Avoiding bridge bashing, but not where it’s needed most

Over 25,000 bridges and a dedicated team of thirteen specialists in the bridge monitoring department. In a country, the UK, where the legacy of a Victorian railway network leads to around five or six strikes every day, having a bridge monitoring department is critical. Except for the fact that the number of British bridge strikes is correct, but the 25,000 bridges and the bridge monitoring team look after the network in Germany.

Avoiding bridge strikes should be a number one priority – and it is … in Germany. The national carrier may be on the receiving end of some criticism for falling standards, but even if the grains are running late, they are running over bridges that don’t have an oversized vehicle embarrassingly wedged underneath. Given the super-strict German road regulations, you could be forgiven for thinking that sort of thing just doesn’t happen – but those super strict Germans are not the sort to leave things to chance.

Pilot proactive programme

Often referred to as Bridge Bashing, and a contender for the national sport, Britain’s rail bridges take a battering. It’s usually an occurrence where a road passes under the railway, and it usually occurs five or six times a day. Across the North Sea, the concept of such carnage is unacceptable.

That’s why the bridge monitoring team is being supplemented by a comprehensive set of intelligent sensors that spot trouble, even if no one else has, or even an errant truck driver. The infrastructure subsidiary, DB InfraGO, where you’ll find those bridge monitors hard at work, monitoring, supported by the deployment of ASC Sensors. Now, the DB bridge experts are working on a pilot programme to make the whole proactive maintenance of critical rail-road bridges more efficient.

Difficult terrain no longer a challenge

The Germans say that being proactive about bridges is simpler, safer and more cost-effective in the long term. “As soon as a system operator or bridge inspector on-site notices an unusual change to a structure, or merely suspects one – we are notified,” reports engineer Peter Krempels, team leader of the measurement unit at DB InfraGO. That could be a movement caused by, for example, a trailing axle delivering a glancing blow to a ground-level spur, but it could as easily be a wagon wheel flat hammering across the tracks. Trains are not immune to giving bridges a bash too.

Peter Krempels’s team, or one locally, moves out to the affected structure with the required equipment, including conventional laser monitoring. The advantage, says ASC, which translates to German Sensor Engineering, is that difficult terrain, such as heavy vegetation, riverbeds or rocky mountain slopes, do not represent a monitoring challenge. That minimises operational interruptions – almost as much as not actually hitting the structure in the first instance.

Extreme reaction is demolition

Bridge measurement is always complex. “Everything we do has an impact on regular operations,” says Krempels. “In the case of rail-road bridges, the entire traffic of the crossing partner underneath usually has to be blocked for taking measurements from below.” Prevention is certainly better than cure when it comes to bridge management. “Following the examination, the operator receives a detailed report with technical recommendations for the continued safe operation of the bridge,” explains Krempels.

In an escalation that’s characteristically German, Krempels says that in extreme cases, this can lead to the demolition and reconstruction of an unstable structure. “With older bridges in particular, this can lead to expensive, long-term disruptions of operations. We want to minimise or prevent these through [applying this] new measurement concept using smart sensor technology, which we are currently testing in a pilot with ASC,” said Krempels. Ah, if only this was Britain.