What Is a Crane?
A crane is a mechanical device that utilizes power (excluding human power) to lift and horizontally transport loads. It refers to both stationary and mobile types within a limited range. The definition of a crane includes two aspects: lifting loads using some form of power other than human power and horizontally transporting the lifted load (which may involve human power). There are no specific requirements for unloading the load.
Additionally, a mobile crane, such as a crane truck, which has an integrated engine and can move to unspecified locations, is referred to as a mobile crane. However, according to the crane and other safety regulations based on the Labor Standards Act, cranes and mobile cranes are categorized as separate mechanical devices.
Uses of Cranes
Cranes are widely used in various work sites and industries, including construction sites, ports, rooftops of buildings, manufacturing plants, and transportation. Different types of cranes are designed to efficiently perform tasks according to specific locations and use cases.
These mechanical devices are commonly employed for tasks such as transporting construction materials and components, as well as loading and unloading cargo, where manual labor alone is insufficient.
Features of Cranes
Advantages
The advantages of cranes include the ability to lift and transport heavy loads that cannot be moved by human power alone. This allows for the safe and efficient lifting and movement of heavy objects in a short amount of time, making it possible to carry out operations in locations where other machines cannot operate, such as during the construction of tall buildings.
Disadvantages
The disadvantages of cranes include the fact that, in addition to those capable of self-propulsion, there are also large cranes that require assembly and installation. In such cases, the time and cost of installation are incurred, and a vast space is often required.
Types of Cranes
Cranes come in various types depending on their intended use. Representative types include:
1. Truck Crane
A truck crane is a crane mounted on a truck, allowing it to move on roads for easy transportation. It is used to lift loads of less than 3 tons, and there are tow trucks with mounted cranes.
2. Rough Terrain Crane
A rough terrain crane, equipped with large tires, can travel on mild soft ground and uneven terrain. With four-wheel drive and four-wheel steering, it is suitable for operations in narrow alleyways.
3. All-Terrain Crane
An all-terrain crane combines the ability to travel on highways like a truck crane and move on mild soft ground and uneven terrain like a rough terrain crane. Some can lift over 1,000 tons, demonstrating significant power even in tight spaces.
4. Crawler Crane
A crawler crane can travel on soft ground and uneven terrain due to its crawler-type traveling mechanism. It can operate in places where tire-based cranes cannot access. However, its drawback is a slower traveling speed.
5. Gantry Crane
A gantry crane is a massive crane device installed on the quay of a port. It is used for unloading and loading containers from cargo ships, playing an essential role in maritime transport.
6. Unloader Crane
An unloader crane is a dedicated crane used in ports to lift coal, minerals, grains, and other cargo from ships to the shore. There are types that use cranes and those that use conveyors for unloading.
7. Overhead Crane
An overhead crane travels on a runway installed near the ceiling of a factory. It is used for transporting large components and other items that cannot be moved by human power alone.
8. Jib Crane
A jib crane lifts loads using a wire and hook extended from the tip of its arm. Recognizable by its long arm, the arm portion is called the “jib.” Large cranes installed on the rooftops of buildings are also jib cranes.
9. Stacker Crane
A stacker crane is used in warehouses and factories for storing and retrieving cargo and parts. Rails are installed on the floor or shelves, and cargo or parts are moved on these rails.
10. Cable Crane
A cable crane is used for transporting materials and pouring concrete during dam construction. It has a structure similar to a cable car and is suitable for long-distance transportation. In addition to dam construction, it is also used in river improvement projects and bridge construction.
Other information on Cranes
1. Special Education for Crane Operation
Completion of special education for crane operation allows the operation of cranes with a lifting capacity of less than 5 tons and the operation of crane cars with a capacity of 5 tons or more.
2. Crane and Derrick Operator License
- Crane and Derrick Operator License (Unlimited)
Allows operation and control of cranes and derricks with a lifting capacity of 5 tons or more. - Crane and Derrick Operator License (Crane Only)
Allows operation and control of cranes with a lifting capacity of 5 tons or more. - Crane and Derrick Operator License (Floor-Controlled Crane Only)
Allows operation and control of floor-controlled cranes with a lifting capacity of 5 tons or more. It also allows the operation and control of cranes with a capacity of less than 5 tons.