Canal boats were loaded on and off of cradle cars that carried the boats on rails up the inclined plane.
At the bottom of Plane 9 West rails fastened to sleeper stones carried the cradle cars into the water of the canal. The cradle cars that rode on these rails would go almost completely underwater with only their timber sides sticking out. Canal boats would be pulled by mules through fenders into the cradle cars before being secured in place by fastening their lines to cleats on the cars. After the boat was secured and the mules were detached, the plane tender, sitting in the powerhouse halfway up the hill, would engage the winding drum and the wire rope, which was attached to the cars with a clevis pin, would then pull the cradle car and boat out of the canal and up the inclined plane. The combined weight of the cradle car and boat could, depending on the cargo in the boat, approached 130 tons.