The University had required that the new contract be run on a pay-by-weight basis, rather than the previous pay-per-lift arrangement, and needed a more accurate overview of the general waste collection operations across its campuses. On-board container ID and weighing was essential in meeting these requirements and Onyx opted for the Sulo system of which it has extensive experience, having adopted it for several other large contracts.

As part of the new arrangement the university has switched from steel bins to plastic 1,100 litre units. Sulo supplied all the new bins fitted with microchip ID tags, and completed the changeover in three days.

Pay by weight preferred

The University of Birmingham’s waste collection was previously handled by Birmingham City Council, on a pay-per-lift basis. When the contract expired the University sought to move to a pay-by-weight arrangement, and put the business out to tender.

“There was also an increasing pressure to improve our recycling rates,” explains Paul Wheldon, Procurement Advisor, responsible for the university’s waste management contracts. “We therefore needed accurate data on the amounts and types of waste being collected at various points round the university.”

Onyx’s Regional Sales Manager Stuart MacPhail said: “The Sulo ID and weighing system generates all the data we need, not only to prepare accurate and fully-accountable invoices under the pay-by-weight regime, but also to provide a detailed picture of the pattern of waste generation around the university, which is a great help in planning frequency of collection at specific sites.”

He added that the system also carried Trading Standards and National Weights and Measures approval, which was an important consideration.

The RFID tags on the plastic bins carry unique electronic identification data indicating the bin, its exact location and type of waste contained. The comb-lift device on the collection vehicle is fitted with an antenna which reads the tags, together with an automatic digital “catch weigher” to weigh the bins as they are being lifted – a process called dynamic weighing because it does not interrupt the lifting operation. The container identification number and weight is automatically fed into an onboard computer in the truck cab where the information is stored together with the date and time of the emptying. At the end of each round a data card (RAM card) is removed from the vehicle computer and the data downloaded into Onyx’s in-house software, which generates invoices and spreadsheets containing minute detail of each lift of every container.

The Sulo bins are deployed at more than 60 locations, serving around 100 buildings on the University of Birmingham’s two main campuses, Edgbaston and Selly Oak. Green bins are used for general waste and blue bins for recyclable office paper. The paper recycling operation has proved very successful and the amount of blue bins sited round the campuses is expected to quadruple by the end of the year. The university is also extending its glass recycling facilities into bars and student residential areas.

“Paying by weight is in our opinion much fairer than paying per lift, and we are closely monitoring the costs of the new contract,” Paul Wheldon reports. “But already the depth of information provided by the container weighing and identification system, which accompanies Onyx’s monthly invoices, is paying dividends in giving us an accurate picture of the waste collection operation in general, and the effect that recycling activities are having in particular.”

Leeds system

Onyx is also using Sulo’s container weighing and ID for an extensive new pay-by-weight waste collection and recycling scheme it is operating for Leeds City Council.

As well as fitting the on-board weighing systems to the four Onyx vehicles currently assigned to the Leeds contract, Sulo also supplied the radio frequency (RF) chips, which carry the bin identification data, for the 700-plus 1,100 litre steel bins that Onyx has assigned to the scheme. Sulo also provided special chips that have been developed to eliminate the RF signal interference that can occur with steel-bodied bins. The chips were fitted on site.

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