FAQ
If, after reviewing the information in this site, you have questions regarding the information or any aspect of the website, please contact us.
1. What does WLL mean on my rigging?
WLL is the abbreviation for Working Load Limit. It means the maximum allowable load that a piece of rigging equipment can safely lift; it is also sometimes called “rated load” or “rated capacity”. Rigging users must be aware that the WLL of a piece of rigging may be reduced by several factors, such as temperature, environment, angle of loading or type of hitch used.
2. What is the difference between a Clevis and a Shackle?
- A shackle is a u-shaped, load bearing connector designed to be used with a removeable pin.
- A clevis is a u-shaped compenent with holes in its prongs, used in a fastening system to connect two parts.
- While they may look similar, it is important to note that a shackle is designed to be load bearing, while a Clevis is not.
3. How many slings can I place on one hook?
This would depend on the style of hook being used. For a regular Single Point Hook it is recommended that a maximum of 2 slings are used on the hook. If the user needs to use more than 2 slings to lift the load, then a collector ring, such as a Link or Shackle, should be used between the Hook and the Slings. If the hook is a Duplex or Quad Hook (2 or 4 pointed) then the Hook points must be equally loaded to balance the forces on the Hook.
4. Is it my responsibility or is it my employer's responsibility to make sure my Rigging is safe to use?
The short answer is, both. Everyone is obligated to ensure the health and safety of the workplace and those within it. We all must work together.
Per the Alberta OHS legislation – Code Part 3 Specifications & Certifications:
- 12 An employer must ensure that:
- (b) equipment and personal protective equipment used or owrn and any explosive used or to be used at a work site
- (i) is maintained in a condition that will not compromise the health and safety of workers using or transporting it
- (ii) will safely perform the function for which it is intended or was designed
- (iii) is free from obvious defects
- (b) equipment and personal protective equipment used or owrn and any explosive used or to be used at a work site
Per the Alberta OHS legislation – Code Part 6 Cranes, Hoists & Lifting Devices:
- 64(1) An employer must ensure that a lifting device is only operated by a competent worker authorized by the employer to operate the equipment.
Per the Alberta OHS legislation – Act Part 1 General Obligations:
- 5(1) Every worker shall, while engaged in an occupation
- (a) take reasonable care to protect the health and safety of the worker and of other persons at or in the vicinity of the work site while the worker is working.
Per the Alberta OHS legislation – Code Part 6 Cranes, Hoists & Lifting Devices:
- 66 If the operator of a lifting device has an doubts as to the safety of workers in the vicinity of the lift, the operator must not move any equipment or loads until the operator is assured that the working conditions are safe.
5. My eyebolts don't have a WLL marked on them. Are they safe to use?
All rigging hardware must be marked to show:
(1) the name or trademark symbol of the manufacturer
(2) the allowable capacity or rate of the load
(3) the grade for alloy eyebolts
If the Eyebolt has the size marked on it, but not the WLL. Make sure you have access to the manufacturer’s specifications to refer to the style, size and material of the particular eyebolt you are using.
If none of the above information is available or visible on the eyebolt itself, do not use it.
When in doubt, throw it out!
6. What is the difference between tonne and Ton?
tonne (t), is a metric unit of measurement which is made up of 1000kgs. A tonne is sometimes refered to as a Long Ton.
Ton (T) is a unit of measurement, commonly used in the USA, which is made up of 2000lbs. A Ton is sometimes referred to as a Short Ton.
There is approximately a 10% difference in weight between a tonne and a Ton. The conversion between the two is as follows:
- 1 US Ton = 2000lbs = 907 kgs = 0.91 tonne
- 1 Tonne = 2205 lbs = 1000 kgs = 1.102 US Ton
Riggers must be aware of the WLL of their equipment and whether the markings are made using the US Standard or Metric system.