Lock 63 1/3 at Mile 154.5 on the Chesapeake and Ohio Canal towpath

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Lock 63 1/3 is located at Mile 154.5 on the Chesapeake and Ohio Canal towpath. It is not accessible by vehicle, so reaching it requires hiking or biking 1.9 miles (one way) downstream from the parking area at the Paw Paw Tunnel. See the Locks and Lockhouses web page for an interactive location map.

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Lock 63 1/3 on the Chesapeake and Ohio Canal is one of three locks that are located on the downstream side of the Paw Paw Tunnel in what is known as the Paw Paw Bends. It is a 1.9-mile hike or bike ride from the tunnel parking area at the Paw Paw Tunnel Campground, but since the towpath is mostly level, it is an easy journey. If you want some serious exercise, you can take the Paw Paw Tunnel Hill Trail on the way to the lock and return through the tunnel on your way back. The trail goes over the mountain starting at the tunnel’s upstream entrance and comes out on the towpath .4 mile from the downstream entrance.

Over the course of six miles in the Paw Paw Bends, the Potomac River zigzags three times and is flanked by rock cliffs. Cutting a canal into the rock along the river would have been next to impossible, so canal engineers had two choices. One, they could dam the Potomac at the downstream end of the Bends so the river could be made deeper and thus navigable at all times. Boats would leave the canal and travel directly on the river.

Illustration of the canal route using the Paw Paw Tunnel (click to enlarge)

A second option was to create a nearly six-mile shortcut around the Bends by cutting through the interior. The only problem was that there was a mountain in the way. With an estimated cost of $33,000 and a completion date of two years, it was decided to tunnel through the mountain, a decision that nearly bankrupted the C&O Canal Company. Work began in 1836, and when the tunnel opened in 1850, twelve years behind schedule, it had cost $600,000. Funds actually ran out, and no work was done from 1842 through 1847.

The C&O Canal Company planned to dig four locks between the downstream end of the Paw Paw Tunnel and the Potomac River but only ended up needing three. Since the entire canal had been planned and the locks were already named, it was decided to skip the nomenclature for Lock 65 and just use the names Lock 62, Lock 63 1/3, and Lock 64 2/3 for the three locks.

Lock 63 1/3 is one of thirteen locks (58 through 71) at the upper end of the Chesapeake and Ohio Canal that was made from a composite of wood and uncut stone. The reason is because this end of the canal was constructed in the 1840s (opened in 1850), and by this time it was evident that the railroad was going to put it out of business. To save money, the walls were made from uncut stones with large gaps between them, which was not going to hold water. A wood lining was attached to help solve the leakage problem. In most cases the wood didn’t work that well, and starting in 1891, much of it was replaced with concrete. That does not appear to be the case at Lock 63 1/3 since the uncut stones are still visible. None of the wood exists today, but you can still see the bolts in the stone walls that held it in place. (Locks were typically made from cut stones that fit tightly together with mortar and had a very finished look.)

Bolts in the wall of Lock 63 1/3 on the Chesapeake and Ohio Canal were used to anchor a wood lining to the stone

While no wood remains on the walls, there is some along the bottom of the lock, with a good bit remaining at the upstream end. I am not aware of wood being used to line the bottom of a composite lock, but perhaps it was. It is amazing that the wood on the walls has disappeared, yet wood soaking in water for 175-plus years is still around. The wood was “kyanized,” meaning it was treated with mercuric chloride to prevent decay. This seems to have worked very well.

Wood at the bottom of Lock 63 1/3 on the Chesapeake and Ohio Canal

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