Specifications of the lockstation

Eight locks (in flight) with a total lift of 24.1 m (79.1 feet).

The Ottawa Locks are the northern entrance to the Rideau Canal. A number of rapids and falls along the Rideau River between Hogs Back and the mouth of the river forced Colonel By to construct a bypass for that section. In September of 1826 By chose the natural ravine where the present day Ottawa Locks are situated as the northern gateway to the canal. With this decision, the community that is present-day Ottawa was established. Hull by this date was a prosperous logging town but there was little settlement on the southern side of the Ottawa River. Once construction on the canal started, land was cleared and the development of Bytown began.

The Construction of the lockstation

The contractor for this job was a partnership of Thomas McKay and John Redpath. It was McKay who did the work on this site. Philemon Wright & Sons were awarded the contract for building an embankment along the route of the canal in Dows Great Swamp. Local workman Jean-Baptiste S. Louis was contracted to dam up a narrowing in the swamp; this, together with the Wrights’ embankment, formed modern-day Dows Lake.

The 8.4 km (5.2 mile) overland channel between the Ottawa lockstation and Hogs Back lockstation is equal parts of excavated channel and flooded natural features, the latter including a portion of Dows Great Swamp and the Natural Gully. Only three sections required full channel excavation, the Deep Cut from the Ottawa Locks to the Natural Gully, Mutchmor’s Cut from the west end of the Natural Gully to Dows Great Swamp and the section from the west side of Dows Great Swamp to Hogs Back.

The original proposal for this site was two sets of four locks in flight separated by a turning basin in the middle. But when the size of the locks was increased in June 1828, there was no room to fit this configuration, and the eight locks had to be built as a continuous staircase. Limestone for the locks was excavated from the cliffs alongside the works. A significant construction challenge was the loose sand that forms part of the valley bottom and the water flowing in from many underground springs.

It was not long until a village emerged. The Sappers' Bridge was also constructed early in the works. It was a stone arch bridge that crossed the canal above the upper lock and connected the buildings on both sides of the Canal. An Engineering office and a Commissariat office were built on each side of the lock site, and a barracks and hospital were constructed on the hill west of the lock, now Parliament Hill. Workshops were also built for carpenters and blacksmiths.

Structures of the lockstation

The Commissariat: Thomas McKay built this building in 1827. It is constructed of limestone and is a fine example of the excellent masonry work performed by McKay. It was one of the first buildings constructed on the canal. The Commissariat office housed the Commissariat staff and was also used as a temporary storage area for canal supplies. Today it is the Bytown Museum, operated by the Historical Society of Ottawa.

Royal Engineers' Office: Thomas McKay was also responsible for the construction of the Engineers' Office. It was a three-story stone building built in 1827 with an exterior design similar to that of the Commissariat Office. It was used as a storehouse and as an office for engineers until 1857 when Colonel Coffin, the Ordnance land agent, moved in. He continued to live there until 1879. At this time the government took the building back because of the need for office space. When the railway from Ottawa to Hull was built in 1901 it actually went through the eastern side of this building. However, vibrations from passing trains eventually caused so much structural damage that what remained was torn down in 1911-12.

Lock Office: the Department of Railways and Canals built the present day lock office in 1884.

Second Lockmaster’s House: The first lockmaster’s house was a log house built during the construction period. A more permanent, stone structure knows as “a defensible lockmaster’s house” was built in 1849-50, located near the site of the Château Laurier Hotel. In 1872 the construction of a new bridge (the Dufferin Bridge) connecting Wellington and Rideau Streets resulted in the destruction of the lockmaster’s house.

Bridges:
  • Sappers’ Bridge – Built in 1828 by the Royal Sappers and Miners and was demolished in 1912.
  • Dufferin Bridge – Built in 1872 as an addition to the Sappers’ Bridge to join Wellington and Rideau streets. Along with the Sapper’s Bridge, they formed a triangle crossing the Rideau Canal. It was demolished in 1912.
  • Plaza Bridge – Built in 1912 to replace the Sapper’s and Dufferin Bridges. The triangular open area, which formerly separated the south side of the Dufferin Bridge from the north side of the Sappers' Bridge, was bridged over to form a single triangular shaped bridge with a plaza in the centre.