Purpose
The purpose of this technical instruction is to detail those actions necessary to ensure that G&S steel pole sections are joined and assembled in compliance with the applicable design standards.
Scope
This procedure applies to the joining and assembly of G&S steel poles.
Due to the overall length of the majority of our Mid Hinged and Fixed Tapered Octagonal Poles, when delivered to site, some of our poles will require some degree of assembly. Please note that that this procedure is intended as a guide only, which is to be followed in conjunction with any currently existing site safe working / Worksafe regulations at the time of installation of the pole.
Procedure Detail
- Lay the pole sections are to be laid out onto wooden bearers so that the pole’s underside is level horizontally. Ensure that these wooden bearers are such a height so that the pole’s baseplate and headframe clear the ground. Also ensure that the wooden bearers are spaced at even intervals so as to support each pole section individually. Ensure that the bearers are not positioned under the slip joints prior to joining so as not to impede the horizontal movement required to join the pole sections together. Make sure that the pole base is wedged to prevent rotation. (See Figure 1) right. Ensure that the pole sections are correctly aligned in relation to the doors, outreach arms and cable exit / access doors.
- The slip joints are the joints where the pole sections meet with the female end of higher section sliding over the male end of the lower section. The minimum slip overlap required on these joints is greater than or equal to 1.5 x the outside diameter (across the flats) of the male end of the slip joint of the lower section. (See Figure 6) below. This 1.5 measurement is a minimum only and the sections should be joined together as tightly as possible to allow for manufacturers tolerances. Mark this measurement on the male end of the lower section prior to joining the sections. If the final slip length is to be recorded, mark an additional spot which is equal to 2 x the outside diameter of the male end of the slip joint of the lower section as a measuring reference. If in the event that the minimum slip is not achieved, the assembly procedure should cease and G&S should be contacted immediately. Erecting a pole which has been joined with less than the minimum required slip could result in serious injury to person(s) or damage to property.
- Ensure the seam welds of the top and bottom sections are aligned. Then slide the female end of the section over the male end of the lower section as far as can be using hand force only. Once this is achieved, two Tirfors, as shown in the diagram to the right, are to be used to assemble the two sections. This is achieved by positioning one Tirfor on either side of the pole. Each Tirfor must be operated in coordination to ensure that the telescoping of the sections proceed evenly about the pole axis. (See Figure 2) right.
- Visually check for air gaps at the slip joint.Under strict supervision, sections are to be joined together by applying a compressive force along the centre axis of the two sections. It is most important that the resultant compressive force is applied coincident with the pole axis, as any eccentric loading may result in a misaligned joint and / or may damage the pole sections due to additional bending stresses. In order to facilitate this, the sections are to be joined one at a time starting from the base sections working towards the top of the pole. The female section being joined should be lifted to the correct level using a suitable sling at the section’s centre of gravity, using a crane or other suitable lifting equipment and aligned with the male section of the joint. (See Figure 1) above. The telescoping of the two sections should continue until no further movement can be achieved. The Tirfor assembly process may be aided by striking the “striking plate” as shown in the (Figure 2) above, with a sledge hammer. The external surface of the slip joints as shown in (Figure 3) below, can also be hammered using a wooden block and hammer to assist in achieving an adequate joint. The wooden block is used to prevent any damage to the galvanizing coating.
- The above process should be repeated separately for each additional section of the pole, being careful to follow the same procedures as above, keeping the pole and newly joined sections, horizontally level at all times.
- On all our Mid Hinged Poles, for sections above the hinge / pivot point only, once the upper section has been properly pressed onto the lower section as per the instructions above. Drill a 17mm hole directly through the centre of the Taper Lock Slip Joint on any one of the octagonal flat faces. Then place 16mm grade 4.6 bolt through the holes and secure with a nut washer and spring washer as supplied with the pole(s). (See Figure 5 & 5A) below. When fastening the nut, the nut is to be snug tight as per Australian Standard AS4100 Clause 15.2.5.2. ie. A few impacts of an impact wrench or the full effort of a person using a standard Podger Spanner. Under no circumstances does this bolt fixing act as a replacement for the correct pressing of the sections together as per the above instructions. This is an added fastening method to the taper lock system. All of the points in this procedure are to be strictly adhered to prior to installing this fixing bolt. If you do not achieve points 1 to 6 above, please cease the procedure and contact G&S Industries before proceeding any further.
- All Mid Hinged Poles are provided with a chain and shackle arrangement welded to the top of the pole adjacent to the pole spigot. This is used as an additional attachment point for light fittings and other equipment in the event that their securing devices on the headframe fail during lowering of the pole. For equipment that cannot be secured by this chain and shackle arrangement, such as spigot mounted light fittings, the procedure below is to be followed. Once the equipment is mounted to the pole spigot, a hole is to be drilled through both the equipment mounting spigot and pole spigot. Care is to be taken not to drill through the cables running through the pole. Then a bolt is to be threaded through both the equipment mounting spigot and pole spigot and securely fastened. This will ensure that the equipment remains fastened securely to the pole upon lowering the pole. For our Mid Hinged Poles, all headframes including client supplied equipment are to be mounted and secured to the pole PRIOR to pole erection. Under no circumstances are the Mid Hinged Pole(s) to be erected without their headframes / equipment attached with the intention of operating / lowering the pole at a later stage to mount the headframes / equipment. This is dangerous and could result in serious injury to person(s) or damage to property. Our Mid Hinged Poles are supplied balanced to carry their required head weight and are to be operated only when their specified equipment and counterweight are installed. (Please see our Mid Hinged Pole Raising and Lowering Procedure) which is located on our website at https://www.gsindustries.com.au/product-procedures/.
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