  Small-diameter Muon Drift Tube (sMDT) chambers have been developed for the
ATLAS muon detector upgrade. They possess an improved rate capability and a
more compact design with respect to the existing chambers, which allows to
equip detector regions uninstrument at present. The chamber assembly methods
have been optimized for mass production, while the sense wire positioning
accuracy is improved to below ten microns. The chambers will be ready for
installation in the winter shutdown 2016/17 of the Large Hadron Collider. The
design and construction of the new sMDT chambers for ATLAS will be discussed as
well as measurements of their precision and performance.
