Major Texas shipping channels that deliver crude oil for more than one-tenth of the nation’s refining capacity were shut for a third day on Monday, as the cleanup from a spill threatened to last through the week. The Houston Ship Channel was shut on Saturday following a collision between a Kirby Inland Marine oil barge and a cargo ship, spilling some 4,000 barrels, or 168,000 gallons (636,000 liters), of residual fuel oil. The channel allows oil barges and cargo ships to sail from the Gulf Coast to refiners and terminals further inland. As of 7 a.m. CST (noon GMT), the channels to Houston and Texas City, Galveston and the Intracoastal Waterway remained shut. The Coast Guard said 43 ships were waiting to go out from the port of Houston and 38 ships were waiting to come in, up from 40 outbound and 35 inbound on Sunday evening. A warning to mariners issued by the Coast Guard on Sunday said portions of the Houston channel and its offshoots to Texas City and Galveston, Texas, along with a portion of the Gulf Intracoastal Waterway, could be closed through March 29 or longer, depending on the requirements of a cleanup. Kirby Inland Marine is operated by Kirby Corp. Cleanup crews have pumped all of the remaining fuel oil from the barge, which has been refloated and moved to a different position near the site of the collision in the channel. Exxon Mobil Corp said on Sunday the closure had not yet affected operations at its 560,500 barrel-per-day refinery in Baytown, Texas, the nation’s second largest. By Terry Wade