| Protecting Motorists in Tasmania |
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| Written by BRIFEN Australia | |
Protecting Motorists in TasmaniaBrifen Wire Rope Safety Fences have been directly credited with saving lives and reducing the incidence of serious injury in numerous impacts... Download pdf version of this article (1.1MB) brifen_Tasmania.pdf (Right click and Save as). click to enlarge  Picture 1 In keeping with its focus of maximizing safety on the State’s roads through the use of wire rope barrier systems, Tasmania’s Department of Infrastructure, Energy and Resources (DIER) has recently installed Brifen TL4 Wire Rope Safety Fences (WRSF) in key locations throughout the State. Totalling some 12,640 metres in length, the new Brifen TL4 fences have been installed in both verge and median locations along some of the Apple Isle’s busiest roads. Following on from installations in Western Australia and Queensland, the new Tasmanian fences not only represent the latest chapter in Brifen TL4’s remarkable Australian success story, they also build on nearly 15 years of success for Brifen WRSF in Tasmania. Indeed, as far back as 1994, Brifen WRSF was being lauded by road authorities and emergency services for its outstanding “life-saving performance” in a major high speed impact along the Tasman Highway in Hobart. Paul Hansen, Managing Director with Brifen WRSF’s exclusive Australian distributor, LB International Pty Ltd, explained: “Brifen Wire Rope Safety Fences have had a long and successful history throughout Tasmania, and have been directly credited with saving lives and reducing the incidence of serious injury in numerous impacts.” “Now, with the advent of the Brifen TL4 ‘high containment’ WRSF, Tasmania is once again at the forefront of the drive to protect motorists and maximise road safety along its roads and highways for all road users,” he added. 
Regarded by many as one of the most significant steps forward in road safety barrier design, the Brifen TL4 fence has elevated wire rope safety fence protection to an entirely new level. Incorporating a unique patented 4-wire rope mix of 3 ‘woven’ ropes and 1 straight rope design plus a high-performance anchor system, the Brifen TL4 fence has been successfully tested and approved to both the USA-based NCHRP350 TL4 Standard for 8,000kg trucks and the European test EN1317 H1 for 10,000kg trucks.
Whilst one of the primary catalysts behind the development of the Brifen TL4 fence was the high percentage of large vehicles such as SUV’s (Sports Utility Vehicles) on US roads, the change in ‘vehicle mix’ that has occurred in Australia in recent years, also makes the Brifen TL4 WRSF ideal for Australian installations. Together with the ever-increasing numbers of large passenger vehicles (such as 4WD’s and SUV’s) and trucks on Australia’s roads, the challenge of delivering road safety infrastructure to meet the needs of our rapidly-changing ‘vehicle mix’ is further compounded by the increase in popularity of small cars that has resulted from the recent increases in the cost of petrol. What’s more, this ‘polarisation’ of vehicle sizes looks set to continue as trucks get bigger and small cars get smaller. Another major benefit of the TL4 design lies within its ability to minimise fence deflection during an impact, and more specifically, the fact that Brifen WRSF is able to provide outstanding protection along roads with narrow median reserves, limited shoulder areas and steep verges. Paul Hansen explained: “As well as having to provide a barrier system that can cater for a ‘polarised’ traffic mix incorporating lighter cars and heavier trucks, engineers are also trying to build road corridors that are flexible and economical ? particularly in terms of making the most of the available transportcorridor.” “The Brifen TL4 WRSF not only provides outstanding protection for a full range of vehicle sizes and types, in both verge and median situations, it also minimises fence deflection during an impact. We believe that this ‘controlled’ and highly predictable performance makes the Brifen TL4 the ideal safety barrier solution ? both in terms of safety and maximising the use of the available transport corridor,” Paul Hansen said. History of Success in Tasmania The 25 new Brifen TL4 fence sections are the latest in a long line of Tasmanian Brifen WRSF installations. click to enlarge  Picture 2 The new Tasmanian Brifen TL4 fences comprise both centre median and verge installations along the Bass Highway and Boyer Secondary Road in the State’s north, as well as along the Southern Outlet, the Murchison Highway, Tasman Highway, Lyell Highway and East Derwent Highway in the south. While Brifen WRSF has always had an outstanding reputation for ‘punching well above its weight’ in terms of its performance during vehicular impacts, Brifen TL4’s impact performance and high-containment capabilities are setting a new standard in Wire Rope Safety Fence performance. “In the last 16 years there have been numerous impacts where the European Brifen 4-wire fence has been successful in preventing a truck or large articulated heavy vehicle from crossing the median reserve into on-coming traffic. These European fences had only been designed and physically tested to withstand an impact by a vehicle with a weight of up 1,500kg travelling at 110kph,” Paul Hansen said. “While these fences all delivered excellent results - in terms of preventing fatalities, minimising injury to the drivers and passengers involved, and minimizing the seriousness of the impacts in general ? the US authorities required taller fences to decrease the possibility of both over-ride and roll-over” he said. “Together with the issues associated with fence deflections during a heavy vehicle impact, there was also the matter of developing an anchor system that would meet the strict ‘impact performance’ requirements specified in the NCHRP350 TL3/TL4 Standards. This was not only critical in terms of gaining TL3 and TL4 certification for the US market, it was also considered to be an important prerequisite in Brifen’s success in ‘narrow median’ fence installations, including the increasingly-popular ‘Separated 2+1’ design now being used in Europe and New Zealand,” he added. The Brifen TL4 WRSF has undergone some of the most stringent testing ever undertaken on a barrier system. Indeed, the Brifen TL4 ‘high-containment’ fence is the result of over seven years of extensive R&D and testing in both the UK and USA. The task of designing a fence capable of managing and maintaining truck deflections within the NCHRP350 TL4 requirements was a major challenge ? one which required a new line of thinking by the Brifen engineers. 
The combination of high centre-of-gravity, greater mass and larger wheels meant that in order to accommodate these changes of geometry and momentum, the TL4 Brifen fences would have to be higher and the post shape would need to be revised. Furthermore, these design changes would have to be made in a fashion that did not reduce the fence’s performance in relation to smaller vehicles. The Brifen TL4 fence and anchor design meets the ‘high containment’ requirements without sacrificing the level of protection that it affords to smaller vehicles. In fact, the combination of a purpose-designed anchor system, the taller collapsible post and new rope spread and weaving design ensures that the Brifen TL4 WRSF delivers improved safety and impact-performance across the full range of vehicles - from small cars, 4-wheel drives and SUV’s, right through to trucks and other heavy vehicles. Furthermore, the Brifen TL4 WRSF’s high predictable performance during an impact makes it ideal for installation in a wide range of locations, including: narrow medians; ‘V-Shaped’ medians; along sloped batters (with profiles of up to 4 Horizontal:1 Vertical); and in verge situations. Covering the SpreadTogether with the overall height of the fence, the modified post and anchor design and the ‘woven’ ropes method, one of the most significant design differences between the older style Brifen TL3 and new Brifen TL4 fence designs relates to the ‘spread’ of the ropes.Whilst the older style TL3 fences feature a concentration of wire ropes within a 100mm range ? thereby maximising the available rope and post capacity within the fence, the new TL4 design focuses on maximising the ‘catch’ area, thereby enabling it to contain larger vehicles, unstable vehicles in cross ‘V-Median’ situations, and of course small/compact vehicles. To achieve this, the Brifen TL4 WRSF incorporates wire rope heights of 980mm, 780mm, 630mm and 480mm and features three woven ropes, with only the fourth (top) rope resting in a slot in the top of the fence post. Designed to provide protection for both large and small vehicles, Brifen TL4 WRSF also incorporates the ‘in-line’ TL3 / TL4 anchor and end terminal, together with the specially designed ‘A’ and ‘B’ saw-cut ‘transition’ posts at each end of the fence. Download pdf version of this article (1.1MB) brifen_Tasmania.pdf (Right click and Save as). This article has been published in October 2007 issue of Highway Engineering in Australia. |
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| Last Updated ( Sunday, 06 April 2008 ) |
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