Packer vehicles for years to come
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• Estimated figures given in the recently published draft British Standard Code of Practice (Part 1) for Storage and Collection of Refuse from Residential Buildings showed the yield per dwelling rising from 3 cu ft per week at a density of 2.1cwt per Cu yd in 1968, to 3.75 cu ft at 1.9cwt in 1975 and 4 cu ft at 1.8cwt in 1980, said Mr T. Crawford, director of public cleansing, Blackpool, at the Institute of Public Cleansing Conference in Torbay on June 5. Thus the forecast showed not only an increase of 14 per cent in weight but also an increase of one-third in volume.
In considering the purchase of appropriate appliances, those responsible had to decide whether the chosen machine would be capable of performing its functions adequately not only in the first year of its life but in the seventh, eighth and ninth, bearing in mind the changing nature of domestic refuse. To put the matter in perspective it was necessary to think in terms of solely side-loaders being purchased for refuse collection today! So that an efficient performance could be rendered in the latter part of the machine's working life it was necessary to choose a unit capable of handling lighter density refuse as time went on. Price, said Mr Crawford, was relatively unimportant as an extra £.500 spread over a 10-year period was .£50 a year, a sum easily recovered if the machine were capable of a greater volume of work. On the question of delivery, he considered four to five months reasonable.
Where an appliance had been purchased that was capable of more work than the unit replaced some adjustment of the rounds, or a reduction in the number of loaders, was essential since otherwise the advantage of a superior product was lost. In his own authority, the Work Study Section would take care of this adjustment after detailed work measurement.
Gravity defied High compaction ratios were now demanded and the stage had been reached in Britain where it was possible to fill a vehicle body with compacted refuse until it could not easily be discharged by gravity tipping. There could in future be an increasing trend towards ejector discharge. An additional advantage of the ejector device was that it was used as a barrier against which refuse could be crushed. The ejector moved towards the front of the body but only under the action of the compressed refuse being forced against it; this ensured that density was equally high front and rear_ The achievement of greater _payloads by the use of mechanisms that produced high rates of compression meant that bodies had to be stronger and heavier. The Construction and Use Regulations limited axle loadings to 10 tons on the rear and 6 tons on the front and this was where questions of unladen weight really arose. Mr Crawford said he felt no doubt that in years to come larger hoppers were going to be absolutely essential. In the US because of the huge number of cardboard boxes handled, collection machines had enormous hoppers. Loading heights were, on average, much lower than in Britain and the majority of new American vehicles used for collection of domestic refuse were of the intermittent compression design rather than being continuous loaders. Was it possible that cleansing officers in Britain could be wrong in demanding that replacements for refuse collection fleets must be of continuous loading design? Bearing in mind the forecast of a one-third increase in volume of refuse over the next 10 years, could the expected bulk he more quickly and efficiently transferred from the hopper into the body by an intermittent grab-and-push-in action rather than by continuous compression loading?
As part of its range, the US Gar-Wood Company made a very small model named the Load Runner. This could fairly be described as a satellite working in conjunction with the main vehicle and it disposed of the problem of removal of refuse from congested areas where the large appliance could not operate. Operated by a loader-driver, it could work in awkward situations where preinously the crews had no option but to carry bins over long distances. When discharging, the Load Runner backed up to the main vehicle, transferred its load into the hopper, so saving any need to travel to a disposal point. The difference in body floor levels was compensated by the fitting of twin rams on the Load Runner which could raise the rear end by as much as 12in.
Mr Crawford's paper continued with an appraisal of compaction systems, dealing specially with the Dennis Paxit 70, SD Pakamatic, G. W. L. Ramillies and Ramillies-Binmaster, Eagle Compressload, Arenco-Alite/Norba, GWL Musketeer, and Perham Shark.
Perhaps in the future, concluded Mr Crawford, they might see collection vehicles fitted with a continuous compaction mechanism operated by a power unit separate from the primary engine. This would enable the driver to assist with loading without contravening safety regulations.
Difficulties in obtaining the necessary completed chassis in time for the vehicle demonstration at last week's Cleansing Conference resulted in some changes in the manufacturers' intended programmes. The promised new Hanger-Eagle design did not appear, being replaced by a trailer version of the Eagle Thuro sewer jetter and a 400gal sign and lighting washer_ With the former, water is provided by an existing tanker vehicle or by a hydrant so that appreciable economies can be achieved by authorities not having full-time use for such
equipment. The specification is generally similar to the full chassis design. The sign washer, which has a maximum working height of 2011 and an outreach on the hydraulic arm of 8ft 3M., is equipped with an auxiliary air-cooled twin. diesel unit for operating the pump and lift gear.
To enable the Yorkshire road sweeper to be fitted to a wider variety of chassis, various modifications have been made in the design. In addition to the normal Super-Pack model a 10 cu yd "mini" was demonstrated by Sheffiex Ltd, its function being collection in congested areas. A now unusual offering by Glover, Webb and Liversidge Ltd, was a barrier loader, a type having its value for out-of-ordinary collections such as old furniture.
The Molex trailer slurry tanker was demonstrated by the Glass Fibre Engineering Co Ltd. This is filled or emptied by a positive displacement unit that emulsifies the material being pumped. There is a rear spreader attachment. When not in active use the tank can be filled with water as a fire standby; jets can be thrown over 100ft from three +in. nozzles.
Demo comment Mr Crawford, presenting his paper at a conference session after the demonstration, was able to comment on the improved Gibson continuous loader and the new SD Revopak, in addition to the appliances dealt with in his advance report. Opening the discussion, Mr J. R. Bonser (Waltham Forest) said that to ensure the economic use of improved vehicles, their operation had to be related to the intake at the disposal plant. An opportunity could be taken to replan the collection rounds so as to take advantage of greater efficiency rather than just integrating a fresh unit into the existing pattern. Mr Bonser praised the screw impeller principle, as compared with the packing plate, because of the former's ease of maintenance.
Routine maintenance of compaction units needed simplifying, contended Mr K. Harvey (Birmingham); they should be made in a complete and easily removable form. Insufficient attention was being paid to the sealing of bodies and noise levels of compaction units required investigation. Instead of offering a local authority any economic advantage the effect of introducing a more efficient vehicle was often only to enable the crews to go home earlier. Mr Crawford said the only replacement compaction unit, so far as he knew, was the Norba where there was a complete screw gearbox that could be used as a service exchange, facilitating the return of the vehicle to duty in a matter of a couple of hours.
Refuse collection had its merits as compared with many jobs in industry, said Mr J. Skitt (Stoke-on-Trent) speaking on
Mr R. S. Barnes' paper (CM last week). From many men he had heard that they preferred the outdoor work and the contact with the public to a routine factory job. He thought Mr Barnes had exaggerated in saying that equipment was not being pooled when necessary between local authorities. Labour relations were too often delegated to middle or lower-level management. Local authorities were likely to get larger in the future and there must not be too many levels of management. There could not be proper respect between Jack and his master if they did not know each other. Mr J. Trow (Sheffield) was disappointed to find that industry as well as local authorities had
• accepted work-study schemes that were costing unnecessary money; the easy way of merely passing on cost increases was being taken too often.