  The energy and momentum spectrum of the spin models constructed from the
vector representation of the quantized affine algebras of type $\B$ and $\D$
are computed using the approach of Davies et al. \cite{DFJMN92}. The results
are for the anti-ferromagnetic (massive) regime, and they agree with the mass
spectrum found from the factorized S--matrix theory by Ogievetsky et al.
\cite{ORW87}. The other new result is the explicit realization of the fusion
construction for the quantized affine algebras of type $\B$ and $\D$.}
