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Another Premiere in Stratford Robert Holden, Contributing Editor
Late in the 2005/06 season the Public Works Department of Stratford put together a new equipment specification that, unbeknownst at the time, would set a new standard in Canada. Having compiled anecdotal and operational information on a myriad of methodologies that had at that point been employed piecemeal by various municipal authorities and contractors, Stratford tied together all the loose ends and created a watershed specification. What they realized were the following facts:
Additionally they would need to work within the legislated vehicle and equipment specifications. Then they would need to find a supplier to bring together what have been traditionally disparate technologies. The phrasing of the tender was to create a triumvirate approach to constructing the desired vehicle. Namely, cab/chassis Sterling, dump body & hydraulics DEL, and the spreader/plow combination Amaco Equipment. This was reflective of the traditional model of passing the carrier along, adding bits until the final delivery. Such a situation can make expediting and accountability difficult to manage. This represented a real challenge, as the truck equipment industry tends to lack the sophistication in hydraulics, the heavy equipment industry takes for granted. This would be like writing a new book on how to do it, right from the start!
This was an application where high duty cycles, reliability and limited downtime would be expected and required. After some deliberation this led to the involvement of Bosch-Rexroth Canada. Formerly known as Basic Hydraulics, they have a long history of industrial and mobile systems design and support. This expertise was to be critical in creating a system that would fulfill the necessary requirements. The specification called for a single, variable displacement axial piston pump with a minimum 100 cm3/rev capacity. Stratford also required a single MCV (main control valve) including main and port reliefs for each of the circuits. The unit would also require a float circuit similar to what is found on most wheel loaders. The float would allow the plow to smoothly follow the roadway contours, unlike traditional snowplows. This was not new or problematic for experienced equipment specialists, and a circuit was designed, incorporating the following items: Series 31 100 cm3 pump, 10 µm pressure and return filters, and an MP18 valve bank. According to Don Tuffnail, maintenance supervisor for Stratford: "All the components could be single sourced from Bosch which makes parts and service more straightforward, particularly over the life of the unit." With communications and hydraulic systems streamlined, the customer also wanted the overall appearance to be streamlined. This included inside as well as outside the cab. DEL of Burlington stepped up to the plate with a made to measure dump body, outfitted to Stratfords' detailed requirements. "We took our standard body and laid out lighting and tie-down needs as dictated by the customer. With the basics completed we then had them come, inspect it and make alterations before final paint and preparation," said Al Huurman general manager of DEL. At this time too, an idea of Don Tuffnails' for a unique mechanical hold down system was realized. The Ro-Ro spreader could be secured with a clamp mounted inside the body and locked in the same manner as the tailgate. In the event of a tip-over, the spreader would still be securely affixed to the carrier. Driver comfort and ease of use was also stressed by Stratford. The Schmidt CL controller was chosen for its simplicity and clarity of operation. Setting a new standard for innovation, the CL control box has an extensive menu structure. All spreading and spraying functions are controlled from here and it is unrivalled in its ease of use and capacity for expansion. To compliment these controls, a single plow control joystick was specified. Similar to the operation of a wheel loader, the driver can control plow position using the 4-way joystick located near the armrest. This reduces driver fatigue and eliminates the unsightly plow control towers of conventional installations. With the easy to load Ro-Ro mounting of the spreader, a similar labour saving method of plow mounting was incorporated into the vehicle. The Schmidt-Tarron multi-blade, spring loaded snowplow utilizes terrain following float hydraulics like a loader, as well as a universal quick coupling mounting plate. Based upon DIN 760060 and adapted for the Sterling chassis, this vehicle has the easiest plow hook-up in use in North America. The driver approaches the plow, connects the hydraulic lines and then secures the two safety bolts. Again, for those accustomed to skid steers and wheel loaders, a fairly typical operation. A revolution for truck equipment in Canada! According to Dave Wilton of Stratford Public Works, "We were very excited to get this unit into operation. Not only will it be our first combination spreader, traditionally we have used wheel loaders rather than trucks for plowing. I'm sure there will be some teething troubles as our crews adjust, but I don't expect any significant problems." What about the five primary criteria we mentioned? Well, each and every expectation was met or exceeded.
Congratulations go out to all those involved from conception to delivery of this benchmark project. Possibly only Shakespeare could have had such an enterprising premiere! |
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Not a newly discovered work by The Bard himself,
but something almost as spectacular!
With the carrier vehicle under construction, the design of a hydraulic
circuit and selection of components was required. The difficulty with selecting
hydraulic componentry is the difference between initial price and long-term
parts and service support. Far too often the wrong pumps or valves are chosen
based solely on price, particularly when truck equipment is involved. 
