  We consider a general 4n-dimensional quaternionic Kahler geometry with a free
action of the torus T^(n+1). The toric action lifts onto the Swann bundle of
the quaternionic Kahler space to a tri-holomorphic action that commutes with
the standard H* action on the bundle. By matching Pedersen and Poon's
generalized Gibbons-Hawking Ansatz description of the total space with the
Swann picture we extract the local geometry of the quaternionic Kahler base.
Specifically, we obtain explicit expressions for the quaternionic Kahler metric
and Sp(1) connection in terms of a set of reduced Higgs fields and connection
1-forms that satisfy a reduced Bogomol'nyi-type equation. We find, moreover,
that these Higgs fields can be derived from a single function V satisfying a
system of linear second-order partial differential constraints. In four
dimensions, corresponding to the case of self-dual Einstein manifolds with two
commuting Killing vector fields, our formulas coincide with those obtained
through a different approach by Calderbank and Pedersen. Finally, we show how
to construct explicit solutions to the reduced Bogomol'nyi and V equations by
means of Lindstrom and Rocek's generalized Legendre transform construction for
a large class of quaternionic Kahler manifolds related to the c-map.
