Culverts- tunnels that channel water under roads. Culverts are used as a substitute for (mainly small to medium-sized) bridges spanning creeks and small waterways as they have several advantages. First and foremost, they provide minimum maintenance, as either earth and roadway cover them or the short crossings are anchored to the ground and supported by abutments. It acts as a canal for directing water under the roadway but also as a dam to keep debris from blocking the roadway. Yet the drawbacks to culverts is that they are not really effective against high water for floodwaters can undermine culverts by washing out the roadways approaching them. In some cases, they can even collapse, swallowing cars in the process, if they attempt to cross them. If they are not washed out by flooding, the high water can cause flooding upstream up until the crossing itself. In summary, engineers should really think about the advantages and disadvantages of culverts before they even implement them as replacements for bridges deemed obsolete.
This mystery bridge deals with a culvert (or should I say a series of culverts) but in order to better understand the logic behind this, we need to look back at the types of culverts that exist and the oldest known culvert known to human kind. There are five different types of culverts that are used today: pipe, box, pipe arch, arch and bridge slab- the first three can be multiple spans, the last two are single spans of up to 30 meters. All of them are usually built of steel, stone or concrete. Only a handful have been built using brick.
The oldest known culverts that exist in the world go very far back- way back to the Bronze Age. There, you can find Arkadiko Bridge in the state of Argolis in Greece. Built between 1300 and 1190 BC, the stone culvert has a total span of 22 meters and an arch span of 2.5 meters. It is one of four remaining bridges of its kind using an Mycenaean arch design, all of them are located near Arkadiko.
The next one in line is a stone arch bridge over the River Meles in Izmir in Turkey. Built in 850 BC, this bridge is the oldest of its kind still in use. In Australia, the Macquarie Bridge, featuring a double-barrel arch culvert, is considered the oldest bridge still in use. The 1816 bridge can be found in the Royal Botanical Gardens in Sydney. The Old Enon Stone Arch Culvert, built by Samuel Taylor in 1871 and spans Mud Run in Ohio, is the oldest known culvert in the US and one that was built using limestone.
The culverts in the Eiderstedt region in the German state of Schleswig-Holstein may not be as old as the aforementioned bridges, nor is it definitely the oldest in Germany- that honor goes to the Stone Arch Bridge (built in 1146 AD) over the River Danube in Regensburg (Bavaria). But given their appearance, they are one of the oldest in the region, let alone in Schleswig-Holstein. The culverts discovered during my tour along the North Sea to Westerheversand Lighthouse consists of box culverts, built using brick as material. They each span a drainage canal which is used to divert water away from the fields during high tides (German: Flut). And despite the bike trail careening along the dikes that are lined along the shores of the North Sea, these culverts are still in use for farm vehicles. The concept is odd, but because farming is practiced in the Eiderstedt region, brick culverts were used along with concrete and sometimes wooden bridges to haul farm vehicles.
The dikes were established in the early 1960s, in response to a massive storm that flooded large parts of western Schleswig-Holstein, Lower Saxony and the City of Hamburg in 1962. 400 people lost their lives in Hamburg alone, as dike failures took them by surprise and almost all of the hanseatic city was under water. With the dikes came the rechanneling of waterways, eliminating natural gullies, as one can see while traveling along the North Sea coast. The damming of the rivers, such as the Eider, Au, Sorge and Treene, caused the massive extinction of marine wildlife, including the sturgeon, which used to lay eggs upstream close to the rivers’ starting point. The last sturgeon was caught in 1969 and there has not been a single sturgeon in the region ever since. The creation of the Eidersperrwerk near St. Peter-Ording put the last nails in the coffin of the natural cycle of the North Sea, protecting farmers and residents from the flooding processes.
Yet the culverts seen in the pics are much older than the dike and drainage systems that have existed since the 1960s. Judging by the green and yellow moss on the brick and the decoloration of the brick and concrete, it is estimated that the culverts are at least a century old, if not older. Unfortunately, there are no records of the date of construction of the culverts, let alone the bridge builder(s) responsible for building them. Not even the German bridge website Brueckenweb.de has any data on the bridges, nor the Dusseldorf-based Structurae.net. Only a map where the author found the structures and the pictures are the only piece of information that is known to exist.
While some records may be available through local authorities in Husum, St. Peter-Ording or Eiderstedt, the chances of finding concrete information is very slim, because the culverts are only 20 meters long with a center span of only 5 meters, and there are dozens of them that are known to exist, aside from the ones that were found near Westerhever.
Do you know of some information on the history of these ancient culverts? Let alone the number of culverts that still exist in the region alone? If so, then please contact the Chronicles and share some information about them. Any clues, including photos, will be of great help. The culverts will be included in the book project on the bridges in Schleswig-Holstein. Information on how you can contribute can be found here. (Hinweis auf Deutsch: Sie können die Information in der deutschen Sprachen übersenden, da der Autor sehr gutes deutsche Kenntnisse hat.)
The culverts and the covered bridge profiled here, are a couple of many bridges the author found during his trip to the Eiderstedt region. However, there are plenty more that visitors should see while vacationing there. The author has a few bridges that one should see while visiting the Eiderstedt region. The tour guide will come very soon.
Author’s notes: Enclosed is a map with the exact location and specifics of the culverts found during the trip. Information on the Great Flood of 1962 in Hamburg/ Schleswig-Holstein can be found here. A video on the event can be found here.
Ironically, an even bigger flood occurred 16 years later after the dikes and dams were built. It all occurred during the year summer never existed which ended with the Great Blizzard of 1978/79 that crippled the northern half of Germany, stranding thousands of motorists and causing massive flooding in Schleswig-Holstein alone. More information can be found here.