The town will get a better idea as to exactly what shape the Pither’s Point dock is in after council on Monday night approved hiring JML Engineering Ltd. to inspect and provide a cost estimate to fix or replace it.
“We’re going to utilize them to look at the dock so council has good information when they consider the future of the dock, and the possibility of repairing it or not,” Fort Frances CAO Mark McCaig said Tuesday.
He noted a decision to fix it potentially could be made this summer, but it will be entirely up to council when they get information back from JML.
“It’s a big decision. There’s a lot to consider,” said McCaig. “It’s not like it was 25 years ago, when that dock was a going concern. Things are a little different now.
“We’re in the management of scarce resources, and council has to make prudent decisions about what the priorities are and where our spending will take place,” he stressed.
JML Engineering Ltd. is being hired at a cost of $9,950. The engineers will visit the site next week in conjunction with a visit to the Five-Mile Dock, which they already were going to be inspecting.
JML will conduct a level survey to estimate the flatness of the overall structure and to establish a temporary benchmark. They’ll also perform soundings around the perimeter of the dock to establish the profile of the lake bed and depth of water alongside it.
JML will visually inspect and record the condition of the dock’s structural components, and check a representative percentage of timbers for signs of internal rot and decay, extracting timber core samples.
They’ll also examine the exterior of the dock, as well as check out the cribs and pilings.
JML also plans to retain Shield Marine and Diving of Emo to perform an underwater investigation, and visually inspect all structural components underwater and at the waterline.
JML estimated the field investigation should take two days.
The engineers then will evaluate its findings, explore rehabilitation and replacement options, and compile a report with cost estimates.
A report of findings then will be submitted to council.
Community Services manager George Bell made the recommendation to council to hire JML Engineering Ltd., based on a report from Operations and Facilities manager Doug Brown.
In a preliminary structural inspection, Brown noted the outer portion of the dock (which is about 200 feet long) has seen lateral displacement of about 18 inches from the first part of the dock (which is 280 feet long).
In other words, it has shifted sideways.
Brown postulated the structural failure this year is due to several factors, including:
•an improper design structure which has very little resistance to lateral force such as that caused by the ice cover over the 2006-07 winter (no batter piles and/or sheet piles or rock cribbing is in place to resist this type of force);
•low water elevation (as a result, more of the wooden piles were sticking out of the water and exposed to oxygen instead of underwater, accelerating deterioration of wood and, therefore, loss of structure strength); and
•low flow of water discharging over the power dam probably reduced the amount of current near the dock, resulting in thicker ice cover than normal (thicker ice cover results in greater lateral force exerted against structure than under normal conditions).
Brown noted engineering firm KGS Group was retained to inspect the Pither’s Point dock back in 1996, when a similar structural failure occurred.
At that time, KGS said the outer portion of the dock was in poor condition due to failing pile supports below the deck.
The town spent $102,300 to repair it. Several piles were repaired and a few new ones installed, but the majority of the work was replacement of dock decking and stringers.
The wooden piles originally were installed in 1935, said Brown. But the estimated useful life of dock and wooden piles ranges from only 20-50 years.
Fort Frances Times
Local News from Across the Rainy River District
