Tower cranes with telescopic tower structures and horizontal jib configurations, such as the QT16-type quick-assembly lower slewing tower crane, often follow a sequential procedure for installation. Below is a detailed step-by-step guide:
1. Stabilizing the Base Frame
- Extend all four support legs and lower the support jacks to lift the tires off the ground.
- Adjust the main beams of the base frame to ensure they are level.
- Secure sturdy pads beneath the support legs for stability.
2. Preparing the Boom
- Straighten the jib by disconnecting the linkage pin from the boom head. This action detaches the linkage from the boom head.
- Rotate the boom head to align it with the boom tail, forming a straight line.
- Fasten the lower chords of the boom head and boom tail tightly using bolts.
- Remove the linkage from the boom tail.
3. Aligning Tower Top Braces
- Pull the top support rods of the tower downward until the lower support rods align in a straight line.
- Secure the alignment with pins.
4. Inspecting the Support Cables
- Ensure that the brace cables are positioned correctly on the upper chord at the rear of the jib.
5. Adjusting the Hoisting Trolley
- Remove the locking pin securing the hoisting trolley to the jib structure.
- Tighten the front and rear adjustment bolts on the trolley, ensuring the pulling ropes are tensioned.
6. Deploying the Steel Wire Rope
- Extend approximately 20 meters of hoisting steel wire rope.
7. Preparing the Ground for Tower and Boom Movement
- Place a steel plate approximately 500 mm wide diagonally on the towing beam of the front axle.
- Lay a steel plate (400 mm × 6000 mm) along the crane’s longitudinal axis in front of the boom to serve as a sliding path for the boom head during tower erection.
8. Erecting the Tower and Extending the Boom
- Operate the dual-drum hoist from the lower control panel to begin the erection process.
- Initially, lift the tower body slightly using the hoist to detach the transport linkage securing the upper tower section to the slewing platform.
- Continue operating the hoist to fully erect the tower. As the tower body rises, the boom head descends, sliding outward along the steel plate track.
- Align the tower base with the corresponding holes on the slewing platform and secure them with connecting pins and fixed shaft plates.
9. Setting Up Structural Cables
- Install the boom pull ropes, tower top brace cables, telescopic adjustment ropes, and luffing ropes.
- Verify the upper end of the outer tower body has no tightened spiral jacks.
10. Adjusting the Inner Tower Section
- Lift the inner tower section 20–25 mm using the hoist.
- Remove the fixing plates on the connecting pins of the inner and outer tower bodies.
- Slightly withdraw the connecting pins to disengage them from the inner tower structure. Secure the pins with screws to prevent unintended re-engagement.
11. Extending the Inner Tower Section
- Operate the hoist to raise the inner tower section.
- During this process, the boom head slides inward along the inclined steel plate track, moving up and aligning closer to the tower body.
- Ensure the boom head is guided carefully using cables to prevent the hoisting trolley from colliding with the tower structure.
- Once the inner tower section fully extends to its limit, the boom head will automatically unfold.
- Remove the guiding cables and continue extending the inner tower until the limit switch activates, cutting off the power.
- Throughout this operation, ensure no cables are damaged or torn.
12. Securing the Inner and Outer Tower Sections
- Loosen the positioning screws of the connecting pins between the inner and outer tower bodies.
- Push the connecting pins inward to lock the sections together.
- Lower the inner tower using the hoist and secure the pins with axle-end plates.
13. Adjusting the Spiral Jacks
- Tighten the four spiral jacks on the upper end of the outer tower body against the inner tower.
- Begin with the two inner jacks before tightening the two outer ones.
14. Securing the Pulley Frame
- Relax the installation wire rope using the hoist and dislodge the pulley frame’s axis from the outer tower body.
- Use the same axis to connect the pulley frame with the luffing pull rope.
- Inspect the steel wire ropes for proper alignment in their grooves.
15. Positioning the Boom
- Continue operating the hoist to relax the installation wire rope and raise the boom to a horizontal position.
- At this point, the boom pull cables should be under tension.
- Ensure the boom head is elevated approximately 300 mm higher than the boom tail for proper balance.
Notes and Precautions:
- 安全第一: Constantly monitor the steel wire ropes and hoisting equipment for any irregularities during operation.
- Alignment Checks: Ensure that all connecting components, such as pins and bolts, are properly secured after adjustments.
- Guidance Cables: Always use guiding cables for the boom head during tower erection to avoid structural collisions.
- Operational Efficiency: Coordinate the operation of the hoist with the movement of components to prevent delays and mishaps.
- Inspection: Perform a final inspection of all connections, ropes, and support structures to ensure readiness for crane operations.
