crawlers

This is yet another subject I could have sworn we had more on. Oh well. From an old thread on Off-world mining: In light of news stories like the one below, not to mention longstanding concerns over supplies of Rare earths and other vital materials already being increasingly squeezed by less...

In the Eighties there was an infamous spate of submarine incidents in Swedish waters, apparently involving mini submarines penetrating close to shore (and even inside harbour areas). From the reports at least some of these would appear to have been fitted with Caterpillar/Tank style Tracks...