The Collaborative International Dictionary of English v.0.48:
Transshipment \Trans*ship"ment\, n. The act of transshipping, or transferring, as goods, from one ship or conveyance to another. [Written also transhipment.] [1913 Webster]WordNet (r) 3.0 (2006):
transshipment n 1: the transfer from one conveyance to another for shipment