Stewart Trailers Unveils Tetrad 35-Tonne Trailer
Founded in 1988, Stewart Trailers is owned and managed by James and Mandy Stewart from their site in North-East Scotland.
A first look at its recent Construction series suggest this is so.
Brought about by requests from contractors for a reliable heavy-duty trailer for general work, and and able to add a silage bin during the season, the series also lends itself to construction and quarry site work.
There are four standard models with volumes 6-11 cu.m and nominal capacities of 12-22 tonnes. The trailers have a heavy-duty chassis that carries a tipper body made from 6mm Hardox 450 steel. Hardox is up to 35% lighter than traditional fine grain steels, resulting in a lower machine tare weight and a greater payload. The material is also extremely resistant to knocks, dents or scrapes inflicted by boulders or rubble; it has rated yield strength of 1100 MPa compared to a typical mild steel's 250 MPa.
Units are supplied as standard on heavy-duty tandem axles; the braked front axles have oscillating beams using oil impregnated nylon bushes for longer service life. Oversize 560-60R22.5 tyres ensure good usability in poor conditions. To ensure some comfort for the operator, col spring drawbar suspension combines with a 25 tonne rated swivel eye coupling or an optional K80 ball hitch.
Calling on its lengthy expertise, the team at Otorohanga has come up with design features to make the unit more durable and user friendly.
With a body width of 2735mm -- versus a container landed import measuring only 2250mm -- the trailers are said to be extremely stable and to travel well over difficult terrain; and their rated capacities are achieved using lower sides, resulting in a lower centre of gravity and increased safety.
Another clever design feature is the lower cylinder mount for the tipping mechanism. This uses a four-way pivot system which counters side-forces that threaten to damage the cylinder, the internal seals or ultimately the trailer body, during emptying on level or sloping ground.
The standard package includes an extended front headboard to protect against overspill, a high clearance hydraulic tail door, a hydraulic parking stand, and, on the safety front, robust mudguards and LED lighting. Options include rear door spreading chains, a sprung steering axle and rollover silage sheets.
Sales and marketing manager Eric Crosby commented "we have supplied a number of units to customers which have exceeded their expectations, and we're now building a number of bespoke units -- a further option with this series".
