Welcome to Dutchdam

     Dutchdam once again top of the list.

     After the exceptionally good results of the wave and collision tests, the Dutchdam has again had its special characteristics confirmed, this time in a report by the Innovation Test Centre of the Dutch Ministry of Transport, Infrastructure and Water Management, published in March 2008.

     The following is a translated quotation from this report:

     5.1 Conclusions.
     On the basis of the results in phases 1 and 2 we conclude that the Dutchdam:
     1. can be employed as a temporary flood defence and fulfils all the requirements and conditions set out by the Ministry.
     2. demonstrates its superiority by the way in which it can be speedily deployed and installed; its appearance is also in keeping with the local architectural ambiance.
     3. is stronger, more reliable and more cost-effective than panel barriers.
     The Dutchdam requires a greater initial outlay, but is more economical to manage and maintain.

     End of quote    

     Another unique achievement by Dutchdam

     Setting up the Dutchdam-Bold (a two-man job) takes no more time than one minute per metre length for the entire system, including the installation of the stanchions.
This can all be done without any help of mechanical means.

     The demountable flood barrier has in this case a defence wall 155cms high and all the panels are locked.

     To achieve a realistic comparison with a traditional system, all the parts are available on site at ground level, apart from the foundations and therefore not dependent on the type of storage used, for example within its own foundations, or transported from elsewhere.

     This exceptionally fast deployment time is just one of the special features of the Dutchdam. 


     Cobouw

     Dutchdam-Delta gets through the toughest collision test

  | Thomas van Belzen

     The temporary, folding Dutchdam-Delta has got through the first wave and collision tests. The Dutch National Water Board wished to establish whether the integrated, innovative aluminium construction is a safe alternative to sandbags or a partitioned defence at high water levels for avoiding an actual dike being breached.
     Location: the Deltagoot belonging to WL Delft Hydraulics in Marknesse, a concrete container 239 metres long, 5 metres wide and on average 7 metres deep. This ‘great technological institute’ chiefly made its name with the test tank by carrying out tests for the Delta Works. Comparable test locations can only be found in America and Germany.
     The Dutchdam-Delta is a folding dam which at high water levels can quickly be assembled by clicking together the parts. Stanchions on the back of the dam hold the construction erect. Nuts and bolts are nowhere to be found in this dam. Designer Corné Rijlaarsdam has already carried off a number of prizes. In Dublin a smaller version of the Dutchdam can be seen. “In the Netherlands too there are a number of plans in hand.

     No, I can’t name names. At the end of the month we expect to get an Australian contract.”, said Rijlaarsdam. The Dutch National Water Board (Rijkswaterstaat) “also believes in the innovative flood defence system”, but wants first to test its validity. “Purely for research purposes we want to know when the dam reaches breaking point”, reported the project leader Mariëlle van Dijk.

     Wave test
     With about a week needed for the preparation it’s not a matter of saying ‘just let’s test it’. The wave test is test 1. A wave generator which can whip up waves as high as  2 metres, makes waves of maximally 40 centimetres high, which simulate extreme river conditions. A gratified Rijlaarsdam watches the first water spectacle. “Yes, it’s looking good. But the real test comes this afternoon.”
     He is referring to test 2, the collision test. Not with a boat, for according to Henk Verheij, project leader of the WL, that is unrealistic for mimicking floating pieces of wood. “At high water in the Netherlands no boat other than a patrol boat is allowed to sail.” A block of wood weighing 300 kilos functions as the colliding object. With a speed of 1 metre per second the mass has an impact of 3000 kilos. After four failed attempts, the fifth produces the first visible crash, which was to bring a successful conclusion to the experiment for Rijlaarsdam. “We have taken an important step, as the last test was carried out on the basis of the toughest European guideline test.” Van Dijk indicated that the dam had not suffered a single scratch.
     In the coming weeks the Dutchdam will be subjected to further trials with extra wave and collision tests with varying wave heights and weights. If the tests are successful, Rijlaarsdam can be confident of receiving a validation document and implementation advice from the Dutch National Water Board.
     The spokesman, Peter Timofeeff, who works as a meteorologist with RTL, also sees good opportunities for the Dutchdam-Delta. “New flood defence systems are a dire necessity for the increasingly bad extreme weather conditions. Our dikes have not all been designed for these.”

     Dutchdam-Delta winner of the Aluminium Award 2006

     During the World Aluminium Congress which met in Essen/Germany on 20 september ult. the Dutchdam-Delta received the "All over" Jury Prize, the Aluminium Award 2006. The prize was presented by Dr. Ulf Merbold (astronaut on three space missions) to the designer of the Dutchdam: Corné Rijlaarsdam. 

     The international expert jury, under the chairmanship of Prof. Katgerman / TU-Delft, said: "It is an innovative Dutch solution to prevent flooding. It is an understandable and flexible product, easy to mount in a short time with a high durability. The way to store the barrier is brilliant. The dam has a big potential to be used all over the world in flood-prone areas".

     "The egg of Columbus 2006" Award 

     This is a joint press report from the Ministries of Housing, Spatial Planning and the Environment (VROM), Economic Affairs (EZ), Agriculture, Nature and Food Quality (LNV), Foreign Affairs (BZ/OS), Education, Culture and Science (OCW), Transport, Public Works and Water Management (VenW), Social Affairs and Employment (SZW), and Health, Welfare and Sport (VWS)

     Dutchdam is the winner of the "Ei van Columbus 2006 Award"

    The expert jury reached the following verdict:
Dutchdam BV, Woubrugge with ‘Dutchdam, the folding flood defence system’
The expert jury named this the winning entry, because “this visionary has an eye to the future and his work can be applied worldwide to address problems arising in places where spatial planning and water are in conflict. The aim of this is to preserve the landscape.

     The expert jury thinks it very valuable that for the purpose of the worldwide application of the Dutchdam, the entrants have already before now embedded this method well  and also built up the necessary networks”.

Download  Dutchdam-Duplo and Dutchdam-Delta brochure (in PDF) .   

Dutchdam, the folding emergency flood barrier

     The Dutchdam is a new hydraulic engineering instrument, a folding emergency barrier, which can be deployed at the point of need in the short-term if water levels rise. Novem awarded a substantial subsidy for research into barriers available on the market, after TNO and Rijkswaterstaat (The Dutch National Water authorities) had concluded that the Dutchdam afforded significant advantages for the environment and public safety in the Netherlands. In the meanwhile this folding flood barrier was recommended by the authorities as the solution of choice for the large-scale hydraulic engineering reconstruction of the Waalkade in Nijmegen.

     Complete on site

     The Dutchdam is a flood-defence barrier, which is immediately deployable in an emergency and is permanently installed in quays or quay walls alongside rivers where there is a risk of flooding. The greatest problems are encountered chiefly in inner cities, where the raising of the existing dykes and quay walls presents considerable difficulties.

     The extruded aluminium folding part of the complete construction is stored in a folded position in a housing construction, which forms part of a foundation construction. Therefore no logistical organisation is needed nor any storage buildings with surveillance staff (as would be required with partition walls).

folded Dutchdam-Delta

     Directly deployable

     This not only has important financial advantages but also offers a rapid deployment time, which greatly aids the safety aspect. As a result of climate change there is a greater likelihood of more substantial rainfall occurring in a shorter time, which means that the immediate deployability of the Dutchdam is very advantageous.

     In addition the very short reaction time makes it possible to make the decision about deployment at a later point in time. Unnecessary costs and the inconvenience regularly associated with flood barriers using partition walls are therefore minimised.

     The Dutchdam is available in two models: the Dutchdam-Duplo and the Dutchdam-Delta

     The Dutchdam-Duplo

     The Duplo features a folding wall of 50 or 80 cms. and folds up inside an aluminium housing construction in a quay or wall. This housing is covered over by the lowest part of the defence wall. It can take traffic and does not produce any obstacles in the immediate surroundings. The “lid” of the system is attached with hinges to the housing and is attached again with a longitudinal hinge to the second defence wall part, which is folded away under the lid. A vertical stanchion, which keeps the parts of the defence wall ready for operation, with a water-tight seal, lies under the folded parts of the defence wall in the housing construction.

     The Dutchdam-Duplo, as it is in eight places along the partly new boardwalks alongside

     the River Liffey in the centre of Dublin/Ireland. The flood barrier is always on standby and for

     deployment requires only a limited number of man-hours. 

     The Dutchdam-Delta

     The Dutchdam-Delta combines a number of unique characteristics. These characteristics make the Delta suitable for application for which emergency flood barriers such as partition walls were never intended. The great operational safety is the result of the high energy absorption potential, the heavy bolting of all the panels and sections to each other and the special functioning of the cover plate as a longitudinal support.

     The Dutchdam-Delta offers a defence wall height of 87, 125, 163 and potentially as much as 201 cms. The Delta is also folded up inside its own housing construction. This is made of concrete and in turn forms part of the foundation construction.

     Because of this the Dutchdam is capable of withstanding heavy forces from, e.g. strong waves breaking against it with objects floating on them, precisely in the region of the waterline (more than 100 kN/m2). For an emergency flood defence this is a high and completely new reference value. Also the fact that the complete flood barrier is completely accessible at ground level makes inspection simple and prevents dramatic and unexpected occurrences, such as are possible in cellar constructions.

     These characteristics offer hydraulic engineers many possibilities for realising responsible solutions in areas liable to flooding. Building ground beside large rivers is very desirable both for housing and for industry, but that is conditional on good measures being taken.

The bars are clearly to be seen which are pushed through the vertical stanchion to connect  all the panels and sections. Nuts and bolts are not used. At any time of the day or night this relatively robust and fast-working technology is very effective.

     
     Without nuts or bolts

     When the Dutchdam is unfolded it forms a completely closed construction. A special feature of the design is that the Dutchdam is assembled without the use of nuts and bolts and for this reason is to a great extent vandal-proof.

     The opposite is true for panel barriers. The uprights for these have to be secured into the front plate with bolts and the panels, which are held in place section by section with clamps, can be relatively simply removed by unauthorised persons, something which has certainly happened in recent years.

     The backbone of the folding flood barrier

     All the component parts of the defence wall of the Dutchdam are not only attached to each other, but also anchored to the ground, which means that in a collision, none of these parts can be forced out of the defence wall. Heavy bars have been positioned in the open spaces of the defence walls and these are pushed via openings in the vertical stanchion to a position half way across the open spaces in the adjacent defence wall parts. These bars form the backbone of the Dutchdam and ensure that the system has a high operational safety.

     The Dutchdam is also equipped with heavy rubber hinge profiles which can absorb shocks. The capacity of the complete system to absorb energy is for this reason very great. In the event of a disaster the Dutchdam will maintain the flood defence function even if there is distortion or displacement, with the result that it is still possible to put a disaster plan into action. This fulfils an important requirement of the Ministry of Transport and Public Works In addition the whole construction can be provided with an alarm installation to work either in the folded or in the unfolded position

     Collision risk

     An emergency flood barrier needs to be able to cope with risks such as collision. In such emergency conditions the colliding objects would be relatively small: a yacht or a rowing boat, floating pieces of roof blown off by the storm, a tree trunk or a caravan swept along by the current and the force of the waves, or barrels and pallets. Large objects, such as ships of some size with a greater draft, would not be able to reach the Dutchdam, for it is placed on a concrete base, which is part of the quay.

     Dutchdam and the infrastructure

     Because of the high operational safety of the system, the Dutchdam offers interesting possibilities for use in raising the height of the infrastructure in areas liable to flooding. The water authorities will check whether the flood defence height of quays, dikes and defence walls can cope with the changing water table.

     Quays and dikes often do not only hold back water, but also form part of the road network and/or public land in and around cities. The raising of these dikes and quays (if of course it is at all possible to do so) involves high expenditure. Checking water levels not only has consequences for the immediate water line but also for the safety and utility of the housing and industrial areas beyond. 

     Thesis: The more complex the infrastructure in areas liable to flooding, the greater the benefits of installing the Dutchdam.

     The differences between raising the height of the dike and installing the Dutchdam

     Raising the core of the dike with the unfolded Dutchdam in it.  When regarded as the projected alternative in those particular zones where a relatively small chance of flooding exists, the Dutchdam can be very effective and contribute to the quality of life and safety in housing and in industrial areas.

     a- Raising the height of the dike

— Extra use of land (often there is no more or insufficient room for this).

— Any possible thoroughfares/tunnels grow longer, exit and slip roads get higher, wider and longer, and the road surfaces need to be renewed, involving cables, mains, drains etc.

— As far as the subsoil can tolerate the heavier structure, correction to the underground services will increasingly occur and become expensive. In addition there will be limitations for the landscape and access roads.

     b- Adoption of the Dutchdam, even when there is a relatively small chance of flooding

— Placing a dam wall down to a depth of stable sand levels (an adjustment-free construction)

— Mounting the Dutchdam, the type, height and place of which can be determined by local conditions.

— According to the above outline the dike top serves as a bumper and limits the risk of collision.

—By placing a dam wall there the chance that the core of the dike will shift during saturation is nil.

     Result

     In addition to the considerable financial advantage, the increased safety has positive effects for the environment and creates an improved climate for investment locally.

     Overseas Projects

Dutchdam looks forward to a number of large-scale hydraulic engineering projects, both at home and in other countries, the first if which will be realised in 2006.

     Ireland

     In the centre of Dublin the Dutchdam–Duplo was installed in eight places at the beginning of 2005, so that at high water gaps in the flood defences could be quickly closed, as these give access to the hanging boardwalks above the River Liffey.

     Japan

     Dutchdam B.V. was invited to take part in a trade mission of the Ministry of Transport and Public Works to Japan, led by the Minister of State, Melanie Schultz van Haegen.
In Japan in particular climatic and water management circumstances regularly occur for which the characteristics of the Dutchdam are ideally suited. These circumstances are caused by the relatively steep and short way that the heavy rainfall has to flow, and every year this causes very great rises in the water level and great inconvenience on a number of occasions within a short period.

     The Test Centre for Innovations of the Dutch Ministry of Transport and Public Works

Both types of Dutchdam, the Duplo and the Delta, have been subjected to the research programme of the Test Centre for Innovations of the Ministry of Transport and Public Works, which makes it easier for the water authorities and the hydraulic engineering bureaus to work with the Dutchdam. Studies by the various experts of the Ministry of Transport and Public Works show that their critical appraisal of new technology serves to highlight the innovative character and strong points of the Dutchdam.

     The design of the Dutchdam is patented by the Woubrugge industrial designer Corné Rijlaarsdam, who last year received the Dutch Design Prize (2004) for professional products for the Dutchdam-Duplo. The hydraulic engineer Jan Bos, on the basis of his wide experience in the field of emergency flood defences, tested the Dutchdam for its compliance with the requirements of the TAW, the technical advice commission of flood defences, now the ENW, the expertise network for flood defences.

     You can download a brochure about the Dutchdam-Delta (in PDF format) which gives a more detailed description of its distinctive characteristics. On the basis of calculations of strength, it shows that what is involved here is dependable technology. The Dutchdam has been developed and tested according to the best Dutch hydraulic engineering traditions and is exclusively produced by reputable ISO-certificated firms.

     The development of the Dutchdam has been financially assisted by the financial subsidy given by Novem and by contributions from SPANBETON B.V. in Koudekerk aan den Rijn, Jos van den Bersselaar Constructie B.V. in Udenhout, and the Design Holding B.V. of the designer.