Agricultural transport operators are eagerly anticipating the weight Increase to
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44 tonnes because this is one sector of the transport industry which will be able to make full use of the extra payload.
Whether hauliers will be able to operate current trailers plated at 38 or 41 tonnes gross depends on wheelbase and body size. "A lot of existing equipment is not capable of being uprated to 44 tonnes," warns GT tipper sales manager Angus Spooner. "There are constraints on wheelbase and body dimensions and there are issues such as ram and load-sensor capability to take Into account."
General Trailers designed its first 44tonne bulk tipper as long ago as 1983, when the concept was first mooted.
The consensus among the bulk trailer manufacturers is that step-frame trailers for 44-tonne operation will be longer and taller. The legal minimum 8.0m between the king-pin and the centre of the rear axle will result In longer wheelbases. Shorter wheelbases may still be legal, but there is a risk that Insufficient weight will be imposed through the king pin, causing trailer axle overloading.
Wilcox expects 8.0 and 9.3m wheelbases to be the most common at 44 tonnes. Because agricultural loads are not as dense as aggregates, capacity on agricultural bulkers will need to increase from 55-60yd3 to 6366yd3 to accommodate the extra payload. That means longer bodies; typically around 10.5m. The other way to increase capacity is by raising the height of the body sides, but this is rarely practical in bulk agricultural work, where a lot of loading is done over the sides by equipment which is incompatible with tall bodywork.
Mont racon points out that although operators have been able to move up from 38 to 41 tonnes and maintain the same body dimensions, a shift to 44 tonnes will almost certainly require higher body sides: "That's the only way to increase capacity and ensure there is sufficient weight far enough forward in the body to avoid overloading the trailer bogie." Bulk hauliers often use lifting axles enhance off-road traction. According to Angus Spooner, front lift axles at 44 tel will be trickier to achieve, depending or body capacity. He also points out that I regulations governing the use of front I axles are about to change: once the vol has reached a certain speed, the axle ol automatically drop.
General Trailers and SDC predict a change in specification for rams used 44 tonnes. SR has previously preferri an eye-ended ram with a sloping front bulkhead, but engineer Tony Sturgess that for 44-tonnes the company Is clu Ing to outer-cover rams and a straigh bulkhead. "It gives more support to th top-stage of the ram when it is fully extended," he explains.
Spooner agrees that while some ran have enough hydraulic pressure to lift I extra weight, once they are fully extern they may not be strong enough to hand the extra lateral forces.
Wilcox is offering a free advice servi for operators who are not sure if their trailers are suitable for uprating to 44 tonnes. Simply give Wilcox the necessar data and it will make the calculations.