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:
Safety First: 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.
