WesWorld

I am talking about the Tunnel between Honshu and Kyushu, not the outrageous big one that was planned between Japan and Chosen.

Whats the exact distance between Kyushu and Honshu?

Quoted

Originally posted by thesmilingassassin
has Japan built any tunnels prior to this one?

Don't you just grab a spade and dig?

Basically, but you usually need a very big shovel, or lots of small ones!

RA,

Kent News April 1st 1936, Dover Council employs two labourers with spades.
Foreman to the two workers "Right then lads off you go, here's all you'll need. (picks up two spades) Your digging a tunnel to France, just head south and you can't go wrong. Have it done by the end of the week."

Hmmm, might be a bit more to it, automated digging machines hadn't been developed in the 1930s had they. So most work was manual labour I guess.

There were various machines developed for the mining industry, so there is an opportunity to use them.

Quoted

Whats the exact distance between Kyushu and Honshu?

The shortest distance I can see with Google Earth is a mere 740 meters (this point is east of the city of Shimonoseki; near that point is a road bridge that is about 860 meters long). The distance between the two islands isn't that big.

With the historical Kanmon tunnel (built between 1936 and 1942), the tunnel to Honshu is 3,604 meters long and the tunnel to Kyushu has a length of 3,614 m. The Shin-Kanmon Tunnel for the Shinkansen (and which opened in 1958) is 18,713 m long.

While I'd love to do it, connecting Honshu with Hokkaido is another matter as that would require to cross +20km of water. The Seikan Tunnel that connects the two islands was built between 1971 and 1988 and is almost 54 km long.

A fair amount of the chunnel was prefab pipes that were lowered into place and fixed at the seams.