When it comes to lifting equipment, errors in spec’ing, usage and maintenance can mean more than just downtime. Because of the heavy loads this equipment is often tasked with moving, one wrong move can mean a serious safety issue as well. So how do manufacturers assess their lifting equipment for best uptime and safety?
Mission Critical Requirements
When it comes to the features that are integral for a mission critical hoist, you first need to define exactly what “mission critical” means to you, says David Comiono, vice president of the material handling equipment manufacturer EMH. “You also need to know the level of precision that is required, the safety issues involved, and your tolerance for pain when it comes to possible crane and hoist downtime,” he explains.
“‘Mission Critical’ success requires an in-depth dialogue between the purchaser and the hoist manufacturer,” Comiono stresses. “Unfortunately, this discussion keeps getting harder and harder to accomplish given workloads and schedules. But for ‘Mission Critical’ success, it’s important for both parties to insist on this dialogue and review. Mistakes are often costly and can sometimes require complete crane hoist replacement.”
There are also a few special issues that should be considered that are beyond standard hoist design. Comiono goes on to explain that this might include the need for additional brakes, special control requirements, and redundant reeving schemes, meaning if one load-carrying element in the system should break, could the crane hoist still hold and carry the load? Other considerations are the need for additional limit switches, motor characteristics, brake type, corrosion protection, wire rope or chain construction, bearing design and the metals you decide to use for construction and manufacture of the hoist.
Safety is Paramount
Besides uptime, safety tends to be top-of-mind when manufacturers consider the use case for lifting equipment. Responsible for hoisting thousands of pounds, in some cases, means the stakes are high. Richard Kat, VP of Sales and Marketing for Engineered Lifting Systems & Equipment, believes training is at the root of any crane safety program — both for crane operators, and especially riggers. “A crane itself is fairly simple: it goes up and down and travels North, South, East and West,” says Kat, but, “the rigging of a load, especially if it’s something that’s big, bulky and heavy, is one of the most important things. If the rigging isn’t right, it could be very dangerous.” Kat recommends having proper ‘below the hook’ accessories — whether it’s chains or slings, or things along those lines.
The OSHA Chain Sling Inspection guide has been in existence since 1975, and offers several regulations regarding fasteners. For example, says the guideline, each day before being used, the sling and all fastenings and attachments shall be inspected for damage or defects by a competent person designated by the employer. Additional inspections shall be performed during sling use, where service conditions warrant. Damaged or defective slings shall be immediately removed from service.
Comiono adds that application discussions, at the outset of any crane operation, need to come first. Once established, “there are a wide of range of new and often inexpensive options available to increase and improve safety.” This includes travel limits, status lights, overload protection, better speed control, radio control, horns, lighting and anti-collision, to name just a few. Beyond that, he concurs that training is paramount. “The need to properly train every operator and maintenance personnel is also extremely important and required by OSHA. Along with that, we believe that proper crane start-up before each and every shift, as well as regular inspection of all safety devices, should be important and routine practices. At EMH, we continue to stress crane safety, and place it at our highest level of priority for all aspects of crane design, manufacture and use.”
According to Comiono, EMH just recently developed a new safety brake designed for installation on the load side to protect equipment and surrounding personnel against load free fall hazards that might occur from mechanical and/or electrical failure within the lifting mechanism. If that should happen, or if the brake detects that the load is out of it’s programmed speed range, a smart and safety homologated speed monitoring device will automatically override the operator and the hoist control by engaging the safety brake instantly. This new safety brake also prevents slippage at low speed when the hoist is stopped.
Complimentary Tech: Transfer Carts
According to Richard Kat, VP of Sales and Marketing for Engineered Lifting Systems & Equipment, a job for a crane sometimes needs a more outside-of-the-box accessory. For example, transferring heavy loads from one crane bay to another can be accomplished by a forklift, but it might be better served on a transfer cart. Here’s why: For something like a 20 ton load, “it’s very expensive” on a forklift, says Kat. A transfer cart, instead, means a crane operator can pick up a load and place it on a transfer cart in the one crane bay, and use the pendant control for the transfer cart and drive it into the other crane bay.
The other reason transfer carts have become so popular, according to Kat, is simply due to the fact that more manufacturers are looking at their manufacturing process and trying to reduce rigging time between assembly stations. “For example, if you’re building a heavy piece of equipment – they’re still built on an assembly line, but they’re bigger and heavier. You’ll have multiple cranes working in the area, riggers involved, craned operators… just to move your product along an assembly line,” he says. “People are now approaching us to build transfer carts instead of rigging with a crane, so they can simply drive it from one station to another, as they continue to add parts to it in the assembly process.”
For more information on the OSHA Chain Sling Inspection, visit www.osha.gov.