In the selection of over-height lifting spreaders for container ports, fixed and telescopic types are the two mainstream types. They have significant differences in structural design, operational adaptability, performance parameters, etc., and need to be selected according to the actual operational needs of the port.
Structural Design: Rigid Fixation vs. Adjustable Telescoping
The main structure of a fixed ultra-high shelf spreader is rigid, with core dimensions such as length and span of the spreader remaining fixed. It is generally only suitable for 1-2 standard container specifications (such as only applicable to 20-foot or 40-foot standard containers). It has fewer structural components and simple connection points, adopts an overall welding process, and the load-bearing frame has stronger deformation resistance, with fewer structural stability deviations during long-term high-frequency operations.
A telescopic ultra-high shelf spreader has an adjustable telescopic arm structure, which can flexibly adjust the length through a hydraulic or mechanical drive system. It is compatible with various specifications of containers such as 20-foot, 40-foot, and 45-foot. It contains complex components such as telescopic guide rails, drive cylinders, and limit sensors. Its structural complexity is more than 30% higher than that of the fixed type, but through modular design, it realizes the quick replacement of key components, with better maintenance convenience.
Operational Adaptability: Single Scenario vs. Multi-Working Condition Compatibility
Fixed over-height lifting spreaders have more efficiency advantages in operations involving single-specification containers. For example, in a port specializing in handling 40-foot standard containers, the locking device of the fixed spreader does not need adjustment, and the single operation cycle time is 5-8 seconds shorter than that of the telescopic type. In high-intensity operations with more than 5,000 TEUs daily, it can handle 200-300 more TEUs daily. However, when the port needs to switch the type of containers for operation, the fixed type requires overall replacement of the spreader, which takes 30-60 minutes, making it difficult to cope with mixed operation scenarios of multiple container types.
The core advantage of the telescopic ultra-high shelf spreader lies in its compatibility with multi-working conditions. Switching the telescopic mode with one click can complete the conversion between 20-foot and 40-foot container types within 10-15 seconds, which is especially suitable for ports with mixed domestic and foreign trade routes and diverse container types. Data from a comprehensive port shows that after adopting the telescopic spreader, the average daily downtime for changing types in multi-container type operations has been shortened from 2 hours to 0.5 hours, and the equipment utilization rate has increased by 15%. In addition, its telescopic arm's fine-tuning function (±50mm) can also adapt to slightly deformed containers, reducing the operation interruption rate caused by container deviations.
Performance Parameters: Stability Priority vs. Flexibility Priority
In terms of load-bearing capacity, under the same material, the rated lifting capacity of a fixed ultra-high shelf spreader can be 5-10 tons higher than that of the telescopic type. For example, a fixed spreadermade of Q345D steel can have a rated lifting capacity of 50 tons. A telescopic spreader of the same material has a rated lifting capacity of mostly 45 tons due to the telescopic structure weakening part of the load-bearing capacity. However, the telescopic type compensates for structural stress through a dynamic balance system. It can still maintain stable operation under 20% partial load, with the partial load tolerance capacity 10% higher than that of the fixed type.
In terms of energy consumption performance, due to its simple structure, the fixed type has no telescopic drive energy consumption, and the energy consumption per unit of operation (per TEU) is 8-12% lower than that of the telescopic type. During frequent telescopic operations, the hydraulic system's energy consumption accounts for 30% of the total energy consumption in the telescopic type. Still, the energy consumption of no-load telescoping can be reduced by 20% through frequency conversion drive technology, with significant energy-saving effects in intermittent operations.
Applicable Scenarios: Specialized Ports vs. Comprehensive Ports
Fixed ultra-high shelf spreaders are more suitable for specialized container ports, especially hub ports with a single main container type and high operation intensity. For example, in ports with an annual throughput of more than 3 million TEUs and a 40-foot container proportion of over 90%, the fixed type's high efficiency and low maintenance cost (annual maintenance cost is 20% lower than that of the telescopic type) can significantly reduce operating costs.
Telescopic ultra-high shelf spreaders are the first choice for comprehensive ports, especially those engaged in both domestic and foreign trade, with complex container types and fluctuating operation volumes. For example, in ports with an annual throughput of 1-3 million TEUs and a ratio of 20-foot to 40-foot containers of about 4:6, the telescopic type can reduce 90% of the downtime for changing types, and the comprehensive operation efficiency is 10-15% higher than that of the fixed type. In addition, for small and medium-sized ports with narrow sites that are difficult to store multiple sets of fixed spreaders, the "one machine for multiple uses" feature of the telescopic type can save more than 30% of the equipment storage space.
In summary, choosing between fixed and telescopic ultra-high shelf spreaders essentially involves weighing the needs of "single efficiency" and "multiple compatibility." Ports need to consider their own container type structure, operation intensity, site conditions, and other factors, avoid blindly pursuing multiple functions or excessive simplification, and achieve accurate matching between equipment performance and operation needs.
