Since Aldercote began manufacturing access platforms in 2001, van mounted designs have evolved slowly. Structures have been designed around mild or medium strength steel, using simple cut lengths of standard sections where possible. This approach is cheap and effective, but means that structures contain a lot of material which adds little to their strength. Control systems have shifted from direct mechanical and hydraulic controls, to electronic, but little of the potential of electronic control has been exploited.
Meanwhile, vehicle weights have been drifting upwards, fuel costs have increased, and personnel costs have continued to rise. Conversely, control, manufacturing and materials technologies have all been getting cheaper and better, making entirely new approaches possible.
These evolving factors mean that the optimum design for today is very different to that of ten years ago. Cheaper, more accurate manufacturing techniques mean that complex, high strength parts can replace straight cut lengths of standard sections. In this way, passive material can be cut out of designs, reducing weight without reducing strength. Better bearing and pin materials mean that “fit and forget” bearings are now affordable. Electronic systems can use cheaper more reliable sensors, connected by plugs and harnesses which are rigorously tested before and after installation. Highly reliable electronic controllers can coordinate sophisticated control functions which improve safety, comfort and productivity.
The HAWK Series is a set of brand new designs which take full advantage of today’s capabilities, while offering the best of the old world where appropriate. The emphasis is on elegant structural designs, combined with high quality components and sophisticated control where required.
Access platform users range from inexperienced operators who hire platforms and don’t know how to treat them properly, to highly experienced and motivated owner operators, who care deeply about looking after their equipment. Purchasers range from the self-employed to the companies who ensure our lights stay on. To cater for the requirements of all these parties, we have developed 4 ranges of platform. They all share the same HAWK series focus on weight reduction, efficiency safety and reliability, but each offers a different combination of sophistication reach and cost.
HAWK V, and HAWK VX ranges are simple articulating boom designs, equipped with direct hydraulic control. The emphasis is on simplicity and robustness. The two boom V range offers a lightweight solution with sufficient range to meet most powered access requirements. The Three boom VX range offers the same qualities with greater height.
HAWK VZ, and HAWK VZX ranges are high performance telescopic designs, designed to offer the largest possible operating envelope and maximize productivity. Features such as dynamic speed optimisation, and slew sensitive outreach mean that more tasks can be carried out faster than ever before. The VZX offers the largest envelope currently available on a 5T vehicle.
All ranges are available on 3.5T vehicles. A more detailed comparison of the four ranges is shown below.
Data Table goes here.
The HAWK Series has been designed around high strength Domex 700 steel from SSAB. This steel has three times the strength of mild steel, and double the strength of commonly used 355 grade medium strength steel.
Using higher strength steel is one way of reducing weight. Further gains are available by developing efficient designs. Components in the VZ range have been designed so that the stress is as even as possible throughout every component. Finite element analysis of the jib at maximum stress is shown below. The tapered shape means that stress levels are similar along the whole length of the boom.
For robustness and ease of use, direct hydraulic control is hard to improve upon, so this is available on the articulating HAWK V and VX ranges. Direct hydraulic control cannot however provide access to the maximum possible operating range. To do this the HAWK VZ and VZX ranges are equipped with control sophistication which until now has only been available on much larger more expensive equipment.
The telescoping VZ and VZX ranges are equipped with “CAN bus” controllers from Parker. These systems are used in safety critical industrial equipment worldwide. On the VZ and VZX ranges, sensors continuously monitor the angle and extension of the booms and the pressure in the cylinders. The controller therefore knows the position of the platform and the stress it is under, and is programmed to prevent movements only when safety limits are being approached. The controller also adjusts the speed of movements, to combine maximum speed with safety and comfort.
The low weight and aerodynamics of the HAWK range mean that fuel consumption is low. In extra urban driving, the fuel consumption of the 5T Mercedes Sprinter carrying a Hawk VZ 135 returned fuel efficiency figures of 33mpg, a decrease of only 4mpg from the official 37mpg claimed by Mercedes for the empty vehicle
All articulations are designed to be maintenance free for a lifetime of ten years of heavy utilisation at maximum load. This is achieved by combining lubricant impregnated polymer bearings with the highest quality chromed stainless pins. No greasing is required.
The slew rings on all ranges are is inside the van, below head height, and can therefore be greased and maintained without accessing the roof of the vehicle.
All valves and controllers are within the column, and therefore easily accessible for maintenance if necessary
All ranges include options with little or zero tail swing. Zero tail-swing means that the “tail” never extends beyond the span of the mirrors of the vehicle.
Every HAWK platform is tested to 150% of the maximum operating load, in the position which generates the most possible stress in the structure.
The stability of every HAWK platform has been tested at above the maximum rated slope, at 150% overload with a flat tyre on the most heavily loaded wheel.
The bucket and harness anchors have been subjected to a drop test equivalent to a 100kg (16st) man falling 1.2m on to an inextensible lanyard. Note that the harness anchors are intended to prevent a fall, rather than arrest a fall. This test has been carried out therefore to show that the system will continue to ensure the safety of operators even in the event of abuse.
All safety critical systems are dual redundancy fail safe.