Northern News Services
Friday, March 9, 2007
FORT SIMPSON - The new Martin River bridge briefly became a sight-seeing destination last week as the structure was moved into location over the river.
From Feb. 23 to 27, staff with Rowe's Construction were under constant surveillance by local residents who drove out to the site on Highway 1 between Fort Simpson and Wrigley to watch the bridge moving efforts. The company had the contract for installing the bridge.
It took the power of a lot of heavy equipment to move the 250 tonne Martin River bridge into place. - Roxanna Thompson/NNSL photo
"People were quite curious," said Owen Rowe.
What viewers witnessed was the movement of a structure weighing 250 tonnes, said Rowe. The new bridge is 66-metres long, approximately 20-metres longer than the existing bridge and 1.5-metres wider. The two sections of the bridge were assembled before the structure was moved into place.
It took a lot of heavy equipment including D8 crawlers, D9 crawlers, a backhoe and some loaders to move the bridge.
One of the most important pieces of equipment was a system that multiplies pulling strength, said Rowe. A similar system is used to pull the Liard River ferry up a hill onto its winter site.
Rowe said it's easier, however, to pull the ferry up because it's on skidways greased with tallow compared to the bridge which was moved over the ground with the help of steel skids that acted like a sleigh.
The bridge was moved across the river on a snowfill that took the company a week to build. They had to fill a space between the river banks that was 35 feet high by 40 feet wide by approximately 180 feet long with snow to have a surface to move the bridge on.
Even with all the equipment power and a snowfill, moving the bridge wasn't easy.
"We went through a couple plans doing it," said Rowe.
A number of different configurations of the heavy equipment were tried.
In the end, all the power was put into pulling the bridge with one crawler being used to keep the structure from moving left or right. Although it took a few days to put in place, the bridge moved forward a little each day, he said.
"All in all it was moved to the satisfaction of the government and to ours, too. It just took a while," said Rowe.
This was the first time that Rowe's Construction has moved a bridge in this way before but they have installed other bridges, said Rowe.
They've also moved barges, which are almost as heavy as the bridge.
"At 30 plus years in the business you have a tendency to do a lot of things," he said.
Now on its abutments, the bridge still has to be raised so a metal plate with rubber underneath can be installed under the bridge before it's bolted down.
Although the structure is in place, motorists will still have a while to wait before they are able to drive across the new bridge.
The ramps on either side of the bridge won't be constructed until sometime in May when the weather is better, said Michel Lafrance, the regional superintendent of transportation.