Editing Neckar (section)

==== Upgrading to a heavy shipping waterway between 1921 and 1968 ====
[[File:Hirschhorn-stauwehr-web.jpg|thumb|left|Neckar-Staustufe Hirschhorn with weir and double barrage]]
In order to provide the rising industrial area around Stuttgart a waterway connection for fully rigged ships, first plannings for channelling of the Neckar between Mannheim and Plochingen began already in 1904. The goal was to be mostly independent from natural impacts as for example low waters or floating ice. With the Württembergian side [[Otto Konz]] (1875–1965) was assigned who remained connected to the Neckar upgrading the rest of his life. A memorandum from 1910 allowed for ships up to 1000 tons, according to plans from 1919 the transportation was planned for the 1200-t-ship.

Because the Neckar was earmarked as a Reichswasserstraße (literally:"realm waterway")  in the Weimar Constitution in 1919 (officially from 1. April 1921), Neckarbaudirektion (literally: "Neckar construction department") was introduced in 1920 whose head Otto Konz became. The department was directly subordinated to the German Reich (often called "Weimar Republic"). In 1921 the German Reich, the Neckar adjoining states Württemberg, Baden and Hessen agreed in a state treaty the upgrading of the Neckar to a heavy shipping waterway. In order to finance the construction project they founded the Neckar AG with a construction loan from the German Reich, the three States and several municipalities in the same year. As compensation the AG received the right to use the simultaneously expanded hydropower until 2034 and to redeem the construction loan with the profits; this right transferred to the Federal Republic of Germany. As chairman of the Neckar AG were elected [[Otto Hirsch]] from the Württembergian ministry of internal affairs and Otto Konz. In consideration of the world famous cityscape of Heidelberg and in order to bring the further barrages in unison with nature and landscape, the architect Paul Bonatz worked for the project (1877–1956).

Construction began immediately along the entire distance in 1921. Along a stretch of 113&nbsp;km length the first eleven barrages between Mannheim and the new canal harbour in Heilbronn were finished in 1935. This canal harbour became later through the further expansion the barrage channel Heilbronn.

[[File:Bundesarchiv B 145 Bild-F079111-0011, Bad Wimpfen, Schiffahrt auf dem Neckar.jpg|thumb|Navigation on the Neckar near [[Bad Wimpfen]] in 1988 with the [[passenger ship]] Neckarbummler of the Personenschifffahrt Stumpf]]
The expansion of the Neckar to a heavy shipping waterway lead to a [[shipbuilding industry]] exclusively for the passenger traffic on the river.<ref name="H.Betz">{{citation|surname1=Helmut Betz|title=Historisches vom Strom – Die Neckarschiffahrt vom Treidelkahn zum Groß-Motorschiff|edition=1. Auflage|volume=Band V|publisher=Krüpfganz|location=Duisburg|at=p.&nbsp;142|isbn=3-924999-04-X|date=1989|language=de
}}</ref> Already in 1926 the brothers Georg (1881–1946) and Andreas Boßler (1884–1961) founded the [[Boßler family|Personenschiffahrt Gebr. Bossler]], which makes the Gebrüder Bossler pioneers for passenger navigation on the Neckar.<ref>{{citation|surname1=Herbert Komarek|editor-surname1= Schifferverein Neckarsteinach e. V.|title=Neckarsteinach 850 Jahre Schiffahrt im Wandel der Zeit|edition=1. Auflage|publisher=Wartberg Verlag|location=Gudensberg-Gleichen|at=p.&nbsp;54|isbn=3-8313-1321-0|date=2003|language=de
}}</ref><ref name="H.Betz" />

While the river was upgraded and the barrages constructed, the [[Neckar-Enz-Stellung]], a defensive fortification against enemies approaching from the West was constructed between 1935 and 1938. It was based between [[Eberbach (Baden)|Eberbach]] and [[Besigheim]] on the natural obstacle of the Neckar river and from thereon followed the [[Enz]] upriver up to [[Enzweihingen]].

Upgrading works were begun near Plochingen at the upper end of the intended waterway and plans existed to make the [[Fils (river)|Fils]] between Plochingen and [[Göppingen]] navigable. The area for a harbour in Göppingen remained reserved in spatial planning until 1978. The construction chairman Konz also ordered the planning of a tunnel through the [[Swabian Jura]] for a waterway [[Ulm]] at the Danube in order to create a waterway between upper Rhine and upper Danube, as the State treaty from 1921 had planned. But those plans were dropped from 1968 onwards.

After 1935 the upgrading slowed down. Until 1943 only six barrages above Heilbronn were constructed, but without locks. Hirsch was forced out of office and murdered in the KZ Mauthausen in 1941. Konz went into provisional retirement because of national socialist repressions. The constructions were mostly stopped during the second world war. Only in 1948 the barrage construction above Heilbronn was continued, until 1952 again led by Otto Konz. The section up to Stuttgart was finished in 1958 and Stuttgart harbour was opened by the president Theodor Heuß together with Otto Konz. With the opening of the Plochingen harbour in 1968 the expansion goal for the Neckar was reached after 47 years of construction. The river was dammed up at 27 locks and thereby had become a heavy shipping waterway from Mannheim to Plochingen.

Every barrage consists of a weir with two to six openings and different gates, a double lock and a remote-controlled hydropower plant next to each other. At seven barrages, where a larger damming up was not possible due to the landscape, a parallel barrage and hydropower canal varying in length from 1.5 to 7.5&nbsp;km has been constructed. At two further barrages a breakthrough exists which cuts of a river bend. In total only 17% of the entire distance from the Rhine up to the mouth of the Rems lie in an artificial waterbed, which means the river character dominates. On the last 32&nbsp;km of the waterway in the area of the less water carrying upper river which is at the same time heavily used economically, almost the entire river bed had to be constructed artificially.