| German WW2 fortification
strategies, techniques and application
and a brief description of the versatile Regelbau concept.
|Regelbau 622, two-group bunker (20 men), 10. Battery, Hirtshals South|
lesson learned in the trenches of WW1
All this can be read in any history book and is outside the scope of this page. But this atmosphere of mutual distrust also was the spark that started the building of huge fortresses in Europe.
belief in fixed fortifications
In Germany they chose a slightly different approach when constructing the opponent to the French border fortifications. They were equally eager to avoid the perils of trench warfare and improve the conditions for the fighting men, but they deliberately did not want to let soldiers succumb to the docile existence and complacent life of the fortress inhabitant. Their response was to design fortifications based on individual bunkers connected with trench work. Troops could live in relative comfort, withstand and survive aerial bombardment or heavy shelling in their bunkers, but had to stay vigilant as they must leave the safety of these positions to fight.
The Wehrmacht operated with three levels of fortification;
Feltmessige Anlage (Field-type constructions)
Verstärkt Feltmessig or "Vf" (Reinforced field-type constructions)
Ständige Anlage or "St" (Permanent constructions)
Furthermore, a ständig bunker was, if used for habitation or as a fighting post, secured against gas warfare, had it's own air-cleaning plant, telephone, radio, heating, lighting and amenities. Some hard their own well for water supply. The "St" bunkers were designed to suit a variety of purposes, each model with its own designated number and eventually grew into becoming the Regelbau concept.
gun position in derelict R622 in the woods surrounding
|Anchor for camouflage net on partly buried bunker at Robbe Nord, Rømø|
|Note the original glow-in-the-dark camouflage paint - active 60 years later|
The comparison to a standard house is only valid however, as to the repeated use of standardized elements. Apart from that a Regelbau bunker looks nothing like your everyday gazebo, and most prominently is the huge dimensions of walls and roof.
Apart from wall thickness, Regelbau bunkers share a series of similar features:
Entrance. If at all possible, the entrance ends in a 90° turn, covered by an embrasure for small-arms firing, protected by a 30 mm steel plate. Fighting posts (where the crew remains inside during combat, as i.e. in a radar-bunker) are further protected by a flanking gun embrasure providing enfilade fire along the entrance side. This is referred to as the close-combat room.
Gutters. This is a later addition to the basic design. Keeping rain water from entering doorways, air intakes and gun embrasures, these gutters also guided burning flame-thrower fuel away.
air intake. Sturdy steel grills protected the air intakes
Room dividers. The size of a Regelbau bunker as well as the number and dispersion of rooms is strictly determined by it's function. Only the required rooms are present and no room is larger tahn absolutely necessary. Internal walls could be cast in concrete or laid in bricks or even wood.
Wall lining. In general, internal walls were lined with wood, partly because of the insulating effect, but also to minimize the effect of concrete blow-off caused by a direct hit on the outside. In later constructions, steel netting was applied in the casting process to improve the latter.
Flooring. In some bunkers you will find a flooring of (usually brown) asphalt tiles. These served as vibration dampers to counter the effects of shelling and bombardment that otherwise cause severe bodily injury to the inhabitants such as factures and damage to internal organs. In many bunkers you will se a warning against just that painted on the walls.
gutters on crew bunker R622
|Wood-lined gun embrasure in Fl243 at Fanø Flak Nord|
hatch for bunker periscope (Seerohr)
at Fortress Thyborøn
mm armored door with man-hole and gas-tight lining in
for ventilation system
10. Battery, Hirtshals
view of gun
embrasure in S449 at Stp. Bulbjerg
(sliding hatch missing)
panels in M152
tiles (vibration dampening) in V196
at Silkeborg Bad
protection. War-gasses being one of the weapons of mass destruction of
WW1, most Regelbau bunkers - including all habitats and fighting posts -
were secured against chemical warfare with air-tight doors, an airlock,
pressure valves, armored air intakes and a air-purification device that
could be either electrically or manually driven. The device created a
higher pressure inside the bunker thus effectively preventing gas to slip through
gaps in e.g. gun embrasures etc. Internal pressure was aligned by the
Well. Some bunkers have their own well, either right outside or inside the bunker. Today this may just appear as a rather deep - and not necessarily covered - hole in the floor, so mind your step!
Antenna. In many bunkers a carving in the concrete wall just outside the armored door can be observed, and in some even a metal fixture has survived. The carving leads to a hole in the ceiling and is designed to lead a segmented, telescopic radio antenna through the roof of the bunker.
Emergency exit. Bunkers with just one entrance often feature an emergency exit. Today this is most often just a hole in the wall, but you can be lucky, as the photo to the right demonstrates, to find an intact exit, complete with metal bars, brick wall and a gravel-filled stepladder tunnel.
|Close combat room in L410a at Aggersund||One-way
in R628 crew bunker at Pikkerbakken
of ventilation system and wall lining in R622
exit, partly opened in
Telephone. Used for communication between bunkers and HQ. Often bears the warning; "Achtung - Feind hort mit!" - Caution, the enemy is listening!
Voice-pipe. For communication between bunker an entrance or the look-out in the Tobruk (see below). A simple and reliable, non-electric system as it is also known on vintage ships.
Heating. All bunkers where the crew had to stay for a prolonged period of time had heating. In larger facilities a form of central heating was quite often used, but in it's form, heating was provided by an oven, using coal or wood as fuel, and with or without a boiler plate for cooking. The chimney pipe was constructed with a trap, leading a hand grenade dumped into the chimney to the outside of the bunker.
Periscope. In some bunkers, e.g. crew bunkers and fighting posts, you will observe a circular, 5 inch aperture in the steel ceiling. This is designed for a retractable u-boat style periscope, enabling the inhabitants to take a 360° peek of the area outside before opening the door. As so much other bunker equipment, periscopes have long vanished from rural bunkers, but working specimens kan be found i.e. at Aalborg Forsvars- og Garnisionsmuseum and at Silkeborg Bunkermuseum.
Toilet. Most often just a bucket with a seat, and placed in the airlock (most suitable, one might argue). In some cases a regular "outhouse" was constructed. Larger command bunkers had internal facilities.
Warnings and other works of art. The lucky bunker explorer might occasionally stumble over inscriptions or pictures, written or painted on bunker walls. In most cases it will be instructions or warnings, but it may also be Nazi insignia, enflaming paroles of courage or even artistic attempts by homesick soldiers to depict sceneries from home or a loved one left behind. Take all the photos you want, but do not disturb or destroy these messages from a sinister past.
telephone in R622
at museum; Forsvars- og Garnisonsmuseet
in mint condition in R622
|Festungsofen WT80 (gas-secured oven for heating and with boiler plate)|
in command bunker at
|Portable toilet at museum; Silkeborg Bunkermuseum, Silkeborg|
Armored copulas. These are found on artillery observation posts, on certain mortar bunkers and in specialized machine-gun or anti-tank gun emplacements. The topic will receive special attention at a later stage. Not to be confused with tank-turret positions.
Tobruk. The Tobruk or "ringstellung" is basically a reinforced foxhole, some with a small, two-man habitat attached to it. The simplest version is named Bauform 201 or 58c, but a a variety of bunkers emerged from it. Tobruks are also an integral part of many larger bunkers, where they serve as observation posts and machinegun positions.
Some similar types housed an 80 mm mortar (Bauform 69), some were furnished with armored turrets provided by obsolete Germen and French WW1 tanks (Bauform 67). This is not to be confused with armored cupolas as stated above. Where turret or cupola has been removed, you can easily tell the difference by the size of the hole, as cupolas in general have a somewhat larger diameter.
Robbe Nord, Rømø
|Tobruk with armored turret from German tank at Battery Graadyb, Fanoe|
|Bauform 231 with armored turret removed at Aalborg Airport|
|See also www.wartourist.eu and www.krigsturist.dk for more information|