The Humber Bay Bridges
In 1994, the Municipality of Metropolitan Toronto Transportation Department initiated a major project to upgrade all the bridges over the mount of the Humber, with the Pedestrian and Bicycle Bridge as the first step. We thank the Department for having the vision to want the new bridge to be striking and highly visible, a true gateway between the then separate Cities of Etobicoke and Toronto.

The City assembled and coordinated the team of architects, engineers, landscape architects and others who developed the 100-metre bridge. The architects and engineers, Montgomery & Sisam and Delean Corporation, conceived twin, inclined, parabolic ally curved tubular steel arch ribs.  Stainless steel rods, suspended from the arches support the floor beams, which, in turn support the concrete deck.  The ends of the 300 tonne steel arches press on concrete abutments sunk 35 metres on deep piles into the bedrock on the river Humber River Bank.

Environmental concerns dictated that it was not cost-effective to work in the Humber River at any time.  The entire bridge was erected standing on the east shore and then moved into position, a tricky manoeuvre that had two moveable cranes on tracks holding up one end, while a barge carried the other end across the river and into position.  The bridge was then lifted up onto its anchors.

Many artistic design features came from Brad Golden and Lynne Eichenberg, in consultation with the Woodlands Cultural Centre on the Six Nations reserve at Brantford.  The steel design linking the two arches is an abstract representation of the thunderbirds, symbolic of the native peoples who occupied the Humber Valley.  According to Brad and Lynne, "The physical role of the bridge is to link tow landforms.  More importantly, the structure metaphorically bridges water and sky, earth and air, human and prehistoric time."  The bronze turtles embedded in the concrete walls symbolize mother earth to the First Nations, as well as the snapping turtles that lay eggs in the sands of Humber Bay.

Stainless steel interpretative plaques, placed under the bridge on either side, trace the history of the river system, and compare the engineering wonder of canoe structures to the structure of the bridge.

Montgomery & Sisam subsequently designed an improved sidewalk railing for the adjacent Lakeshore Road Bridge.  In keeping with the theme, their design included stainless steel totemic masks that reflect and talk back to the thunderbirds.  A concrete barrier wall built between the road and the sidewalk carries additional native icons.

The Humber River Pedestrian and Bicycle Bridge has won ten architectural, engineering and urban design awards.  Some believe it to be the most beautiful bridge in Canada.  Even if this description can be disputed, it is a welcome North American interpretation of European bridge engineering and architecture.  It seems fitting that a second nearby bridge, built over Mimico Creek, should have a European architect.

In 1997, it was the Toronto Department of Parks and Culture who had the vision to insist that the Mimico Creek Bridge, although much smaller in scale, should be a true comparison to its larger sister.  The Department sponsored a design competition.  Delcan Corporation knew of a remarkable new pedestrian bridge in Ripoli, Spain, the La Devesa Bridge, made with a single inclined arch.  Delcan approached its architect, the world famous Santiago Calatrava*, and in partnership, they won the competition.

At first glance, the Mimico Creek Bridge seems incomplete and of precarious stability.  Standing on the wooden plank walkway, one finds the bridge's solidly-proportioned superstructure is reassuring, although the source of its stability remains mysterious.  The engineering concepts behind this stability are lengthy and complicated, but for those interested, a good explanation is available in a paper prepared by Professor Alan Sibbald, as Chairman of the Edinburgh and East of Scotland Association Institution of Civil Engineers, at www.napier.ac.uk/depts/cte/projects/ice/ch_addrs.html.

The 100-metre Humber River Pedestrian and Bicycle Bridge cost over four million dollars; the smaller Mimico Creek Bridge, originally supposed to span 90 metres, had a budget of only $650,000.  The cost of the steel and skilled workmanship required for the Delcan-Calatrava bid came well over this total, and the Parks Department realized that no innovative or striking bridge could be constructed for the full span within their budget.  At Delcan's suggestion, the Department and the Toronto Regional Conservation Authority designed new wetlands and river training works, not only lowering the required span to 44 metres, enabling the design of a bridge that suited the budget, but also adding to the interest of bridge users.  The combination of the shadow patterns formed by the bridge, the reflection of light on the water and the natural contours of the wetlands are a photographer's delight.

Our elegant sister bridges are true landmarks and proud ambassadors for Toronto and Humber Bay Shores.

*Santiago Calatrava's work includes the soaring arches he designed for the BCE Place Galleria in downtown Toronto and the Olympic Sports Complex built in Athens for the 2004 Games.  More about his work can be found at http://www.calatrava.com/.

Source:  Humber Happenings - Vol. 7/Issue 1/Spring 2005, Author:  Fiona Maarhuis