Collaborative shipping refers to multiple independent shippers consolidating their freight flows to share the same set of carriers for goods transportation, in order to reduce cost. In this paper, we design a collaborative shipping marketplace for spot shipments, where the shipping demands are bundled dynamically without premeditated planning by the shippers. Collaborative shipping requires a neutral third party as an orchestrator, who identifies the bundling opportunities, matches with the carrier, and allocates the cost among the shippers. We propose a Blockchain based application that enables decentralized and transparent participation of shippers and carriers in choosing the matching of bundled demand with supply, without an orchestrator. A multi-disciplinary approach with techniques from multi criteria optimization, group decision making, cooperative game theory, and electoral voting are used to develop the distributed collaborative shipping application using Blockchain.