During the hundreds of classes, Columbus McKinnon’s training team has conducted over the years, there are a variety of questions that arise regarding the use, maintenance and inspection of overhead cranes and hoists. So, I wanted to take this opportunity to outline seven of the most common concerns, myths, and misconceptions we’ve received from crane and hoist operators and technicians during our classes.
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Answer: According to ASME B30.11, rated load markings are not required on monorails but are recommended. Before marking the monorail, a qualified person must determine the rated load on the monorail beam. Once the monorail is marked, the rating should be legible from the ground floor. ASME’s recommendation also applies to marking the rated loads of hoists on the monorail. For more information on hoist marking guidelines, see ASME B30.16.
Answer: The short answer to your question is “yes.” However, ASME B30.16 stipulates that when a system is comprised of components with different rated capacities, the rated load of the “system” shall be based on the lowest-rated individual component.
System is defined as the combination of Monorail, Hoist and Trolley in the case of a Monorail and Crane; Hoist and Trolley in the case of an Underhung Crane.
ASME B30.16-1.3.2 states that the supporting structure, including trolleys, monorail, or crane, shall be designed to withstand the loads and forces imposed by the hoist for the rated load.
Important note: As of , ASME B30.11 Monorails & Underhung Cranes and ASME B30.17 were consolidated. This was done to better harmonize the standards, as many people have noticed in the past that B30.11 and B30.17 had similar wording and, in some instances, were exactly the same. This can cause confusion when referencing and interpreting the standards. Therefore, the ASME committees for both standards came to a consensus and created only one standard that refers to Cranes & Monorails (With Underhung Trolley or Bridge). This standard is ASME B30.17. You can see a cover page of the standard here
Answer: There is no specific time period during which load tests must be performed once the initial installation is inspected and load tested. Some states require operators to load test hoists and cranes every four years, but, in most cases, if the hoist is not altered, repaired or modified, it can remain in service indefinitely without a load test being required.
Answer: This depends on the type of crane. OSHA regulation .179 applies to top-running overhead and gantry cranes with top-running trolley hoists. For these types of cranes, monthly inspections of the hoist’s chain, wire rope and hooks are required with a recorded certification. This certification record must include the signature of the person who performed the inspection and the identifier of the chain, wire and hook that was inspected. If a hoist and trolley are underhung, frequent inspections are required, but written documentation is not.
Answer: According to ASME standards, you must be a “qualified person” to inspect and repair cranes and hoists. A “qualified person” is a person who, by possession of a recognized degree or certificate of professional standing, or who, by extensive knowledge, training and experience, has successfully demonstrated the ability to solve or resolve problems relating to the subject matter and work. These individuals do not have to be professional engineers.
Answer: Hoist disassembly is not always required for yearly inspections. What is found during the inspection typically determines how far you need to break down the hoist. Be sure to reference the manufacturer’s OEM manual when disassembling any hoist.
Answer: According to OSHA .184 and ASME B30.9, slings do not require latches on the hooks, unlike hoist and crane hooks where latches are required unless they constitute a hazard.
Cranes are different from other pieces of construction equipment because – at their most basic function – they do not require other machinery or power to function. The bulldozer, excavator, or tractor required some form of power – whether it be steam or gas, or oil. Much modern construction equipment dates back to some time in the s. Not the crane. The crane is the grandfather of all construction equipment.
A crane is a machine that is used to lift and move heavy loads, machines, materials, and goods for a variety of purposes. They are used in all different sectors of industry, from construction to manufacturing to shipbuilding and material loading. Cranes are common along skylines as they are necessary to build the skyscrapers we so often see in our cities today.
The boom is the most recognizable part of a crane. The boom is a long arm that can either be telescopic or fixed. They take on a variety of roles depending on the type of crane and how it is built. They are able to work without jibs and are sometimes the main component on a crane.
The jib of a crane is the lattice-type structure attached to the end of the boom. Using a lattice-type build helps to reduce the weight it adds to the front of the boom. It is fixed in length and cannot be extended or retracted like a boom can. Some versions of mobile cranes have a jib fixed to the end of the boom to help move and lift materials.
The jib or jib arm has one main purpose: to help keep the material clear of the main support so that it doesn’t hit it while being moved.
That being said, jibs are not always required and are often looked at as extra pieces that can be used when needed.
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The name “counterweight” pretty much describes their purpose: to counter the weight on the front of the crane while lifting material to prevent tipping. They help add stability to the machine and generally increase stability.
Many cranes have adjustable counterweights so that they fit the specific requirements of a load or job. On tower cranes, for example, the counterweight can be seen at the other end of the jib.
Outriggers may be one of the most important factors for crane safety. The function of an outrigger is to supply additional support. The purpose of an outrigger is to distribute the load of the crane over a large enough area so that the crane itself doesn’t tip over or become unstable. All outriggers should either meet or exceed the weight requirements of a crane or job.
Outriggers do not compensate for unstable land. OSHA requires cranes to be assembled on firm ground that is drained and graded sufficiently. Supporting outriggers are meant to be used in conjunction with proper ground standards and do not make up for unstable ground.
Finally, the crane must have some way for materials to be attached to it. The most typical way this is done is through a hook. The lifting hook on cranes is usually equipped with a safety latch to prevent the material from slipping off the hook in transit.
Crane lifting hooks are often made of steel or wrought iron. Hooks for heavy-duty cranes and loads are usually heat-treated and forged in order to make the hook as strong as possible.
Whatever the date was, it’s clear that the idea of using a machine to lift, move, and place building materials came way earlier than you may think. Unlike many other ancient civilizations that used manual labour or ramps to move equipment, the use of a mechanism to simplify the task speaks to the mindset of the Greeks. After all, they are also responsible for geometry, the alarm clock, the lighthouse, democracy, and even central heating.
According to architectural historian Allessandro Pierattini from the University of Notre Dame in Indiana, “no previous civilizations are known to have used it, and it has remained central to building construction without remarkable changes for nearly 25 centuries – because it was perfect.”
It could be argued that the use of lifting tongs and Lewis irons doesn’t equate to a crane but the makeup of their machine with the cranes we know today really aren’t that different.
The use of a simple pulley system transitioned into being man or animal-powered to provide some extra strength. In turn, this turned into a manpower treadwheel which allows for the cranes to lift heavier objects.
By the Middle Ages, the crane was adapted to help load and unload ships at docks as well as assist in construction. Since the cranes on docs would be more fixed, many were built into stone towers or larger wooden structures. At this time, the crane itself was still most often made of wood.
The name speaks for itself! Mobile cranes are one of the most basic types to see in construction. Fitted with a steel truss or telescopic boom mounted to a platform, this type of crane can be moved to, from, and around a site as needed. The platform in question could be wheeled, on a rail, or even fitted to a truck if needed.
Mobile cranes are often used for general construction and roofing. They are powerful enough to move materials and equipment while being less permanent than a tower crane.
Crane operation safety is unique to other pieces of equipment because the machine itself isn’t moving. With tractors, dozers, and backhoes, the machine moves around, driving around people, and carrying equipment with a driver responsible for checking all blind spots and using proper signals.
With cranes, the operator is in a fixed position and it is the material itself that is moving. Safe operations of and around cranes depend just as much on the operator as it does on those on the ground. While the operator needs to use best practices for lifting and moving materials, contractors should stay a safe distance away from the loads, heed the warning about moving materials, and communicate property with the operator.
Cranes have been working alongside humans for over 2,500 years to build cities and neighborhoods. The ability to lift heavy materials and equipment has allowed us to build buildings that reach the skies.
The next time you see a crane or work alongside one, take a moment to appreciate the history behind it and the unique connection that this machine gives us to builders of the past.
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