Instances of Numeracy Instances of Numeracy in Recycling and in Recycling and

Refuse Collection.Refuse Collection.

CategoriesCategories

Spatial AwarenessSpatial Awareness CountingCounting EstimatingEstimating ComplianceCompliance

Spatial AwarenessSpatial Awareness

• Driving dual controlled trucks, having a Driving dual controlled trucks, having a reverse sense of mirror usage is critical.reverse sense of mirror usage is critical.

• Right hand side small mirror is used for Right hand side small mirror is used for checking roadside hazards.checking roadside hazards.

• Left hand side mirror is for lining up arm Left hand side mirror is for lining up arm with binwith bin

• They still need to check over their left They still need to check over their left shoulder for bins that are not lined up.shoulder for bins that are not lined up.

Using Mirrors

Spatial AwarenessSpatial Awareness

• Left hand mirror is positioned so that Left hand mirror is positioned so that midpoint of arm is visible, for quicker midpoint of arm is visible, for quicker pick up.pick up.

• Bin is grabbed halfway up for effective Bin is grabbed halfway up for effective lifting and preventing it from falling into lifting and preventing it from falling into hopper, as bins are tapered at bottom.hopper, as bins are tapered at bottom.

Best position of arm

Spatial AwarenessSpatial Awareness

• Older suburbs with less off-street Older suburbs with less off-street parking, they can collect only 80-90 bins parking, they can collect only 80-90 bins in an hour because they have to get out in an hour because they have to get out of the truck to move the bins between of the truck to move the bins between parked cars.parked cars.

• In suburbs with more off-street parking, In suburbs with more off-street parking, drivers can pick up between 200 - 300 drivers can pick up between 200 - 300 bins in the same time.bins in the same time.

Hazards that slow the rate of pick up

Spatial AwarenessSpatial Awareness

• Impatient driversImpatient drivers• Tree branches on kerbsidesTree branches on kerbsides• Narrow streets esp. with treesNarrow streets esp. with trees• Tradesmen often park anywhere, lacking Tradesmen often park anywhere, lacking

consideration for bin collectors, who consideration for bin collectors, who then have to get out of their trucks to then have to get out of their trucks to move bins.move bins.

Other Hazards

Spatial AwarenessSpatial Awareness

• Sometimes they must drive onto next Sometimes they must drive onto next pavement to line up with bin of previous pavement to line up with bin of previous house, which can be hazardous if many house, which can be hazardous if many tree branches get in the way.tree branches get in the way.

• One proficient driver used his ‘Exit not One proficient driver used his ‘Exit not Approach’ strategy, driving as if exiting Approach’ strategy, driving as if exiting the cul-de-sac, then backing up to line the cul-de-sac, then backing up to line up more closely to bins, then picking up up more closely to bins, then picking up as he drives out.as he drives out.

Cul de Sac positioning

Spatial AwarenessSpatial Awareness

• If I reach the weight limit while I’m in If I reach the weight limit while I’m in the middle of a street, I choose a house the middle of a street, I choose a house next to a clearing to stop at, as a next to a clearing to stop at, as a landmark.landmark.

• I stop at a corner house and leave the I stop at a corner house and leave the lid open. lid open.

• Leave the bin at a slight angle, Leave the bin at a slight angle, compared with the rest.compared with the rest.

Where do you restart once you return from the transfer station?

CountingCounting

• We have a starting point and a finishing We have a starting point and a finishing point, one street at a time.point, one street at a time.

• Bin counter does the counting. Bin counter does the counting. • Sometimes people accuse us of not Sometimes people accuse us of not

collecting their bin, but we generally collecting their bin, but we generally know the run very well.know the run very well.

How do you check whether you’ve collected all the bins in the area?

CountingCounting

• As you get used to the area, you have As you get used to the area, you have an idea of how many bins there are in a an idea of how many bins there are in a street.street.

• You also get to know which bins will be You also get to know which bins will be out and when.out and when.

Do you have an idea how many bins there are in any one street?

CountingCounting

• Number of binsNumber of bins• Arm hours (maintenance)Arm hours (maintenance)• Weight of load Weight of load

What does the bin counter tell you?

CountingCounting

• 240 for heavy areas and 300 for light 240 for heavy areas and 300 for light areas, if there are no distractions or areas, if there are no distractions or emergencies. emergencies.

• Beginning drivers Beginning drivers collectcollect about 120/hr, about 120/hr, average drivers 300/hr. average drivers 300/hr.

Most number of bins collected in an hour?

CountingCounting

• Did maths as part of engineering course Did maths as part of engineering course and soccer skills. and soccer skills.

• Health and safety representative in a Health and safety representative in a previous job previous job –– skills help me with skills help me with thinking safety first. thinking safety first.

• Logistics from armed forces experience.Logistics from armed forces experience.

Are there any counting skills from your culture or past experience that

help you in this job?

CountingCounting

• Yes, there is one area with large Yes, there is one area with large sections that has been sub-divided asections that has been sub-divided a lot lot in the last two years, since we’ve in the last two years, since we’ve started.started.

• The number of bins have gone up The number of bins have gone up

from 160 to over 240.from 160 to over 240. New sub-divisions being developed with New sub-divisions being developed with

5000 to 7000 homes will need new 5000 to 7000 homes will need new routes on maps.routes on maps.

Do bin numbers change over time in an area?

Estimation – Spatial & Sensing

•See overfull bins, so “square them up” on the lift (to avoid spillage) •Accommodate refuse truck drivers and look for passing areas along the road•Feels heavier if the arms move slowly or strain so probably concrete or dirt in there•Feel heavier when activating the control stick

• Wait until level areas along roads for Wait until level areas along roads for accurate readings of scalesaccurate readings of scales

• Returning bins onto sloping verges, Returning bins onto sloping verges, need to be stableneed to be stable

• Deciding on route e.g. dependent on Deciding on route e.g. dependent on remaining bins to get as close to (the remaining bins to get as close to (the scheduled) count of 300scheduled) count of 300

• You can sense when you’re getting You can sense when you’re getting full from the hopper inside camera full from the hopper inside camera (refuse trucks don’t have weight (refuse trucks don’t have weight limitations)limitations)

Estimation – TimingEstimation – Timing• December bin numbers, weights are December bin numbers, weights are

generally up … more barbecues, etc so generally up … more barbecues, etc so consistently 4 loads, but in winter bins consistently 4 loads, but in winter bins go out less, so maybe three loads.go out less, so maybe three loads.

• School holidays - less traffic on the School holidays - less traffic on the road, so shorter peak traffic hoursroad, so shorter peak traffic hours

• Contractors fill diesel when required Contractors fill diesel when required since they pay for itsince they pay for it

Employed drivers fill each afternoon Employed drivers fill each afternoon • Stop-start motion tough on brakes. Stop-start motion tough on brakes.

Tyres last about three monthsTyres last about three months

• Before 7 am you get a good flow but if Before 7 am you get a good flow but if between 7 to 8 o’clock add 10, 15 to 20 between 7 to 8 o’clock add 10, 15 to 20 minutesminutes

• Always estimating how far they can go / Always estimating how far they can go / load up before returning /unloadingload up before returning /unloading

• Arms on refuse trucks go up and down Arms on refuse trucks go up and down about 1400 times a day, so the belts do about 1400 times a day, so the belts do wear down.wear down.

• Can go to streets and predict ten Can go to streets and predict ten minutes collecting here, half an hour minutes collecting here, half an hour there, etc . . .there, etc . . .

Estimation – Estimation – MeasuringMeasuring 2½ to 3 metres reach to the side2½ to 3 metres reach to the side Have about 4 tonnes (3.96t) worth of Have about 4 tonnes (3.96t) worth of

recycling capacityrecycling capacity Hill readings generally inaccurateHill readings generally inaccurate Truck’s about 10,070kg when empty. Truck’s about 10,070kg when empty.

Add driver’s weight, and a full tank of Add driver’s weight, and a full tank of diesel, full weight will be 10,260kg; if diesel, full weight will be 10,260kg; if diesel is a quarter full, it is 10,200kgdiesel is a quarter full, it is 10,200kg

Start at 5.30 am, first pick up at six. Start at 5.30 am, first pick up at six. Try to work outside rush hoursTry to work outside rush hours

• When truck is two-thirds full, we stop When truck is two-thirds full, we stop regularly and check. Some light days regularly and check. Some light days we don’t use scales, because total we don’t use scales, because total 9½ t on, anticipate only 750 bins9½ t on, anticipate only 750 bins

• Refuse bins are 120 litre capacity but Refuse bins are 120 litre capacity but some houses only need 80Lsome houses only need 80L

• When cars park on both sides of When cars park on both sides of narrow roads, truck drives through narrow roads, truck drives through with margins of 2-4 cm each sidewith margins of 2-4 cm each side

Estimation – NumberEstimation – Number In May this run was 965 bins – so a In May this run was 965 bins – so a

fourth load was needed for that. In July fourth load was needed for that. In July the same run was 841 bins so the the same run was 841 bins so the difference of 120-130 bins means we difference of 120-130 bins means we could do it in 3 lots of 270-280. could do it in 3 lots of 270-280.

Planning the route out of here, depends Planning the route out of here, depends on a load of around 270 to 280 bins. on a load of around 270 to 280 bins.

That day, expecting less weight and his That day, expecting less weight and his anticipated 841 total, he knew from anticipated 841 total, he knew from experience there were another 3 - 4 bins experience there were another 3 - 4 bins left to complete the second load of 275, left to complete the second load of 275, so a third load would finish the run.so a third load would finish the run.

Estimation – LocalityEstimation – Locality• Socio-economic nature of an area Socio-economic nature of an area

has a lot to do with bin weights. has a lot to do with bin weights. • Operators find lower income housing Operators find lower income housing

areas, load weights are a lot higher.areas, load weights are a lot higher.• However, some higher income However, some higher income

housing areas sometimes have housing areas sometimes have heavier bins because the periodical heavier bins because the periodical magazines in bins use heavy paper; magazines in bins use heavy paper; probably heavier than anything else probably heavier than anything else they regularly collect.they regularly collect.

ComplianceCompliance Too much weight results in a penalty Too much weight results in a penalty

going across the scale going across the scale Penalties are on a graduated scale Penalties are on a graduated scale

based on compaction ratio (of 180). based on compaction ratio (of 180). Related to the cubic space in the Related to the cubic space in the back of the truck (22.5 or 25 or 29 back of the truck (22.5 or 25 or 29 mm³³). If you go over that e.g. over ). If you go over that e.g. over 4.32t or 320 kg contractors get 4.32t or 320 kg contractors get individual fines while employed individual fines while employed drivers lose their company its bonus.drivers lose their company its bonus.