The upgrade of the Vertex Detector to form the central part of the SIlicon Tracker in DELPHI

The DELPHI Vertex Detector has undergone a final upgrade to meet the physics requirements at LEP200. The old Vertex Detector has been made longer by 24 cm and is now the barrel part of the SIlicon Tracker with a Very Forward part at both ends. The configuration and first results on the stability and performance of the barrel part is reported.