EOT Crane

An EOT Crane (Electric Overhead Travelling Crane) is one of the most commonly used types of overhead cranes in industrial environments. These cranes are primarily used for lifting and moving heavy loads horizontally across a work area. They consist of parallel runways with a traveling bridge spanning the gap. Here’s a detailed look into EOT cranes:

An EOT Crane is a type of overhead crane powered by electricity, designed to lift and move heavy objects. It is often found in manufacturing plants, warehouses, and industrial facilities. EOT cranes are designed for a range of applications, from light-duty to heavy-duty lifting tasks.

Types of EOT Cranes:

1. Single Girder EOT Crane:

•    Structure: Features a single girder (beam) across the span and a hoist that moves on the bottom flange of the girder.
•    Capacity: Suitable for light to moderate loads, typically up to 20 tons.
•    Advantages: Simple design, cost-effective, lower weight, and easier to install and maintain.
•    Applications: Small workshops, warehouses, or areas with limited headroom.

2. Double Girder EOT Crane:

•    Structure: Features two girders for additional strength and the hoist runs on top of the girders.
•    Capacity: Ideal for heavy-duty operations, capable of lifting loads exceeding 20 tons.
•    Advantages: High load-bearing capacity, greater hook height, and can support auxiliary equipment.
•    Applications: Heavy industries like steel plants, shipyards, and large-scale warehouses.

Components of an EOT Crane:

1. Bridge:

    The bridge is the main structural component that spans the gap between the two parallel runways. It supports the trolley and hoist, which carry the load.

2. Runways/End Carriages:

   The runways are fixed on the building structure, and the end carriages move along these runways. They allow the crane to travel the full length of the building.

3. Trolley:

   The trolley moves horizontally along the bridge. It houses the hoist and moves the load left or right across the span of the crane.

4. Hoist:

   The hoist is the component that lifts and lowers the load. It can be either wire rope or chain-based and is powered electrically.

5. Electric Motor:

   The electric motor powers the hoist and the trolley’s movement. It may also control the movement of the bridge across the runway.

6. Control System:

  -Pendant Control: A handheld control unit attached to the crane via cable, is used to operate the crane.

  -Radio Remote Control: Wireless control system that allows operators to control the crane from a distance, enhancing safety.

7. Brakes and Limit Switches:

   These components ensure safe operation, preventing the hoist from lifting beyond its rated capacity or moving beyond a specified point.

Working Principle of EOT Cranes:

• Vertical Movement: The hoist lifts or lowers the load using electric power.
• Horizontal Movement (Trolley): The trolley moves horizontally along the bridge, shifting the load left or right.
• Longitudinal Movement (Bridge): The entire bridge moves along the rails installed on the runways, transporting the load across the working area.

These three motions allow the crane to lift, move, and place heavy loads in different parts of the workspace with precision.

Advantages of EOT Cranes:

1. Efficiency: Capable of handling very heavy loads with minimal human intervention, improving productivity in industrial settings.

2. Space Utilization: EOT cranes use overhead space, leaving floor space available for other operations.

3. Precision: Modern control systems allow for highly precise movements, reducing the risk of damage to goods.

4. Versatility: EOT cranes can be customized to meet specific load capacities and operational requirements.

5. Safety: Equipped with advanced safety features like limit switches, overload protection, and emergency stop systems to ensure safe operation.

Applications of EOT Cranes:

1. Manufacturing Plants: Used for transporting raw materials, components, and finished products across various stages of production.

2. Steel Plants: Used for handling large volumes of steel, including coils, sheets, and ingots.

3. Shipbuilding Yards: EOT cranes are vital in moving large ship components and machinery.

4. Warehouses: For material handling, loading, and unloading in large storage facilities.

5. Power Plants: Used in maintenance operations to lift heavy equipment like turbines and generators.

Safety Features:

1. Overload Protection: Ensures the crane does not lift loads beyond its rated capacity, preventing accidents and equipment damage.

2. Limit Switches: These switches automatically cut off power when the hoist reaches the top or bottom of its range, or when the trolley or bridge reaches the end of its travel.

3. Emergency Stop: Provides an immediate way to stop the crane in case of an emergency.

4. Anti-Collision Devices: These devices prevent the crane from colliding with other structures or equipment in the facility.

5. Braking System: Ensures the load stays in place when the crane is not moving.

6. Single Phase Prevention: Refers to the protection mechanism that prevents damage to equipment, particularly motor.

7. DVR (Dynamic Voltage Restorer) : is used to protect the crane’s electrical system from voltage power sags, swells, and other power quality issues.

Maintenance of EOT Cranes:

Regular maintenance is critical to ensure the safe and efficient operation of an EOT crane. Maintenance tasks typically include:

• Lubrication of moving parts
• Inspection of cables and wire ropes for wear and tear
• Checking the electrical components, motors, and control systems
• Replacing worn-out parts like hoist ropes, brakes, and limit switches
• Ensuring proper alignment of the runway rails and bridge

EOT Crane Standards:

EOT cranes are built according to national and international standards to ensure safety, reliability, and performance:

• Indian Standard IS 3177 and IS 807 (For EOT crane design and manufacturing in India)
• British Standard BS466