a b s t r a c tThe construction of a km 3 -scale neutrino telescope -the Gigaton Volume Detector (GVD) in Lake Baikal -is the central goal of the Baikal collaboration. During the R&D phase of the GVD project in 2008-2010 years the basic elements of GVD -new optical modules, FADC readout units, underwater communications and trigger systems -have been developed, produced and tested in situ by long-term operating prototype strings in Lake Baikal. The prototyping phase of the GVD project has been started in April 2011 with the installation of a three string array (prototype cluster) which comprises all basic elements and systems of the GVD-telescope in Lake Baikal. We describe configuration and technical design of the GVD, present selected results obtained during 2008-2010 with prototype strings, and describe configuration and design of the 2011 prototype cluster.

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