Blasting the Schwalleck

MAGYARUL

Despite the fact that sirens throughout the city had given half an hour's notice of the historic event, the explosion of the Schwalleck rock in Grein, which overlooks the Danube, caused serious collateral damage. Collapsed walls of apartment blocks, roads buried by debris and damaged railway embankments signalled the beginning of the process of making the "Austrian Iron Gates", the infamous Strudel Strait, navigable. 

The Schwalleck peninsula. A detail from the map of Strudengau. (Leopold Franz von Rosenfelt, 1721.)

The term "Austrian Iron Gates" is no coincidence, the Strudengau in Austria was as much a dreaded passage for sailors as the Iron Gate, Islás or Tachtalia on the Lower Danube. On this 25-kilometer stretch, the Danube cuts its way through the 300-million-year-old granite cliffs of the Bohemian Massif between Ardagger/Dornach and Ybbs/Persenbeug, where the rocky reefs and the whirpools they create have caused the destruction of many ships, for example between Wörth and Werfenstein. Just as the (second) regulation of the Iron Gates began in 1890 with the blowing up of a symbolic rock, the Grében, so the regulation of the Strudengau began with explosions, the first being the castle of Donaudorf on the right bank near Ybbs on 20 December 1955, and the second being the blowing up of the left bank of the Schwalleck promontory near the town of Grein in Upper Austria.

Outlook from the Schwalleck towards the town and castle of Grein.

Until Friday, 13 June 1958, at 12.30 pm, the Schwalleck Cliff reached far into the Danube, and in a very bad place, for navigation, as the drift line of the river led ships travelling downstream straight into it, while above it, at the mouth of the Greinerbach, a shoal was formed where flating ice were regularly stuck, and the cross-section of the river at the cliffs was also narrowing, causing the river to speed up, which made life difficult for sailors heading in the opposite direction, towards Linz. Geographically, the 250-260 m high Schwalleck was a counterpart to the cliff on which Grein Castle was built at the end of the 15th century, and these two heights defined the local skyline, the town of Grein being either depicted from here or depicted as being on the picture. It was about 40 to 50 meters above the Danube's zero level.

The doomed Schwalleck, and the evacuated buildings at its foot. (source)

It was originally topped by a cross called Halterkreuz, the origin of which is told in a local legend: a shepherd from Grein used to graze his cattle near the cliff during high water. While grazing, he was trying to fetch scrap wood out of the flood, which he wanted to store for firewood during the winter. When he tried to drag a large branch ashore, he slipped and fell into the water. Unable to swim, he desperately squeezed the drifting branch and, fearing for his life, vowed that if he managed to escape, he would place a cross on the shore to the glory of God. The river eventually swept the branch ashore, where he managed to cling to a tree hanging in the water and was lucky to escape. He kept his vow and the so-called Shepherd's Cross stood at Schwalleck Cliff until the explosion. [1] There was another cross here, the Schwalleck Kreuz, which was also destroyed by the blast, but was later reerected on the side of the cliff face opposite the Halterkreuz [2]. 

The moment of the explosion (source)

Austria's first hydroelectric power plant on the Danube was built jointly with Germany between 1952 and 1956, on the border between the two countries, just next to the unique Jochenstein cliff, which fortunately was not blown up along with the statue of St John Nepomuk on it. Austria then began to barrage the Danube, and construct the next power station which was located at the lower end of the Strudengau, between Ybbs and Persenbeug, precisely because of the navigability of the Strudengau. 

On 11 June 1958, the mayor of Grein sent out a leaflet informing the population of the impending explosion. The precaution was certainly justified, as there were already inhabited houses less than 100 metres from the Schwalleck cliff, which the town did not wish to demolish. Some nearby structures had to be sacrificed, such as those built at the base of the cliff. Doors and windows had to be left open, parked cars were removed, and valuables and furniture were moved to the far corners of the rooms for safekeeping. However, due to the proximity of the site, the blast caused significant damage to the city [3]. 

Landscape after the blast (source)

On that day, 5,800 kilograms of explosives blew up the cliff, from which more than three hundred thousand cubic meters of stone were then extracted in several stages, ensuring the unobstructed flow of ice and the necessary width of the shipping lane. Interestingly, a small cliff was left as a memorial between the Danube and the new main road, and the Shepherd's Cross was put back on it when the works were completed. Since then, the vegetation has conquered the cliff, the cars the new route and the boats the less dangerous bend in the river. The Ybbs-Persenbeug hydroelectric power station has raised the water level by 11 metres at the power station, about 5 metres at Wört and slightly less at Grein, and has removed the rapids, reefs and cliffs of the Strudengau. There is now no threat to navigation on the uniform river.  

The boulder of Halterkreuz left as a memento (forrás)

Everyone seems to have well served. If you're passing by, you don't miss anything, as if everything was already like this. What we don't know doesn't hurt. To those whose hearts we might have hurt by this old story, we apologise. 

But we will continue.  

Translated with DeepL.com (free version)

Danke an die Autoren des Österreichischen Donaubuchs für die Idee!

[1] https://www.grein.at/Tourismus/Sehenswuerdigkeiten/Halterkreuz

[2] https://www.grein.at/Tourismus/Sehenswuerdigkeiten/Schwalleck_Kreuz

[3] https://www.im-fundus.at/das-greiner-schwalleck-gefuerchtetes-schifffahrtshindernis/