[URBAN NOTE] "The modernist Bloor-Danforth line at 50"

[rfmcdonald]

Chris Bateman writes at length at Spacing about the architectural modernism of the different components of the Bloor-Danforth line.

One of the biggest challenges faced by the subway’s engineers was how to connect the Bloor Street and Danforth Avenue sections of the line. Two significant barriers—the Rosedale and Don valleys—stood in the way.

The TTC investigated various options, including tunnelling all the way to the east end, but ultimately chose to use the existing lower deck of the Prince Edward Viaduct.

Built at a cost of $90,000 during construction of the bridge in the 1910s, the lower level was designed to carry streetcars at a time when the city was planning underground lines across the city. Ultimately, the deck sat dormant for more than 40 years before the TTC converted it for subway use.

In all, using the Prince Edward Viaduct cut $10 million off the cost of building the Bloor-Danforth line.

Though there was also a viable subway deck on the Rosedale portion of the Prince Edward Viaduct, the TTC found it didn’t quite line up with the planned location of Sherbourne station, so a new bridge was required.

The solution, supplied by architect John B. Parkin and U.S. engineering firm DeLeuw, Cather & Co., was an open spandrel structure with a sweeping reinforced concrete arch. The deck, almost 17 metres above the valley floor, was almost entirely enclosed to prevent train noise disturbing residents of the nearby Kensington Apartments.