General information on the “Immerhof”

Fortification CORF with artillery of 81mm.

SF Thionville

It is a beautiful fortification whose underground quartering is completely concreted, contrary to other fortifications of this area where quartering, very deeply buried (and thus protected well), is out of apparent stones.

In 1940 it is bombarded several times, without success, by the German troops.

Caption plan. H: men; B: crenel under concrete; C: bell; T: turret; Infanterie_: armament of infantry; Artillerie_: artillery armament; Observatoires_: armoured observatories
In top: the coordinates are in geographical system WGS84


Large a thank you with the photographers who made us share their passion.

d_kemmel.jpg Dominique KEMMEL

ph_goeltl.jpg Gerald GOELTL

ph_maillot.jpg Luc SHIRT and his daughter


Photograph opposite: Mixed entry (men and ammunition) protected, in a traditional way, by an anti-tank JM/AC47.

Click: zoom of the photograph opposite

f19_entree_fm.jpg Moreover, the immediate surroundings of the entry are protected by a FM.


Photograph opposite: room of shooting of the block of entry. The AC47 is out of battery (reconstitution). The JM which occupies the same crenel is thus in “unobtrusive” position.

f19_entree_jm.jpg JM out of battery (the AC47 is in unobtrusive position).

f19_entree_jm2.jpg Crenel for JM.

GFM. Tube acoustic

The tops of the entry are protected by two model GFM “with” of which the interior is not completely “traditional”. Indeed, on the photograph opposite one will notice that the observation post, on an adaptable mobile floor in keeping with lookout, is equipped with an acoustic tube making it possible to communicate with the chief-observer of block. In many fortifications CORF the link is made primarily by telephone.

Let us note that the acoustic tube, of a cost of installation relatively low and of a null cost of maintenance, is more reliable than the telephone especially in moist environment. On the other hand it loses of its effectiveness since the distances from transmission exceed several tens of meters.

f19_entree_gfm2.jpg The station of listening is at the bottom of one of the two GFM. Each tube, out of galvanized iron of 10cm of diameter, corresponds to a GFM.


The GFM is a station of watch. But as it is also a station of shooting for FM, it is equipped with a central sheath of evacuation of the worn casings (photo opposite).

f19_entree_gfm4.jpg At the bottom of the GFM a tight box collects the casings of FM. A ventilator makes it possible to eliminate poison gazs and the residues from powder.

f19_entree_gfm5.jpg This GFM is not “traditional” because its ventilator is not directly on the tight box but a little further, with breast height, which is of use more practical than in most GFM of other fortifications CORF.

bichel_bas_cloche.jpg Example running of position of the ventilator (Shelter of the Bichel-south).


Photograph opposite: Principal gallery on the level of quartering and the junction towards block 3 (towards the left of the photograph).

f19_entree_galerie.jpg Gallery in the vicinity of the block of entry.

All at the bottom of this part of the principal gallery one notices the presence of a crenel of FM of “interior defense” which protects, inter alia, the access to the quartering and the blocks of combat.

Block 1

Above block. The turret of machine-guns dominates the whole of the accesses of the block. With far one distinguishes TM from block 2.

GFM of block 1

This GFM is curiously positioned because its field of view prevents it from playing its part of overall watch fully. It occupies the position usually reserved for a bell JM. With top of it one can see the turret of machine-guns.


Block 2 - TM

B1 and B2 (respectively on the right and on the left on the photograph), each one, are equipped with a turret of machine-guns. The two blocks are perfectly symmetrical and give, at the zone, an important anti-personnel fire power.

Click: zoom of the photograph opposite

f19_2.jpg Blocks 1 and 2 are with strong current of the ground. They thus do not have a frontage and, a fortiori, not of traditional grids of air intake to feed their room of neutralization. These armor-plated mushrooms make it possible to protect their air intake practiced through their flagstone.

Above block 3

Block 3 (on the right) is very close to the block of entry (on the left). One sees, here, only their GFM.

Click: zoom of the photograph opposite

Frontage of block 3

B3 is a mixed block: artillery with turret of 81, infantry with crenel JM and bell GFM.

Click: zoom of the photograph opposite

f19_b3.jpg It is also on the level of this block (in frontage) that leave the exhaust fumes the generators.

Turret of 81. Cupola

Turret of 81 with, on the line of the photograph, the GFM of protection of the accesses of the block.

Click: zoom of the photograph opposite

Not to be taken for target by enemy tended shootings, as it draws under 45° it can technically be installed in a light basin. It is the case. The disadvantage of this kind of positioning is that flammable fluids, poisons or, can penetrate in the fortification by the drains arranged to evacuate rain water.

f19_t81_red.jpg On this photograph, the turret of 81mm is moving vertical (put out of battery or setting in eclipsed position).

Turret of 81. Orders

Post pointing of the turret

f19_t81_com.jpg All the operations can be made starting from this station, except the loading of the mortars of 81 for which two being useful must be held close to the weapons.

f19_t81_balancier.jpg Under the station of pointing, the lower level of the turret is articulated on a beam allowing a setting out of battery effortlessly. The turret is put out of battery by an electrical motor but a man can also put it out of battery by means of a simple crank. It is a safety in the event of power cut.


It is of this casemate, located in the quartering, which all the orders bound for the various bodies leave Immerhof.

Ordering of Immerhof

Room of the commander of work (Requiston captain in 1940)

f19_cap_requiston.jpg The Requiston captain

f19_chambre_com2.jpg Another sight of its room


The generating factory is equipped with two Renault groups producing of the alternative course for the whole of the installations of the fortification.

But like the engines of the turrets function with D.C. current, the alternative course is transformed into D.C. current by dynamos (in the foreground on the photograph).

f19_usine2.jpg Reconstitution of environment

f19_usine3.jpg Photograph of the one of the two Renault groups.


This workshop is used by the electrical engineers (Genius) to carry out all the minor repairs to be made on the various bodies of the fortification.

Room of the filters

The fortification is tight. Its air is drawn outside then it is distributed in the various buildings after being cleansed (neutralization of poison gases) in the filters of the room of neutralization.


f19_cuisine2.jpg Reconstitution of environment


The men eat in their room, which avoids the construction of specialized buildings.

Click: zoom of the photograph opposite

f19_chambre.jpg In this fortification the rooms are on 3 levels of bed (2 levels are more current than 3).

f19_chambre_hop.jpg Let us notice the presence of a covered arched ceiling of armor-plates to protect the crew against the Hopkinson effect.

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Slide show on the “Immerhof”; B.E.R Cima ©2006-2009

0_*; Related files; 1_*; General information; 2_*; Photographers; 3_*; Entry; 5_*; Block 1 - TM; 6_*; Block 1 - GFM; 7_*; Block 2 - TM; 8_*; Above of B3; 9_*; Frontage of B3; 10_*; Headquarters; 11_*; T81 - Cupola; 12_*; T81 - Orders; 13_*; Machine; 14_*; Workshop; 15_*; Cook; 16_*; Room; 17_*; The commander; 18_*; Gallery; 20_*; Filters; 21_*; GFM. Tube acoustic