Name one important advantage of wire rope, as compared to chain, for hoisting
How is the following achieved in the construction of wire rope:
- crush resistance
How is the following achieved in the construction of wire rope:
- abrasion resistance
How is the following achieved in the construction of wire rope:
- flexibility
How is the following achieved in the construction of wire rope:
- strength
- for a given diameter rope, the fewer wires in a rope, the greater the strength
How is the following achieved in the construction of wire rope:
- corrosion resistance
- stainless steel must be used in a corrosive, acidic environment
Which grade of wire rope is most commonly used in industry and what is its strength?
- - breaking load of 110-120 tons per square inch
Describe the following terms:
- FC
Describe the following terms:
- IWRC or WRC
Describe the following terms:
- strand core
What is a lay length?
Describe the construction of right regular lay wire rope
How is Lang’s lay rope constructed and what are its advantages and disadvantages?
advantages
disadvantages
What are the advantages of preformed wire rope?
How is wire rope classified?
example - 6 x 31 Warrington Seale, IWRC Right, regular lay
6 - number of strands
31 - number of wires per strand
Warrington Seale - indicates the configuration of wires in each strand
IWRC - indicates the type of core used in the rope: Independent Wire Rope Core
Right, regular lay - specifies the way wires and strands are wound
How is the size of wire rope measured?
Describe how to:
- choose the right rope
- ensure that the rope is in good condition
Describe how to:
- maintain the rope properly
Describe how to:
- use the rope correctly
Describe how to:
- use related equipment correctly
Why does wire rope need to be lubricated?
– the wires become embrittled from excessive corrosion and break easily (embrittled means made more brittle by molecular change)
– the wires in a rope are subject to frictional wear as they move together during operation. Lack of lubrication increases wear and reduces strength
– ropes not in regular service or those not considered as operating ropes are vulnerable to weathering. If the weathering wears through the external lubrication, excessive moisture can gradually leach out the internal lubricant. This causes the core and wires to rust and deteriorate
Describe how a wire rope is lubricated
1 - ensure that the rope is clean and dry before the lubricant is applied
2 - use a light, penetrating cleaner to soften the built up grime before removing it. Contact the lubricant supplier regarding the proper cleaning oil to use. Do not use gasoline or kerosene, since too much of it will remove the internal lubricant
3 - the main objective in external lubrication is to fill any gaps in and between the strands so that a complete seal is provided. The frequency required depends on the particular installation
4 - apply the lubricant using one of the following methods depending on the viscosity of the compound applied, the length of rope involved and the limitation of the facilities:
4a - light oils
– apply light oils by brushing, running the rope through an oil bath, spraying, drip method or mechanical force feed
4b - medium and heavy oils
– apply medium- or heavy-weight lubricants warm. Apply them by brush or by running the rope through a funnel containing the lubricant. Or use an air blast provided that only dry air is used and all safety precautions are taken
5 - even though brushing and dripping methods of lubricating long ropes are tedious, they give you time to inspect the rope
6 - the rope should be properly lubricated at all times. Inspect the rope often to see when it must be done
Describe the correct method of unwinding wire rope from a spool
1 - a quick way of mounting a spool is to use a length of pipe and some blocking
2 - do not take wire rope off the side of the spool a wrap at a time, as this often results in kinks
3 - when taking a length of wire rope from a spool, rotate the spool on a spindle or turntable, or roll the spool along the floor
4 - before cutting a length of wire rope from a reel, “seize” or wrap each side of the proposed cut. Use friction tape, or, if the end is the be welded, light wire. If one end of the wire is to go through a hole in a drum, a good practice is to “braze” or weld the end and then remove the seizing
5 - if using an impact cutter to cut the wire rope, keep the cutter in the same position throughout the cut
6 - after removing a length of rope from a spool, wind the slack back onto the spool and tie down the free end
Determine the anchorage point on a drum for a right-lay-overwound rope
1 - the right hand represents right-lay rope
2 - the index finger shoes the approach of the ropes
3 - the position of the back of the hand indicates whether the rope is overwound or underwound
4 - the position of the thumb shows where the rope is attached to the drum