Safe working load crane

Types of safe working load cranes

The safe working load crane refers to the maximum load amount a crane can lift safely without breaking or causing any functional issues. Numerous types of cranes exist for different purposes. Here are some common types of cranes and their corresponding SWL.

• Mobile crane: A mobile crane is an all-terrain vehicle with lifting capabilities. Mobile cranes have SWL that varies depending on the size, model, configuration, and the specific setup at the time of use. Generally, mobile cranes can handle anywhere from a few tons to over 1,000 tons for larger models.
• Tower crane: Tower cranes are used in large construction projects and have a fixed base. A tower crane's safe working load typically ranges from 10 to 20 tons for standard models. However, some larger heavy-duty tower cranes can have safe working loads of 30 tons or more.
• Overhead crane: Overhead cranes are commonly used in factories and warehouses, which can also be known as bridge cranes. SWL for overhead cranes can vary depending on the design and configuration. Many overhead cranes have SWL ranging from a few hundred pounds up to 15 tons. Some specialized models may have SWLs greater than 15 tons.
• Suction crane: A suction crane employs suction cups to grasp and move items. It is ideal for transporting flat and smooth objects like glass, metal sheets, and plastic. The SWL of these types of cranes depends on the number and size of the suction cups and the configuration of the crane. A common setup with four large suction cups might have an SWL of 2 tons.
• Jib crane: A jib crane is a kind of fixed crane with a horizontal arm (the jib) that swings the load. They are often used to move items short distances. The jib crane SWL generally ranges from small models with 0.5 tons to larger ones with about 15 tons. The safe working loads of the jib cranes vary based on the crane's height, reach, and design.

Specification & Maintenance

• Maximum Load Capacity:

  The maximum load capacity of a crane is the highest weight it can lift. This is usually measured in tonnes or thousand kilograms.

• Safe Load Indicator (SLI):

  An SLI or GCR (Gross Crane Rating) shows the load a crane is safe to lift at any moment. This is displayed on a digital screen in the crane cabin.

• Crane Types:

  A way to define a crane is by its design or purpose. Tower cranes are tall and get built with the buildings they are used on. They are then dismantled in pieces once the project is completed. Luffing cranes are similar but have a cross-shaped design. Mobile cranes, on the other hand, have wheels or tracks for movement. They are mounted on trucks or built as all-terrain units. Gantry cranes have wheels and run on a track laid out on the ground. They are easily movable for lifting heavy items from one place to another.

• Age of Crane:

  This is the period the crane has been in operation. Conventional cranes can age quite a bit now - nearly 20 years. The older the crane gets, the more assistance it will require to operate efficiently.

• Frequency of Use:

  A crane's SWL is affected by how often it is used. Cranes that operate constantly will require more maintenance services.

• Maintenance:

  Regular maintenance checks and services increases a crane's lifespan. It also allows the crane to operate safely and efficiently. When a crane is frequently used, it will require more maintenance services. Clients will need to consider its maintenance schedule before deciding how often it will be used.

• Condition and Environment:

  A crane’s machine parts can wear down if they are exposed to harsh conditions. Extreme temperatures can put a strain on parts, causing them to break down faster. Businesses may need to schedule more maintenance services for cranes that are regularly used in harsh environments.

Usage scenarios of safe working load cranes

Industrial cranes are used in many industries, including construction and mining, to lift and move heavy materials. They are an important part of factories where large machines are built and assembled, such as the automobile industry.

Here is a list of industries where cranes are frequently used:

• Construction: Cranes are widely used in the construction industry to assemble buildings, particularly high-rise structures. Common tasks include placing concrete forms, installing structural steel, lifting heavy construction materials, and positioning prefabricated modules and equipment. Tower cranes are the most widely used type of crane in the construction industry, as the vertical lifting ability is ideal for handling construction materials at height.
• Mining: In the mining industry, cranes are used to assemble and maintain large mining equipment, as well as for the extraction of heavy materials from the earth. Common types of cranes used in mining include: portal cranes, which are used for the stacking and reclaiming of materials at mining sites; harbor cranes for the unloading of ore and coal at the docks; and offshore platform cranes, which are used for maintenance and support of oil rigs and other offshore structures.
• Heavy Industry/Manufacturing: Industries that handle and move heavy materials, such as steel and aluminum production, require the use of heavy-duty machines. An example of a machine often used in these industries is a gantry crane. Gantry cranes are mounted on wheels or tracks, which allows for the horizontal movement of heavy objects. Gantry cranes are used for tasks such as handling large steel coils and sheets, large extrusions and assemblies, as well as for loading and unloading of heavy-duty equipment and machines.

Aside from the construction, mining, and heavy industry/manufacturing listed above, cranes are also used in other industries to perform various lifting and moving tasks. Here are a few examples:

• Maritime/Shipping: Container cranes are the dominant type of crane used in shipping and material handling in ports. Container cranes are large, vertical towers with horizontal beams that can move containers on and off large cargo ships. Other types of container cranes include vessel-to-shore (VTS) cranes and yard cranes. The yard cranes transfer containers to and from inland transport networks.
• Aerospace: The aerospace industry uses specialized cranes for the assembly of large aircraft. An example of a specialized crane would be an overhead crane used for lifting large and heavy aircraft components and sections during aircraft assembly operations.
• Wind Energy: The wind energy industry uses cranes in the construction and maintenance of wind farms, particularly for lifting large and heavy wind turbine components.

How to choose a safe working load crane

• applicable circumstances

  The kind of crane that is suitable for the particular circumstances of a working environment should be chosen. An overhead crane may be the best choice if there are high ceilings and no obstruction. However, a mobile crane may be the best choice if the weight or distance are issues, or if there's a need to move the equipment from one place to another.

• capacity

  It is critical to determine the crane's lifting capacity. Every type of crane has its own maximum weight that it can lift. Selecting a crane whose capacity is greater than the heaviest item that it will lift is essential.

• safe working load (SWL)

  The SWL is the maximum load that a crane can safely lift. It's important to pay attention to the crane's SWL when choosing a crane. The SWL is normally marked on the crane, along with a label showing the safe operating limits, which include the inspection and maintenance requirements.

• energy source

  Consider the type of energy required to operate the crane. Will it be manually driven, or will it use fuel or electricity? A properly selected crane will suit the operating conditions and lifting requirements.

• operator training

  It is important to choose a crane with a properly trained operator. Because of the risks involved in operating a crane, choosing an operator with the relevant knowledge and experience is essential. Consider the operator's ability to follow the crane's load chart and properly calculate the weight of items to be lifted.

• maintenance requirements

  A well-maintained crane will have a long service life and will be safe to operate. When choosing a crane, consider its maintenance needs. Choose a crane with easy access to parts and components so it can be routinely inspected and serviced.

Q&A

Q1: How does a safe working load crane help the economy?

A1: Crane machines lift heavy materials, increasing productivity by reducing the time used to transport materials. This boosts economic growth.

Q2 How do operators determine the Safe Working Load of a crane?

A2: The manufacturer's specification indicates the crane's maximum safe lifting capacity. Also, consider the materials' weight and distribution, the rigging used, and the local crane regulations and guidelines.

Q3: What are the consequences of exceeding a crane's SWL?

A3: Exceeding a crane's safe working load can cause mechanical failure, tipping, and uncontrolled falling, which may cause injuries and fatalities. It can also damage the load, equipment, and property.

Q4: What measures can be used to ensure a crane is operated within its SWL?

A4: Understand the crane type and its safe working load. Use weighbridges and load cell systems to measure the weight of the lifted materials. Plan all lifts to ensure weights are known and rigging limitations are considered. Use marked cranes in the overhead facilities with the indicated safe load for all personnel.Maintain communication during the lift between the crane operator and ground personnel. Use properly trained and qualified operators familiar with the crane's operation and the safe working load concept.