Tip of the Iceberg
As demonstrated on the Edbro stand at Tip-Ex 2012, tipping vehicles come in all shapes and sizes. Peter Smith, sales and marketing director with Edbro, explains why so many design options are available.
To the untrained eye, tipping vehicles may seem to be a fairly simple affair; a body is built to transport a load and a tipping cylinder is attached to eject the contents at the journey’s end. However, everyone in the industry knows that haulage is a numbers game. Increased payloads and tipping cycles translate directly to increased profits, which is why Edbro work with some of the biggest body builders in the UK to develop bespoke tipping solutions that are tailored to the exact requirements of each vehicle’s application.
Understanding the haulage requirements of a vehicle is essential to body builders when designing a tipper. If a vehicle will be hauling one material through its life it is possible to design the body to maximize payload, reducing weight to ensure that the maximum safe load can be carried. A vehicle that will carry varied materials needs to be designed for all possibilities; this may reduce payload but will increase its flexibility.
The frequency of tipping must also be considered. A vehicle that will be travelling many hundreds of miles between tips would benefit more from lightweight tipping gear, while a vehicle that will tip many times a day within a short radius would favour a fast-acting and robust solution.
Of the many vehicles that were on display at Tip-Ex, all be broken down into one of two main categories: aluminium bodied or steel bodied. Both body types offer distinct benefits to the customer, so it is important to be sure which is required at the beginning of the specification.
An aluminium body offers improved weight saving over a steel body while still ensuring high levels of torsional stiffness and maximum stability. Vehicles that will be hauling bulk materials such as sand or fine aggregates will benefit from increased payloads which can equal many thousands of pounds in increased profit each year.
Like many body builders, Wilcox Commercial Vehicles Ltd specialize in the construction of lightweight aluminium bodies, manufacturing a number of designs for both rigid trucks and tipping trailers. Sales and engineering director Chris Bartlett estimates that for every 100kg saved, nearly £5,000 of extra profit can be generated over a vehicle’s lifetime.
However, where aluminium offers weight savings, steel can offer savings on unnecessary repair and maintenance bills in tougher applications. While steel is heavier it is also a lot stronger and more resistant to wear, making it longer-lasting in industries with particularly abrasive materials. If a vehicle is likely to be subjected to high-impact loading, for example during muck-away operations, then steel is more suitable.
The overall size and design of the tipper body is also critical in ensuring that it increases full-life profits. Applications where dense materials are being moved are not likely to require large trailers, as they could never be completely filled due to the excessive weight involved and would also increase fuel use unnecessarily. It is also possible to reduce the drag of a tipper through advanced aerodynamic designs; however, this would only tend to be used on a vehicle that made frequent long journeys.
SDC Trailers Ltd, one of the largest trailer manufacturers in the UK, produce aerodynamic, ‘smoothsiders’ which reduce wind resistance. Designed for transporting less aggressive aggregates, the chassis is inclined to ease tipping and lightweight aluminium extruded side panels are used to reduce drag. This design produces a significant fuel saving over more traditional ribbed designs over long distances, but would be impractical and costly if shifting earth from one area of a work site to another.
One design criteria that is also heavily dependent on the material that will be hauled is the angle to which the body must be tipped in order to ensure that the full load is adequately ejected. Accurately calculating the ideal tipping angle allows the correct specification of cylinder, which, in turn, reduces the tipping cycle time and the hydraulic equipment weight. Edbro offer a tipping angle guide to help hauliers when specifying new tippers, and the company’s expert team is always happy to discuss specific applications with customers and recommend the lightest safe solution. Most tippers are built to provide a tipping angle of 45–50° with little thought for dedicated operations moving just one material type. Easy-to-tip materials such as coke, ash and cinders are generally ejected at an angle of less than 35°, whereas extremely compact excavated earth will need an angle of at least 50°.
As with tipper bodies, the design of tipping cylinders has evolved greatly over the years to provide a variety of options, each of which offers its own unique benefit. Rigid truck users who opt for lightweight bodies can further reduce weight by opting for lightweight hydraulics. Developed specifically for the UK market by a British company with UK design and manufacturing facilities, the Edbro CX14 is the lightest 8x4 gear available at just 477kg for the full kit, inclusive of oil. The CX14 offers customers a substantial increase in payload, boasting a saving of up to 230kg against competitors. In monetary terms, for most operators that would provide an additional income of more than £1,200 per year.
Alternatively, operators looking for a very high-lift capacity and fast-acting solution may opt for a TS32. This style of twin-cylinder under-body tipping gear comes into its own in heavy off-road tipping, where uneven ground is a factor, due to the stabilizing benefit of the high-tensile steel frame.
Having specified a tipping body and the tipping gear, there are several useful accessories that can be added to the tipper which are designed to enhance safety and/or improve operation. Load-weighing systems are able to accurately measure the weight of a truck’s contents to ensure every kilogramme of potential payload is reached with every load transferred. Equally, inclinometers and overhead-voltage sensors are available to reduce the likelihood of tippers overturning on uneven ground or hitting overhead power cables.
As with the rest of the specification process, the advantages of each option should be weighed up against the possible negative consequences. If a vehicle will regularly pick up its load from a yard it is worth considering that most facilities now operate highly accurate weighing systems which would render an on-board weighing system largely redundant. On-board weighing systems clearly offer many operators advantages in legal compliance but they reduce the maximum legal payload and increase the build cost of the vehicle. Equally, tipper safety equipment only needs to be specified when there are likely to be real hazards to be avoided in a vehicle’s operations.
Over the years a wealth of design ingenuity has been invested in improving tipping technology to produce profitable vehicles which are tuned for many different industries. This article merely scratches at the surface of the ways in which different load requirements or tipping frequencies could affect the specification process. To find solutions tailored to readers’ specific application requirements, it is always best to speak to one of the UK’s many expert body building firms, in conjunction with Edbro – the only British cylinder manufacturer.