Closed ATM View - PDBF-0002-2009
STATEMENT OF REQUIREMENT TO CONSTRUCT ROADS AT VLF TOWER TWELVE TO SUPPORT THE GUY WIRE
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1. Naval Communication Station Harold E Holt (NCSHEH) is sited on the northern most tip of the peninsula known as North West Cape. The Very Low Frequency (VLF) antennas are large spider webs of wire supported in a top hat arrangement. The centre tower ‘Tower Zero’, rises to a height of 387.9 metres. The other towers are spread out in two concentric rings around Tower Zero; the towers of the inner ring are 364 metres high while those of the outer ring are 304 metres high. Buried in the ground beneath the antenna array is 386 kilometres of bare copper ground mat.
The thirteen towers are supported by 357 guy wires. These guy wires have exceeded their life expectancy and a guy wire replacement program has therefore been implemented. In order for this to occur new roads are required for vehicle access. Road Construction Requirements
2. The scope of work required is to construct two (2) new roads to support the installation of VLF guy wires. The two (2) new roads shall be capable of carrying heavy duty vehicles and machinery weighing up to sixty tones.
3. The terrain consists of light scrub and sandy soil with some areas having a water table that is difficult for heavy vehicle and machinery to access. Therefore it is required that adequate roads are built to enable access to the work areas during typical weather conditions on the Northwest Cape.
4. The access roads shall be built of crushed coral. The heavy duty roads shall extend from the base of the tower twelve (12) to a minimum of one hundred and fifty (150) metres towards the outer guy piers and shall be a minimum of six (6) metres wide. From the one hundred and fifty (150) metre point the road shall remain at six (6) metres wide but can reduced to a standard coral road and shall extend a further minimum of one hundred and eighty (180) metres on tower legs one (1) and two (2).
5. The coral base shall be made available at no cost from the Commonwealths quarry. However, it will be at the contractors cost to excavate and transport the coral or any other road base to the sites.
6. When the contractor has completed their excavation of the Commonwealths quarry the contractor shall return the cliff face to reflect as it was prior to excavation by the contractor. Any stockpiled crushed coral taken to build roads shall also be replaced.
7. The contractor shall provide as part of their quotation drawings detailing all the roads positions and construction details.
8. Should the need arise to excavate a section of any guy pier mound approval is to be obtained from the Commonwealths representative prior to any excavation of any guy pier mound. It is the contractor’s responsibility to make good any damage caused during the excavation of any guy pier mound.
9. The road locations are:
a. Tower 12 leg 1 on the South-western side of the guy wires.
b. Tower 12 leg 2 on the South-eastern side of the guy wires.
10 Winch Pads
A set down area for winches being a minimum of 10 metres by 10 metres shall be developed and shall be a maximum of 1.2 metres below the height of the guy pier mound. All scrub bushes are to be cleared and the pad levelled with crushed coral where required.
11. The set down winch pad areas are to be located a minimum of 16 metres behind the outer guy connection point to enable the establishment of the fleet angles.
12. An access road to the set down winch pad area shall be developed spurring off from the new road. They shall be 6 metres wide with a maximum pitch of 30 degrees.
13. The set down winch pad areas are to be constructed at the location listed below.
a. Tower 12 leg 1 level 4 guy pier
b. Tower 12 leg 2 level 4 and 5 guy pier
14. Ground PlaneThe ground plane is a web of copper wires that extends from the helix house to a 300 metre boundary in all directions and is generally 300 millimetres below the surface. During the road building process it is unlikely the under ground plane screen will be encountered as earth works are beyond its boundary. However, should contact be made with the ground screen all due care must be taken to avoid damage to them. Should the ground plane become damaged it must be reported to the Commonwealth representative immediately and repaired at the contactors cost.
15 Government Furnished Material Subject to operational availability the Australian Government may be able to provide the following Government Furnished Materiel to the contractor on request. Conditions will apply:
a. ACCO 2350G Tipper 11 cubic metre capacity b. Champion Volvo Grader 720A with a 14 ft Blade
c. Bulldozer Dresser TD20G
d. Protec Boxer Road Compactor/Vibrator 11 Tonne
16. Quotations are to be supplied with four discrete lines as detailed below. The Commonwealth will treat all lines as options and reserves the right to accept or not accept any or all of the options submitted:
a. Construction of roads only utilising Government Furnished Equipment;
b Construction of roads only without utilising Government Furnished Equipment;
c. Construction of roads and construction of set down winch pad areas and access roads utilising Government Furnished Equipment;
d. Construction of the roads and construction of set down winch pad areas and access roads without utilising Government Furnished Equipment.
17. The successful supplier and their personnel will receive a safety induction brief prior to commencement of the project. Approximately one hour should be allowed for this briefing.
Manager Logistic Support
NAVCOMMSTA Harold E Holt
PO Box 125
Exmouth WA 6707