Container gantry crane is designed to improve the efficiency of container yard operations. It is responsible for stacking, loading and unloading containers, and the transportation of containers is done by a container trailer. The typical containers gantry cranes include two main types: rail mounted gantry crane and rubber tyred gantry crane.
Details of Container Gantry Cranes
Rail mounted container gantry crane
Rail mounted gantry crane, also known as RMG crane, is a great choice for handling and stacking large containers. It runs along the track, lifting and stacking containers within the specified range of the container yard.
One of the typical RMG crane parameters are as follows: the gauge is 23m, rated lifting capacity under spreader is 40t, lifting speed at full load is 23-30m/min, no-load lifting speed is 46-60m/min, trolley travelling speed is 63-70m/min, and crane travelling speed 50-120m/min. The lifting mechanism, trolley mechanism and crane travelling mechanism are mostly controlled by AC frequency conversion. The hoisting mechanism is generally in the form of a single drum, and it can also be designed in the form of a double drum as required.
Rail mounted container gantry crane parameters:
- Lifting Capacity: 30.5t~100t
- Lifting Height: 15.4~18.2m
- Lifting Speed: 12~40m/min
- Work Duty: A6
- Power Supply Mode: cable reels or slip line
The advantages of RMG container crane:
- Electric drive, save energy and reduce pollution
- High yard utilization
- Relatively simple mechanical structure
- Reliable operation and easy maintenance
- Computer control can be used to realize automation of yard operations.
Rubber tyred container gantry crane
Rubber tyred gantry crane or RTG crane is of maneuverability and flexibility when handling large containers. The frame is supported on 4, 8, or 16 large tires without inner wheels. The number of wheels is determined by the wheel pressure on the site. The crane traveling mechanism is driven by two or four wheels, equipped with manual correction system and anti-collision device. The trolley travelling mechanism adopts rack type or two-wheel or four-wheel drive. In terms of safety facilities, there are overload protection, diesel engine overspeed protection, signal devices with high water temperature or low oil pressure, wind speed indicator, anti-typhoon anchoring device, emergency stop button, etc.
Rubber tyred gantry crane parameters:
- Lifting Capacity: 20t~65t
- Span Length: 22~28m
- Lifting Speed: 20~30m/min
- Operating Temperature: -20℃~40℃
- Power Supply Mode: cable reels, sliding wire, diesel powered
The advantages of RTG crane:
- Effective use of the yard space.
- The construction cost of the yard is relatively low.
- The operation is very simple.
- The equipment maintenance and management technology is mature.
- Straight-line automatic control device can be used to realize automatic control of travelling trajectory.
- Connected to computer system, it is easier to automate yard operations.
Comparison of RTG and RMG Container Cranes
- RTG crane requires diesel generators to provide fuel, and requires routine maintenance and inspection of diesel generators, so it consumes more energy than RMG crane.
- RTG crane is a bit cheaper than the RMG because RMG requires infrastructure such as rails.
- RTG crane can be moved to other places more conveniently, without the help of tracks.
- RMG crane can have a larger span and greater stacking height, so it is more convenient and faster to load and unload containers transported by the rail.
The Main Structure of Container Gantry Crane
- Lifting mechanism
Lifting mechanism consists of electric motor, disc brake, reducer, and duplex drum.
The wire rope drum lifting mechanism is driven by an AC motor, and a single-layer rope groove drum is driven by a closed spiral gear reduction box to wind the rope. The motor has enough power to ensure good acceleration performance.
An elastic coupling with a brake disc is provided between the hoisting motor and the reduction box. The brake is a hydraulic push rod disc brake released by a spring brake push rod.
An overspeed switch is provided on the high-speed shaft end of the hoisting mechanism. When the motor speed exceeds 115% of the rated speed, the entire machine is stopped in emergency.
Detected by the weight sensor, when the load under the spreader is between 100% and 110% of the rated load, the rated load indicator light in the driver’s cab is displayed. When the load under the spreader exceeds 110% of the rated load, the buzzer alarms, the overload indicator flashes, and the PLC prohibits the lifting mechanism from continuing to lift upwards, but allows the lifting speed limit to drop and lower the load.
- Trolley travelling mechanism
The trolley running mechanism generally consists of a wheel set, a motor, a reducer, a brake, a coupling, etc. or a three-in-one reducer and a guide wheel set.
- Crane travelling mechanism
RMG crane travelling mechanism mainly consists of three-in-one reducer drive, rail clamp, buffer, wheel clamp, etc.
RTG crane travelling mechanism usually consists of three-in-one reducer drive, chain transmission mechanism, hydraulic steering system and so on.
Selection of Container Gantry Crane
The selection of container gantry crane needs to be comprehensively considered based on factors such as the terminal’s capacity, collection and transportation methods, terminal road area, environmental protection, investment costs and operating costs. If you are unsure as to which type of gantry crane is right for you, please provide some basic information so we can help you select the right one for your application:
- Rated lifting capacity
- Lifting height
- Stacked container layers
- Number of containers passed
- Base distance
- Other special requirements
Interested in our container gantry crane or want to get a free quote? Send your inquiry today.