THE DRECHT TUNNEL

IN NOVEMBER 1977 THE DRECHT TUNNEL UNDER THE OLD MAAS NEAR DORDRECHT IN THE NETHERLANDS WAS OPENED TO TRAFFIC. IT LIES ON THE ROUTE OF STATE HIGHWAY 16 WHICH HAS BEEN UPGRADED TO MOTORWAY STATUS. THE STRUCTURE CONSISTS OF FIVE SECTIONS; A PORTAL AND A STRETCH OF TUNNEL ON EITHER SHORE TOGETHER WITH THE UNDERWATER TUNNEL PROPER. IT IS TO DATE THE WIDEST SUBMERGED TUNNEL IN THE WORLD. THE ANTICIPATED TRAFFIC VOLUME REQUIRED AN EIGHT LANE TUNNEL. THEY ARE ARRANGED AS FOUR TRAFFIC TUBES WITH TWO INTERMEDIATE SERVICE TUNNELS. THE EXTERNAL WIDTH OF THE STRUCTURE IS 49 M. THE THREE INTERMEDIATE SECTIONS WERE CONSTRUCTED IN A DRY DOCK, FLOATED INTO POSITION AND JOINED UP. THE TOTAL LENGTH OF THE TUNNEL BETWEEN PORTALS, I.E. INCLUDING THE SECTIONS CONSTRUCTED IN OPEN CUT, IS ABOUT 570 M, THE OVERALL LENGTH INCLUDING THE RAMPS IS 840 M. THE TOTAL COST WAS MORE THAN 130 MILLION DUTCH FLORINS.