Bulk gritter for multi-lane highways
Page 31
If you've noticed an error in this article please click here to report it so we can fix it.
• A new design of bulk hopper road gritting machine intended for multi-lane highways or motorway snow clearance has recently completed field trials and is now being produced as a demountable, independently driven unit or is being purpose built to individual council specification by Econ Engineering Ltd, at its Ripon, Yorkshire, plant.
Using hydraulic power extensively to operate most of the selective controls and drive functions this new gritter (Series M) allows greater flexibility in the distribution of sand or salt over a spread pattern of up to 35ft. Material discharge from the 5-9 cu yd hopper can be kept directly related to the road speed of the gritting vehicle with an infinitely variable width of spread or change of spread pattern being obtainable.
Constructed on a unit basis to allow easy maintenance (the whole belt conveyor /drive system can be removed by unscrewing five bolts only), the new gritter uses two hydraulic pumps in a self-contained and independent hydraulic system to power the various functions. Motive power is provided by a simple take-off from the vehicle's propeller shaft, all main hydraulic functions being served by an infinitely variable displacement pump unit while a fixed displacement pump with variable valving is used to power the single high-capacity distribution spinner.
The new gritter has the facility for hydraulic unloading of unused material to avoid storage of wet sand or salt in the hopper, with attendant corrosion problems. When gritting has finished the conveyor belt drive can be set to discharge the residue from the hopper, the discharge chute being hinged and swung sway to permit free fall of the material.
In field trials the gritter has been found to be capable of spreading wet salt at rates as low as oz /sq yd evenly over the full width of a three lane highway at speeds as high as 50 mph, a rate which meets in full the recommended BS. 1622: 1960 Specification for preventive gritting.