Manufacturing Problem Suspected as Cause of Shinkansen Crack
Osaka, Feb. 28 (Jiji Press)--Inappropriate manufacturing work is the suspected cause of a crack found in the undercarriage of a Shinkansen bullet train during its operation last December, West Japan Railway Co. said Wednesday.
Undercarriage maker Kawasaki Heavy Industries Ltd. shaved the surface of undercarriage frames at some spots during the manufacturing process. On these spots, the steel was thinner than required under the standards for the product.
In the December incident, a small crack is believed to have been caused to a frame during welding work and to have spread because the shaved frame lacked strength, said the railway company known as JR West.
A similar problem with steel frame thickness has also been confirmed on 100 units of Kawasaki Heavy undercarriages owned by JR West. The Shinkansen operator has started replacing them.
Kawasaki Heavy said its internal rules ban such frame shaving work.
[Copyright The Jiji Press, Ltd.]