Entrenchments of covering defence line

Trenches and entrenchments and other field straightenings are the basic installations of Mannerheim Line, but not the concrete pillboxes-monsters whom was one for 1,5-2 kms of front. The pillbox itself is helpless, you can ride on heavy soviet tank KV-1 close to its casemates and disperse them in fine dust easy. But, when the pillbox is surrounded by trenches with desperate infantry armed by sub-machine-guns "Suomi" and "cocktails [for] Molotov", the war began is very different...