Chicago Tug: Up and Down

In Chicago we have the appropriately named Chicago Lock. As with many familiar things its existence has been minimized even though its historical significance is great.

It is a simple lock. To equalize water levels between the Chicago River’s Main Branch and Lake Michigan it opens one gate or the other a smidgen, and lets the water in or out. Of course the Main Branch’s flow was reversed — much to the horror of all that live downstream — and so the lake flows into the river.

Up until my late forties there was several feet difference between the lake and river. So much so that during the process of locking the boat it would wildly swing in the turbulence. It was all we could do to hang on to the skimpy lines that the lockmaster provided for we were not allowed to use our own dock lines to hold in place.

Then one year, after record high water levels the lake started to recede and it has never recovered. I remember once after a night of especially heavy rain, we motored our sailboat Lenore to the lock at the end of the boating season and were turned back. The river was higher than the lake and had to be drained by a complicated formula of opening locks and draining water into the Mississippi and beyond.

Now Carrie Rose finds herself in a waterway controlled by locks: forty-four to be exact. The Trent Severn is particularly interesting especially for three of its locks. Two of these are hydraulic and one, the Big Chute, is, well it is hard to describe. The Big Chute refers to the cataract next to the lock that spills down 58’ into the next portion of the waterway.

The Big Chute is a marine railway on steroids. It is like a wet, dry dock. The boat is driven into hanging straps, secured by lifting the boat a bit and then it moves up on rails over the hill and is gently settled back in the water 58’ higher or lower depending on which way you’re going. Carrie Rose barely knew what hit her. We arrived, they flagged us in and ten minutes later we were tied up to the lock’s overnight pier.

The next unique lock was the Kirkfield Hydraulic Lift Lock. Here too we were whisked in, being the last boats for the day and again in ten minutes we were tied up to its overnight space on the wall. The hydraulic in the title refers to the way it works. It consists of two big tubs full of water balanced on a humongous steel shaft. An underground series of valves connect them.

Boats are driven in and tied off. Then the upper tub is filled with a foot of water more than the lower and the whole contraption moves. Slow at first, then it accelerates. While leaning over the rail to photograph the process it came up fast enough that I instinctively back away. One tub, boats and all went up and the other tub with one extra foot of water went down. The operation was so smooth that it was a shock to find ourselves forty-nine feet higher. I fired up the engine; we untied from the tub and motored into a long narrow concrete lined canal.

Kirkfield Lock was the culmination of a long day going up. We traversed Gamebridge (11’), Thorah (14’), Portage (13’), Talbot (14’), Bolsover (22’) and Kirkfield (49’) locks for a grand total of 123 feet up. It was one hot sweaty day and we were wasted. Carrie Rose was sealed as tight as possible, the generator started and our much appreciated but wimpy air conditioner turned on. The sun was low on the horizon before we dared to venture out into the diminishing heat.