Have you ever been caught in a traffic jam? Maybe on the beltway or I-95? And I mean a big traffic jam. Not just an hour or two. I mean a whole day.
Well, that was the situation here on the canal back in the 1870's. After a five day trip from Cumberland on a boat loaded with coal, captains could be stuck in traffic a whole day - if not more- waiting to unload down in Georgetown.
And then maybe you'd think, "I wish there was an exit ramp around here!"
Well, the exit ramp turned out to be something called the Inclined Plane. Now this was first proposed in 1844 and again 20 years later, but they didn't get around to building it till 1875.
The Inclined Plane was a complex structure composed of a big "bathtub" with doors on either end and a ramp that you could use to slide canal boats down to the Potomac River and back up again. It's "bathtub" part, or caisson, was awfully big: 112 ft. long, by 16 ft. wide by 8 ft. high.
The fully loaded caisson -boat and water - weighed 400 tons - that's about 20 school buses. You needed a lot of support for all that weight, so the caisson rested on six six-wheeled trucks fitted onto four iron rails, 600 ft. long. And with a system of cables and pulleys, you'd roll the caisson down on those iron tracks at a four and a half degree grade. As the caisson was going down, two 200 ton counterweights on either side were going up. The whole thing was powered by a turbine engine that used water from the canal.
Once you got your boat out into the Potomac, you could hook up to a tugboat that pulled you all the way to Indian Head, Maryland, to a government coal depot.
When the Inclined Plane opened in 1876, it was the largest in the world. In 1878, a model of the Inclined Plane was exhibited at the Paris World's Fair.
But there was a big accident in 1877, when the anchors for the pulleys snapped, and a loaded caisson and the counterweights plunged to the bottom of the plane. Three men were killed. After that, the caisson still carried boats, but the water was drained away before the caisson moved.
There were some upgrades made. Steel rails replaced the iron ones. Then they started to use steam power. In 1878, around 1,900 boats used the inclined Place.
The success of the Inclined Plane was short lived. Canal traffic began to decline and it was used only sporadically through 1889, when a big flood hit. Then, finally around 1907, the Washington and Maryland Railroad tore it up. Now the Capital Crescent Trail goes through where the Inclined Plane used to be.
By the way, if you're traveling by car, you can still take a bypass around Georgetown. It's called the Whitehurst Freeway. Some things never change.