Everything You Need to Know About Crane End Carriages

The crane end beam is the terminal structure of the bridge frame, connecting to the main girder and mounting the traveling wheels.It primarily supports the crane’s movement along the rails.Inside the end beam are usually integrated a drive motor, gearbox, and wheel set.These components transmit power to the entire crane, enabling longitudinal motion.In bridge cranes, the end beam supports the structure moving on elevated rails.In gantry cranes, it connects to the legs, bearing the gantry frame and traveling on ground rails.Because the end beam’s quality and precision directly affect crane safety, lifespan, and efficiency,understanding its structure and working principle is essential for selecting the right model,ensuring stable operation, and performing effective maintenance.

What Is a Crane End Carriage?

Definition of End Beam:The end beam is a structural unit installed at both ends of the crane bridge.It connects with the main girder and enables the crane to travel along the rails.

Main Functions of the End Beam

• Support the main girder and distribute loads:It connects directly with the main girder to form a stable frame.The end beam transfers the weight of the load and the structure evenly to the traveling mechanism and rails, preventing deformation or fracture.
• Install wheels and fix traveling components:The lower part of the end beam is equipped with a wheel set, which is the key contact point between the crane and the rail.It bears the total weight and lifting load, ensuring smooth rolling while protecting components and reducing wear.
• Drive the crane’s movement:The end beam usually contains a motor, reducer, and brake system.These components transmit power to the wheels, moving the crane along the rails.The brake locks the wheels when needed, preventing inertial sliding and ensuring safety.

Common Structures of the End Beam

• Welded box-type structure:The end beam is typically made of high-strength steel plates welded into a box-type structure with internal stiffeners.This design enhances rigidity and torsional resistance, providing moderate weight, high load capacity, and reduced vibration and deformation during operation for smoother crane travel.
• Driven and idler ends configuration:

A crane usually has two end beams:

• Driven end: Equipped with a motor, reducer, and coupling, it drives the crane through powered wheels.
• Idler end: Lacks power devices and moves passively through idler wheels to maintain bridge balance and guidance.
• Overall, the structural design of the end beam directly affects the crane’s operational stability, lifespan, and maintenance convenience.It is a critical component in both bridge and gantry cranes.

• Wheels & Bearings:The wheel is a key component of the crane’s traveling system.It is usually installed beneath the end beam and bears the crane’s total weight and load.With high-precision bearings, it ensures smooth crane movement, reduces friction, and extends service life.

• Drive Unit / Motor + Gearbox:Installed on the driven end beam, the motor and gearbox transmit power through the drive system to the drive wheels, enabling the crane’s longitudinal movement.The drive unit must ensure high transmission efficiency, low noise, and reliable braking performance.
• Coupling & Shaft Connection:The coupling connects the gearbox to the motor or wheel shaft, compensating for minor misalignments and transmitting torque.The drive shaft transfers power between the two wheels, ensuring synchronized rotation and preventing rail deviation.
• Buffer & Wheel Guard:Both ends of the end beam are typically equipped with rubber, spring, or polyurethane buffers to absorb impact at the travel path’s endpoint.Some designs also include protective covers and anti-collision blocks to ensure safe operation and protect internal components.
• Electrical Connection & Limit Switch:The electrical system includes motor terminals, conductor bar or cable reel connections, and travel limit switches.The limit device automatically cuts power before the end beam reaches the rail’s end, preventing derailment.

Types of Crane End Carriages

Single Girder End Carriage

• Structural Features:Single-girder end beams are typically used for single-girder bridge or gantry cranes.They consist of two short, independent end beams welded or bolted to both ends of the main girder.The cross-section is usually a simplified box or channel type, giving a compact, lightweight structure.
• Applicable Scenarios:Commonly used in workshops, warehouses, or assembly areas with medium duty, small span, and moderate lifting capacity.
• Key Advantages:With a simple design, it offers low manufacturing and maintenance costs.It is easy to install, space-saving, and energy-efficient during operation.

Double Girder End Carriage

• Structural Features:Commonly used in double-girder bridge or gantry cranes, it consists of two long box-type end beams.These are rigidly connected to both main girders with high-strength bolts, enhancing overall load capacity.The end beam has a larger cross-section with internal diaphragms for greater torsional and load resistance.It often includes multiple wheel sets and independent drive units to ensure synchronized crane movement.
• Applicable Scenarios:Ideal for heavy-duty, high-frequency, or long-span operations in industrial plants, steel mills, shipyards, and ports.
• Key Advantages:Offers smooth operation and high load capacity.Can be equipped with large electric hoists or trolleys to meet complex lifting requirements.

Top Running vs. Under Running