Following a collision, stranding, or sinking or an oil spill, a port or channel may be partially or completely closed, sometimes for days or even weeks. The costs of such closure, including lost business and maritime traffic disruption, can run to many millions of dollars. The collision and subsequent sinking of the sulfur barge Duval 2 in the Houston Ship Channel in 1992 is a case in point. The barge was split almost in two and effectively blocked the channel to all traffic for 24 hours. Limited one-way traffic resumed after the barge was pushed to one side of the channel; two-way traffic was not restored for almost two weeks. Some 200 ships were delayed, causing operational disruptions to local refineries and other industries. The added operational expenses per vessel, for each day delayed, averaged $20,000 (American Waterways Operators, personal communication, April 1993).
Salvors assist in minimizing or even preventing the closure of ports and waterways by rapidly repairing or removing vessels that block passage, or by minimizing the amount of oil spilled from damaged vessels and thus the duration and extent of cleanup operations. In the Duval 2 incident, salvage was prolonged because resources were slow in arriving. Salvage equipment had to be dispatched from New Orleans, and passage to the job site was delayed by fog. A foreign-flag heavy lift barge was available in the Houston area, but requests for its use were not made.
The closure of ports and waterways is a particular problem in the Gulf of Mexico region, due to the narrow channels that must be negotiated to reach or depart from key ports and heavy traffic in those channels. The problem of port closure due to vessel incidents, however, is not limited to Gulf ports. For example, in 1990, the oil tanker BT Nautilus grounded in the Kill van Kull Channel of New York Harbor, spilling over 6,200 barrels of heavy oil and causing partial closure of the busy waterway for several days.