"lavish" Regelbauten of the Aachen-Saar Programme, the final construction phase was dominated by massive financial constraints. For example, observation cupolas and flank firing positions were no longer provided and the rooms were smaller. Expansion of construction projects from 1941 to 1944 In 1940 work was ordered on a number of construction projects in Western Europe. Amongst the first were the Dover Strait guns begun in July 1940 and included Todt Battery. Building began in February 1941 on the Saint-Nazaire submarine base Following the first effective commando raid in March 1941 Operation Claymore and with the planning of Operation Barbarossa, Hitler decided in June 1941 to strengthen the west against possible attacks. The Channel Islands were chosen to become major fortifications, followed in 1942 with the order to build the Atlantic Wall. A mass of equipment was needed, cement, sand, gravel and steel to construct the concrete fortifications, weapons and armour plate for defence and hundreds of thousands of workers. To offset shortages, equipment from French and other occupied armies were incorporated in the defences, casemates designed for non-German artillery, anti tank and machine guns and the use of turrets from obsolete tanks in tobrukstand pill boxes (tobruk pits). The labour came from an expansion of the Organisation Todt, who contracted with building construction companies from Germany and occupied countries to undertake the work. The OT provided them with equipment, supervisors and labour. Labour comprised skilled volunteers, engineers, designers and supervisors, who were paid and treated well, second came volunteer workers, often skilled technicians, such as carpenters, plumbers, electricians and metal workers, again these workers were paid, took holidays and were well treated. Next came unskilled forced labour, paid very little and treated quite harshly, lastly came effective slave labour, paid so little, badly fed and treated very harshly. New designs were added to the Regelbau system, some were variants on existing designs, modified to suit local conditions, others were created to encompass new weapons, such as improved radar units, V-weapons and weapons captured from occupied countries. Where army or naval engineers were responsible for a major construction, rather than the OT, the construction often did not follow the Regelbau system. See also Regelbau 638 List of surviving elements of the Siegfried Line Literature Dieter Bettinger, Martin Büren: Der Westwall. Die Geschichte der deutschen Westbefestigungen im Dritten Reich. Vol. 2: Die technische Ausführung des Westwalls. Biblio Verlag, Osnabrück, 1990, . Harry