The paddle shaft is located slightly aft of amidships. It is the largest feature on the site regularly exposed above the river bottom. The structure is actually two shafts, one on the port and one on the starboard side, joined in the middle by the cranks. The baseline passes through the cranks at 102 feet. The shaft is twelve inches in diameter.
A wooden piling rests over the entire length of the port shaft extending north 35 feet from the crank. It is very likely a piling that once marked the site as a navigation hazard but has since been pulled out of the bottom and dropped on the site. It has been left off the site map to provide an unobstructed view of the shaft.
In 1883, Ross's workers removed the pillow blocks holding the paddle shaft in place and moved it from its mountings (Russell 1883). They pushed the starboard end well aft while the port shaft shifted only slightly aft of its original alignment. This movement also pulled the starboard crank off the crank pin. The crank pin is normally attached to only one crank and rides free in the other. This arrangement is called a drag link and allows the paddle shaft to shift as the guards settle without straining the cranks (Ward 1860:105-106). On the Maple Leaf the crank pin is attached to the port crank.
The wrought iron cranks on the center end of each paddle shaft are attached to the shaft by heating and shrinking over the end (Ward 1861:105). Their overall length is 6 feet 10 inches with a thickness of 10 3/4 inches at the paddle shaft tapering to 8 inches at the crank pin. The distance between the center of the paddle shaft and the crank pin center is 5 feet 6 inches, making the piston stroke 11 feet. This confirms historical documentation indicating an 11 foot stroke (Heyl 1969:171).
The port shaft is broken 14 feet from the crank, near the outboard end. Two narrow bands encircle the shaft near the crank and probably mark the location of one pillow block mount. The bands are 1 1/2 inches wide and are spaced 12 inches apart. Unexpectedly, this is the only feature noted on the shaft. The eccentric used to power half of the engine's valve system is conspicuously missing.
The short section broken off the port shaft is 5 feet 10 3/4 inches long and located slightly aft of the main shaft. This piece carried the radial paddle wheel and includes two paddle wheel flanges and wooden paddle arms. The flanges are 4 feet 5 inches in diameter, 10 inches wide and spaced 30 inches apart. The paddle arms projecting into the river bottom are partially intact but all of the paddle arms above the mud are broken off at the flange. Each wooden arm is attached to the flange with two bolts. The arms are approximately 8 inches wide and 2 inches thick. Arm length was not recorded but paddle wheel diameter was 27 feet (Heyl 1969:171) making the arms approximately 12.5 feet long when allowing for the shaft and flange.
The starboard shaft is complete and undamaged despite being pushed aft on the out board end. It is also vertically displaced, rising approximately 2 feet from the crank to the end. The starboard shaft is actually two pieces joined by a large coupling located 4 feet from the crank. The coupling consists of two flanges that fit over the end of each shaft segment. The flanges butt together and are fastened around the perimeter by large bolts (Figure 6). The Maple Leaf broke its paddle shaft shortly after leaving the port of Charlotte, New York on July 16, 1859. The local Rochester, New York newspaper mentions the installation of a new shaft (UA July 16, August 1, 1859). It seems instead, the old shaft was fixed or a new section added with the use of the coupling. Both the port and starboard shafts were manufactured at the same time by the Kingston Foundry when the Maple Leaf was built. The port shaft was forged as one section indicating the starboard shaft was also originally one piece. The coupling is evidence of repair work.
Two cast iron paddle wheel flanges are attached near the end of the shaft to hold the starboard wheel paddle arms. They are spaced 4 feet 2 1/2 inches apart on center. Each flange is 2 feet 9 1/2 inches in diameter and 12 inches wide at the base. Twenty wooden paddle arms were bolted to the out board side of each flange. They measured 7 by 3 inches and tapered at the end to fit the flange. The inside flange has been broken in half leaving the lower portion in place under the shaft with paddle arms still attached. The lower ends of all the arms are deeply embedded in the bottom making it impossible to determine their length or to examine the floats. All of the paddle arms on the outside flange are broken off.
The flanges on the port and starboard side are very different. The Maple Leaf had a career punctuated with breakdowns, repairs and rebuilding (Girvin 1993:71-99). When the shaft broke in 1859, the starboard flanges may have been damaged. Cast iron is brittle and the flanges could easily crack if subjected to too great a stress. Another possible explanation is an incident that occurred in 1854 involving damage to one of the paddle wheels. During passage to Toronto, one of her wheels was "carried away by the sea" (DU April 17, 18, 1854 in Girvin 1993:78). The type of repair and which wheel was damaged are not mentioned. While either incident could have resulted in new flanges, there is no way to determine the precise date or reason for the replacement.