  The dynamics of spherical particles driven along an interface between two
immiscible fluids is investigated asymptotically. Under the assumptions of a
pinned three-phase contact line and very different viscosities of the two
fluids, a particle assumes a tilted orientation. As it moves, it causes a
deformation of the fluid interface which is also computed. The case of two
interacting driven particles is studied via the Linear Superposition
Approximation. It is shown that the capillary interaction force resulting from
the particle motion is dipolar in terms of the azimuthal angle and decays with
the fifth power of the inter-particle separation, similar to a capillary
quadrupole originating from undulations of the three-phase contact line. The
dipolar interaction is demonstrated to exceed the quadrupolar interaction at
moderate particle velocities.
