Troy Moore slowly and carefully adjusts both the rudders and the throttle on the tugboat Lincoln as he maneuvers into the lock at The Dalles Dam. As pilot of Shaver Transportation’s tugboat Lincoln, he’s pushing four giant barges, each 42 feet wide, all more than 200 feet long with the longest nearly 300 feet, lashed together and filled with 13,000 tons of wheat. The tow — that’s what he calls the whole assembly of barges and tugboat — just barely fits in the lock, and Moore listens intently to deckhand Sean Malloy as he calls out numbers.“120 ... 110 ... 100,” Malloy said, telling Moore just how close the bow of the front left barge is from the long wall of the lock and how much space he has to port — the left side of the tow — so he can maneuver. t’s something these inland sailors do at every dam lock and at every approach to a grain terminal. The tow is more than 600 feet long, and even five decks up in the Lincoln’s wheelhouse, Moore can’t easily see around the bow of the two front barges 500 feet in front of him.