Let $f:X\rightarrow B$ be a well-behaved $T^{3}$-fibration, $b_{0}\in\Delta$ a point. The monodromy group of $f$ at $b_{0}$ is the image of $\pi_{1}(U-\Delta,b)\rightarrow SL(H_{1}(X_{b},{\bf Z}))$, where $U$ is an open neighbourhood of $b_{0}$ as given in Definition 1.2, and $b\in U$ a base point.