1. Loading and Hauling

2. Cycle Time = Fixed Time + Variable Time
Fixed Time = spot time, load time, maneuver time, Dump time
Variable Time = travel time
Resistance
Total Resistance = Rolling Resistance + Grade Resistance
Rolling Resistance due to tire flexure and surface penetration
Grade Resistance due to grade of incline

3. Rolling Resistance 40#/ton on hard surface rubber tired
30#/ton if radials
T4-1
Rolling Resistance increases 30#/ton/1” penetration
Rolling Resistance Factor = 40# + (30# * inches penetration)
Rolling Resistance = Rolling Resistance Factor * tons

4. Grade Resistance
% of vehicle weight acting parallel to incline surface
Negative going downhill Positive going uphill
20#/ton
Grade Resistance Factor = (20# * % grade)
Grade Resistance = Grade Resistance Factor * tons
Effective Grade (%) = % Grade + Rolling Resistance/20

5. Altitude 3% power loss per 1000 ft
Using turbocharger allows power to stay constant up to 10,000 ft

6. Traction Power available to move vehicle
Rimpull – used for wheeled vehicles
Pull available at rim of driving wheel
Drawbar pull – used for tracked vehicles
Power available at hitch
Maximum usable pull = coefficient of traction * wt on driven wheels (for tracked vehicles and all wheel drive vehicles this is total wt)
T 4-2

7. Performance Curve Retarder curves
Maximum speed for a given load F 4-1, 4-2
Retarder curves
Maximum speed going downhill in gear

8. Travel Time Cannot use max speed Need to account for start up and stop
Average speed factors T 4-3
Max spd * Ave spd factor = speed for haul

9. Dozers Tractor w/ front mounted earthmoving blade Crawler Rubber tired
Low ground pressure (6 – 9psi)
Excellent traction
Rubber tired
Hi spd
Can compact soils
Can operate on paved surfaces

10. Dozers Attachments Rakes, scarifiers, rippers
tow compactors, scrapers, wagons
Blades
F4-7, F4-8
Performance based on power vs blade size
Hp/ ft of cutting edge -> blades ability to penetrate hard soils
Hp/loose cy -> blades ability to push soil

11. Production 5 bullets pg 96 show how to determine blade volume
Blade load (LCY) = HWL
Fixed cycle time – maneuver, change gears, start loading, dump
Variable time – time to doze and return
Can decrease by using reverse to return
T4-4, 4-5

12. Job Management Downhill dozing Slot Dozing Blade to Blade
Increases blade load
Cycle time reduction
Slot Dozing
Increases blade capacity up to 50%
Blade to Blade
2 dozers together
Combined capacity > 2x 1 dozer

13. Care for tracks and undercarriage
Must keep tracks clean
Must keep undercarriage clean and in good repair
Don’t run at hi spd over rough terrain
Minimize turns
Try to balance left and right turns and up & down slope operation

14. Loaders Tractor with a front end bucket Wheeled or tracked
Excavate soft – medium hard material
Load hoppers and haul units
Stockpile material, backfill ditches
Moving material

15. Loaders Wheel Loaders Tracked Loaders Backhoe loader F 4-11
High mobility
Not all terrain but low ground pressure
Modern are articulated F 4-9
Tracked Loaders
Can operate in most soils and on steeper slopes
Slower over longer haul distances=> less productivity F 4-10
Backhoe loader F 4-11
Attachments – augers, snow blades, forklifts, dozer blade, crane booms

16. Skid Steers Small wheeled loader w/ rigid axles
Steers by braking wheels on one side
<10,000# weight
Lift capacities of 600 – 6300 #
Can also be tracked
List of attachments pg 100
Also mini excavators

17. Material Handlers Rough terrain forklifts Common Lull Max lift 9000#
Max height > 60 ft
Move materials around site
Eliminates hand carrying or use of other equipment for carrying

18. Loader Production Average Bucket load x cycles per hour
Cycle time = loading, dumping, making 4 reversals in direction, traveling minimum distance T 4-6, F 4-14
Bucket Capacity is heaped T3-1 and use fill factor T3-2
Ex 4-7

19. Job Management Cutting tires major problem
L-5 tires – rock extra deep tread should be used when dealing with shot rock
Keep water out – lubricates rock /rubber cutting
Need to know tipping load – may limit amount of material in bucket
Loader size & productivity based on site limitations