In a Nutshell: Wire Rope Series
By Colin Rice of Colin Rice Exploration and Training (Pty) Ltd
The technical articles that have been published so far in the Hoisting Operations Series have been focused on aspects of steel wire rope. This has been done because every drilling operation uses steel wire rope at some time in the hoisting cycle and so a good understanding of the capabilities and limitations of steel wire rope is critical.
The technical articles published in this series covered:
The construction of wire ropes - the interesting video of how wire rope is made was popular with our subscribers
The properties and selection of wire ropes
Different types of wire rope terminations
Defects in wire ropes and how to inspect a rope and,
We proposed a set of discard standards that could be applied to wire ropes used in our industry.
The full Wire Rope Series is available at the bottom of this page or you can view it here.
So, what does this mean for you and your drill site?
Hoisting drill rods is without doubt one of the most hazardous operations in every drilling operation. It is at this time that the drill is under the greatest load and also the time that heavy drill rods are being handled. A failure of any element of hoisting equipment will have catastrophic consequences and so it is critical that everyone involved has a good understanding of the capacity of the drill rig hoisting system and of the loads that the drill will lift at any particular time in the drilling cycle. We will publish further technical articles in the future on aspects of hoisting but for now, we have extracted some practical tips that you and your staff can apply on site.
Practical hoisting system and steel wire rope tips
All hoisting systems must be designed so that the system complies with the legal requirements of the country in which the drilling operation is taking place. In many countries the law is silent on this aspect and so we should then apply “best practice”. In most countries that I have worked in, a factor of safety of six (6) is applied to steel wire ropes and so I suggest that you use this factor when designing or certifying the hoisting system.
All steel wire ropes (hoist ropes, wireline ropes and auxiliary winch ropes) must be supplied with a valid and complete test certificate to certify its Proof Breaking Load (or Mean Breaking Load). Take a look at the article on Wire Rope Properties for more information.
A copy of each test certificate must be held on site in the Safety File or other secure place.
All wire ropes must be supplied on a spool so that it can be spooled onto the hoist drum or winch without inducing twists and kinks into the rope.
All wire ropes and all elements of lifting equipment must be inspected on a daily basis as a part of the pre-start inspection procedure. The proposed discard standards are a good basis for the inspection of wire ropes.