The recent woes that have gripped Japan's train networks are due to structural issues related to ageing equipment as well as a lack of young engineers, said Transport Minister Keiichi Ishii yesterday.
His comments came a week after a shinkansen bullet train was pulled out of service 3½ hours into its five-hour journey because of a crack in an undercarriage and an oil leak.
The steel frame of the undercarriage was just 3cm away from snapping into two, train operator West Japan Railway Company (JR West) said yesterday, admitting that this could have caused a major high-speed derailment.
This was the shinkansen's first serious safety breach in over 50 years.
In another incident last Saturday, three train services in Yokohama were suspended for as long as seven hours after an overhead wire snapped.
Mr Ishii said yesterday: "Besides structural complications in the ageing equipment, contributing to the spate of recent incidents is the increasing lack of young engineers who want to do such jobs."
Money allocated to the maintenance of the shinkansen in the next Budget, according to public broadcaster NHK.
He added that an expert panel will look into how to combat the structural problems and how to woo more young engineers.
Public broadcaster NHK, quoting sources, reported yesterday that 348 billion yen (S$4.2 billion) will be allocated to the maintenance of the shinkansen in the next Budget.
The works will centre on three major lines in Hokkaido, Kyushu and Hokuriku.
Meanwhile, the two train operators responsible for the recent service disruptions have apologised to the public. JR West executive vice-president Norihiko Yoshie said yesterday that the incident has "betrayed the absolute trust in the safety of the shinkansen".
JR West runs the shinkansen service Nozomi 34 that was pulled out of service on Dec 11 on its way from Hakata station in Fukuoka to the Tokyo station. The train would have covered the Osaka-Tokyo route, which is Japan's busiest.
Mr Yoshie said there was a 16cm crack in the base of the steel frame of the undercarriage, which also had 14cm-long damage on both sides. It was manufactured by Kawasaki Heavy Industries in 2007.
An inspection the night before the incident had not yielded any irregularities, he added.
The train was grounded only three hours after the first red flag - a burning smell - was sounded by the conductor.
Separately, the East Japan Railway Company (JR East) apologised for last Saturday's incident, after the overhead wire snapped at about 10.55am local time. Full service resumed only at 5.40pm - and passengers had to disembark from the trains and walk along the tracks.