SOME POINTS ON BIN DESIGN

Press, Volume CVI, Issue 31089, 18 June 1966, Page 8

SOME POINTS ON BIN DESIGN

TN a booklet it has published A the East Coast Farmers’ Fertiliser Company, Ltd., says it is convinced that the provision of adequate weatherproof storage for fertiliser on the farm, right alongside the point of loading into the aircraft, is the logical way for the farmer to ensure that his fertiliser is available on the spot in good order for spreading when he needs it. Provision of “on the farm” storage also makes it possible to spread fertiliser orders more efficiently and economically and keep the price of fertiliser as low as possible. The booklet says that bulk bins fall into two broad groups—ground level filling bins and high level filling bins. Within each of these groups have been developed in New Zealand a number of variations in design, materials and construction of bins to suit a wide range of requirements. Starting Point

From the starting point that a ton of fertiliser occupies 33 cubic feet of storage space, it is a simple matter for a farmer to work out the cubic capacity of the storage space that he will need to provide in a bin to house his annual tonnage of fertiliser. The decision as to the exact dimensions of a bin to provide that cubic capacity will depend in the first place on whether it is to Be filled from ground level or high level and on a number of other factors. Having resolved this, there are further considerations which will influence the farmer in his choice of a bin which is best suited to his requirements, of the type of roof which will give good weather protection and allow for efficiency of operation, and of the construction materials to be used in the project.

After looking at a series of bins of different designs, the booklet says that there are some important features in design, construction and location which merit stressing. Access and Location: One requirement is the provision of "all weather” access for trucks from a road gate on the farm to the point of delivery into the bin. The location of the bin should be as near as practicable to the point of loading into the aircraft Floors: These should be built with a slight fall, say lin in Bft, from back to front. Floors should also have a slight camber from the centre to each side to allow for any moisture to run off to the sides. Drainage: Effective drainage is an essential for dp bulk

bin sites. In the case of high level filling bins a field tile drain just below the floor level on the filling side and running for the length of the bin, not more than 6 inches

out from the wall, is a necessity.

Dimensions: With a ground level filling bin, the height of the walls should be restricted to 4ft unless it is intended to use a front-end loader or dozer to pile the fertiliser above tip-truck level. The width of the bin should be either 12ft, or multiples of 12ft, which is the width required for operation of a tiptruck. Length of the side walls can be such as to provide the required cubic capacity of the bin with the optimum height and width for the particular conditions.

In a high level filling bin the height of the wall on the tipping side should not be less than 7ft 6in, and the walls can be built higher if conditions make this desirable. For efficient operation, the width of this type of bin should, be 12ft. When height and width have been decided, the length of the bin will be determined by the cubic capacity required. Roofing: The advantage of a permanent weatherproof roof, whether of the sliding, lifting or fixed type cannot be too strongly stressed. Provision must also be made to secure the roof against possible damage by high winds. In general, site and terrain conditions, capacity requirements and location will decide the type of bin that is needed. Financial considerations will determine the materials which are used in its construction. Generally speaking the cheaper the materials that are used the less permanent the installation will be, the greater the maintenance that will be required and the

less effective the protection afforded the contents from the weather.