Funneling Air. Ventilator Shafts, IJ-tunnel North, Amsterdam, The Netherlands
Amsterdam's northside is separated from the centre by that famous river 't IJ. Ferries ply back and forth across its waters from the Central Train Station.
From about 1850 plans were being made for more efficient tunnels to connect both parts of the city. To that end two tunnels were constructed just outside the city center: the first and the second Coen-tunnels, respectively in 1966 and 2013. But perhaps more famous is the central IJ-tunnel opened in 1968. It's 1682 metres long and lies 20.32 metres below Amsterdam's 'average flood water level of Het IJ' (NAP).
An automobile tunnel like this, of course, needs to be ventilated. Architect Enrico Hartsuyker (1925-2013) in 1956 designed northern and southern ventilator shafts. His original plan was to have them as rounded funnels, but in practice they became squared off cones.
The photo shows the two at the north end of the tunnel.
Funneling Air. Ventilator Shafts, IJ-tunnel North, Amsterdam, The Netherlands
Amsterdam's northside is separated from the centre by that famous river 't IJ. Ferries ply back and forth across its waters from the Central Train Station.
From about 1850 plans were being made for more efficient tunnels to connect both parts of the city. To that end two tunnels were constructed just outside the city center: the first and the second Coen-tunnels, respectively in 1966 and 2013. But perhaps more famous is the central IJ-tunnel opened in 1968. It's 1682 metres long and lies 20.32 metres below Amsterdam's 'average flood water level of Het IJ' (NAP).
An automobile tunnel like this, of course, needs to be ventilated. Architect Enrico Hartsuyker (1925-2013) in 1956 designed northern and southern ventilator shafts. His original plan was to have them as rounded funnels, but in practice they became squared off cones.
The photo shows the two at the north end of the tunnel.