Monday, May 26, 2008

More on the Susquehanna Canal

We're still in the field in Calvert County through tomorrow (Tuesday), weather permitting. I thought I say a little more about the Susquehanna Canal, and specifically the Octoraro Locks.

The canal was completed in 1803 and fell into disuse around 1830, the new Susquehanna Canal on the Harford County side of the river taking its place.

The Harducoeur map of 1799 shows a portion of the canal as planned. The locks on which the Archeological Society of the Northern Chesapeake is currently working appear near the center of the image above, on the right hand side of the confluence of Octoraro Creek and the Susquehanna River. (If you are having trouble visualizing where it is today, the right hand side of the map is roughly north and the locks are just below the Conowingo hydroelectric dam.)

In 1817 Benjamin Henry Latrobe, one of the nation's first premier architects and canal engineers, redrew an earlier map of his showing the canal locks as-built (see below).

The locks are indicated just above the center of the image. Latrobe accurately depicted the locks as perpendicular to the main axis of the canal. That is to say, whereas Harducoeur expected the canal locks to be in line with the canal, Latrobe understood that they would not. The canal paralleled the river and, just before reaching Octoraro Creek, turned 90 degrees to the river, the engineers taking advantage of the topography to effect the decent in elevation with one set of three locks. The canal, upon descending through the locks, turned 90 degrees again, this time to parallel the river as before, extending downstream to a viaduct that carried the canal over the creek.

The current archaeological effort examines the construction of the locks and investigates buildings associated with the construction, operation, and maintenance of the canal.


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