In a world full of automation and tech, it’s the simplest solutions that are often the best. Two companies – one manufacturer and one rental firm – make the case for manual chain hoists. Tony Rock reports.
LGH is a UK-based lifting equipment rental company, with more than 50 years of experience and operations in North America and Europe, while Tiger Lifting manufactures and provides a full range of hoisting and winching products globally. In the following Q&A, Phil Smith, European asset manager, and Andrew Williams, group safety, health, environment and quality co-ordinator, both of LGH, and Alice Inglis, director at Tiger Lifting, discuss why manual chain hoists remain an important tool within the lifting industry.
WHY WOULD SOMEONE CHOOSE A MANUAL CHAIN HOIST OVER AN ELECTRIC ALTERNATIVE?
Phil Smith: It’s the cheapest option. The purchase price is significantly lower than an electric hoist. For the sort of brands we’ve got in the fleet… for a one-ton electric hoist we would probably pay approaching £3,000. But we would buy [a manual chain hoist] for £90 to £100. That will be reflected in the sale rate and the rental rate as well. So it’s a much cheaper option.
Alice Inglis: In the current climate, budget is a significant factor in project planning and the manual hoist will be cheaper than an electric – or pneumatic [air] – hoist of the same capacity. In general, manual hoists will do what electric and pneumatic hoists do but are likely to be a more costeffective option.
PS: Generally speaking, they’re lighter too, size for size. You’ve not got a big, heavy electric motor in there. Obviously, you don’t need power, so that makes them more versatile – you haven’t got to plug them in anywhere or rely on a power supply.
Andrew Williams: It’s a versatile hoist because it’s lightweight. It’s something you can move from A to B very, very quickly.
AI: [They are] easier for the operator to manoeuvre and position, which can be an important factor in the planning and implementation phase for a lifting operation.
PS: You can also ‘fleet’ with them. So, with certain models, you can transfer loads from one hoist to another, effectively bringing the load out at an angle to meet another hoist. You generally can’t do that with electric hoists. You’d normally see that maybe in a ship, where they’re lifting something in a boiler room, and they will transfer it from one end to the other by using this ‘fleeting’ operation. AI: Tiger Lifting’s Professional range of manual hoists are perfect for projects where fleeting loads is critical, whether that be in tight headroom spaces or open ground where a power supply is not available. These hoists have our patent protected Quad Cam brake system and have undergone a full and comprehensive testing regime that was drawn up by industry specialists and Tiger’s mechanical engineers to provide evidence that these units can be safely used for fleeting and cross-hauling applications up to 45° without de-rating [operating at less than its rated maximum capability].
AW: One of the key elements to a chain block [another name for a manual chain hoist] that is not focused on these days is it’s precision. From a lifting point of view, where you are using an electric hoist and pressing a button, you’re relying on waiting for that motor to cut out. Now it takes a millisecond or whatever for the motor to stop, but that can [equate to] a couple of millimetres going down, and if you’re trying to land a load on a precise place – maybe over a shaft or over some fixing bolts – the manual hoist, because it’s slower and you’ve got more control over it, is more precise in lowering the load down, rather than with a clunk, if you will, that an electric hoist can potentially give you.
On some of the more expensive electric hoists, mainly used with overhead cranes, you can buy items that are controlled and precise, but [when looking at the rental market], a manual chain will be much more precise.
IN WHAT ENVIRONMENTS IS IT BETTER TO USE A MANUAL CHAIN HOIST?
PS: With electric, of course, you can’t use that in areas where there’s any risk of spark, whereas with hand chain hoists you don’t have the same risk.
AI: They can be used in environments that might not be suitable for other types of hoists, or when no electrical power nor air supply are readily available at the operation site. Spark-resistant chain blocks and lever hoists [a type of manual chain hoist] are built for use in potentially dangerous areas – environments which may be explosive or highly volatile, where an electric chain hoist wouldn’t be suitable. At Tiger Lifting we have a full range of hoisting and lifting equipment that meets the requirements of the ATEX Directive 2014/34/EU, with thirdparty verification. This includes upgrades to hooks, internal components and chain where required to minimise the potential for explosion. Using hoists specifically engineered for extreme environments is a key benefit of these types of manual hoists.
AW: Where there is a shutdown on a major industrial site – say, a petrochemical site – they would want something that they would be able to bring in for short or long-term rental. We would obviously have serviced it, examined it, supplied it with all the current paperwork and legislation that it would need on that particular site. The company can go out and use the equipment – take valves out, gearboxes, whatever it may be, for refurbishment. They can then take the chain block down from where it’s hung and take it to another part of the plant to do another piece of work with it etc., and at the end of the shutdown send it back up to us, and we do all the refurbishments on the equipment, making it safe to use on the next rental.
It’s very much ‘get it in, use it, put it away, send it back, and [repeat for] the next shutdown’. The company would bring in a brand new set of chain blocks – nice and fresh – and start all over again.
没有评论:
发表评论