Much work has been done on the existence and uniqueness of broken Lefschetz
fibrations such as those by Auroux et al., Gay and Kirby, Lekili, Akbulut and
Karakurt, Baykur, and Williams, but there has been a lack of explicit examples.
A theorem of Gay and Kirby suggests the existence of a broken Lefschetz
fibration of S^4 over S^2 with a 2-knot fiber. In the case of a spun or
twist-spun torus knot, we present a procedure to construct such fibrations
explicitly. The fibrations constructed have no cusps nor Lefschetz
singularities.Comment: 28 pages, 21 figure