Regelbau

The Regelbau was a standardized bunker built by the Germans in the Siegfried Line (Westwall) and the Atlantic Wall as part of their defensive fortifications prior to and during the Second World War. The term is German and means "standard design".

Purpose
There were several advantages to standardizing the design and construction:


 * 1) Retention of proven design features when building new bunkers
 * 2) Simpler manufacture of large quantities e.g. of armoured and ventilation components and simplified ordering from the industrial manufacturers involved
 * 3) Easier surveying of construction sites with regard to the strategic situation
 * 4) Simplified construction process
 * 5) Easier supply of materials to the construction site

Extent of standardization
As early as 1933 the Army command began work on the standardization of defensive works with their publication of the Order for the Construction of Permanent Fortifications (Vorschrift zum Bau ständiger Befestigungsanlagen) or B. st. B. In addition to general directions, it also contained very specific regulations on the armoured components (Panzerungsteilen or P-Teile) and ventilation components (Lüftungsteilen or ML-Teile) to be used. The most important aspect of standardization was construction thickness (Ausbaustärke). This referred to the thickness of the walls and ceilings of the bunker. In the four years it took to build the Siegfried Line, changes were repeatedly made to the list of components to be used. The reasons for this were continual developments in weapon technology as well as the availability of armoured components and raw materials (steel) in general.

Construction thicknesses (wall and ceiling thicknesses):


 * A = 3.5 metres
 * A1 = 2.5 metres
 * B new = 2.0 metres
 * B old = 1.5 metres
 * B 1 = 1.0 metres
 * C = 0.6 metres
 * D = 0.3 metres

Development of Regelbau designs from 1936 to 1940
Following the occupation of German territories west of the Rhine, fortress engineers began the construction of the Siegfried Line in 1936. In doing so they were able to benefit from their earlier experience of bunker construction. In compliance with the Versailles Treaty, they had already built the Wetterau-Main-Tauber position and Neckar-Enz position before 1936. When, in 1936, construction started on the Siegfried Line itself, they were able at the outset to utilize designs from the two earlier fortifications. From these existing plans, fortress pioneers rapidly developed improved bunkers that were built from 1937. This building phase was named the Engineer Construction Programme and was characterized by bunkers built to B1 standard thicknesses (see above). Since the thickness of these structures was soon considered to be too weak and because there was a large number Regelbau designs (and hence confusion), new types were developed and implemented from 1938. These new designs were achieved largely by simplifying and reducing the number of Regelbau types. This new building phase was called the Limes Programme. Also new was that fortress engineers were no longer in charge of construction; instead Organization Todt (OT) took over, promising Hitler it would deliver the number of structures he wanted. Plans for the Limes Programme did not envisage the inclusion of the cities of Aachen and Saarbrucken and they therefore ended up in front of the planned line of fortifications. That changed in 1939 with the Aachen-Saar Programme. From 1939, yet more new Regelbau bunkers were designed for the construction programme that saw increases in the construction thicknesses. From then on, only bunkers that met the in "B new" and "A" standards were to be built. With the outbreak of the Second World War on 1 September 1939, priorities for the construction of the Siegfried Line changed. The renewed shortage of raw materials led to the development of a new series of Regelbau designs, the so-called wartime standard designs or Kriegsregelbauten. After the "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.

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, ISBN 3-7648-1458-6.
 * Harry Lippmann (ed.): Die Regelbauten des Heeres im Atlantikwall, Cologne, 1986, (IBA-Informationen Sonderheft 10, ).
 * Rudi Rolf: Der Atlantikwall. Perlenschnur aus Stahlbeton. AMA-Verlag, Beetsterzwaag, 1983, ISBN 90-6474-025-9.

Regelbau