Most people won’t pay much attention to a bridge they’ve driven over as they cruise down the highway.
But a pair of combat engineers from the 5th Engineer Regiment have become familiar with dozens of bridge undersides in south-east NSW following bushfires that swept the region.
One is Lance Corporal Rick Williams, a civil engineer and surveyor when not serving with the Army Reserve.
“We’re looking to see how deep fire has burned into the hardwood, to see if there’s any structural issues,” he said.
“It’s amazing to see how fire gets into a structure; a lot of ember attacks got into termite-eaten wood and just burnt through it.
“With steel, we’re looking to see if the fire has been hot enough to twist or warp the steel members.”
For the most part, bridges in the region held up well according to Corporal Ross Lorenz, a civil engineer whose resume includes bridge-building projects on the Pacific Highway and Hunter Expressway.
“One extreme example was chard remains at the bottom of a gully, but overall the bridges are looking good,” he said.
“A lot of them look like they are 20 to 30-plus years old. They handled the fires pretty well with some minor or moderate maintenance required.”
The pair reports their findings to local councils who prioritise repairs or further inspections.
Despite a background in concrete bridges, Corporal Lorenz said there was some crossover with the wooden structures.
“There are some idiosyncrasies in wooded bridges,” he said
“But our work is about knowing what aspects of the bridge accomplish and how much load is going through them.
“Then we assess how much damage they can sustain while still being functional.”
Despite most of the region’s bridges made of wood and steel, the sappers did get to inspect one concrete structure; out of the fire zone but slightly stressed because a heavier route was closed.
“We were inspecting for overload damage. It held up quite well but it does have some maintenance issues,” Corporal Lorenz said.
“I was having a lot of fun knowing exactly how things were supposed to be.”
There may be scope for 5th Engineer Regiment sappers to make temporary fixes for some bridges but major repairs would be done by local council’s specialist contractors.
Despite the average motorist not paying much attention to a bridge they drive over, Corporal Lorenz said it took a big effort to maintain and a bigger effort to construct.
“It was 35 seconds for someone to drive over all the bridges that were part of a civil project I worked on, yet it took us 12 months to build them all.”