How to get the most out of your sweeper brushes?
Jan Tylapp and Wayne Corbitt from sweeper brush manufacturer, Osborn Unipol, explain how Local Authorities can prolong the life of their sweeper brushes and increase the efficiency of street cleaning operations. Ann-Marie Knegt reports.
(Local Authority Plant Vehicle - LAPV Sept. 2009 - http://www.lapv.co.uk)
Can you use any other brushes than those specified by the sweeper manufacturers?
"Often people think that every brush is the same." Not so, says Jan Tylapp, Business Development Manager Road Products for Osborn Unipol, "This is a common misconception and you shouldn’t just fit any brush to any sweeper without some adjustments." He explains that manufacturers design a sweeper arm exactly to be used with a particular side or front brush, connecting the "wrong" brush will affect the sweeper’s performance, as there may be differences in the angle of the sweeping material to the holding plate.
This could be as much as 10 degrees, or more. This means that if the splay angle of the brush is different from what the arm is calibrated for, it will not come in contact with the surface correctly, and therefore not clean the street properly or wear out prematurely. Operators should note how much of the brushing material comes into contact with the road surface on their OEM brush an if using someone else’s brush adjust the angle of sweep to correspond to the same surface contact. This would also avoid bouncing or tracking and although this is not a problem on most sweepers it can be a nuisance on sweepers using large and heavy front mounted brushes.
As far as widesweeps are concerned every OEM knows it is important to use the correct weight of material as well as the correct plastic or wire composition. Likewise every LA should be aware that skimping on material to save money is usually a false economy. Longevity on these brushes can vary by as much as 35% and more depending on the make-up of them. The shrewd manager will take into account all these factors before committing himself to any particular supplier.
What is the worst an operator could do to affect the sweeper brushes?
"Many sweepers now come with a facility for increasing pressure," explains Tylapp. "We advise our customers to be careful when using these applications, because it means that a brush can be knocked out in two hours, instead of two weeks. Sweeper drivers tend to turn the power thrust function on and then forget about it. The increased pressure wears out the brush wires, but instead of wearing out the tips, it wears it on the sides, and destroys the brush."
Raised drain and manhole covers are another potential hazard which can bend effectively destroy a widesweep brush causing undue expense and lost time. In this case the sweeper driver needs to give advance consideration to the street he is sweeping and take note of any protrusions which he will need to avoid. At times it is not always possible to sweep every bit of the road surface and an experienced operative, correctly, will not even try.
Wayne Corbitt Head of UK Sales & Marketing adds that it is more cost effective to sweep regularly and often, than to prematurely wear a brush out. In his opinion people tend to sweep too much and too aggressively, which has detrimental effects on the whole machine. In rotating machinery everything that rotates is connected to some bearing application, so when pressure is applied to a specific area, not only will the brush splay out, it also means that the required surface contact, which the brush has been designed for, will not be achieved, and therefore the surface is not getting the right treatment.
"It also directs axial thrust pressure back into the bearing – not designed to cope with those kind of pressures – causing excessive wear an teat, which considerably reduces the life of the sweeper. There are other consequential effects, including warranty claims back to the hire company, or the manufacturer that supplied the sweeper. In addition, fuel economy is reduced, by taking more power and draining the electrical system’s resources and therefore the sweeper itself," says Corbitt.
It all adds up, and of course putting the pressure facility on also causes extra noise.
How does speed affect sweeping operations?
Local Authorities and contractors are under pressure to use limited resources, but have to remain service orientated as their Duty of Care. Therefore sweeper fleets tend to carry out double shifts, and sweep for longer hours. Often drivers will increase sweeping speed in order to get by, and according to Tylapp and Corbitt, this can be hazardous. Tylapp explains that a sweeper should always be operated within the limits set by the manufacturer. "Any faster than that, and damage may be caused to the brush arms, arm supports or the brushes themselves which will then need to be replaced. And in operations where a wire side brush is being used, driving at speed may cause wire strands to shear off and damage cars, buildings and even hurt people.
This problem can be compounded if the brushes aren’t set correctly and the sweeper is driven at speed. Then without question they will wear out prematurely, rather like a rubber pressed down too severely and being forced to rub itself out instead of just removing surface dirt. A sweeper is a sweeper and not a bulldozer. And like with any application, to prolong brush life requires correct fitting, adjustment, some skill and care.
How can driver training improve operations?
Both Tylapp and Corbitt are big advocates of talking to drivers and their management teams, and addressing these problems from a very early stage in a sweeper driver’s career. "We like to show that we are investing in their career, by creating brushes that do a better job over a longer period of time.
"On the other hand, drivers, that have been in their career for a long time, and who take great pride in doing an excellent job and in their machine can provide us with great feedback. It is extremely important that people understand the implications of the decisions they make in the cab, and the sooner they understand, the better they carry out their work," comments Corbitt.
He adds that for people who have been in the street cleaning business longer, the streets might have changed, because if you compare the streets of 1980 with 2009, there are many things that are completely different, such as tarmac surfaces. Tylapp and Corbitt try to set up meetings with people who have been in the business for longer, and gauge feedback by providing them with field samples, testing out new developments and different combinations of brushes. Corbitt emphasises that this is a touchy type of approach, because drivers can feel everything through the pedals and the steering in the sweeper that they are operating. He welcomes dialogue and invites people to talk to him and his colleagues. "We have a section of "Best Practice" tips in our catalogue, and in one case one of the fleet managers actually copied this page, and put it on the wall in the workshop for all personnel to see how a sweeper should be operated and on how to get the best life out of brushes, which is especially relevant in today’s tight economic climate," he concludes.
Osborn Unipol provides brushes for several major sweeper manufacturers.
Jan Tylapp (above) and Wayne Corbitt (below) have both got extensive industry experience. Tylapp has been in the street cleaning industry for 38 years, and Corbitt worked as a qualified engineer, before starting at Osborn Unipol.