Crossing the humber
the humber river heritAge bridge inventory
www.trca.on.ca
Toronto and Region Conservation Authority
Humber Watershed Alliance, Heritage Subcommittee
Newly Released, July 2011
PREAMBLE
In 2008, I was introduced to the Humber River Heritage Bridge Inventory to provide advice on one of the identified heritage bridges, slated for de-designation and subsequent demolition. Having recently recommended to the Canadian Society for Civil Engineering that they increase their activities in heritage bridge conservation, I was happy to participate in this inventory project as such initiatives highlight the significant and oſten overlooked relationship between engineering advancements and our cultural heritage.
Over time the widespread loss of heritage bridges has occurred for a variety of reasons: deterioration, changes in highway requirements, or damage by storms like Hurricane Hazel. Today, however, with increasing attention towards cultural heritage, creative solutions are being explored for preserving heritage bridges.
Protecting, conserving and celebrating our heritage bridges contributes to not only a greater understanding of the development of approaches to modern day engineering but also marks our progress as a nation, from early settlement to today’s modern and progressive communities.
Roger Dorton, C.M., Ph.D., P.Eng.
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TABLE OF CONTENTS
EXECUTIVE SUMMARY ............................................................................................................................................. 3 1.0 INTRODUCTION................................................................................................................................................. 5
1.1 Background........................................................................................................................................................ 5 1.2 Project Goals...................................................................................................................................................... 6 1.3 A Brief History of Bridges in Ontario ............................................................................................................ 6
2.0 PURPOSE................................................................................................................................................................ 8
2.1 Scope................................................................................................................................................................... 8 2.2 Application and Limitations of Project.......................................................................................................... 8
3.0 HUMBER RIVER WATERSHED PLAN: PATHWAYS TO A HEALTHY HUMBER .............................. 9
4.0 METHODOLOGY............................................................................................................................................... 10
4.1 Primary Data Stage......................................................................................................................................... 10
4.1.1 Site Assessment Process .......................................................................................................................... 10 4.1.2 Landowner Contact Program................................................................................................................. 11 4.1.3 Margins of Error Identified..................................................................................................................... 12
4.2 Secondary Data Stage ..................................................................................................................................... 12
4.2.1 Municipal Heritage Committees............................................................................................................ 12 4.2.2 Community Networks............................................................................................................................. 12
5.0 RESULTS ............................................................................................................................................................... 13
6.0 EVALUATION OF BRIDGES OF HERITAGE SIGNIFICANCE............................................................... 15
7.0 OPPORTUNITIES............................................................................................................................................... 83 8.0 NEXT STEPS ........................................................................................................................................................ 84 9.0 CONCLUSION..................................................................................................................................................... 85 10.0 ACKNOWLEDGEMENTS................................................................................................................................. 86 BIBLIOGRAPHY........................................................................................................................................................150 EPILOGUE...................................................................................................................................................................151
LIST OF FIGURES
Figure 1: Humber River Bridges of Heritage Interest.................................................................................................. 4 Figure 2: Preliminary Results from Site Assessments ............................................................................................... 11 Figure 3: Watercourse Crossings Characterization by Type of Structure ............................................................... 13 Figure 4: Humber River Heritage Bridge Inventory Map Index ............................................................................. 82
LIST OF TABLES
Table 1: Total Humber River Watercourse Crossings and Bridges of Heritage Significance by Municipality... 13 Table 2: Image Examples of Watercourse Crossings in the Inventory .................................................................... 14
LIST OF APPENDICES
Appendix A: Map of Humber River Watershed ....................................................................................................... 87 Appendix B: Map of Humber River Watercourse Crossing Sites ........................................................................... 88 Appendix C: List of Humber River Heritage Bridge Inventory Orthographic Site Assessment Maps ............. 89 Appendix D: Orthographic Site Assessment Maps................................................................................................... 90 Appendix E: Humber River Heritage Bridge Inventory Field Checklist and Data Base Spreadsheet .............111 Appendix F: Land Owner Contact and Permission to Enter Form......................................................................112 Appendix G: Humber River Heritage Bridges Designated under the Ontario Heritage Act.............................114 Appendix H: A General Overview of Ontario Bridge Types ................................................................................116 Appendix I: Details and Photographs of Humber River Bridges of Heritage Significance ..............................117 Appendix J: Excerpt of Sections 27 and 29, Part IV of the Ontario Heritage Act ..............................................147 Appendix K: Conceptual Heritage Tourism Trail in the City of Vaughan ..........................................................148 Appendix L: Pedestrian Trail Networks within the Humber River Watershed ..................................................149
Toronto and Region Conservation Authority, Humber Watershed Alliance, Heritage Subcommittee
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EXECUTIVE SUMMARY
Spanning waterways from headwaters to mouth, heritage bridges in the Humber watershed have played a fundamental role to the development of Canada. By connecting communities and their economies, they have promoted growth and progress throughout the ages. Serving as definitive community landmarks and contributing to our cultural character, heritage bridges link us to our shared past.
ere are contemporary challenges to promoting and protecting heritage bridges. With extensive urbanization occurring in the Humber watershed, heritage bridges are oſten sacrificed for efficiency as they compete with changing transportation needs. Furthermore, heritage bridge design that may contribute to community character is discouraged in new bridge construction to reduce costs and expedite approvals. As a result, the unique cultural heritage of the Humber watershed diminishes as its population increases.
e proposal to conduct the Humber River Heritage Bridge Inventory came from the Heritage Sub-committee of the Humber Watershed Alliance in 2008. e goal of this study is to promote the Humber’s Canadian Heritage River designation with its associated heritage and recreational values; to guide the listing or designation of heritage bridges by local municipalities under the Ontario Heritage Act; and to educate and raise public awareness of these unique features through heritage tourism and conservation planning.
roughout this project, various mapping techniques, site assessments of public and private properties, and local community-based knowledge were applied to identify culverts, abutments, and functional bridges along the river. Once heritage bridges were identified, they were evaluated based on criteria set out by Ontario
Regulation 9/06: Criteria for Determining Cultural Heritage Value or Interest as provided by the Ontario
Heritage Act. In total, 33 heritage bridges and associated vestiges were identified. e Humber River Heritage Bridge Inventory is designed to promote the recognition and protection of heritage bridges in the Humber watershed as infrastructure essential to the preservation of community character and the development of social capital. e findings from this research will contribute to an emerging discourse on heritage conservation planning in Ontario, as well as watershed management practices in the Humber.
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Figure 1: Humber River Bridges of Heritage Interest
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1.0 INTRODUCTION
In our steady march towards growth and progress, opportunities to protect, restore and celebrate our Canadian heritage resources are oſten overlooked.
Promoting these valuable assets in our communities, enhances our character and strengthens our national identity. ough some of our heritage resources may be less recognized than those of other nations, they are vast and impressive, from regal court houses to elegant homesteads and majestic rivers to forgotten settlements.
Amongst these treasures, our heritage bridges stand out as symbols of our national advancement. Despite being a country defined by immeasurable water resources, today our roadways are seamless with few, if any, obstructions; people hardly notice when crossing over once formidable and dangerous waters. But it wasn’t always that way.
In the not-too-distant past, bridges were catalysts for community development and landmarks that entire villages were built around. As unreliable wooden bridges were replaced with more substantive structures, such progress was cause for celebration; town folk gathered, speeches were made, bands played! As community meeting places, bridges were where cherished memories formed - the local swimming hole, favourite fishing spot, covered skating rink, and in some cases – romance . . .
Over time, engineering methods advanced and bridge construction, design and materials changed. Increased attention to vehicle safety required straight, clear sightlines and stronger capacities to carry longer and heavier loads. With these requirements, the bridges of wood, stone and steel truss began to disappear and with them, their charm and character faded into the past.
Today, communities across Ontario are looking for contemporary uses of their heritage assets as a means of economic and social renewal. e Humber River Heritage Bridge Inventory contributes to this movement, by seeking to protect, restore and celebrate the Humber’s heritage bridges as a focus for community identity.
As noted author David J. Cuming wrote,
“Apart from buildings that we use as places of worship, no structure has proved so challenging to our ingenuity, nor stimulated our imagination more than the bridge … e spans we see today in our surroundings – in our communities, on our way to work, or to places to which we holiday – have a genealogy that extends far into the past and far beyond those boundaries that define Ontario.” (Cuming, 1983)
1.1 Background
In 1999, the Humber River was designated a Canadian Heritage River (CHR) by the Canadian Heritage Rivers System (CHRS) Board, as part of Canada’s national river conservation program. is milestone was achieved aſter years of community activism during a time when urban rivers were generally considered unsuitable for CHRS inclusion. It was due to the persistence of the Humber watershed community and the TRCA that a CHR designation for the Humber was obtained.
e completion of a community-led watershed management plan, the presence of community activism, voluntary and public engagement, and the ability to demonstrate the significance of the river’s natural and human heritage values to the development of Canada, are the key requirements to obtaining a CHR designation. As part of the designation process, public engagement took place through a participatory planning process, which resulted in the completion the Humber’s first management plan entitled, Legacy: A Strategy for a Healthy Humber (1997). e plan was led by the community-based Humber Watershed Task
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Force, formed in 1994 which has since become the Humber Watershed Alliance (HWA). Legacy underscored the significance of the Humber, its current conditions and strategies for the future, and two years aſter its completion, the Humber watershed (Main and East branches) was designated for its significant human heritage and recreational values and their contribution to the development of Canada (Appendix A).
e CHR designation is not guaranteed in perpetuity. In order to merit continued presence in the CHRS program, representatives of the Humber must continue to preserve and support the Humber’s heritage and recreational values.
e Humber River Heritage Bridge Inventory (HRHBI) aims to do just that; by identifying the existing heritage bridges in the Humber watershed, the HRHBI supports the human heritage and recreational values unique to the Humber watershed and promotes them as meaningful contributions to community planning and local cultural awareness.
1.2 Project Goals
Heritage bridges are essential infrastructure for our communities. Representing feats of engineering marvel and ingenuity, the Humber’s heritage bridges are definitive community landmarks. As remnants of our cultural heritage, they remind us of the historical significance of waterways to the development of the country, which is a nation defined by its natural wonders. Within this spirit, the Heritage Sub-Committee (HSC) of the Humber Watershed Alliance (HWA) initiated the Humber River Heritage Bridge Inventory (HRHBI).
e HRHBI is a comprehensive inventory of all watercourse crossings in the Humber. e goal is to identify bridges of heritage significance that are worthy of heritage designation under the Ontario Heritage Act and to promote heritage conservation planning from a watershed perspective.
1.3 A Brief History of Bridges in Ontario
Fording riverways was oſten a dangerous necessity of travel prior to the introduction of bridges in Ontario. With the arrival of the first settlers, formal roads were built to support the surveying of land for parcel allotment, allocation and subsequent clearing for agriculture. rough the execution of these activities, the riverways of Ontario posed substantial obstacles to safety and efficiency.
e clearing of the forests for roads and agriculture provided an abundance of timber which was used to construct Ontario’s first bridges. e first bridges were built with two long straight logs placed across the river with a continuous series of smaller logs laid across the span and levelled with dirt to form a deck. Over time however, with the gradual disappearance of the forests, the supply of large logs diminished which forced bridge builders to devise other methods. Since most early Ontario bridge builders were settlers, they drew on their knowledge of barn and roof construction and began erecting king and queen post truss type bridges across southern Ontario. Timber truss bridges were immensely popular in Ontario until the 1890s, aſter which sizeable examples are rare (Heritage Resources Centre, 2004).
Another natural material that early Ontario builders utilized was stone where available. Stone bridge construction was naturally restricted to the arch form which had been built in Europe for centuries before. Additionally, the difficulties of high quarrying costs and transportation, as well as a shortage of skilled craſtsmen, resulted in only a few stone bridge projects. e structures that were erected were mostly built between the 1850s and 1880s and located primarily in market towns (Heritage Resources Centre, 2004).
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Cast iron bridges were introduced to Canada with the arrival of the railroad in the 1850s. ough used in the United Kingdom from the early 1800s for arches and beams, there was little iron industry in Canada until later. Faring well in compression but not tension, cast iron bridges had many beam failures.
In the 1870s and 80s wrought iron bridges were introduced to bridge construction in some of Ontario’s wealthier market towns such as Paris, Brantford, and London. Wrought iron bridges were expensive to erect due to the high cost of materials and the required skilled labour. Yet wrought iron had good tension, compression and improved strength and was not brittle like cast iron. Wrought iron was used for plate girders and many different truss types, which were largely developed in the United States. ey were no longer used aſter 1900, when the era of “catalogue” bridges started. e period in which these bridges were constructed was even more short-lived than that of stone arches, mostly due to the introduction of steel as a construction material (Heritage Resources Centre, 2004).
Steel became an affordable bridge construction material and quickly took over. Developed in the 1860s, Ead’s Arches in St. Louis in the US, was the first major user of steel in 1873. e period coincided with better analytical capability; creation of the first engineering school in Canada at the University of New Brunswick; and the emergence of the Canadian Society of Civil Engineers in 1886 (principal founders Keefers, Gzowski, Fleming). Railways produced the first bridge specifications aſter 1870 and steel became the major material for bridge construction aſter 1870, replacing wrought iron. Steel was less expensive to erect and possessed greater strength than its iron predecessor. A variety of truss type structures, including the Warren and Pratt style truss bridge, became increasingly common as did the use of steel girders. Upon their introduction as a strong, long lasting, affordable bridging option, steel bridges immediately began to appear across Ontario. Before long, steel bridges dominated much of the Ontario landscape. Steel has higher strength in compression and tension and better quality control but rusts more than wrought iron.
Shortly aſter the turn of the century, concrete was introduced as a bridging option. Although concrete was used in various formats during Roman times, it wasn’t until it was rediscovered in Portland England in 1855 that this forgotten material was used again to produce concrete of higher quality, strength and durability. Used then for mass concrete walls, abutments and footings, concrete was good in compression but cracked in tension. At first, concrete bridges were built in the simple arch form, with the first concrete tied arch being built across the Etobicoke River in 1909 by the notable Frank Barber, consulting engineer and Vaughan Township Engineer. Concrete bridges became popular because they offered simplicity in traversing the many creeks and streams which weaved through the Ontario landscape, while utilizing local labour and materials. Simple solid slab bridges were the ideal choice for crossing these numerous short spans, while beams were cast to tackle the larger obstacles.
By the 1930s concrete challenged steel as the primary bridge construction material and was especially popular in southern and central Ontario where aggregates were readily available and easily transported. e rigid frame bridge style was introduced in 1931 and quickly gained favour for use as a highway overpass. Concrete continued to grow in popularity primarily due to its great flexibility of design and variety of uses and today, concrete is the primary bridge building material in Ontario. However, steel reinforcing of concrete in tension areas resulted in even wider use for beams as well as arches in particular. Developed first in France in the 1880s, the first super structure use in Ontario was for the arch bridge in Massey in 1906. e first rigid frames were introduced on the Queen Elizabeth Highway in 1938 and then widely used on Highways 400 and 401 in the 1940s and 1950s. Reinforced concrete replaced mass concrete for walls, abutments, piers and footings in the 1930s.
Pre-stressed concrete was the next major invention in bridge construction materials. Developed by Freyssinet in France in the 1930s to eliminate cracking of concrete in tension areas, the first of these beams was installed in Ontario in 1954. Pre-stressed concrete can be cast in place either pre or post tensioned forms and remains the most widely used bridge construction material today.