tower monopole
This specification document covers the projection principles for antenna mounted monopole towers to be used in GSM base station installation projects
When there is a conflict between various standard specifications or engineering design data, the most stringent standard specification shall be used as the basis after approval.
If revisions to the relevant standards are to be published, it is the contractor's responsibility to comply with the new standards and update production to those standards after approval has been obtained
The metric system will be used in the measurements.
3. Design principles
Unless otherwise requested by the customer, the tower will be designed according to the following heights.
Unless otherwise requested by the customer, the tower will be designed according to the following heights.
Single pole can be polygonal slip joint or flanged manufacture
All monopole antennas shall have accessories for antenna mounting, cable retention, ladders to the top of the structure as well as safety railings and hangers, grounding, lightning conductor systems and aircraft warning light systems
The Contractor shall design calculations, outline drawings, fabrication and assembly drawings, fabrication drawings and bill of materials prior to delivery.
It must be designed to make operation and maintenance easy to perform.
Structural and connecting elements will be dimensioned in accordance with the latest issue of Steel Transmission Tower Design Guidelines - ASCE issued by the American Society of Civil Engineers (ASCE).
A ladder will be built on the monopole for maintenance and operators to climb up the tower. Step spacing is a maximum of 30 cm. Safety railings and fall arrest devices shall be provided to attach to access ladders.
The design of the tower allows the installation of aircraft warning lights and copper arresters at the highest point, with a minimum length of 1.2 meters. Aircraft warning lights should be easily accessible.
The contractor is responsible for obtaining results from tower design, acceptance testing and quality assurance to demonstrate compliance with all conditions specified in these specifications.
The Contractor shall not use the designed monopole for any other purpose without the prior consent of the Client.
Each monopole should be designed to be in an optimal dodecagonal horizontal cross-section (since rocking and vibration should be kept to a minimum) and self-supporting, calculated from a tension-compression force system.
The life of the monopole should be at least 30 years.
5. Platform
Monopoles are available with or without top platform upon request and/or approval by Oman Mobile.
· The diameter of the top platform should be 3.0 m, and for monopole antennas without a top platform, a small shallow circular area should be provided for access to the antenna.
· Platforms should be fitted with non-slip floors, properly bolted to a suitable load bearing structure. Additionally, the platform floor must not allow tools and objects to fall.
· The top platform should be provided with footrests (h=15cm) and guard rails (made of two electric currents) with a height of not less than 110cm according to the current regulations.
· Work platforms should be accessed through hatches with opening and closing systems.
The hatch should be able to remain open if necessary.
All underground connections to the grounding system shall use the Cadweld method.
7. Steel elements
If the connecting elements are flanged, the number of attachments and the eccentricity of the attachments are kept as low as possible.
· Dimensioning of elements and connecting elements will be in accordance with the latest issue of Steel Transmission Tower Design Guidelines - ASCE published by the American Society of Civil Engineers - ASCE.
· The necessary holes for grounding must be designed.
· Monopolar connection and fixation: The monopolar base plate is fixed to the concrete base with anchor bolts and is properly grouted
· If required, the Contractor shall conduct his own on-site survey and shall be responsible for obtaining all dimensions and levels required to properly manufacture the steelworks.
· It is the contractor's responsibility to make each piece to the correct form and size.
· The Contractor shall notify the Engineer of the date of commencement of fabrication, shall keep the Engineer informed of the fabrication schedule, and shall allow the Engineer or his representative full access to his factory at all reasonable times to be at any stage of his fabrication. It must be clearly understood by the Contractor that any material and workmanship that does not conform to this specification, whether at his workplace, on site or at the installation location, shall be rejected and replaced to the full satisfaction of the Engineer.
8. Unipolar Load Assumption
For monopole designs, the following loads must be considered: Antenna Loading:
· N°6 mobile antennas, each weighing 15 Kg and measuring 2.58 x 0.3 x 0.15 m.
· N° 2 solid parabolic antenna with an average weight of 25 Kg and a diameter of 0,6 m.
N° 2 solid parabolic antenna with an average weight of 45 Kg and a diameter of 1,2 m.
other loads
Static loads on auxiliary equipment such as feeders, feeder joints, antenna structures and other installation equipment.
Wind speed:
· Design wind speed is 160 Km/h (45 m/s).
· The operating wind speed (at which maximum twist and tilt should be ±0.5 degrees) should be 120 Km/h (34 m/s).
10. Cable Ladders and Stands
vertical cable ladder
Vertical cable ladders can be external brackets on monopole poles close to the ladder or used to suspend cables in
Internal J-hook inside the monopole.
11.
Entry Ladders and Fall Protection Systems Monopoles shall be equipped with hot dip galvanized ladders and an approved safety system. The safety system should include a fall arrester (mouse) that can move freely on a steel cable or a fully continuous track and which locks itself in the event of a fall to protect the individual from falling. Ladders should be at least 400mm wide. The spacing of the step rungs (minimum thickness 16 mm) should be a maximum of 250 mm and they should be able to withstand a concentrated load of 1 kN (gM = 1.5). There should be no obstacles on the feet after climbing the ladder.
12. Fasteners
Bolts, Nuts and Washers
Attachment bolts, nuts and washers shall meet any of the following standards (or equivalent):
