Blaine Harden, reporting for the Washington Post back in 2010:
The nose of a bullet train is not particularly well-suited to the expensive and highly specialized mass-production machinery that molds and cuts metal to make hundreds of thousands of cars, trucks and toasters. The number of high-speed locomotives built for each bullet-train series in Japan is quite limited, from 40 to 120.
[…]
“The most cost-efficient way of transferring computer-assisted 3-D design to metal is with a hammer,” said Tatsuto Yamashita, who, unlike his father, never spent much time swinging a hammer.