SHIJIAZHUANG -- China's first set of intelligent inspection robots for freight trains has been put into operation at Huanghua Port in North China's Hebei province, showing a maximum capacity of inspecting 10 trains a day.

Wang Peng, deputy general manager of the Suning maintenance branch of the China Energy Railway Equipment Co Ltd, said that the robots have achieved a 100-percent common fault recognition rate of trains.

"The robot set — one inspecting the train's underside and two checking its sides — can inspect 54 carriages in 135 minutes," said Wang.

Since its first operation on May 11, the robotic inspection facility has been applied in the train maintenance depot of Huanghua.

Wang said the number of side-inspecting robots is expected to reach 10 in four months. At that time, the inspection task, which previously took 16 people over 50 minutes to complete, will be accomplished by the robot team in just 27 minutes.

Zhang Hao, a dispatcher in the workshop who oversees the robotic operation, said the intelligent robots photograph key areas while inspecting a 648-meter-long freight train with 54 carriages to collect fault information.

"The 15 cm-thick robot can finish a round trip of checking the train bottom in less than three minutes, capturing and documenting all suspected fault points before returning to its position for a charge and awaiting the next command," Zhang said.

Meanwhile, the two robots working on the sides are each equipped with two mechanical arms, featuring three sets of joints for vertical, horizontal, and rotational movements. It takes approximately 2.5 minutes for the pair to complete scanning a single train carriage.

The set of three robots takes 9,450 high-definition images during train inspection. The intelligent system can promptly provide analysis results through data comparison, clearly indicating the location and over 120 types of suspected faults.

"Robots indeed work with higher precision than humans," acknowledged Lyu Dawei, a veteran maintenance worker who uses specialized tools to measure wheel dimensions during train inspection.

He said it is particularly difficult to check the train's bearings at the bottom, with the narrow gap of less than 50 cm from the ground.

"During manual inspection for cracks or oil leakage, I had to crouch down to get a closer look. After inspecting 54 carriages, my legs feel numb," he said.

There are over 400 personnel engaged in technical inspection operations at the port, working on four shifts around the clock. All freight trains completing transportation at the port must go through inspections here.

Huanghua, as an important energy port in north China, is expected to see more than 50,000 freight train arrivals this year, mainly for coal transportation.