Okayama subsea collapse at Mizushima Refinery16 February 2012
An under-construction subsea tunnel in Okayama, Japan collapsed last week with six workers inside. One managed to escape but two bodies had been discovered as T&TI went to press.
Initial searches were limited to 90 minutes by severe site conditions and it was not clear if water was continuing to enter the tunnel. Divers struggled with visibility in the shaft. A police spokesman said, “They were swimming into debris and into each other. There were also fears that the debris could cut the pipes on their dive gear.”
The Japan Times reported that contractor Kajima said that the machine excavating the tunnel had been halted 50 minutes prior to the disaster. It added that the corporation could not confirm that an electrical problem had been reported.
A Kajima spokesman told T&TI, “Kajima’s focus is now on assisting the search and rescue operations for our missing workers on the project. We are working with the police and fire services among others and are fully cooperating with the investigation.
“We, Kajima, have started to investigate the cause of the accident ourselves but have not yet been able to clearly identify it. We have not decided if we will disclose the results to the public.”
Construction began on the 140m-long tunnel in 2010. It was designed to be U-shaped, 11m in diameter and 30m underground. JX Nippon Oil and Energy Corporation operate Mizushima Refinery, which opened in 1961.
The surviving worker told police that he thought he heard a voice should ‘danger, leave’ before water came gushing in.