This paper presents measurements of the mass of the W vector boson
from the CDF and D0 experiments using data collected at sqrt s = 1.8 TeV
during the 1994-1995 data taking run.  CDF finds a preliminary mass of M_W =
80.43 +/- 0.16 GeV and D0 measures a mass of M_W = 80.44 +/- 0.12 GeV.