Contractor at Work
Forty-year flashback: Today’s techniques
By Peter Lewington
By Peter Lewington
June 13, 2013 – Drainage Contractor magazine is celebrating its 40th anniversary in 2013, and to celebrate, we’re taking a look back at what made the headlines 40 years ago with Forty-year flashback, a series of articles from the magazine’s first few editions.
The following article, originally published in the Fall 1973 issue of Drainage Contractor, was written by Peter Lewington, the founding editor of Drainage Contractor magazine.
Twenty-one years ago, when I purchased my present farm at Bryanston, Ont., a familiar sight around the village was a retired farmer who was known to be “about the best man in a ditch bottom.” He was kept busy installing clay tile by hand, just as his grandfather had done.
Such a lifestyle was an anachronism then, but now it is almost inconceivable. Canada has moved from the labourer to the laser.
Land forming is no longer restricted to such traditionally high-priced land as Kent and Essex counties in Western Ontario. The farm enlargement policies of several provincial governments have encouraged the changing on the rural topography; large fields, high capacity equipment and early planting are the order of the day. Drainage makes it all possible.
Where are open ditches preferred and when should clay, concrete or plastic tile be used? The questions which must be answered and the decisions which must be made are numerous. Fortunately, the Ontario Farm Drainage Association has now issued a “Recommended practice for construction of subsurface drainage systems.” It is a timely and comprehensive guide:
Does the soil contain chemicals which will affect the long-term performance of the drain? Iron deposits, for instance, are capable of plugging tile and filters. A well-conceived drainage plan should be drawn in advance of construction. Other planning precautions include obtaining permission, where necessary, to cross easements, roads or railways. The precise location of buried cables and pipelines should be established during the planning stage.
Inspection and handling of material
All drainage material should be inspected prior to and during installation. The material should be suited to the use and meet the standards established by the association. Clay, shale, concrete and plastic pipe all have their vulnerable aspects during storage and installation. Following a final inspection, any defective or damaged material should be replaced.
Safety and self interest are not far apart. Sensible safety factors increase the chances of good work; the Workmen’s Compensation board has punitive conditions for operators who significantly differ from safety norms.
Maintaining grade and direction
The association details the acceptable traditional cross-arm and grade stake methods. Other options include the optical and electronic grading devices. Formulae are provided for permissible variations from the planned grade. Procedures are detailed for correcting over-digging, excavating rock and installing filters where necessary.
Many of the provisions are more common sense; such as plugging the upper end of all drain pipes and blinding open trenches at the end of the day’s work. Drain tile spacings vary with the soil.
One thirty-second of an inch is suggested for silt and sandy soils; one-sixteenth inch for loam soils; one-eighth to one-quarter inch in clay soils; and one-quarter to three-eighths inches in peat or muck soils; this is reduced to one-eights inches in well-decomposed peat soils.
Perforated tile should be laid with the perforations close to the bottom of the drain. With plastic tubing, the shape, number, spacing and area of water inlets must all meet the association’s Product Standard for Corrugated Plastic Drainage Tubing.
The construction standards committee of the Ontario Farms Drainage Association has foreseen many problems and detailed acceptable procedures. The recommended practice for construction of subsurface drainage systems makes reference to unstable soils, rodent gates, erosion control, filling trenches, drafting a drainage plan and inspecting the tile installation.
Today’s techniques are complex but clear; they have been devised in the interests of good drainage.
Peter Lewington emigrated to Canada from England shortly after World War II, in which he served in the Royal Navy’s Fleet Air Arm. After settling on a farm near London, Ont., he soon became an agricultural writer. His encounter with the devastation of cropland soils of his own and neighboring farms by contractors laying gas and oil pipelines led him to new topics of interest to farmers. Peter was the founder editor of Drainage Contractor magazine and died in 1992.