Anti-spray is not so simple
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• Only since 1984 have motorists had a legal right to see better in wet conditions. Then anti-spray legislation for new commercial vehicles became compulsory — though many operators had been retrofitting spray suppressant equipment for some time.
If you have been behind a truck on a wet road, you have probably already noticed a reduction in the spray thrown out by the wheels. Current legislation demands a 65% water collection performance — most of the equipment available easily exceeds this figure — and compliance with BS. AU 200/2A. There is no doubt that many accidents have been avoided by fitting this equipment and making overtaking a much clearer situation.
The idea behind the equipment is very simple and, as tests have shown, can be very effective. Spray suppressants come in two forms and have different purposes. The first consists of a continuous strip of polypropylene filaments which look like sweeping-brush bristles. These are secured around the outside of the mudguards to trap the spray from the tyres and divert it to the bottom edge where it loses its velocity.
The second type of equipment looks like a normal mudfiap but has a more efficient method of water trap on the inside. This resembles a plastic doormat and has the same purpose as the filaments. The methods of fitting these antispray aids vary from one manufacturer to another.
On the UK market, there are two major manufacturers, Monsanto and Schlegel, although it is the former which has the prestigious BSI Kite Mark and is probably the market leader. Monsanto markets its device as Clear Pass and Schlegel designates its product as Cats Whiskers.
Since 1984, spray reduction equipment has been fitted by the truck and trailer manufacturer or their dealers in an assembly line routine. Fitting time involved is thus minimal. In a retro-fit situation times are longer — up to two hours for a steering-axle kit. But, dependent on the system used, this can be reduced to nearer 30 minutes per axle with a skilled fitter.
Using a simple clip method, a single sheet of bristles is cut to size around the outer edge of the mudguard and secured by pop rivets or self-tapping screws. A mud flap is usually suspended from bolts. This method can also be used for greater security on the mudguard valance. For more effective suppression, the inner (chassis) side of the mudguard can be used. A further increase in suppression efficiency can be gained by fitting a mudflap to the front of the wing.
As an alternative for single axles a new, fully suppressed mudwing is available for even speedier replacement. In normal use, anti-spray equipment is very durable and needs little maintenance. Tailor-made kits are available for most trucks and trailers with prices starting from around £15 per axle, though more sophisticated kits can cost upwards of £100 per axle.
At the moment, legislation demands only that the equipment fitted meets BS. AU 200/2A requirements, though Monsanto would like to see a situation where only products bearing the BSI Kite Mark can be used. This would, Monsanto argues, ensure conformity to an independent, third-party certification. Although the fitment of a spray suppression system is compulsory, the effectiveness varies. Today, operators can innocently fit spray containment devices which, because there is no distinguishing mark, do not comply with the BS Specification and thus render themselves liable to prosecution. This normally applies only, however, in the retro-fit market as new vehicles and trailers are, in the main, supplied with either Monsanto or Schlegel products.
Surprisingly, for a product which is a mandatory fitment the disadvantages of anti-spray equipment are practically nil. It is argued that some products trap not only water but mud and other debris thus reducing their effectiveness and increasing the vehicle weight. To combat this the major brands incorporate self-cleaning features.
In fact, the extra cost on the price of new vehicles would seem to be the only real complaint. A typical price for spray suppression is around £388 for a 4x2 tractive unit and tandem-axle trailer. Considering the total price of both tractor and trailer, this is a very small sum indeed, especially with the potential advantages of spray suppressant equipment to other road users.
Apart from the road safety aspects such as safer overtaking, improved rear vision, clearer cab windows and mirrors, spray reduction can reduce cleaning and maintenance and protect undercarriage components. Both factors can cut down unproductive off-the-road time.
While the product might look unimpressive, the inherrent requirements are very demanding indeed. The suppressant equipment must seal the gap round the tyre under all conditions of loading; it must be able to treat steered wheels effectively, not damage the tyre if held in continuous contact and must not interfere with wheel removal.
It must control spray in all weather conditions, perform under heavy surface water conditions and be corrosion resistant to all the chemicals normally used on the road. It must not clog with fibrous material from the road nor be damaged by clogging or freezing in icy conditions although it must be as close to the road surface as possible, again in all conditions, to control the footprint plume.
On top of all this, it has to be low in weight, porous and flexible for safety reasons, simple to fit, without involving modification to the vehicle, has to be cheaply and easily replaceable to reduce costs and, finally, perform at all speeds.
Which means that what, initially, looks to be a remarkably simple piece of equipment has no less than 16 items of criteria in its design and functions; the advantages of which can be clearly seen by every driver.
Abal Engineering Turbo 76
• Abal Engineering makes and markets a bolt-on system for existing or new mud wings and vehicle bodywork as a replacement for normal mud flaps; both flaps and side valances are offered. The suppressant surface of the latest Abal flaps, which are made from reinforced rubber, incorporate a series of angled ribs. The flaps come with pre-drilled fixing holes.
Standard flaps from Abal cover widths from 380min to 610mm, and lengths from 508mm to 1,170mm and include a 1,220mm x 203mm side valance. A range of standard fitting kits is also marketed, these include flaps, valances, anti-sail bars and bolts covering flap widths from 460mm to 610mm and lengths of 1,070mm and 1,170mm.
Boydell & Jacks (Sales) Turbo 77
• Spraybreaker anti-spray flaps and valances comprise thick pads of porous plastics material attached by their edges to relatively firm backings. Spray collected by the pads is converted to water which can drain away between the two components. Boyden & Jacks says that the pads can be removed from their backings for steam cleaning and that in dry operation, the pads vibrate against the backings to shake out mud or grit.
The range of Spraybreaker equipment includes flap sizes from 305mm to 610mm width, and 406mm to 1,220mm length, plus 1,220mm side valances, 203mm or 305mm deep. Other sizes can be supplied and a range of eight side valance/flap kits for trailers is available, these including anti-sail bars and fitting bolts and covering sizes of 460mm and 610mm width, 1,070mm and 1,220mm length, and 1,220rrun valances 203mm and 305mm depth.
Dana Turbo 78
• One of the first participants in the UK vehicle anti-spray market, Dana (Intertruck) now produces a redesigned version of its spray suppression mudflaps and valances — Misty II. These have a onepiece moulded rubber structure with fullwidth, open ribs and vertical side channels. In the earlier version, the ribs were horizontal but now they are at a slight angle so that water thrown up from the tyres should be contained within the flap and directed upwards between the ribs to collect in the side channels from where it runs down onto the road surface.
The angle of the ribs has been established in research aimed at minimising the escape of spray. The built-in side channels enhance the rigidity of the flaps to the extent that anti-sail bars are not needed. Misty II flaps come with, or without, fitting kits in sizes to suit all commercial vehicle applications in widths from 380nun to 610mm, and lengths from 560mm to 1,220mm, and in the case of valances there are two standard sizes — 1,220mm x 203mm, and 1,350mm x 305mm.
Albert Jagger Turbo 79
• Albert Jagger markets the Aquamaster spray suppression equipment as complementary to its range of commercial vehicle body hardware components, plastics mudwings, and so on. Both flaps and valances are included together with appropriate bracketry, anti-sail bars and complete fixing kits. The spray suppressant surface of Aquamaster flaps has small evenly spaced cones moulded in a regular, open-type pattern into reinforced rubber backing which is carried in U-section vertical members.
The product is available as semi-trailer flap and valance combinations or in sizes to fit mud wings and so on. Seven standard sizes flap provide widths from 406mm to 610mm and lengths of 560mm or 1,120mm and there are two standard side valance — 1,220mm x 203mm and 1,220mm x 305mm. Other sizes can be supplied to order.
Millwood Rubber (1986) Turbo 80 • As specialist rubber moulder to the automotive industry producing a wide range of products in natural rubber, Neoprene, Nitrile and SBR, Millwood markets anti-spray material under the name Sprayaway from rubber compound. The suppressant surface of the material is a closely spaced pattern of small diameter and relatively long rubber "columns". Most requirements can be met, however, by a standard range of flaps from 305mm to 610mm wide, by 460mm to 1,220mm long, and 1,220mm X 102mm, 150mrn, 203mm and 305mm valances are available. The material can be supplied in simple cut -form or mounted in perimeter framework.
Monsanto Turbo 81
• Monsanto was the first company (in 1979) to launch commercial vehicle antispray equipment with its Clear Pass systems and has dominated this sector since then. The suppressant material comprises a haphazard labyrinth of 1 9mm polyethylene strands moulded onto the high-density, reinforced polyethylene backing sheets which form the flaps and valances. While individual components are available in a range of standard sizes, a comprehensive variety of kits is marketed for front and driving axles of rigid trucks and tractive units and for all configurations of trailer axles.
Front steer axle kits from Monsanto are fitted on production by several manufacturers and where appropriate top valances have Clear Pass material fixed to the inner wing faces. The same applies to driven and trailer axles where hinged or fixed valances have the material applied to the inner faces. Monsanto claims to have a specially designed kit for every standard make of heavy goods vehicle and every The choice of kits depends on a number of specific dimensions — tyre width, tyre spacing (on tandems and triples) and body underside to ground (with flap and valance systems). With these kits it may be necessary to modify flap sizes in some applications, but this presents no problem since material can be cut to size.
With regard to availability of Clear Pass material for replacement purposes or where a customer has special requirements, Monsanto offers a range of standard sizes of flap from 305nun to 660mm wide, and from 610mm to 1,220mm long, and side valances 1,220mm long, and 200mm or 300mm deep, Netlon Turbo 82 ei The spray suppression systems offered by Netion are based on flaps and wing lining material combining three complementary high-density polyethylene mesh structures secured to a moulded rubber back sheet. Each component plays a specific part in converting spray into water droplets and the portion of flaps below the bottom of the fixed wings have integral chevrons moulded in the back sheet and side vertical channels to return the water to the road, For application to curved mudwings on steered and non-steered axles NetIon has two systems, the Standard Device and the Compact Device. With the former the flaps are one metre long and are bolted to the inside of the wing with just the stiffened portion, 550nun long, protruding below the edge. This is said to give a performance well in excess of the BS. AU 200 requirement. In both cases, widths from 400mm to 635mm are available.
NetIon also has two for non-steered axle applications. Both use the suppressant material as already described, one being the Valance Moulding System where it is applied to the rear and sides of individual squared-off half-wing polyethylene mouldings for each set of wheels and the second the Long Flap and Valance System which follows the lines of conventional side valance and rear flap equipment but with the upper portion of the suppressant material fixed to the inner face of a rigid "extension moulding" in polyethylene bolted to underfloor bracketry or framework.
Resi nj et Developments Turbo 83
• Resinjet took over manufacture of reinforced plastics mudwings from M & G (Tankers), and continues to offer the Spray Rider suppression equipment as an option on its current range of products.
The system uses Schlegel Cats Whisker spray guards in the wing side valances and long-bristle components below rear edge flaps to provide integrated equipment in standard form.
Roland Tilts (UK) Turbo 84 IN The ExSpray spray suppressant material marketed by Roland Tilts takes the form of a three-dimensional mesh of black plastics thread embedded in a stiff, reinforced black plastics backing. The material is sold in a range of sizes appropriate to use as flaps and wing and valance linings.
In the case of material for use in mudwings, there are 12 standard sizes with widths from 380mm to 610mm, and lengths from 380nun to 1,220mm. There are four full flaps for trailer systems with widths of 460min or 610mm, and lengths from 1,070tnm to 1,220mm. Three sizes for use in trailer valances measure Schlegel (UK) Turbo 85 II The originator of the Cats Whisker spray suppression system, Schlegel markets a variety of standard kits using this equipment for fitment to mudwings at both steered and non-steered axles. The basic system comprises "bristle" filaments fitted as valances to the outer or both sides of curved oE fabricated wings and, according to model, to the front edge also. At the rear, a spray-reducing brush can be fitted to the wing or to a short mud flap.
A variety of standard kits is marketed by Schlegel, these covering different types of equipment and virtually all makes of commercial vehicle. The company says that if a standard kit cannot be supplied, it will be custom made to the customer's requirements. The latest Schlegel system is the Clip-Fix, which uses easily fastened clips to retain the filament on the edge of the wing. This is a low-cost design offering universal fitting for mudguards of any radius; it is simple to install and is light in weight
Plusbrand Turbo 86
• Only side valances for non-steered axles are produced by Plusbrand, a relatively recent entrant in the field. The valances are made from 4.5nun thick black polypropylene, with thinned horizontal strips at two points to allow "hinging", and with a horizontal top face for mounting to the underside of the vehicle floor.
A lower vertical face is 100mm in depth and has fixed to it plastics strand spray suppressant matting. The valance shape and attitude in the operating position is defined by shaped brackets to which it is secured by plastics press studs, the main intention being to provide a valance which can easily be hinged out of the way when required (for maintenance purposes). Alternative sections and lengths of valance are to be available.