"The reinforcement of the eastern border barriers along the sector and zone border was continued with the construction of additional walls, the installation of new barricades of wire, T-girders and wood and the erection of sometimes mobile screens. In some cases, alarm systems, and in one case signal flare launchers, were installed in the barricades," the West Berlin police write in their monthly report about developments at the sector and zone border in February.
Progress report by the West Berlin police for the month of February 1962 (in German)
