Container Gantry Crane
Container Handling
برزیل
A Brazilian customer needed to handle both 20-foot and 40-foot containers and planned to stack them three tiers high. Based on the container sizes, workload, stacking method, and required site coverage, نوکلئون determined the spreader type, lifting height, crane duty class, and cantilever dimensions step by step. The final solution was a 37-ton double-girder container gantry crane.
An Inquiry Requires More Than Lifting Capacity
The customer had already provided the required lifting capacity and approximate dimensions during the initial inquiry. However, these parameters alone were not enough to determine the complete configuration.
To develop the proposal, نوکلئون confirmed the following operating conditions:
• Whether the spreader needed a container rotation function
• Approximately how many containers would be handled each day, including the proportions of empty and loaded containers and the numbers of 20-foot and 40-foot containers
• How many tiers the containers would be stacked
• Whether the requested cantilever dimension referred to the total structural length or the effective handling distance
These details affect the spreader functions, lifting clearance, and crane duty class. Quoting only according to the rated lifting capacity could omit functions required for the actual operation or add mechanisms that the customer did not need.
Key Specifications Determined From Actual Operating Conditions
After receiving information about the container types, daily workload, stacking arrangement, and site layout, نوکلئون evaluated the spreader type, crane duty class, lifting height, and working coverage separately. This allowed each parameter to correspond to the customer's actual handling requirements.
One Telescopic Spreader for Two Container Sizes
A container spreader connects to the top corner castings of a container through its twistlocks. Because the distance between the corner castings changes with the container length, a fixed-length spreader cannot directly accommodate both container sizes.
For this project, نوکلئون supplied one telescopic spreader for 20-foot and 40-foot containers. Its telescopic mechanism adjusts the twistlock positions, allowing the same container gantry crane to handle both container sizes without requiring two separate spreaders.
The customer confirmed that the containers did not need to be rotated during operation, so a spreader rotation mechanism was not included. The final rated capacity under the spreader was 37 tons. The actual handling load was checked according to the combined weight of the container and its cargo.
Below are the container dimension drawings and photos of the actual lifting gear provided by the customer.。
Daily Handling of 14 Containers Led to an A5 Duty Class
The number of containers handled each day and the proportion of empty and loaded containers affect the operating frequency and load conditions of the crane mechanisms. They are also important factors in determining the crane duty class.
The customer expected to handle approximately 14 containers per day, including six empty containers and eight loaded containers. About seven would be 20-foot containers and seven would be 40-foot containers.
Based on this operating pattern, نوکلئون further assessed whether the initially proposed A4 duty class was appropriate. During the technical discussions, the crane duty class was adjusted to A5.
This adjustment shows that selecting a container gantry crane requires more than confirming the maximum lifting capacity. The daily number of handling cycles and the proportions of empty and loaded containers must also be understood. Cranes with the same rated capacity may require different duty classes when their operating frequencies and load spectra are different.
Three-Tier Stacking Required More Than Three Container Heights
The customer initially proposed a lifting height of approximately 10 meters as a preliminary estimate. After the requirement for three-tier stacking was confirmed, the required lifting clearance had to be calculated according to the actual pick-and-place process and container travel path.
The height of a three-tier container stack is not necessarily the same as the lifting height required from the crane. Placing a third container on top of an existing two-tier stack and carrying a container over an existing three-tier stack require different amounts of vertical clearance.
Container height, the spreader connection position, travel path, passing clearance, and safety allowance all need to be considered during crane selection.
After the parameters were calculated, the final lifting height was set at 12 meters under the spreader. The general arrangement drawing identifies this dimension as the effective lifting height available after the spreader is installed, rather than the overall structural height of the gantry crane.
• Lifting height: 12 m under the spreader
• Span: 15 m
• Rated main lifting capacity: 37 t under the spreader
• Hoisting speed: 0.83–8.3 m/min
• Trolley travelling speed: 3–30 m/min
• Crane travelling speed: 3–30 m/min
• Power supply: 380 V / 60 Hz / three-phase
• Control method: Remote control
A Single-Sided Cantilever Extended Handling Beyond the Rails
The span of a gantry crane mainly covers the working area between its two rails. When containers need to be picked up or placed outside the rails, the lifting trolley must travel beyond the crane leg. A cantilever is therefore required to extend the spreader's working range beyond the main span.
For this project, the customer needed to handle containers outside the rails. The customer initially requested a 3-meter outer cantilever. However, it was necessary to confirm whether this referred to the cantilever's total structural length or its effective handling distance.
Some customers treat the effective cantilever distance and the cantilever length as the same measurement, although these two dimensions are normally different.
After repeated confirmation with the customer, نوکلئون established that the actual requirement was a 3-meter effective working distance. The final design therefore used a total cantilever length of 5.5 meters and a 3-meter effective cantilever.
The revised drawing identifies both the total cantilever length and the effective handling distance, making the selection of the cantilever dimensions easier to understand.
Manufacturing, Shipment, and Online Installation Guidance
After the configuration was finalized, نوکلئون organized the production of the gantry crane structural components, lifting trolley, telescopic spreader, and related parts. Crane rails and a cable reel power-supply system were also supplied.
The equipment was disassembled for transportation. Individual components were wrapped or packed in cases, while long structural members were supported on timber blocks and securely tied down.
The cargo was transported from the factory to Nanjing Port, loaded onto a vessel, and shipped to the Port of Salvador in Brazil. The customer carried out the installation locally, with online installation guidance provided by نوکلئون.
Below are actual photos of the production and transportation of this container gantry crane.
Matching Crane Specifications to the Actual Operation
This project translated the customer's handling method and site requirements into specific decisions regarding the spreader, crane duty class, lifting height, and working coverage. This reduced the deviations that could result from selecting a container gantry crane based only on lifting capacity and approximate overall dimensions.
When purchasing a container gantry crane, buyers can provide the container sizes, maximum combined handling weight, stacking height, and site layout. They should also explain where the containers need to be picked up and placed.
نوکلئون can help verify the required information, determine a configuration suited to the actual operation, and provide subsequent installation support.
من Novia هستم که به مدت 10 سال در صادرات جرثقیل مشغول هستم و در 20 کشور به مشتریان خدمات ارائه می کنم. من ذخیره ای از دانش حرفه ای در مورد ساختار و عملکرد انواع جرثقیل ها دارم. از نقل قول گرفته تا طرح طراحی تا تحویل، من خدمات یک به یک را به شما ارائه می دهم تا مقرون به صرفه ترین و حرفه ای ترین راه حل جرثقیل را به شما ارائه دهم. اگر نیاز به خرید جرثقیل دارید، لطفا برای آخرین خدمات با من تماس بگیرید.
