Sj-5. Inside the western casemate

This installation is considered as largest construction of Mannerheim Line. It length is about 80 m, thickness of the roof is 80 sm, thickness of walls of fighting casemates is near to 130 sm. The reinforced concrete with resistance to compression up to 600 kg/sq.sm was used. The roof maintained to hold direct hits of 280-mm shells. There were machine-guns Maxim (1910) on the special casemate mounting. The embrasures can be covered by armored stove-doors. The pillbox has three armoured observation cupolas.