Vehicle detection software and metal frames have been put ahead as two attainable methods to protect railway bridges after last week’s spate of bridge strikes.
On Tuesday (31 August) alone, there have been 9 collisions. These adopted a separate bridge strike in Plymouth on Monday the place a bridge was hit by a Tesco lorry.
The incidents have underlined the problem posed to Network Rail by bridge strikes, with consultants suggesting varied options.
VPS Group Intelligent Transport Solutions building and infrastructure gross sales director Mike Fitzgerald highlighted the potential for overheight vehicle detection methods (OVDS) to watch visitors and supply warnings to autos susceptible to hitting a bridge.
The methods do that by utilizing a mixture of applied sciences, comprising digital ‘goalposts’ that mix sensors mounted on good towers, variable message indicators and alarm methods.
Fitzgerald emphasised the distinction the know-how could make.
“Most low bridges depend on signage near and above the bridge to warn drivers in regards to the danger. But drivers develop into virtually overfamiliar with these indicators in order that they’re usually ignored or missed,” he mentioned.
“An OVDS can provide a proactive resolution that actively displays visitors on routes the place overhead obstructions pose a strike danger, and supply strike warnings through an digital variable message signal to drivers of autos which might be too massive. The flashing on of a warning signal immediately at an oncoming lorry driver considerably reduces the prospect of a bridge strike.”
Fitzgerald added that for “notably weak websites” – for instance throughout building work – 24/7 monitoring could be supplied.
“We have additionally added a visitors mild system in sure cases which stops the vehicle reaching the bridge,” he mentioned. “This mixture of applied sciences efficiently warns overheight autos in time.”
Bridge skilled Bill Harvey additionally emphasised the necessity to enhance driver behaviour and supply enough warnings.
“In most circumstances, bettering clearances is out of the query,” he mentioned. “It is essentially a query of driver competence and the regulatory system is absolutely too tender.
“Any warning must be contained in the cab and it must be attainable nowadays to design one thing moderately low cost that would supply that warning, whether or not triggered by the bridge or by sensors on the vehicle.”
Harvey added that the majority masonry bridges are “remarkably resilient”.
He mentioned: “The one in Plymouth final week had the worst conceivable assault, with a vehicle arising from under and solely hanging the arch about 0.5m from the sting. That left so little weight above that the vehicle could carry the arch stones proper out.
“Even there, although, the harm was restricted to the sting and a wise engineer was capable of get the trains working once more on single monitor pretty rapidly.”
There are on common round 5 bridge strikes per day (near 2000 yearly), costing National Rail and Highways England round £20M per 12 months.
Last week Network Rail chair Sir Peter Hendy informed NCE that bridge strikes could result in a “catastrophic” accident on the nation’s railways.
“A lorry or bus hitting a railway bridge isn’t an accident,” he mentioned. “It’s a failure {of professional} operators and drivers to correctly plan their routes and know the peak of their autos, and might trigger fatalities and severe accidents for street customers, delays for each street and rail travellers, and could trigger a catastrophic railway accident.”
Like what you have learn? To receive New Civil Engineer’s daily and weekly newsletters click here.
