WIRE ROPE SAFETY FENCE
STANDARDS
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Introduction | |
Definition |
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Basic Criteria | |
Design Requirements |
INTRODUCTION
This standard is based on the UK Department of Transport Standard TD 32/93 and
subsequent recommendations and approvals by the Highways Agency (UK) and has been prepared to conform to Australian practice. It specifies the requirements for wire rope safety fences for use on verges and central reserves (medians) on new and existing roads, including motorways.
The specification requirements and the LB Series of Drawings for the BRIFEN Wire Rope Safety Fence (WRSF) are shown in the document entitled "Specification and Drawings for the Brifen Wire Rope Safety Fence".
The wire rope safety fence described in this Standard complies with the performance testing criteria for the level of vehicle containment defined in NHRCP350 Level 3 and the CEN, MIRA and VTI tests. The Standard also sets out the essential layout requirements and limitations on the use of wire rope safety fence.
Any request for a departure from this Standard shall be referred to Brifen Limited (UK). This standard updates the current standard and includes modifications in line with current Australian practice.
This standard should now be used for all schemes specifying Brifen WRSF.
DEFINITION
General Description of Fence
2.1 The fence consists of three or four tensioned galvanised steel wire ropes having a top rope height of 585mm and a lower rope height of 490mm supported by galvanised steel posts at nominally 2.5m or 3.2m centres. The two(or one) upper ropes are located in a slot in the top of the posts and the two lower ropes are interwoven along the fence between each pair of posts. The ropes are joined and tensioned by means of rigging screws provided at intervals not exceeding 154m. The ends of the ropes are attached to anchors embedded in the ground or to surface mounted anchors. Where the length of the fence is greater than 1385m intermediate anchors are used. To provide continuity two ropes (ie one upper and one lower) of the four ropes are anchored at each intermediate anchor. The connection between each rope and its anchor is designed to uncouple when a vehicle impact occurs in the vicinity of the anchor. The movement of the released rope is restrained by a safety check rope.
2.2 "Set-back" is the unobstructed horizontal dimension between the traffic face of the wire rope safety fence and the edge of the:
(f) paved surface adjacent to the verge. (Note: paved surface comprises carriageway, hardshoulder or hardstrip).
(g) Carriageway adjacent to the central reserve. (See figure 1)
2.3 "Clearance" is the unobstructed horizontal dimension between the rear of the wire rope safety fence and:
(a) the traffic face of an obstruction (eg. Overbridge supports, sign posts, rock face etc)
(b) the opposite carriageway on a central reserve where there are no obstructions and there is only one safety fence between the carriageways.
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Basic Criteria | |
Design Requirements |
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