Cushion the blow

Fitting a consistently safe crash cushion into a tight road space, such as a tunnel, is an engineering challenge. What is required is a solution that is compact and easy to install, but still achieves the highest levels of safety

Words | Snoline, Italy

Approximately 30% of fatal accidents on the road involve single-vehicle, non-pedestrian accidents in which a car runs off the road and impacts with a rigid roadside object. Now, Snoline by Lindsay has a new range of redirective crash cushions, the Tau Tube family, available in various configurations, covering applications from narrow to wide, and entirely made in Italy.

This new crash cushion family is available from a 50km/h (31mph) up to a 110km/h (68mph) configuration. The complete range received the CE marking in 2014. The system is fitted with a rear support that transfers longitudinal forces to the ground and so it is independent from either hazards or guardrails, and therefore behaves in an ideal way – as a free-standing system.

The CE mark is a universally accepted symbol of conformity to European Directives and can only be applied to a crash cushion once the manufacturer has undergone a rigorous process of checks and inspections from an approved body. As part of the CE certification process, the manufacturer must produce a comprehensive technical file for the product, which must include the testing details and reports. The Tau Tube system easily passed all the crash tests required of it at an official testing facility.

Easy installation

The Tau Tube family is very easy to install because Snoline by Lindsay is able to supply the barriers pre-assembled. As a result, the installation process is limited to anchoring of the crash cushion to the ground. This improves installer safety and reduces installation time; in fact, in normal conditions, a system can be laid in just one hour, by three people. Moreover, the Tau Tube family doesn’t need any maintenance,

since it is constructed using galvanized steel and an aluminum alloy for the tubes that is highly corrosion-resistant and environmentally friendly.

Thanks to their innovative design and materials, Tau Tube systems are much lighter than most similar systems, saving further costs on shipment.

An additional benefit is the post-impact reusability of the system: up to 70% of it can be reused. This results in considerable savings in inventory and maintenance costs. This is particularly important for road authorities that are looking to minimize maintenance costs.

Standard transitions are provided for almost all EN 1317 barriers and guardrails, but in special cases Snoline can investigate new solutions in its dedicated technical department, offering customized applications.

How it works

The system works using aluminum tubes to absorb the energy from an impact and dissipate the accident’s force. The barrier’s galvanized steel structure and steel guides are responsible for the transmission of crash forces into the lateral guiding, and thereby into the ground.

The Tau Tube is much shorter than most comparable solutions: the 50km/h crash cushion is 1.9m (6.2ft) long, while the 110km/h parallel crash cushion is 5.9m (19.4ft). As a result of its compact size, Tau Tube can be used in locations where it has been impossible to install normal crash cushions, such as tunnels, underpasses or other confined spaces. Also, the material used to manufacture the Tau Tube system is completely inert, so suits locations where toxic gases are particularly undesirable due to fire regulations, such as in tunnels.

Another innovative feature is that Tau Tube can be used both as permanent crash cushion, on asphalt and concrete, and as temporary crash cushion with a steel plate. In the temporary crash cushion application, pins can be placed on the ground and removed easily, and this does not affect the performance. This application represents an excellent solution for cases that need a temporary system that can be quickly installed, uninstalled, moved and reinstalled. n

Left: The Tau Tube

crash barrier from Snoline by Lindsay is an excellent safety upgrade for high-speed roads

Below: It is

also compact enough to fit into confined spaces