Floating gate
The floating gate , also known as the blocking ship , served to protect the areas along the Vienna Danube Canal from ice rushes and floods. It was designed by Wilhelm Freiherr von Engerth , put into operation on December 13, 1873 and finally scrapped after the Second World War .
Investment abutments
The axis of the floating gate was located 166 meters below the Brigittenauer Spitz, as the Danube Canal had narrowed sufficiently here to be able to build a ship that was sufficiently stable for the expected pressures that would exert water and ice.
The left ( Brigittenauer ) quay wall was given a lens-shaped indentation in which the floating gate was moored when it was not needed. Shortly below this parking bay, the quay wall protruded towards the middle of the river. In an emergency, the floating ship should support itself at one end at this corner.
On the right ( Nussdorf ) bank, it was not possible to support it on a similar corner of the wall , since excessive forces would have arisen when the barrier was opened by pulling the transverse ship against the water current.
Therefore a niche was built into the quay wall, which was covered at the top. The mortise gate and the attachment gate were located in this niche .
The mortise gate was turned outwards via a rack via a capstan , which was located on the top of the cover and had a gear at the bottom , and this turning movement in turn moved the attachment gate out of the wall niche and thus formed the second abutment for the floating gate.
Both the mortise gate and the attachment gate were steel framework constructions that absorb the forces and pass them on to the quay wall on which the mortise gate is supported.
In order to open the floating gate again, mortise and installation gate were turned back into the niche via the capstan. The barrage was then driven aside by the current to the Brigittenau bank.
The blocking ship could be brought to sink by means of ballast , but was not allowed to sit on the bottom of the 48.85 meter wide barrier. For this reason, four cast iron bases filled with concrete were made to keep an opening 95 centimeters high.
This created a high flow velocity with a corresponding destructive force. Therefore, the bases were placed on a concrete slab 126 centimeters thick and 30 meters long.
Floating gate
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The floating gate, also known as the Sperrschiff, was a non-propulsion and symmetrical ship that was only moved by human power using winds and the flow of water in the Danube Canal, as Wilhelm Freiherr von Engerth refused to build a steam-powered cable winch because of the high costs.
It was manufactured in the John Cockerill steelworks in Seraing ( Belgium ) under the direction of chief engineer J. Ritter von Kraft, an Austrian. The ship was assembled in the shipyard in Linz ( Upper Austria ).
- Dimensions:
- Length: 48.6 meters
- Largest width: 9.5 meters
- Width at the ends: 1.0 meters
- Height: 5.7 meters
- Weight: 440 tons
The steel sheets on the straight walls and on the floor were 10 to 12 millimeters thick and riveted.
- Furnishing:
- Steam boiler ( tube boiler ) with 30 square meters of heating surface
- Two centrifugal pumps (165 cubic meters of water each per hour)
- Two hand-operated leak pumps
- manual ballast loading device for ballast stones (loading: 1,000 stones per hour, unloading: 600 stones per hour)
- Steam heating, which should prevent the pipes from and to the pumps and valves from freezing .
2,000 kilograms of cast iron were constantly on board as ballast, up to 1,200 granite stone cubes, each 17.5 kilograms, were loaded as required, and the water tanks were flooded in order to achieve the required depth.
The use of the floating gate was made dependent on the water level at the Ferdinand Bridge - today's Sweden Bridge.
The floating gate was "sunk" using ballast during high tide, but the ship was not allowed to sit completely on the ground. The sinking depth of the floating gate also had to be constantly adjusted to the respective water level of the Danube.
To protect against drift ice or ice rushes , it was sufficient if the floating gate was moored across the Danube Canal between the two abutments. Hardly any ice floes were pushed through under the barrage due to the ship's straight side walls. It was important that the floating gate could rise or fall according to the respective water level.
After several years of use, the experience was made that the ship did not meet the purpose and in the summer of 1878 the Alt-Ofener shipyard ( ⊙ ) had repairs carried out, which cost 60,000 guilders . (In 1873 the cost of the barrage ship including bank protection structures was 500,000 guilders.)
The floating gate was later equipped with additional "ice needles". These were steel rods that were attached to the ship's wall, reached to the floor and served as rakes .
Nussdorf weir and lock system
After the completion of the Nussdorf barrier (Nussdorf weir and lock), the floating gate continued to be used until the First World War . It was only scrapped after the Second World War.
The structural measures on the quay walls have been preserved to this day. On the Brigittenauer Ufer, the lens-shaped indentation in the quay wall and the corner for support can still be seen, as can the wall niche on the Nussdorfer Ufer, which housed the stem gate and the supporting gate. The capstan with which this construction was moved has also been preserved.
literature
- Wilhelm Freiherr von Engerth: The floating gate to cordon off the Vienna Danube Canal . Published by Carl Gerold's Sohn, Vienna 1884.
- Bertrand Michael Buchmann u. a .: The Danube Canal - history-planning-execution . Magistrate of the City of Vienna, Vienna 1984.
Individual evidence
- ↑ Little Chronicle. (...) The blocking ship. In: Neue Freie Presse , Morgenblatt (No. 5062/1878), September 30, 1878, p. 5, bottom center. (Online at ANNO ). .
Web links
- The history of Danube regulation in Vienna wien.at accessed on December 13, 2013
Coordinates: 48 ° 15 '37.3 " N , 16 ° 22' 9.1" E