> a diesel driven tunnel boring machine !? I'm not a tunnel building specialist, but a cursory search seems to indicate that tunnel boring machines commonly al

> a diesel driven tunnel boring machine !? I'm not a tunnel building specialist, but a cursory search seems to indicate that tunnel boring machines commonly already are electrically powered by simply using a very long high voltage cable stretching all the way from the tunnel entrance. Whether that cable then connects to the electricity grid, or to a bunch of temporary diesel generators stationed outside of the tunnel is a different matter, which in any case doesn't bear on the tunnel boring itself.