Twin tube 6.6 km-long undersea highway tunnel using two 11.3 m-diameter Herrenknecht Mixshields from an artificial polder at Terneuzen on the south side to 20 m-deep concrete caissons at Ellewoutsdijk on the north side. Face supported by water/bentonite mix and all spoil is pumped to surface separation plant. Much of the tunnel will be in the very dense Boom clay which varies in thickness between eight and 38 m in the middle of the Schelde, but sand above and below this stratum is of variable quality, sometimes containing glauconite. At deepest point tunnel is 65 m below sea level, and machines are designed to work up to 8.5 bar. Two pressure chambers on each TBM allow transfer of divers by transport capsule from a pressurised habitat at surface to the face for continuous operations, saturation diving over long periods if necessary. Interlocking gasketed lining of 7 segments and key. 26 cross-passages planned at 250 m intervals where five-ring special sections are being installed on advance and freezing will be necessary. Service duct installed at floor level and invert backfilled on advance. Rear 160 m of TBM gantry supported by roller brackets installed to sidewall. Two Schoma locos required on each material train to cope with 4.5% gradient at entrance ramp. TBMs have advanced 600 m in east tube and 500 m in west tube. Contracting jv KMW are to design, construct and maintain tunnel for first 10 years of operation. Opening date March, 2003. Visit www.westerscheldetunnel.nl for further information. February 2000.The record-breaking saturation diving operation conducted at 6.5 bar pressure to install 12 larger profile cutters on each of the TBMs has been successful and both machines are boring again. The changeover took six working days for each machine, and 11 days including decompression. See Hall of Fame entry or visit www.herrenknecht.de August 2000.   KMW reports both TBMs 2 km into 6.6 km drives following recent installation of profile cutters by divers when excessive pressure in waterbearing sands caused distortion to shields. Now advancing at 14 rings/day in Boom clay without difficulty. Visit www.westerscheldetunnel.nl and www.herrenknecht.de December 2000.   The two Herrenknecht Mixshields excavating the Westerschelde tunnel are reported to break record after record. 'Sara', the machine boring the east tube, has recorded an advance of 32 metres in just 24 hours. Only 724 metres are still to go to reach Zuid-Beveland. 'Neeltje Suzanna' only has to bore 210 metres and is expected to arrive in Ellewoutsdjik at the end of January, 2002. Visit www.westerscheldetunnel.nl and www.herrenknecht.com 03/02.   'Sara', the second Herrenknecht Mixshield has completed on 12th February the east bore of the Westerschelde tunnel project following 'Suzanna' which reached its final destination on the west tube three weeks before. See Hall of Fame entry or visit www.herrenknecht.com and www.westerscheldetunnel.nl 09/02.  Her Majesty Queen Beatrix of the Netherlands inaugurated the Dutch longest road traffic tunnel on 14th March. The Zeeuwsch Vlaandren province is cut off from the other parts of the Netherlands by the Westerschelde port entrance to Antwerpen. The new link will provide a faster and more economical route for around 27,000 vehicles a day between Ellewoutsdijk in Zuid-Beveland and Zeeuwsch Vlaanderen near Terneuzen. Central Zeeland and Zeeuwsch Vlaanderen will be permanently linked together. The tunnel is a 6.6 km-long undersea highway tunnel consisting of two tubes, each with two 3.5 m-wide lanes, with 26 cross passages every 250 m. The builders are KMW (Kombinatie Middelplaat Westerschelde), a JV of Philipp Holzmann, Wayss & Freytag, Franki, BAM Infrabouw, Heijmans and Voormolen. 'Sara' and 'Suzanna', two Herrenknecht Mixshields, 11.3 m in diameter, started from an artificial polder at Terneuzen and bored through to 20 m-deep concrete caissons at Ellewoutsdijk. The bulk of the tunnel is running at up to 60 m below sea level, making it the deepest ever to be driven. Both tubes have a concrete lining of 53,000 segments. The €726 million tunnel is open to road users since 15th March. Visit www.westerscheldetunnel.nl and www.herrenknecht.com 12/03.