Double Trolley Overhead Crane for Tanzanian Hydropower Plant: Anti-Corrosion Design

The Tanzanian client procured two double girder overhead cranes for hydropower plant, requiring double trolley configuration, customizable parameters, and suitability for humid operating conditions.

We provided a customized QE double trolley overhead crane solution, designed to meet lifting capacities of 40+15t and 40+10t. The equipment is engineered in accordance with the local 400V/50Hz/3Ph power supply standard and features anti-corrosion protection to suit the humid site environment. All performance parameters comply with project construction specifications and fully meet the heavy-duty lifting requirements of hydropower plant operations.

Core Procurement Requirements

• Lifting Operation Requirements: The equipment must meet the heavy-duty lifting conditions of a hydropower plant, adopting a double trolley configuration to ensure smooth and reliable operation.
• Parameter requirements: Key specifications such as lifting capacity, span, and lifting height shall be customized according to project requirements and comply with Tanzania's 400V/50Hz/3Ph power supply standard. The operating speeds of all mechanisms shall be coordinated with on-site lifting cycles, while the control system shall ensure ease of operation together with flexibility and precise control.
• Operating environment: The equipment shall be suitable for hydropower plant conditions in Tanzania, with strong resistance to corrosion and moisture. Key components such as motors shall meet the required protection rating to prevent moisture ingress, thereby minimizing the impact of environmental conditions on service life and operational reliability.

Customized Solution

1. Customized Lifting Solution: Double Winch Trolley Design

• Winch trolley for heavy-duty applications: The winch trolley is adopted to provide higher load-bearing capacity, making it suitable for heavy-duty hydropower working conditions.
• Double trolley configuration: Each overhead crane is equipped with two independently operating trolleys. The auxiliary trolley can be used for turning operations during component assembly processes.
• Variable frequency speed control for smooth operation: Both hoisting and traveling mechanisms are equipped with VFD (variable frequency drive) control, ensuring smooth start-up and braking without impact. The system also provides precise positioning capability, improving operational efficiency and safety.
• Modular design of key components for easy maintenance and replacement: The motor, reducer, and brake are designed in a separate modular layout, allowing each component to be serviced or replaced independently without disassembling the entire mechanism.
• Dedicated maintenance-friendly structure for convenient inspection: The wire rope drum adopts an independent support design for individual disassembly and replacement. A dedicated maintenance platform is provided to ensure safe and convenient access for routine inspection and servicing. The brake is designed as an independent unit, allowing direct observation of brake pad wear. It features automatic compensation and manual release functions, with optional brake lining wear alarm function, making adjustment and maintenance simple and efficient.

2. Technical Parameters: Fully Customized to Client Requirements

All dimensional, electrical, and operational parameters are precisely tailored and calibrated according to client specifications, with optimized control systems to ensure full compatibility with project requirements and local power standards.

• Dimensional parameters: Both cranes are designed with a span of 12.8m and a lifting height of 12m. They are configured with dual lifting capacities of 40+15t and 40+10t respectively, fully meeting the dimensional and load requirements for hydropower lifting operations.
• Voltage: The electrical system is designed in compliance with the local 400V/50Hz/3Ph power supply standard in Tanzania, enabling direct connection to the local grid without additional modification and ensuring stable power operation.
• Operating speed and control mode: The operating speeds of each mechanism are properly configured to match the project's lifting cycle. The control system adopts a dual-mode operation of pendant control and remote control, ensuring both operational convenience and flexibility, and adapting to different working scenarios within the hydropower plant.

3. Environmental Adaptation Solution: Anti-Corrosion Design for Hydropower Humid Conditions

To meet the environmental adaptation requirements of the project site, advanced surface anti-corrosion treatment and motor protection design are applied to enhance resistance against corrosion and moisture, ensuring suitability for hydropower operating conditions in Tanzania.

• Steel plate treatment: All steel plates are treated with Sa2.5-grade shot blasting, effectively removing surface oxide layers and impurities, and providing a strong foundation for subsequent coating adhesion.
• Anti-corrosion coating system: The surface is coated with an epoxy zinc-rich primer plus a chlorinated rubber topcoat. Compared with conventional coatings, this system offers stronger corrosion resistance, effectively protecting the structure from humid environmental exposure and extending service life.
• High protection-class motors: The motors are designed with an IP54 protection rating and Class F insulation. They offer excellent dust and moisture resistance, effectively preventing dust and water vapor from entering the motor interior, reducing component damage risk, and ensuring stable operation in humid hydropower environments.

Delivery Results

• After contract signing, production and shipment preparation of two customized QE double trolley double girder overhead cranes were completed within approximately two months.
• Operational efficiency and safety performance both met project expectations. The A5 duty classification configuration is well suited to hydropower plant working conditions.
• The electrical system is fully compatible with the local 400V/50Hz/3Ph power grid, ensuring stable operation. The anti-corrosion system of epoxy zinc-rich primer plus chlorinated rubber topcoat, combined with IP54-rated motors, enables the equipment to reliably adapt to hydropower operating environments.
• The client highly recognized the customized design, product quality, and manufacturing workmanship. With extensive experience in crane export to Africa, we provided full-process services covering design, production, and shipment, laying a solid foundation for on-site installation and long-term operation.

If you also have crane procurement requirements—such as customized overhead cranes, gantry cranes, or other lifting equipment, or needs related to power supply adaptation, outdoor anti-corrosion protection, or special functional customization—please feel free to contact us.

With years of experience in crane export and customized solutions, we can provide one-to-one crane design services based on your project conditions, lifting capacity, span, local power supply, and environmental requirements, along with tailored quotations and full logistics and after-sales support. From product development and manufacturing quality control to sea freight, customs clearance, and on-site guidance, we deliver a complete one-stop crane export solution.

Zora Zhao

Expert in Overhead Crane/Gantry Crane/Jib Crane/Crane Parts Solutions

With 10+ years of experience in the Crane Overseas Export Industry, helped 10,000+ customers with their pre-sales questions and concerns, if you have any related needs, please feel free to contact me!

WhatsApp: +86 189 3735 0200

Email: zorazhao@dgcrane.com