How To Mount Roof Antenna Mast?

March 11,2022

This paper introduces the installation of roof antenna mast.

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Preparations Before Construction

Measurement: The surveyor shall release the mast to position the auxiliary line.
Fastening of cable and wind line: Before lifting the mast, fix the manual chain and use the manual chain conveyor rope.
Re-inspection of components: After the entry of mast segments, re-check the geometric dimensions of components. Check the size and cleaning condition of butt welding joint L on site, without rust, oil, etc. Spot check on the full penetration weld of the component.

After checking the mast and confirming that it meets the design and specification requirements, draw the installation center line at both ends of the mast.
Four point lifting is carried out by using the side connecting lug at the upper end of the mast

The first section of mast installation, from the reserved hole slowly down to the emplacement layer, adjust the mast position, so that the mast base aligned with the center line. Wedge iron is placed on the beam before placement to adjust the mast verticality.
Put the second mast into the hole in the same way, connect it with the first mast and fix it with bolts, and set up four cable wind ropes. The cable wind ropes can be pulled and connected to the concrete column and inclined beam. After being in place, correct the verticality, tighten the connecting bolts and spot welding.
The connection method for other sections is the same as before.

When the mast corrects perpendicularity in the floor, the positioning auxiliary line of each floor is used to measure the distance between the auxiliary line and the center line of the mast to accurately adjust the perpendicularity of the mast.
After the mast is lifted to the emplacement layer, two theodolites are used to observe the perpendicularity of the mast from the adjacent direction of 90 degrees at the same time, and the second cable wind line is used for adjustment.
In order to ensure the stability of each mast, in addition to each section in place after 4 cables wind rope, up in the mouth of the mast along the outer wall of the support frame, and in the mouth of the scope of the section and section of the connection is laid springboard, support frame, the foot pipe and the outer wall of the mast gap between the smaller the better, the gap can be wedge-iron plug. The perpendicularity of the mast can be corrected by tightening or loosening the wedge iron.

After all sections are in place and the verticality is remeasured, the welding joints are cleaned and welded upward from the joints of the first and second sections.
The welding adopts ordinary manual arc welding, electrode is E4303, diameter φ 5mm, φ 4mm.
Each joint shall be symmetrically welded by two welders, and the same joint shall be welded once until the welding is completed.
All welders who participate in welding have corresponding qualifications
After welding, ultrasonic inspection on the weld, qualified rear can be promoted.

Prepare four manual reverse chains, set four cable wind ropes, prepare guide brackets around reserved holes in the emplacement layer,
Make the lifting support and guiding device in the basement,
Install lifting jack and lifting rod, check the connection of each part, adjust the synchronization of the jack.

The lifting speed of the thousand catties is about L00mm/min. While lifting the mast, release the cable and wind rope, and adjust the spacing of the guide wheels to make the mast move smoothly and vertically upward.
Mast can not be lifted in place at one time, the middle must stop, every lift L000mm, adjust a jack synchronization, adjustment of three jacks: suspension, a thousand jacks adjustment.
When the mast is raised to the emplacement layer, the suspension is fixed and the guide connections are checked.
Weld four supports about l000mm above the mast base, connect them with the temporary fixed steel beam, and place the mast on the temporary beam.
Secure the second cable wind line.
Unload lifting jack and winding machine.
Calibration of overall mast verticality.
Seal the top hole.
When the concrete reaches the strength of R28, remove the temporary fixed beam and cable wind rope.
Finally, along the climbing ladder, cut off the cable wind rope pulling lug plate and temporary beam rigid support, and smooth it.

WEISILI is a specialized antenna mast manufacturer, welcome to contact us.