Kazemat, tussen Rijnauwen en Vechten Utrecht

English translation

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Description

Cluster 41.

Introduction

CAST STEEL CUPOLA CASEMATES TYPE G are reinforced concrete, closed machine-gun emplacements, which usually formed part of dispersed defensive works with trench systems, group nests, group shelters, obstacles and the like. In 1936, as a supplement to the reinforced concrete casemate, the so-called cast steel cupola casemate was introduced in the Netherlands, which was based on a system already applied in France in 1917. The armour cupolas used were small in size (favourable with regard to visibility and hit probability), round in shape (favourable with regard to deflecting hits and strength), relatively simple to produce in series and they had an 'external' firing aperture (favourable with regard to gases and sound). Moreover, they could be manufactured in the Netherlands, which significantly reduced dependence on foreign countries. A first order of 100 pieces in the Netherlands (at DEMKA) was followed by a second of 50 pieces from the Belgian Soc. Anonyme John Cockerill. In total, over 700 must have been cast in a short time, but only a few have survived. The cast steel cupolas, with a diameter of 1.75 m and thicknesses of 10-14 centimetres, were installed in multiple casemate types with resistance classes W 12-15 and W 21-28. Shortly before the start of the Second World War, so-called Cupola Casemates Type G were constructed at various locations in the Dutch lines, in particular in the Ijssel line, the Maas line, the Grebbelinie (each approximately 150) and the New Dutch Water Line (approximately 80 in a reinforced version of 14 centimetre thickness). The usual construction of reinforced concrete with one or more fixed firing apertures was thereby abandoned in favour of a system that had a firing direction to be projected within variable limits (up to 270°), within a cast steel cylinder with a cupola roof. The firing aperture in the cupola formed a rounded rectangular 'eyebrow' of approximately 10 cm thickness, which protruded several decimetres outside the cupola and provided protection for the machine-gun positioned inside. The firing aperture and the access to the casemate, which was located in a recess behind the cupola, could be sealed 'gas-free' from inside. Most cupolas were placed in Standard Cast Steel Cupola Casemates Type G. Standard Cupola Casemates in the NHW were equipped with a heavy machine-gun as armament. During the Second World War, the vast majority of cupolas in the interior were demolished by the occupier from the casemates - partly by blowing them up - to be recast for other steel requirements. On the coast they were partly incorporated into the defence, but were mostly demolished after the war anyway. As a result, complete cupola casemates are rare; they can still be found, among other places, at Fort Vechten. The concrete bases of the cupola casemates are less rare. For example, there are multiple concrete remains of Cast Steel Cupola Casemates Type G in the complex 'Intermediate Position Rijnauwen-Vechten', including one to the north of the Fort near Rijnauwen, near a Group Shelter Type P.

Description

Remains of CAST STEEL CUPOLA CASEMATES TYPE G are relatively low, almost square, concrete bases of approximately 7.00 x 6.50 x 3.00 m (w x d x h), with a backwards sloping surface at the height of the recess made for the cupola. The specimens present on the Houtense Vlakte as part of the 'Intermediate Position Rijnauwen-Vechten complex' have all been blown up and show serious concrete damage as a result; the cupolas have been removed and remelted. The casemates are not accessible, as they have been filled with rubble at the location of the missing cupola. The bases of the casemates lie reasonably visible in the terrain, as they needed to have a fairly clear field of fire in the direction of the local (traffic) infrastructure and accesses. One is located to the north of Fort Rijnauwen in the municipality of Utrecht.

Valuation

The remains of the CAST STEEL CUPOLA CASEMATES TYPE G in the Intermediate Position Rijnauwen-Vechten complex are of general importance because of:

* Cultural-historical values as components of the New Dutch Water Line as designed by C.R.T. Kraijenhoff and initially realised from 1815 by him, Jan Blanken and Major-Engineer Willem Offerhaus and subsequently reinforced and improved by others for more than a century.

* Military-historical values as part of a continuous military defensive line between the former Zuiderzee and the Biesbosch. This consisted mainly of a coherent system of inundation fields and associated inundation means and fields of fire. This system was supplemented with various types of built or constructed defensive works from different periods which served or contributed to closing off terrain not to be inundated or other accesses.

* Architectural-historical values, in particular as an expression of military-strategic architecture, which is based on: a. the system of inundation and access defence (19th and 20th century), b. the race with strengthening offensive means (20th century) c. the system of 'living' field fortification in depth (20th century)

These are components from the period 1939-1940. These components are examples of reinforced concrete cupola casemates (Type G), now without earth covering and without cast steel cupola (later removed).

* Ensemble value and situational values as components of the New Dutch Water Line. Also because of the functional and physical coherence with the other components of the complex.

* The components are representative (characteristic) because they are clearly recognizable as components of a dispersed defence line added to the existing fortification system.

* The components are moderately well-preserved, as a result of wilful dismantling by the German occupier during the Second World War, but they can still be well recognized as built objects in the field.