A Custom-Engineered Hydraulic Container Unloading System
The ZCT-RT20 is a customized container unloading tilter engineered by ZFITA for a specific container handling and unloading application.
Instead of adapting a standard machine to the customer’s operating conditions, the equipment was developed around the project requirements, including truck positioning, container locking, lifting, hydraulic tilting, door operation and automatic control.
The project required more than a simple container tilting frame. It involved a coordinated mechanical, hydraulic and electrical system designed to handle the complete unloading sequence.
Project Overview
The ZCT-RT20 project was developed based on the customer’s project requirements and container drawings.
The equipment combines a fixed frame, front tilting frame, side tilting frame, left and right lifting frames, a container spreader frame, hydraulic cylinders, hydraulic power system, monitoring system and electrical control system.
The project specification identifies the equipment as a 35 t container unloading tilter, with a rated lifting capacity of 40,000 kg.
Key Project Data
| Item | Specification |
|---|---|
| Equipment | Container Tilter |
| Model | ZCT-RT20 |
| Rated lifting capacity | 40,000 kg |
| Tilting method | Dual hydraulic synchronized tilting |
| Tilting angle | 0°–53° |
| Tilting speed | 2°/s |
| Total power | 18.5 kW |
| Power supply | 380 V / 3 Phase / 50 Hz |
| System pressure | 20–26 MPa |
| Operation | Automatic / wireless remote / manual |
| Container door operation | Hydraulic |
| Container locking | Hydraulic |
| Main structural material | Q355B |
| Control system | Siemens PLC |
| Electrical components | Schneider |
| Approx. equipment weight | 14,000 kg |
The Engineering Challenge
One of the main requirements of the project was to accommodate positioning deviations when the truck enters the unloading station.
In actual operation, a semi-trailer may not stop in exactly the same position every time. A fixed connection between the truck, container and unloading equipment can therefore create alignment problems.
ZFITA addressed this requirement by incorporating adjustment functions between the lifting structure and the container spreader.
The ZCT-RT20 provides adjustment in three directions:
Front-to-back adjustment: ±200 mm
Left-to-right adjustment: ±200 mm
Height adjustment: ±200 mm
This gives the equipment greater tolerance for truck positioning and vehicle-height variations during operation.
Six-Direction Position Adjustment
The adjustment system is integrated into the equipment structure rather than treated as a separate accessory.
A transverse hydraulic cylinder allows the spreader frame to move in the front-to-back direction. A longitudinal adjustment cylinder controls left-to-right movement, while the lifting cylinders provide vertical adjustment.
The three adjustment axes work together to compensate for differences between the truck position and the required container engagement position.
For a project with automated container engagement, this type of positioning capability is important because the machine must reliably locate the container before locking and lifting.
Hydraulic Container Locking and Spreader System
The ZCT-RT20 uses a dedicated spreader frame incorporating hydraulic container locking and door operation functions.
Two twist-lock mechanisms are installed at the ends of the spreader frame. Hydraulic cylinders rotate the locking heads to engage with the container corner castings.
The locking mechanism also includes feedback for the engaged and disengaged positions.
The spreader incorporates hydraulic mechanisms for container unlocking and locking, while a separate hydraulic mechanism operates the container doors.
This allows several operations that would otherwise require manual intervention to be incorporated into the equipment cycle.
Synchronized Hydraulic Tilting
The main tilting movement is driven hydraulically.
The project uses two tilting cylinders with synchronized hydraulic control to coordinate the movement of the structure. The lifting cylinders are also controlled through synchronization valves to maintain coordinated lifting movement.
The hydraulic system includes alarm and recovery functions, allowing the equipment to resume operation after adjustment when required.
Counterbalance valves are also specified on the hydraulic cylinders to help prevent uncontrolled downward movement in the event of an external hydraulic hose failure.
These functions are part of the overall hydraulic design rather than add-on features.
Automated Unloading Sequence
The ZCT-RT20 can be operated automatically, by wireless remote control or manually.
In automatic operation, the unloading cycle is designed to coordinate multiple mechanical and hydraulic functions.
The basic sequence is:
The side tilting frame moves into the combined position.
The lifting frames are combined.
The lifting system raises the lifting frame.
The truck backs into the unloading position.
The system identifies the container top lock-hole position.
The spreader engages the container.
The container is unlocked.
The container door is opened.
The unloading tilting operation is performed.
The container is returned and the door is closed.
The container is locked.
The system provides a task-completion signal.
The exact operating sequence is controlled through the project’s electrical and hydraulic systems.
Mechanical Structure Designed for the Application
The ZCT-RT20 is built around a multi-frame structure consisting of the fixed frame, front tilting frame, side tilting frame, lifting frames and spreader frame.
The main load-bearing components use Q355B or higher-grade structural material specified for the project.
The front tilting frame is connected to the fixed frame through a bearing and shaft arrangement. The side tilting frame and lifting frames are coordinated through hydraulic cylinders and combination mechanisms.
The spreader frame integrates the container locking, door operation and positioning adjustment functions.
This configuration allows the different movements to work together as one unloading system rather than as independent mechanisms.
Control and Safety System
The electrical system was designed with control, limit and interlock protection.
The project specification includes a main isolation switch, emergency power-off functions, motor protection, travel limit switches and other protective functions.
The emergency stop circuit uses a safety relay arrangement, and the remote controller also includes an emergency stop button.
Limit switches are provided for defined movement boundaries, while buffers are incorporated into the tilting mechanism to reduce impact during movement.
The equipment structure and electrical enclosures also require reliable grounding as part of the installation requirements.
Designed Around the Customer’s Equipment and Process
The ZCT-RT20 demonstrates an important part of ZFITA’s engineering approach.
The starting point was not simply a standard container tilter model. The project began with the customer’s requirements and container drawings, followed by the development of the unloading equipment around the actual operating conditions.
The final system therefore combines:
Mechanical structural design
Container positioning
Hydraulic lifting and tilting
Hydraulic container locking
Container door operation
Synchronized hydraulic control
Automatic sequence control
Wireless and manual operation
Electrical and safety protection
This type of integration is particularly important when a container unloading machine needs to become part of a larger bulk material handling process.
From Custom Design to Finished Equipment
For ZFITA, customization means more than changing dimensions on an existing machine.
The engineering process considers how the truck arrives, how the container is engaged, how it is locked, how the hydraulic movements are coordinated, how the operator controls the equipment and how the complete unloading cycle is completed.
The ZCT-RT20 project is a practical example of this approach.
It shows how a container unloading tilter can be developed as a complete hydraulic and electrical system around a customer’s specific operating requirements.
Looking for a Custom Container Unloading Tilter?
If your application involves non-standard truck positioning, container locking, unloading angles, hydraulic door operation, automation or integration with other bulk material handling equipment, a standard container tilter may not provide the required configuration.
ZFITA can review your container drawings, truck information, unloading requirements and site conditions to develop a customized container unloading solution.
Contact ZFITA to discuss your project requirements and container unloading application.
