... sail through the canal and under the Aerial Lift Bridge. The gargantuan counterweights slowly descend, raising the 900-ton span of the Aerial Lift Bridge nearly 140 feet in the air to allow 1000-footers [ore boats carrying taconite pellets] and salties [ocean-bound ships] to pass into the harbor. The canal was excavated in 1871 and is a deceptive 300 feet wide and 1,650 feet long. The first aerial transfer was erected in 1905 and modernized in 1929 to what you see today. It can rise to its full height in 55 seconds.