This post originally appeared on http://www.taipeitimes.com/News/taiwan/archives/2016/04/19/2003644318.
[Editor’s Note: The bridges need to be inspected once every two years. The Institute of Transportation sees drones as being a faster, safer and more efficient solution.]
With more than 2,000km of bridge infrastructure nationwide, workers previously had to climb bridges to carry out inspections at high cost and personal risk.
The Institute of Transportation said that it has developed a system to inspect bridges using uncrewed aerial vehicles (UAVs).
Institute statistics showed the nation has more than 30,000 bridges on freeways, provincial highways and county roads, with a total bridge infrastructure distance of more than 2,070km.
On average, there is one bridge for every square kilometer of roadway — a higher density than Japan or the US, the institute said.
The bridges need to be inspected at least once every two years, the institute said, adding that the UAV system was developed to meet demand in a faster, safer and more efficient manner.
The institute said bridge maintenance workers check different parts of a bridge by climbing the infrastructure, which is time-consuming and potentially dangerous. Special machinery or small ships are used to inspect bridges with high piers and those spanning waterways.
The costs and time needed to inspect bridges with higher traffic volume or in remote areas is high because maintenance workers need to use large machinery, the institute added.
Apart from UAVs, the institute said that it has integrated GPS, sports cameras, laptops and other equipment. Maintenance workers can program UAVs to a flight route using an application developed by the institute to capture images of a bridge, allowing inspectors to assess the condition of the infrastructure.
The UAVs cost NT$150,000, which is less than the cost of a bridge inspection vehicle, the institute said.
Traffic lanes do not need to be closed when inspecting the bridges using UAVs, it added.
The institute said it used a UAV to inspect Taipei’s Yuangshan Bridge, which took two minutes.
The institute estimated that inspections take at least 30 minutes if maintenance personnel physically inspect a bridge.
At least three to four people have to be dispatched to complete maintenance work, the institute said.
Despite the development of the system, the institute said it is yet to replace the current system, adding that it is enhancing the system to increase its value and lower flight risks.