8 March 2011

Reinforcing History at Mintlaw Bridge

Red Deer Alberta - For nearly a century the Mintlaw Bridge has loomed over the Red Deer River, the coal black trestle one of our few remaining connections to the age of steam.
 
Besides being an impressive piece of railway engineering, the former Alberta Central Railway, and later, Canadian Pacific Railway Ltd. span is a historical treasure and the second longest bridge of its kind in Alberta.
 
But time and the elements had taken their toll, and that's what brought a team of consultants and construction specialists to the picturesque river valley about six kilometres southwest of Red Deer on Monday. Their job was to prop up the west end of the bridge, where decades-old timber supports were being slowly crushed under the weight of the steel girders above.
 
A temporary support was put in place until a permanent steel pier can be slipped under the bridge later this month to eliminate a dangerous sag that had developed.
 

Red Deer County Mayor Jim Wood came to watch as a crane from Timcon Construction (1988) Ltd. hoisted the bridge up a few centimetres so it could be placed on the new supports.
 
There is no doubt in Wood's mind that it was worth saving the bridge, which was sold to the county for $1 in 2009.
 
"You're kind of in awe when you stand up on the other end and see how long this structure is. It's amazing."
 
"I can see this was quite a structure in its day when it was built, and it still is."
 
The view from the end of the bridge is impressive. The span covers 633 metres and towers 33 metres above the frozen river below. Only a railway bridge in Lethbridge is longer.
 
"It's definitely part of our heritage," said Wood.
 
The future of the bridge is undecided. The repair bill for Monday's work came in at $122,800. But it would cost an estimated $2 million to provide a new deck, railings, pier repairs, and reconnect the two ends to the banks. A few metres of the bridge was removed many years ago as a safety measure.
 
"At this point in time, council has not made a determination (on the future) of this bridge, but felt it was very important to preserve this historical site," said the mayor.
 
The bridge and an associated right-of-way is owned by the county. Some in the public would like to see the former railway line become a walking and cycling path. But the county will go to the public for input before considering such an ambitious trail project.
 
Consultant Paul Carrier didn't hide his enthusiasm for the project, which involved researching original engineering drawings and other documents. His team at Edmonton-based CIMA+ even tracked down a document signed by Prime Minister Sir Wilfred Laurier approving the original railway line, which at that time was for the Alberta Central Railway.
 
"We were excited, just the sheer history of this project," said Carrier of their reaction to getting the call to look at the bridge.
 
Construction on the bridge began in 1911 and was finished a year later. The pier that had rotted and its concrete base do not appear to be original, but are likely at least 50 years old.
 
The last train rolled across the bridge in 1981 and little was done to maintain it in the following years.
 
Timcon project manager Stan Cappis said besides the pier problems, the bridge has held up well over the decades.
 
"Apparently, it's in really good condition. There was a little bit of creaking when we lifted it up, but that was to be expected.
 
"Considering it's close to 100-years-old, there was six milimetres difference between one side and the other. So it's very rigid still."
 
The county is considering what other repairs may be useful. The east pier may also eventually have to be replaced but it has not rotted as badly.
 
Paul Cowley.