce the type of lubrication from the area of application of the rope, but in case of any particular requirement dependent on your own customised requirement, do specify the same.

15. Tests
If special testing is required from external Testing agencies, e.g. from ABS,Lloyds, the same should be specified while sending the enquiry. Other wise, as a valid proof of the quality Usha Martin product, each and every rope is supplied alongwith a Test Certificate giving all relevant rope details, like tensile grade and braking load.