The city of Haarlem wanted to create a barrier free passage where a main arterial route for motor traffic and a main cycle route along a river bank crossed each other’s paths. But there was no space for an overpass, and a tunnel right next to a river was not such a great idea either. So designers came up with the plan to lead the cycle route through the river under the approach span of the two existing drawbridges for the arterial road. A perfect idea, but there was just one small problem: there was not enough clearance, the bridges were almost 30 centimetres or a little under a foot too low. So what do you do? That was not so hard in a country full of civil engineers who specialize in dams, dikes and flood gates: you simply lower the cycle route below the water level so that there is enough head room for the people cycling there.
The designers also faced some other challenges in building this bridge/underpass under the existing Buitenrustbruggen. One house boat had to be removed and there was a lot of paperwork involved because of the “building in open water”. The main difficulty was building a structure that wouldn’t start to float in the fluctuating water level of the river ’t Spaarne. That is why the cycle path was built in a steel waterproof “box” with a height of just 50 centimetres, that is kept in its place with sufficient weight. The river water level can rise and fall without the box moving. The gutter and the rain water drainage are hidden in the box, all you see is a row of holes. Two pumps take care of keeping the surface of the cycle path – below the water level of the river – rain water free and dry. A final and important challenge was making this underpass so attractive that people on their bicycles would want to use it. The designers tackled all these challenges very successfully.
The design was by IPV Delft creative engineers. I have shown you other examples of their work before. Most notably the Hovenring in Eindhoven and a cycle bridge in Enschede. What all three have in common is the way the lights are fitted in the railings. The design of the Haarlem bridge/underpass was formalised in August 2009. The structure was opened to the public late June 2011.
The cost for this innovative bridge/underpass was 2.31 million Euros, paid for by the province of North-Holland (80%) and the city of Haarlem (20%). The steel bridge is 110 metres long, 6.5 metres wide and the steel alone weighs over 200 metric tons. It was shipped to Haarlem from the factory in Amsterdam in one piece. The extra weight to keep it in place was only added on the final position, which sank the bridge in position on the previously constructed foundation under water to which it was firmly connected.
In the video you can see that it is heavily used by all types of people cycling on a variety of bicycles. The city of Haarlem can be proud to have created one more barrier free cycle route in the Netherlands. And cycling under the water level on a cycle ‘bridge’ is a unique experience, even in the Netherlands.
Video showing the semi-submerged Haarlem bicycle bridge
Google Streetview shows the old situation: a level crossing. This level crossing was removed shortly after the underpass/bridge was opened. The bridge can be seen in the CycleStreets photo database.
BICYCLE DUTCH 
An older example of bridging water and tunneling infrastructure can be found in Berkel & Rodenrijs. http://goo.gl/maps/jezMx As you can see, the cycle path is not submerged, but too low to have a safe crossing for cyclists. 1.90m or something.
That is beautiful, and inspiring! There is a place in my city where such a bridge/underpass could be appropriate. However, one of our river’s issues is that although the flow is controlled by dams in various places, the water level can change quite dramatically, sometimes very rapidly. Is this not an issue here? If it is an issue, how has this been planned for?
In the netherlands water level is controlled very finely.
The water management authorities sometimes talk about raising lowering water levels in some lake by 1 cm.
There’s an example in today’s papers: the railroad bridge over a new canal is too low, being 7,21 meters above water level instead of 7,25 meters. As a temporary solution the water level in the canal has been lowered, but that is not to be the final solution, because the water level is then too low for the deepest-lying ships.
This is incredible!
The old situation would be dream infrastructure in Britain… If they ever build such an underpass in Britain, it would be about 50cm wide, with gates every 20 metres and without the pump at the bottom. When they realise it gets flooded, they’d install “cyclist dismount” signs.
I like the Coppermill video. I guess it passed health&safety checks because it’s not a fire hazard?
Thanks for another interesting post. The British comparison is ridiculous. Thanks also to platinum for that one.
Fantastic, and I also noticed that the cost of this appears (on the face of it) to be a lot less than a similar piece of infrastructure that would be needed to accommodate motorized vehicles. I wish my country would wake up to the spectacular mindset of the Dutch. I salute you my dutch friends!
I’m not saying that the Haarlem underpass is not a good solution, I’m just wondering if a bicycle underpass with the roadway below the surface of the river is particularily unique. There are two of them in Swedish city of Gävle, which is a fairly lousy bicycle city by Dutch or Danish standard, albeit not built as submerged bridges.
There are many locations (also in the Netherlands) where a cycle track is below the water level of a water right next to it. But those tracks are usually on one side and they are separated by a wall that keeps the water out. (See this example.) The difference here is that it is a bridge with on either side water that is higher than the surface of the cycle track.
[quote]The difference here is that it is a bridge with on either side water that is higher than the surface of the cycle track.[/quote]
… and with water under the cycle track connecting the two bodies of water.
That is beautiful.
Meanwhile in Britain…
That’s the National Cycle Network Route Number 1 you’re criticising there!
It would have been better if the video had been filmed after rain, to show the four inches of muddy water in the dip. Also the dip was a lot less smooth last time I went through a few weeks ago, more stones and more churned up. Oh and you have to look out for the occasional car going through (!)
perfect for my recumbent bicycle…:-)
So that’s why you need a helmet!
For the dogs this underpass is fine.
High quality water working technique for the sake of cycling. It’s hard to get more Dutch than that.