His tow, like most, was 105 feet wide. The lock chamber is 110 feet wide. To park his 1,130-foot, 19,200-ton craft, he had as much space as a car does in a crowded parking lot.
From a fascinating piece on the New York Times website about two ageing locks on the Ohio and the traffic that passes through them.
h/t Alex Tabarrok on Marginal Revolution