Tony Rock talks to a crane engineer to understand the maintenance issues that can affect manual chain hoists.
Phil Simpson is an engineer at CraneServe, a UK crane maintenance and inspection company. On the job, he encountered various types of lifting equipment, including electric and manual chain hoists.
The types of problems he sees include problems with safety locks, chain stretch, hook stretch, twisting and wear on the upper return sprockets.
Overloading is often the cause of such problems when people use equipment to perform tasks for which it was not intended; for example, using a hand chain hoist to load the load and then using a crane to lift it further.
“Obviously,” Simpson said, “that kind of thing tends to overload the crane and then stretch the chain or break the brake pads or something like that.”
“You tend to find that the inside of the brake rotors can become contaminated with grease and grease, and the atmosphere they’re in affects the type of contamination they can get,” Simpson said. “Obviously in a dusty environment, dust can get in and contaminate the brake rotors, which can cause loads to slip and things like that.”
He continues: “If you’re lubricating a chain, you need to consider the environment. For example, if you work in a welding shop where there’s a lot of contaminants in the air (welding particles or even a dusty environment), then if you apply thick lube to the chain, all the contaminants are in the air “that may occur will stick to the chain. So when it goes through the top back onto the sprocket, it essentially pulls in debris. This creates an abrasive paste and makes things a lot harder. Oops.”
As Simpson points out, there are alternatives to oil-based lubricants: “Obviously, if you use a very thin lubricant in wet conditions, or if you use a thick oil-based lubricant, it may drip. Typically, a spray is recommended. PTFE, dry molybdenum or graphite lubricant “a dry lubricant suitable for these conditions – so that it does not drip and contaminate the product.” He added that he recently reported to an existing paper mill that customers were recommending a dry lubricant.
While Simpson argues that customers are responsible for maintaining their equipment to the required standards under the Provision and Use of Work Equipment (Puwer) Regulations, the reality is that they often don’t even carry out pre-use checks.
“Of course they should do an inspection before using any type of lifting equipment,” he said. “But obviously nine times out of 10 they don’t. They just check a box and say they looked – and in fact it can be very dangerous.”
CraneServe offers an inspection program to its customers, as Simpson explains: “Different situations require different types of inspections at different times. We typically develop a review plan where we sit down with the client and say, “Listen, what do you want?” Check? or “We recommend doing this at this time.”
“Their delivery vehicles are used 24 hours a day, seven days a week,” he began. “We throw out five every week, take them apart, check them, re-lube them and put them back into the system.
“We will develop an inspection plan and write our own report. It’s essentially a checklist: have you checked the bearings, bushings, etc.? Then if we make any repairs, we will document it and let the customer know.
“Obviously you can do this with any type of lifting equipment and crane service – as long as there is a history of the equipment and a time frame.
“If it is used regularly, is subject to shock 24 hours a day, and is lifted close to a safe working load, you might recommend checking it every three months or every six months, depending on the equipment and environment.”
“I think it’s very important to be honest. Proper training makes a big difference,” Simpson said.
“I think a lot of cameramen are completely unaware of what they’re actually seeing, and there have been a few times where I’ve pointed something out to a cameraman and they’ve said, ‘Oh, I don’t know.’ .
“I would probably suggest getting some training and then having inspection cards ready before use so you get the assigned visual confirmation that the equipment has been inspected. Even if it’s a weekly inspection, a monthly inspection, a daily inspection.” inspections. Inspections, etc., if they are carried out by a person having the necessary knowledge and training for this purpose.”
Simpson said the training will help operators spot signs of danger before they become a safety hazard. He said the first thing he does is start with the hooks and check to see if they are twisted or stretched. For example, also ask if the fuse is working and is it turned on? Typically, if the hook is stretched, the safety pin will not engage and will “flip over.” And check the bearings and chain, mainly the link seats. As Simpson says, if a chain link shows any signs of wear, “it’s best to nip it in the bud and replace it before it gets worse.”
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Post time: Dec-07-2023