Rigging pt. 1
Schaus-Vorhies is proud to offer several services through our many companies. We offer services as varied as contracting and water treatment. One service we offer that applies to almost any industrial setting is rigging.
A building project is going to need heavy construction materials lifted up to the top of the building. A chemical plant is going to need to replace an out-of-date tank. A car manufacturer may need a new conveyer belt installed. Rigging is necessary for all of that, and fortunately, Schaus-Vorhies can do it all.
Rigging is also an inherently dangerous activity. Anything could go wrong. A gust of wind could shift a load, causing it to slip out of the rigging. A stressed shackle could give way. A sling could get cut on a sharp edge, causing a load to be dropped. Any time something is being rigged, there is the potential to do extensive damage to equipment or do serious harm to a person. That’s why Schaus-Vorhies takes rigging safety seriously.
To the untrained eye, rigging seems to be nothing more than wrapping a couple of ropes around a load, hooking it up to a crane, and putting it where it needs to go. Rigging done right should look that easy to an outside observer. However, to do it so well, it seems easy is anything but easy. It takes training, dedication, and hard work to become an expert rigger.
Here are just a few things that our riggers at Schaus-Vorhies need to understand before rigging and picking so much as a barrel of water:
- Calculate the weight of the load – This is essential as it affects everything else about the job. The weight of the load affects what kind of slings are needed, the shackles used to connect them to the hook, and even what type of lifting device to use. There are different ways of determining a load’s weight. The most obvious is to see if there is a manufacturer’s plate that will have the weight on it. There may also be some supporting documentation with the load that will have the necessary information. A second way is to weigh the load. This is done by hooking a dynamometer up to the load (go very conservative here on the slings and shackles that were chosen). Use the weight to determine if you need different slings. Finally, if you don’t have any helpful documentation or dynamometer on hand, you may need actually to calculate the load. This can only be accomplished if you know what the load is made of. If you know that, you can look up what the material weighs, take some measurements, and make the necessary calculation. Then the load angle multiplier (the amount of load your rigging actually sees based on the angle it is at) has to be factored in.
- Sling configuration – What kind of load you are lifting has a huge effect on the rigging used. If it is at all oddly shaped or unbalanced, it may require slings of different lengths, possibly even the use of a come-along to ensure that the load is picked straight. Other types of load can be picked with a simple vertical sling. One lifting point in the center of the material makes a lift with just one vertical sling very easy. Other times, a tank may require a basket configuration, or a long run of pipe might need a choker configuration. Understanding this is very important as the different configurations affect just how much weight the sling can really handle.
- Drifting a load – Very often, a load isn’t going to be simply picked up from one open area to another and set back down. Especially if a piece of factory equipment is being installed, the load is going to need to be transferred from one hoist to the next. Whether it is being transferred between mobile cranes or simple chain falls, drifting a load has to be done with the utmost care and attention to detail. Failure to do so could result in the load bouncing off equipment, damaging itself or other, already installed pieces of equipment. This is especially true in the case of a canister partially full of fluid that can suddenly shift the weight of the load.
These are just a few of the skills and pieces of knowledge a rigger at Schaus-Vorhies has to be intimately familiar with to get the job done safely. We’ll look at more of these skills next time.