HIGH MAST LIGHT POLES
DESCRIPTION
The high mast with raising and
lowering gear system is a safe system due to reliable service hoist which
raises and lowers the fixtures ring for maintenance purposes.
Raising & lowering
gear system consists of the following major parts as shown in our catalogue:
1- Head Frame.
2- Luminaries Ring.
3- Single or Double Drum Winch.
4- Portable power tool with
Portable Electrical Motor.
The raising & lowering
system is a special electromechanical arrangement which is procured by us .
High Mast Shape:
The high masts (15-40m) are usually made out of
continuously tapered steel shafts with polygonal shape of sixteen sides, with
dimensions and thicknesses complying to the structural design analysis and
suitable to suit the raising & lowering mechanism.
Shafts are made from steel
sheets folded to required shape and welded longitudinally by automatic arc
welding machine
Shafts are made out of multiple
segments depending on the height of the mast, each segment will have length of
not more than 12m, with minimum overlap of 1.5
times of the female segment across flat.
Circular or Square base plate
with holes suitable for the anchor bolts is welded to the bottom of the shaft
by double fillet weld according to international standard, base plate will be
open in the centre to allow cables in.
Base plate dimensions given in
our drawings are complying with structural design analysis and the foundation
requirements.
Anchor bolts to fix the base
plate to the concrete foundation are supplied with the required nuts and
washers and having the size and dimensions as per the structural analysis.
Shaft is provided with a door
opening at a convenient height with dimensions and size complying with the
requirements of the raising & lowering mechanism. Door opening is
reinforced to maintain shaft strength; In addition, a rubber gasket is fixed
around the door frame for weatherproofing.
Door cover is fixed to the
shaft by using steel Hinges.
An Earthing lug is welded
inside the shaft at the door opening level and equipped with the required
bolts, nuts and washers for earthing.
Straightness, tolerances and
plumbness of the pole are maintained within permissible limits according to
international standards.
DESIGN
Design wind speed is 160 Km/hr
or as per the customer request multiplied by gust factor of 1.3 (Gust speed is
208 Km/ hr or as specified in the project specifications)
Design of high masts is
performed utilizing Computer software to analyse the high mast shaft, base
plate and anchor bolts.
MATERIAL
Material used to fabricate the
high mast components will be in accordance of international standards and as
per the project specifications.
FINISHING
No welding, cutting or drilling
is done after galvanising.
The anchor bolts including nuts
and washers are hot dip galvanised according to ASTM A 153.
