Paul Sauer Bridge - Storms River
Riccardo MORANDI: Engineer
Bruno DESIRELLO: Engineer
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This is one of five large concrete arch bridges located along South Africa's beautiful N2 Garden route from Port Elizabeth to Cape Town, the Paul Sauer or Storms River bridge was the first and possibly most interesting to be built along the 2-lane highway.
In 1954 CONCOR CONSTRUCTION appointed Professor Riccardo MORANDI of Rome to construct a bridge over the Storms River to link Port Elizabeth to George via the N2. Prof Morandi did this from Rome from photographs and verbal information, without being on site, in conjunction with the constructing engineer, Mr Bruno Desirello. Morandi only visited the site once the structure was finished!
The bridge over the Storms River is unusual for having inclined spandrel supports that radiate out from the main arch rib. The approach supports are also inclined in the opposite direction - balancing out the profile of the entire bridge. The use of inclined supports is a Morandi trait visible on nearly all of his bridges.
Not as readily evident is the unique construction method by which Morandi built the bridge. Morandi had both sides of the arch built vertically above the foundations with a climbing framework on either side of the canyon. The two sides were then carefully tilted outward over the gorge until they could rest on each other at the crown [see diagram on website cited below].
This was one of the first arch bridges in South Africa with a span of 100m over the gorge at a height of 123m above the river. When the two semi arches were lowered by crane to fit into position above the gorge was a nerve-racking experience. When asked if the two halves would fit, Mr Desirello said that if they did not fit together he would commit suicide! On the due date the two halves were lowered but did not fit! This resulted in an urgent phone call to Rome for advice. Prof Morandi told them to wait until the afternoon to allow for a cycle of thermal expansion and shrinkage before trying again. At 4:30 pm the two halves slotted perfectly into position, raising a huge cheer from the assembled crowd and a relieved "Thank You!" from Desirello.
Shortly after it being taken into commission a service station was built adjacent to the bridge. In 1986 the Storms River bridge was widened and rehabilitated. Corrosion damage was repaired using impregnating inhibitors and silane cream. Elastic protective coatings were also applied to protect the arch and columns. In 1991 the Forestry Department decided to sell the petrol station at a private auction. During 2008 Plaatbos and Tsitsikamma Mountain Reserve were handed over to SanParks, leaving the Petropoort surrounded by a National Park and the Storms River as their Eastern Boundary.
This bridge was built 15 years prior to Van Stadens and 28 years before the 3 Bloukrans-area arched bridges in 1984. The largest and most famous bridge on the route is the Bloukrans bridge - Africa's highest ever at 216m. This is also the only highway in the world outside of China or Italy to have 3 bridges in excess of 152m in height.
See also Structurae
All truncated references not fully cited below are those of Joanna Walker's original text and cited in full in the 'Bibliography' entry of the Lexicon.
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