Cranes and Hoists

Cranes and hoists are mechanical devices used in tunneling and underground construction to lift and move heavy loads vertically and horizontally.

Definition:

Cranes and hoists are mechanical devices used in tunneling and underground construction to lift and move heavy loads vertically and horizontally. They consist of various components such as a mast, boom, jib, hoist mechanism, and controls, allowing for efficient and controlled lifting operations.

Uses/benefits:

Load Handling: Cranes and hoists are primarily used for lifting and moving heavy loads in tunneling and underground construction projects. They are essential for tasks such as material handling, equipment installation, and structural assembly.
Efficiency: These devices provide efficient load handling, allowing for faster and smoother operations. They enable precise positioning of loads, reducing manual labor and increasing productivity on the construction site.
Safety: Cranes and hoists enhance safety by minimizing manual lifting and reducing the risk of accidents or injuries associated with heavy lifting. They provide better control and stability during load movement, ensuring the safety of workers and equipment.
Versatility: These equipment can be utilized in various tunneling applications, including shaft sinking, tunnel excavation, equipment installation, and material transport. They are adaptable to different load sizes, weights, and site conditions.
Access and Reach: Cranes and hoists offer the capability to access and reach elevated or hard-to-reach areas within the tunnel or underground structure. This enables efficient work execution and facilitates construction activities.
Flexibility: They can be configured with different attachments and accessories, such as grabs, hooks, buckets, or personnel cages, to accommodate specific tasks and requirements.
Project Management: Cranes and hoists play a crucial role in project management by providing the means to handle heavy loads efficiently. They contribute to timely completion of tasks, reducing construction timelines and costs.

Specifications:

Load Capacity: The load capacity of cranes and hoists determines the maximum weight they can lift safely. It is specified in terms of tonnage or lifting capacity.
Reach and Height: The reach and height specifications indicate the maximum horizontal reach and lifting height of the crane or hoist. They determine the range of movement and the ability to access different areas within the tunnel or underground structure.
Lifting Speed: The lifting speed specification indicates how quickly the crane or hoist can raise or lower the load. It is usually specified in meters per minute (m/min) or feet per minute (ft/min).
Controls: Cranes and hoists can have different control mechanisms, such as manual controls, remote controls, or computerized systems, offering varying levels of precision and automation.
Power Source: They can be powered by electricity, diesel engines, or hydraulic systems, depending on the specific application and site conditions.
Mobility: Some cranes and hoists are mounted on tracks or wheels, allowing for mobility within the tunnel or construction site. Others may be fixed in position or mounted on structures.

Types:

Tower Cranes: Tower cranes are tall, fixed-base cranes with a rotating boom. They are commonly used in larger tunneling projects where high lifting capacities and long reaches are required.
Crawler Cranes: Crawler cranes are equipped with tracks for enhanced mobility on rough terrain. They provide stability and lifting capabilities for heavy loads in challenging underground conditions.
Mobile Cranes: Mobile cranes are versatile and can be transported to different locations. They are suitable for smaller tunneling projects or sites with limited space.
Overhead Cranes: Overhead cranes are installed on elevated tracks or gantries, allowing them to move horizontally along the tunnel or underground structure. They are commonly used in workshops and maintenance facilities.
Hoists: Hoists are vertical lifting devices commonly used for transporting personnel, equipment, or materials within the tunnel or vertical shafts. They can be wire rope hoists, chain hoists, or pneumatic hoists.

Cranes and hoists are critical equipment in tunneling and underground construction, enabling efficient and safe lifting operations. The selection of the appropriate type of crane or hoist depends on factors such as load requirements, site conditions, and project specifications. Proper training, operation, and maintenance are essential for their safe and effective use.