Engineering professor says flaws occur during manufacturing
A civil engineering expert said yesterday that cracks found in the welding of KCRC East Rail trains were not a safety issue, a view supported by the experience of London Underground, which uses similar rolling stock.
Hung Wing-tat, an associate professor at the Department of Civil Engineering at Hong Kong Polytechnic University, said: 'The cracks found in the trains are not a problem unless they are becoming wider and wider. However, after all these days since they were first discovered, they have yet to detect any widening of these cracks, which suggests they have always been there.'
Dr Hung added that as long as the cracks remained on the surface and did not develop into the structure, they did not pose any danger.
He said KCRC safety standards were not called into question. It had not been wrong to not immediately notify the government about the cracks. 'The trains are under guarantee for 30 years, so had the KCRC done anything without the supplier's instruction, the guarantee would have been made void. They did the right thing to inform the London manufacturer and attach nylon belts to the major components until the manufacturer could inspect the parts.'
He added that many materials developed hairline cracks - defined by Dr Hung as a very short crack that is about one-tenth of a millimetre wide - when they were cooled too quickly following production.
