One of the problems with discontinuing a large-scale hog operation is what to do with the remaining facilities. After a fire destroyed the barn on the Netley Hutterite Colony, about 25 miles north of Winnipeg, Man., the members decided to discontinue hog production. That left the farm with a very large, 123-foot diameter liquid slurry tank they no longer had any use for.
The tank, which was erected in 1994, had spent the last two years sitting unused until colony member Paul Hofer decided to repurpose it. “I’d been thinking about it for two years,” he says. “We needed some storage and this is the cheapest idea I could come up with.”
Hofer was aware another colony in Alberta had converted a much smaller, but similar, tank to grain storage use, so he decided to apply the same concept to the Netley tank. But instead of using it for grain, this tank would be converted to a cold storage building. “We’re going to put lumber and shelving into it (among other things),” says Hofer. That will help the colony accommodate its new furniture-building venture.
To begin the conversion, the top ring of steel was removed from the tank, lowering it from 23 to 18 feet. To create the drive-through door, a section of steel wall was unbolted and removed. “We’re going to use a roll-up door,” he adds. “We were going to put in an overhead door, but there is no support for it.” To keep the tank’s rigidity intact, a stiffener ring compensates for the missing door sections. A walk-through door was cut into the steel near the large entrance.
Constructing a roof began by installing a piece of surplus oil-field pipe vertically in the centre of the tank, the same way a single tent pole is used. “The centre pole is 50 feet high,” explains Hofer. “It’s 20 inches in diameter.” That means it’s very sturdy. The colony was able to find the pipe at a surplus supplier in Souris, Man. Hofer says the members of the colony did their own engineering on the project to determine how much strength the pipe would need, admitting it involved a little trial and error.
At the top of the pole, a piece of two-inch diameter pipe was formed into a five-foot circle to provide a strong base for the centre of the canvas tarp they intended to use for a roof. To act as rafters, 43 two-inch-wide ratchet straps — the same kind used to hold down loads on a truck — run radially from the ring at the top of the centre pole to the top of the tank wall. Each strap attaches to the tank at the joints between the steel panels where the wall is strongest and able to support them.
Having ratchets permanently fixed to each strap makes maintenance a little easier. “We can go around and tighten them if they loosen,” says Hofer.
The colony hired Winkler Canvas, at Winkler, Man., to fabricate expected. “That’s a story in itself,” chuckles Hofer. The way the tarp was originally rolled up made it difficult to spread out once it was
the canvas roof tarp. “We told them what we needed and they built it for us,” he adds. The tarp uses 12-ounce canvas material. “It’s the heaviest they make,” adds Hofer. At its centre above the support ring on the pole, the tarp has a triple layer of fabric for extra durability.
But getting the 1,500 pound roof set in place proved to be a little more difficult than anyone set in place at the centre peak. “It needs to roll out in all four directions at the same time,” he says. On the first attempt the tarp only rolled one way, so the entire piece eventually slid off between the straps near the top of the tank where the gaps are widest.
After rolling it up again in a way that allowed it to evenly spread out across the entire roof at once, and with 15 helping hands, they lifted it back up. The second attempt worked.
At the top of the tank wall, the tarp is held six or seven inches to the outside, which helps keep the interior dry. One-inch ratchet straps secure the tarp to to the outside of the walls. “The important part is to keep it from moving around and wearing,” Hofer says.
For a total investment — aside from the slurry tank itself — of about $15,000, the colony turned an unused structure into almost 12,000 square feet of dry storage. And now that they’ve been through the process, there is one thing Hofer says they might do differently, if they had to do it again. “I’d like to see someone try it with a lower pitch (on the roof). Right now it has a 30 degree pitch. The snow slides off of it nicely, but I think it could be lower.”
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To keep the tank’s rigidity intact, a
stiffener ring compensates for the missing door sections