Mystery Bridge Nr. 86: Brick Culverts spanning Drainage Canals and Gullies along the North Sea

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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.

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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.

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Arkadiko Bridge in Greece. Photo taken in 2012 Flausa123 courtesy of wikipedia

 

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.

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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.

 

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Detailed markings of one of the culverts. Look at the rust and moss that has developed over the years.

 

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.

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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. and here.

 

 

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The Bridges of Friedrichstadt, Germany

The Stone Arch Bridge and the market square with the Dutch facade housing in the background. Photo taken in August 2012

Located seven km (or four miles) south of the fourth largest city in Schleswig-Holstein, Husum, at the junction of the Eider and Treene Rivers, seven kilometers inward from the North Sea, Friedrichstadt appears to be a typical small town in the northernmost state of Germany with rows of small houses, farmland scenery with cattle and sheep grazing in the fields, and people greeting each other with “Moin! Moin!”. The town prides itself on its tourism and the typical specialties with fish, just like the rest of the cities up north. But Friedrichstadt also prides itself on its history and multiculture. Founded in 1623 by King Friedrich III and despite surviving four wars with its neighbors plus persecution of certain races, Friedrichstadt is one of the cultural points of interest, where large groups of Dutch, Frisans, Danes, Jews and Germans speaking northern dialects have lived for almost 400 years. It was a center commerce point for trade with empires from Russia, Scandanavia and Prussia, but is now a tourist attraction, where thousands of tourists from over 100 countries visit every year.

The town was built using Amsterdam as the ante-type, featuring canals that slice through the town of 2,300, but encircling its beloved Dutch-style houses, and like the Dutch capital, the city is loaded with bridges of different types and coming from different eras of time. Eighteen Bridges can be found in this city, including two major crossings over the Eider just outside the city limits and some key notables in the town itself. Each of the crossings can be reached by foot, by bike, or by boat, with most of them telling a story or having a picture showing its history, making the town proud of its history and heritage.  While one can write a library about the town’s 18 bridges, which is unusual for small town standards (a town of that size could have 3-5 bridges on average pending on location), this guide shows you the most important bridges you will see when spending a few hours in this quiet but important historic town.  Each bridge has a brief history, but photos for you to see, courtesy of not only yours truly, but also many contributors, who were willing to step forward to help. The credits will be provided at the end of the article.  So without further ado, we’ll start with the outer edge of town with the two Eider Bridges and work our way towards the Treene.

Inside the Friedrichstadt Arch Bridge. Photo taken in August 2012

Friedrichstadt Arch Bridge

Spanning the Eider River at the southwest end of town, this bridge represents one of the finest works of Friedrich Voss, who had constructed six bridges along the Baltic-North Sea Canal, including the Rendsburg High Bridge. Built in 1916, three years after the world-renowned bridge was open to rail traffic, the Friedrichstadt Arch Bridge features three spans- the center span being a two-part draw bridge; the outer spans being steel through arch bridges. Up until the 1950s, it was a toll bridge, where money was gathered based on the size of the vehicles and the goods being carried across. That means one could pay 400 Pfennig for driving a truck across but only 20 Pfennig when walking across. The tolls have long since been lifted and the draw bridge span is seldom used nowadays, the bridge has received its regular wear and tear as it serves traffic in and out of Friedirchstadt from the south, connecting the town with Heide. It just recently celebrated its 100th anniversary with a marathon and other celebrations.  Despite being renovated only once (in 2006), the bridge still can handle a sizeable amount of traffic today and is expected to continue to do so.

Photo courtesy of the Friedrichstadt City Archives
Photo taken in August 2012

View of the Friedrichstadt Railroad Bridge from the Friedrichstadt Arch Bridge. Photo taken in August 2012

The Friedrichstadt Railroad Bridge

This bridge is one of the more popular structures in Schleswig Holstein and northern Germany. First built in 1887, the bridge featured multiple-span truss bridges with a swing span at the river crossing, with the purpose of providing passengers with rail service between Hamburg and the Island of Sylt, located in the North Sea at the Danish Border. The first bridge featured five bowstring arch spans on the north end of the Eider, followed by two Whipple through truss spans that were separated by a bowstring arch span, as shown in the picture below:

The first bridge after it opened in 1887, looking from the north end. Photo courtesy of the Friedrichstadt City Archives

In 1908, the spans were replaced, one by one with another set of trusses, which featured from south to north one Pennsylvania through truss with A-frame portal bracings, one bowstring arch swing span, another Pennsylvania through truss and five polygonal Warren through truss spans. Photographer H.D. Kienitz provided a diagram of what the spans looked like below:

Diagram courtesy of H.D. Kienitz, used with permission

Five years later, an identical was built alongside the 1908 bridge and for 74 years, the bridge provided two-way traffic before a major reconstruction job took place in 1987 and lasted seven years. It consisted of replacing the bowstring arch swing span with a polygonal Warren through truss  swing span that was operated electronically and removing the 1908 span in its entirety, reducing the number of tracks on the railline to only one. This is what the bridge looks like before and after the facelift:

The duo truss bridges before the facelift in 1987. Photo taken by H.D. Kienitz, used with permission
The northern Warren trusses at the time of the facelift. Photo taken by H.D. Kienitz, used with permission
Sideview of the bridge before the facelift. Photo taken by H.D. Kienitz, used with permission
Photo of the main spans after the facelift. Photo taken in 1997 by H. Doose, used with permission.

 

 

 

 

 

 

 

 

 

 

The Friedrichstadt Railroad bridge still serves traffic today, which consists of the NOB Train services, which stops regularly at Friedrichstadt, and the InterCity lines, which starts at Westerland on the Island of Sylt and runs through Hamburg going to destinations in the south. It is unknown whether there will be another two-track bridge built at this site soon. It depends on the number of passengers travelling through the western part of Schleswig-Holstein and the problem with bottlenecks at this site. Right now, with four national raillines and the options available for rail travel in the region, it appears unlikely. That might change in the five years….

Fast Fact: Apart from the InterCity line connecting Sylt and Hamburg, the three other national lines include Hamburg-Luebeck- Copenhagen (crossing the Fehmarnsund Bridge), Hamburg-Rendsburg-Flensburg-Kolding (crossing the Rendsburg High Bridge) and Hamburg-Neumuenster-Kiel, the latter two of which carry ICE-Train services, whereas the second and third lines have international connections to Scandanavia.

Red Arch Bridge at Ostersielzug. Photo taken in August 2012

The Arch Bridges of Friedrichstadt:

It is unknown how many arch bridges were built during the time of the town’s infancy. But if one counts the Eider crossing, there are four arch bridges that still serve Friedrichstadt today, regardless of its shape and form. While there is little to no information about the Red Arch Bridge, located behind the main highway, as well as the modern arch bridge located near the police station (both in Ostersielzug), the most famous of the bridges is the Stone Arch Bridge, which is located at the eastern entrance to the market square. Built in 1773, the bridge is one of the oldest structures still standing in Germany. The one-span structure was renovated in 1981 by strengthening and widening it to provide traffic across the canal, which continues to do so today. It is one of the most photographed places in the town and provides tourists who eat at the ice cream parlor next to it with a picturesque background of the city.

Passenger Boat passing through the Stone Arch Bridge. Photo taken in August 2012
Cyclist crossing the Holmertor Bridge with the Mittelburg Bridge in the far distant background. Photo taken in August 2012

Wooden Bridges in Friedrichstadt

It is unknown how many wooden bridges existed in Friedrichstadt, for they differed on location and design. But today there are at least four bridges remaining that were built made of wood, most of which feature triangular deck trusses supporting wooden support piers and three of which can be found along the northern Mitteburgwall canal, the same one where the Stone Arch Bridge is located. A pair of notable bridges should be noted here. The Middle Bridge, located next to the Stone Arch Bridge, is known as the Holmertor Bridge and featured a bascule bridge supported by a wooden tower, as depicted in a painting provided by the city. It was replaced at the end of the 19th century.  The Kuhbruecke (Cows Bridge) is located at the mouth of the Treene adjacent to the Blue Bridge and is the third bridge located at the site. A lock is located right next to it and protects the town from flooding from the Treene River.

Painting of the Holmertor Bridge before its replacement. Photo courtesy of the Friedrichstadt City Archives
Cow’s Bridge, oblique view. Photo taken in August 2012

 Blue Bridge. Photo taken by the author in 2012

Blue Bridge:

The final bridge on this tour is the Blue Bridge. Located over the Treene River in the district of Westersielzug, this bridge is the only one in the city that features a double leaf bascule bridge, one of the most common types of bridges to be found in Schleswig-Holstein. Yet this bridge represents a historic symbol for the city as about a handful of these bridges were constructed in the 1800s, including this bridge which was recently profiled as a Mystery Bridge and is also in the running for the Ammann Awards. That bridge was located in the same district as the Blue Bridge, according to the City Archives. Serving as a gateway to the historic city center from the north (and the train station), the Blue Bridge was constructed in 1991 to serve as a historic marker to the bridges that have long since been lost. However, the main spans were lifted only once in its lifetime. Reason? While the plan was to use the Treene as a thoroughfare, it was blocked thanks to a fixed span located to the west of the bridge. Since then, the bridge practically serves as a fixed span, even though technically it is a bascule bridge. Nevertheless, it is mentioned a great deal through boat tours and other notes in the travel guides and is a treat to those wanting to visit Friedrichstadt.

Author’s Note: The fixed span mentioned here has been in service since the 1970s. Its predecessor was the Kreisbahnbrücke, a polygonal Warren pony truss bridge that used to carry trolly traffic to the city from the train station.

Kreisbahnbruecke. Photo courtesy of the Friedrichstadt City Archives

To sum up, Friedrichstadt is a city full of history and surprises, no matter which aspect one is interested in. The city has 18 bridges, which is unusual, however, each one tells a story, which is worth listening to or reading about when spending time there, regardless of bridge type and size.  The city may be small, but its history and heritage makes Friedrichstadt a must-see place when visiting Schleswig-Holstein.

A map of the bridges is enclosed so you know of their location:

The author would like to thank Christiane Thomsen at the Friedrichstadt City Archives, Rainer Butenschoen, Dietrich Doose and H.D. Kienitz for their help in providing information and photos on the bridges in Friedrichstadt.

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