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Canadian bridge failure litigation

Back to Media and Events $8M Saved Following Abington Consultation - Case Study 94 1 Million Pound per Annum Potential Savings Through Project - Case Study 167 100kW Electron Beam Machine for Framatome - Case Study 52 100kW Electron Beam Machine for Framatome - Case Study 52 10X Saving in Material Handling Costs - Case Study 438 15% Increase in Production of Flue Products - Case Study 440 1980s Material - A Question of Fracture Toughness - Case Study 407 20% Reduction in Project Management Costs - Case Study 436 20% Savings in Welding Operations - Case Study 437 A Crushing Reply - Technical Advice Casebook - Case Study 162 A Cut Above the Rest - Especially When It Comes to Titanium - Case Study 35 A Novel Approach to Offshore Wind Power ...But Where and How Much? - Case Study 413 A Novel NDT Technique for Inspecting Offshore Structures A Novel X-Ray Inspection System for Counterfeit Component A Tough Choice - Made Easier by Talking to the Right People - Case Study 381 Abington Work Behind Standards Revision - 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Case Study 91 Alnmaritec Evaluates Friction Stir Welding for Deck Plate Construction - Case Study 563 Analysis of Flaws in North Cormorant Jacket Saves Shell 45m - Case Study 169 Array Ultrasonic Measuring of Fatigue Crack Growth Rates Assessing Plant Life - Case Study 184 Assessing the Fitness-for-Purpose of Root Defects in Offshore Structures - Case Study 36 Assessment of Electroslag Welds for UK Infrastructure – London 2012 Olympics - Case Study 623 Assessment of Power Station Header Weld Flaws - Case Study 233 Automated Ultrasonic Inspection and ECA of Riser Tie-In Welds Offshore - Case Study 110 Barrikade - Case Study 203 Barrikade® - A Fire Resistant Composite Insulation Material Developed by TWI - Case Study 230 Biggest Girth Weld Test Gets Underway - Case Study 342 Bridge Behaviour - Case Study 4 Burning Desire to Succeed - Case Study 454 Bursting with Efficiency - Case Study 53 Call in the Experts - Welding Procedures and Fracture Toughness under Scrutiny - Case Study 389 Canadian Bridge Failure Litigation - 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Simulated in the Lab - Case Study 374 Regional Technology Project Pops Welded Bubbles - Case Study 447 REMO – Online Remote Condition Monitoring of Tidal Stream Generators - Case Study 596 Repair of Hydropower Station Turbine Casings to a Tight Deadline - Case Study 246 Repair of Steel Viaduct - Case Study 101 Research Project to Bring Down High Cost of Autoclaving - Case Study 581 Residual Stress and Structural Integrity using Thermography Resilient Rubber - Case Study 107 Resistive implant welding of fibre reinforced thermoplastics Revalidation of Gas Field Facilities - Case Study 127 Rework of MCM Die Bonds - Case Study 89 RISKCalc in UltraPIPE in Texas - Case Study 350 RISKWISE for Tanks Applied in Malaysia - Case Study 351 RISKWISE for TotalFinaElf's Refinery in Belgium - Case Study 190 RISKWISE Software used in Japan - Case Study 318 RISKWISE™ RBI Planning Software - Case Study 444 Roll Bar and Cage Lead Time Reduced by 75% - Case Study 434 Rubbing Along Nicely …Tailored Training in Linear Friction Welding - Case Study 415 SAFERAIL Prototypes Minimise Wheelset Failures - Case Study 508 Search for a Welded Solution Ends with Election Beam - Case Study 379 Second Opinion Sets Client's Mind at Rest - Case Study 419 Self-Piercing Riveting - Case Study 151 Self-Piercing Riveting Case Study of Volvo FH12 Truck Cab - Case Study 154 Self-Piercing Riveting for Electric Window Winders - Case Study 157 Self-Piercing Riveting of Sunroof Framework - Case Study 156 Serious Savings from Service Assessment - Case Study 223 Shallow Cracks Help! - Case Study 74 SimCoDeQ - Process Monitoring of Composite Materials Manufacturing Simulation of Roll Cage Manufacture - Case Study 201 Simulation Tests Robot Feasibility - Case Study 47 Small Sample Analysis Solves a Problem - Case Study 73 Software for Plant Inspection Analysis - Case Study 194 Software to Predict Distortion and Improve Fatigue SOIMON – Fast and Reliable Technology for In-Situ Soil Inspection - Case Study 608 Solder Materials for use in 'Down Hole' Data Loggers - 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Published on 22 January 2013

TWI was involved as technical experts for the defence in a lawsuit following the failure in 1984 of the Valleyfield lift bridge on the Saint Lawrence Seaway in Canada. United Dominion Industries, TWI's client, and Canron Inc. who designed and built the failed lifting mechanism respectively, were sued by the Saint Lawrence Seaway Authority (SLSA) in a case that concluded in 1993. If the Saint Lawrence Seaway is a large navigable channel between the Saint Lawrence river and the Great Lakes. It was completed in 1959 and the Valleyfield bridge numbers one of many complex structures along its length. The bridge carries road and rail over the Seaway and can be raised vertically to allow shipping to pass.

The lift bridge operates on a counterweight basis. Ropes pass from each of the four corners of the 1250 ton lifting span over larger pulleys (sheaves) of about 5m diameter to counterweights, each weighing 1/2 of the weight of the span. The sheaves have 500mm diameter forged axles (trunnions) which rotate on greased bearings, the grease being distributed by means of grooves cut both in the bearings and on the trunnions. Grooves in the latter are not normally recommended but were provided at the specific request of SLSA.

Valleyfield lift bridge, Canada.

Valleyfield lift bridge, Canada.

In 1962 (three years after the bridge opened) problems occurred with the bearings when grease fell in abundance on to the road and railway below. To solve this, SLSA decided to block the grooves on the trunnions with silver solder (babbitt metal). They realised that this would not adhere to the surface of the grooves so to provide a key, " diameter holes were drilled at 45◦ every 3 inches along the grooves.

In November 1984 the bridge was in mid course when one of the counterweight sheave trunnions broke free and fell down onto the platform. The road, rail and seaway were rendered unusable and, consequently, ships which were waiting to pass through the seaway became stranded in the ice for several months.

Composite photograph showing SE and NE towers. The broken shaft and sheave have not yet been taken down.

Composite photograph showing SE and NE towers. The broken shaft and sheave have not yet been taken down.

Investigation revealed that the trunnions had failed by fatigue, cracks having initiated from the severe stress raisers caused by the three" diameter anchor holes nearest to the shoulder of the trunnion and thus subjected to the highest bending stress which alternated with every revolution of the sheave. Furthermore, beach marks on the fracture surfaces could be related to the shipping seasons (the seaway is closed every winter during the freeze up). These showed that cracks had been growing ever since the modifications were made in 1962.

The judge concluded that the defendants were not responsible for any of the modifications which led to the failure, these having been carried out under the supervision of the SLSA. Better maintenance procedures could have averted the disaster as the cracks could easily have been detected during in-service inspections.

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