First Air-Supported Dome Silo

First Air-Supported Dome Silo CROP STORAGE Silos 50 You ve never seen anything like it an air-supported dome silo made from the same material being used for dome football stadiums baseball parks and tennis courts It s working out great and could well be the farm silo of the future predicts New York dairyman Terrence Weigel of Sauquoit In addition to silos air domes may also be the answer for farmers looking for low-cost housing for cattle or hogs or for machinery storage So far as Terrence knows the dome silo he and his son Terrence Jr had custom built is the first and only one of its kind The air-supported roof covers a trench silo measuring 46 ft wide and 65 ft long The silo is divided lengthways into two 23 ft wide bays Its poured concrete walls are 12 ft high Until last December when the dome roof was installed the Weigels spent three frustrating winters feeding silage out of the roofless trench We had to use chain saws and axes to get the frozen silage out Besides all the extra work we were feeding a lot of frozen silage to our cows We decided early last year that the only solution was to install a permanent roof over the trench says Terrence who with his son milks 50 cows plus another 50 or so replacements Told that a conventional wood or metal roof for their trench silo with a 10 ft center arch would cost between $50 000 and $20 000 the Weigels decided there had to be a better and cheaper way We checked out several of the new domes recently built for sports stadiums and tennis courts then asked a local tent-making firm Brownie Tent Rentals in nearby Clinton if they d be interested in working with us to custom-fabricate and build an air-supported dome silo Says Gregory Brown co-owner of Brownie Rentals: We welcomed the Weigel s challenge with open arms They came up with a basic design for the roof and even made up a miniature model Using their specs we decided what type of material to use and how to put it all together into one piece I made up three additional models before we went ahead with the actual roof Total cost of the dome was right at $4 000 about one-third the cost of a conventional wood or metal roof This cost included $3 000 paid to Brownie Tent Rentals for the roof itself and the balance for lumber and other materials used in building a supporting arch under the dome The Weigels provided their own labor Once they had erected the supporting framework to hold up the roof when deflated it only took them 2 hrs to put the roof on and have it fully inflated Because we ve only used it since last Christmas we obviously don t have enough experience to make solid claims But so far we couldn t be happier with it reports Terrence We ve had no frozen silage to feed and it has been a genuine pleasure to work in the silo this winter compared to what we had to put up with in the roofless silo At this early stage I wouldn t be at all surprised if trench or bunker silos covered with low-cost air-supported dome roofs of this sort to prevent freezing and to keep out snow and rain become the silo of the future There s no silo on the market easier to fill And with the low-cost dome roof feeding out the silage is quick and easy The total investment per ton of storage capacity is far less than for upright silos The dome itself is made of 18 oz vinyl coated nylon fabric with 2 in wide polyester webbing similar to seat belt material sewed over every seam for added strength and stability The dome roof has shown good resistance to strong winds And it hasn t been bothered in the least by snow The wind sweeps snow off the roof so there s virtually no buildup on the roof itself explains Gregory Air temperature inside the dome has never dropped below freezing If it s zero degrees outside it ll run about 40 degrees inside Gregory predicts that the dome will last at least 10 years For filling or when the silo is empty the roof can be removed and folded up in a couple hours It folds into a compact package measuring about 2 ft in dia 5 ft wide and weighing about 700 lbs If the material is torn or punctured it is easily repaired There is virtually no maintenance and the cost of keeping the roof inflated is only pennies a day The Weigels used a 24 in squirrel cage fan operated by a 1 1/2 hp electrical motor to simultaneously inflate the dome and ventilate their adjacent dairy barn Air from the fan can be shunted via manual divider to move inside air - or a combination of inside and outside air - to the dome We get some moisture condensation on the underside of the dome roof but it s not enough to bother anything We can reduce the amount of condensation by adjusting the fan to bring in more cold outside air and less warmed air from inside the barn explains Terrence Air is ducted from the barn to the silo via a 24 in dia tube made from old 55 gal steel drums One end of the roof extends to ground level to cover the open end of the trench For daily feeding the Weigels use a Bobcat loader to load silage into a home-built electric silage cart made from an old cement cart The silage cart is driven in and out a side door adjacent to the barn There s also a side door in the center dividing wall for entering the second bay The 5 ft by 8 ft door is equipped with a rope-controlled vinyl curtain which keeps the opening air tight when closed When loading out silage for each day s feeding the door curtain is opened via a rope-pulley arrangement to let the electric silage cart through If it s not windy outside we leave the side door open and let the roof deflate and rest on the support arch It will fully inflate again in a couple minutes when we close the door If it s windy we keep the air-lock door closed while loading the silage cart so as to keep the dome fully inflated explains Terrence It would be relatively easy to design a large airlock door to allow a large conventional tractor and loader or a silage wagon or truck to go in and out of the silo for each day s feeding Gregory points out He adds that his firm has custom manufactured tents and other enclosures in a wide variety of shapes and sizes up to 60 ft wide and more than 300 ft long We d be happy to work with any FARM SHOW readers interested in having an air-supported dome built for storing silage or grain or for housing livestock or storing machinery

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