Load and Haul Fleet Selection Based on Fixed Plant Production

Load and Haul Fleet Selection Based on Fixed Plant

Production

Load and Haul Fleet Selection

Based on Fixed Plant Production

Ways to Estimate Productivity !!

The typical view is machine centred …

What are we going to do ?

• Review an approach which uses Crusher Output to drive fleet selection.

• Use a simple spreadsheet to manage this processe.g. no bunching or cycle mismatch included.

• Tie in the relevant concepts of earth and rock moving into this process.

• Seek to reinforces the outlook thatYou can’t Manage what you don’t Measure !

What are the Production Targets and Rates for Fixed Plant?

How much Time is Available?

What is the Load Area Production Rate ?

How much of an Hour does the Loading Tool

spend Loading?

What is the Match of Loading

Tool and Haulers ?

What does our Reality look like?

What is the Key Characteristic of the Material?

What are the Cycle Times for Haulers and Loading

Tool?

Key Questions Addressed

What Primary Load & Haul Production is required?

Bunching and Cycle Mismatch

Quarry Contacts• Queensland and Northern Territory

• Paul Soden Hastings Deering, Brisbane

• New South Wales • Andrew Black WesTrac, Sydney

• Victoria• Ian Collins William Adams, Melbourne

• Tasmania• Stuart Mc Donald William Adams, Launceston

• South Australia• Mark Taylor Cavpower Adelaide

• Western Australia• Steve Sakich WesTrac Perth

Any Questions ?

TheThe EndEnd

Concepts

• Time Available• Work Days per year• Work Hours per Day• Job Efficiency – Work Minutes per Work Hour• Load Area Activities

• Material Density• Load Factor and Fragmentation

• Fleet Match• Cycle Times• Bucket to Body Sizing – Effective Pass Ratios

• Bucket Fill Factor

Concepts

• Time Available• Work Days per year• Work Hours per Day• Job Efficiency – Work Minutes per Work Hour• Load Area Activities

• Material Density• Load Factor and Fragmentation

• Fleet Match• Cycle Times• Bucket to Body Sizing – Effective Pass Ratios

• Bucket Fill Factor

Availability & UtilizationAn Example

Job Efficiency FactorsMismatchBunchingOperator Efficiency (85% Job Efficiency)

Utilization LossReady, but unmannedShift ChangeLunch & MeetingsScheduled Downtime &PM's (87.5% Utilization)

Off Time LossHolidaysWeather

(4.1% Off Time)

Machine Availability LossUnscheduled Downtime (90% On-Shift Availability)

PRODUCTIVE TIME 6615 HRS

735HRS

1050HRS

360HRS

Machine Operating Hours (6615 HRS)

Machine Scheduled Hours (7350 HRS)Mine Scheduled Hours (8400 HRS) Total Annual Hours (8760 HRS)

10 % of

7350

4.1 % of 8760

12.5% of 8400

Work Hours Available per Year

Work Days per Year

• Full Days 220 days

• Partial Days 48 days

• Partial Day Factor 0.50

Load & Haul Work Hours per Day

Load and Haul Scheduled Hours / Day 10 hoursless Non Operational Time

MobilisationToolbox Talk - Inspect - Transit 20 minutesTransit - Refuel - Shut Down 20 minutes

Breaks including Transit timeAM / PM Breaks 20 minutesLunch 45 minutes

Subtotal of Non Operational Time 1.75 hours

less Non Primary Load and HaulStock movement 0.75 hoursOverburden 0 hours

Subtotal Non-Primary Load and Haul 0.75 hours

Work Hours per Day 7.5 hours

Job Efficiency /Work Minutes per

Work HourJob Efficiency is one of the most complex elements of estimating production since it is influenced by factors such as operator skill, minor repairs and adjustments, personal delays and delays caused by job layout. An approximation of efficiency, if no job data is available, is given below.

EfficiencyOperation Working Hour Factor Day 50 minute hour 0.83 Night 45 minute hour 0.75

These factors do not account for delays due to weather or machine downtime for maintenance and repairs.You must account for such factors based on experience and local conditions.

What about time lost for watering the load area ?

Analysis of Face Loader Activity

Load Area Activity of Wheel Loader

Preparing to Load17 %

Loading Truck54 %

Non-Loading Activities

30 %

Clean Floor3 %

Predig Pile8 %

Remove Oversize17 %

Maintain Floor2 %

Concepts

• Time Available• Work Days per year• Work Hours per Day• Job Efficiency – Work Minutes per Work Hour• Load Area Activities

• Material Density• Load Factor and Fragmentation

• Fleet Match• Cycle Times• Bucket to Body Sizing – Effective Pass Ratios

• Bucket Fill Factor

Density of Materials

Material Bank Loose Load kg/m 3 kg/m 3 Factor

Gravel - pit run 2179 1930 .89Earth-dry 1900 1510 .80Earth- wet 2020 1600 .79Clay – natural bed 2020 1660 .82Topsoil 1370 950 .70 Shale 1660 1250 .75Granite -broken 2730 1660 .61Limestone 2610 1540 .59

Full Table in PHB 42 P27-4

Concepts

• Time Available• Work Days per year• Work Hours per Day• Job Efficiency – Work Minutes per Work Hour• Load Area Activities

• Material Density• Load Factor and Fragmentation

• Fleet Match• Cycle Times• Bucket to Body Sizing – Effective Pass Ratios

• Bucket Fill Factor

LOADFixed Time

RETURNVariable Time

HAULVariable Time

DUMPFixed Time

CYCLE TIME

Machine Production

Delays

Operator Skill

Target Truck Load Time2 minutes

Target Exchange Time0.7 minutes

Target Pass MatchLoader / Hauler = 3-5

Excavator / Hauler = 4-6

Loading Tool / Hauler Pass Match

Concepts

• Time Available• Work Days per year• Work Hours per Day• Job Efficiency – Work Minutes per Work Hour• Load Area Activities

• Material Density• Load Factor and Fragmentation

• Fleet Match• Cycle Times• Bucket to Body Sizing – Effective Pass Ratios

• Bucket Fill Factor

Material

Moist LoamSand and Gravel MixRock - Well BlastedRock - Poorly Blasted12 –20mm Aggregate

BFF as % of Heaped CapacityA - 100-120 %B - 95-110 %C - 80 - 95 %

50 - 75 % 85 - 90

Bucket Fill Factor (BFF)

A

BC

PHB 42 Pages 4-156, 9-161

BFF for Wheel Loader buckets tend to be

5 – 10 % higher than Excavator buckets due to different angles of

repose for SAE rating.

Quarry Contacts• Queensland and Northern Territory

• Paul Soden Hastings Deering, Brisbane

• New South Wales • Andrew Black WesTrac, Sydney

• Victoria• Ian Collins William Adams, Melbourne

• Tasmania• Stuart Mc Donald William Adams, Launceston

• South Australia• Mark Taylor Cavpower Adelaide

• Western Australia• Steve Sakich WesTrac Perth

Any Questions ?

TheThe EndEnd