Tankhindernis, Werken aan de Karnemelksloot. Naarden (Gooise meren 27)

English translation

The text above is the record as published by the Rijksdienst voor het Cultureel Erfgoed, in Dutch. The English below is a machine translation made by TreeAlive, not by the Rijksdienst voor het Cultureel Erfgoed; it has not been checked by a person. Where the two differ, the original is the record. Report a translation error: privacy@treealive.com

Description

Cluster 9. Tank Obstacle.

NEW HOLLAND WATERLINE Introduction

CONCRETE BLOCK OF TANK OBSTACLE as component of linear and access defence with anti-tank ditches, group shelters, casemates and similar structures.

Naarden lies on the high ground between the Naardermeer and the Zuiderzee, which formed an access to Amsterdam and was one of the most important fortified towns of the Old Holland Waterline. The waterline was primarily based on inundation of low-lying lands in order to prevent the enemy from passing. However, Naarden lay on the high slopes of the Gooi, which made inundations difficult. It was decided to excavate the high ground. The Works at the Karnemelksloot are part of the attempts to hold water around the fortification of Naarden. In 1787 a dam lock was installed in the Karnemelksloot to hold the inundation water. To protect the dam lock, two small moated earthen lunettes were created in 1787 on either side of the Karnemelksloot. Besides the defence of the lock, they also served to prevent the enemy from passing Naarden on the south. These lunettes were demolished in the French Period but at the time of the New Holland Waterline around 1873-1875 were enlarged and provided with buildings. The fort keeper's dwelling Naardermeer 7 must also date from this period. The fortifications of the New Holland Waterline soon proved outdated. As a result of improvements in artillery, effective fire could be brought to bear from ever greater distances. Therefore, during the mobilisation periods of 1914-1919 and 1939-1940, additional defensive works were constructed in front of the actual works in the form of group nests, group shelters, gun casemates and obstacles. On the east and south side of Naarden, a defensive line several kilometres long was established during the mobilisation period 1914-1918. At the Karnemelksloot, barbed-wire obstacles and shelters were installed. In 1926 the Works at the Karnemelksloot, simultaneously with the fortification of Naarden, were officially decommissioned as a defensive work. Nevertheless, during the period 1935-1940 a tank obstacle was constructed at the Karnemelksloot.

The erection of obstacles to hinder or delay the advance of enemy troops has a long history. Important artificial obstacles were traditionally, among others, ditches, waterlLines, felled trees and disabled bridges. With the advent of mechanical (such as steam trains) and motorised (armoured vehicles and tanks) means of transport, heavier materials were deployed, including steel and (reinforced) concrete obstacles. One of the systems applied from the mid-1930s onwards consisted of obliquely erected and pointed steel (H-section) beams, which not only greatly impeded the passage of such vehicles but could also inflict heavy damage on them. Such obstacles could be assembled from one (Type I) or two rows (Type II) of section beams. Tank obstacles were usually constructed from interconnected systems of barriers, in which in addition to water (including especially anti-tank ditches and inundations) concrete and steel constructions (the actual tank obstacles) delayed progress. The slots in which the bars could be inserted could be closed by means of cast-iron covers. On the eve of the Second World War, the Dutch army used anti-tank ditches and concrete blocks with steel section beams in the New Holland Waterline among other things. The number of tank obstacles constructed in the Holland Waterline is not known; around the year 2000 approximately 10 (reasonably) recognisable ones still remain, of which 1 is complete. Another well-known obstacle was the tetrahedron - a movable triangular concrete block (also executed as a steel construction) that could be applied in groups at checkpoints and bridges.

Description

CONCRETE BLOCK OF TANK OBSTACLE on the access of the dyke road het Naardermeer between the actual lake and the Karnemelksloot, slightly south of the dam lock and the Works at the Karnemelksloot. Of the obstacle, two concrete strips remain in the side verges (approximately 40.00 m wide), with the Karnemelksloot on one side and a smaller ditch along the dyke road het Naardermeer on the other. The profile bars have been sawn off to ground level. Originally the obstacle covered the entire width of the dyke with side verge.

Valuation

The CONCRETE BLOCK OF THE TANK OBSTACLE is of general importance because of:

* Cultural-historical values as component of the New Holland Waterline as designed by C.R.T. Kraijenhoff and initially from 1815 realised by him, Jan Blanken and major-engineer Willem Offerhaus and subsequently strengthened and improved by others for approximately 125 years.

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

This is a component from the period 1935-1940. The component is an example of a remnant of a reinforced concrete, cast-iron and steel obstacle specially constructed for defence against assault vehicles and/or tanks, which formed part of a linear, further partly consisting of (anti)tank ditches and adjoining inundations, obstacle.

* Ensemble value and situational values as component of the New Holland Waterline. Also because of the functional and physical coherence with the other components of the complex and by its location in a potential access to the Fortress Holland.

* The component is fairly rare because relatively few recognisable tank obstacles remain.

* The component is poorly preserved, but can still be recognised in the field in its original function.