For 10 points, name this strategic arrangement, replaced by the "VT" during the Continuation War, which attempted to provide a series of fortifications against Soviet invasion for Finland.
Many of its details were planned by the officers Rappe and von Heijne, and revised by Colonel von Brandenstein. It was not ready in time for the "Extra Rehearsal," and a total lack of security procedures on it allowed enemy forces to enter as tourists and make sketches of this structure. It replaced earlier proposals by Fabritius and Enckell, and much of it was built as a training exercise for the Engineer Batallion, starting in the region of Inkilä. Reinforced concrete and protection plates were dropped from this due to a rise in the price of steel, and parts of it were simply strategically placed mounds of soil known as "slope cuts." Its specifications included bunkers which could withstand three direct hits from six-inch howitzers and a 120-degree range of machine gun fire, and it incorporated the natural barriers of the Vuoksi and Suvanto lakes. For 10 points, name this strategic arrangement, replaced by the "VT" during the Continuation War, which attempted to provide a series of fortifications against Soviet invasion for Finland.
Many of its details were planned by the officers Rappe and von Heijne, and revised by Colonel von Brandenstein.
the {Mannerheim Line}