Caterpillar Product Information

Performance Report

For Dealer Sales Personnel

July 1999

Cat D8R vs.Komatsu D155AX-5

To determine the performance advantage of the D8R compared tothe Komatsu D155AX-5.

Objective

May 3, 1999Date

Caterpillar Proving Ground Tucson, ArizonaLocation

Peter Stauffer, Sr. Marketing Rep, GenevaKelly Todd, Caterpillar Tucson Proving Grounds OperatorBill Nordsiek, Sr. Performance/Application Engineer

Field Data By

Bill NordsiekWritten By

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Test Tractor Specifications Test Tractor SpecificationsD8R %

D155AX-5 D8R AdvantageSerial Number 70018 7XM433

Hours 157 648

HP (kW) 310 (231) 305 (227) (1.60)

Weight Lbs 89,650 84,750 (5.50)(kg) (40 665) (38 443)

WT:HP (kW) 289:1 (176:1) 278:1 (169:1)

Shoes in. (mm) 24 (610) ES 22 (559) ES

Track Length 126 (3200) 126 (3200)in. (mm)

Bottom Rollers/ 6 8Side

Carrier Rollers/ 2 0Side

Blade Height 67.25 (1708) 67.75 (1721)in. (mm)

Width End Bits 156.75 (3981) 154.00 (3912)in. (mm)

The test site consisted entirely of hard red clay and was ripped by aD9R, watered, and graded to provide consistent test conditions.

Test Site

Test DescriptionEach tractor dug five slots and the cycle times were recorded. Theslots were then cross-sectioned to determine the volume of materialmoved. Using the cycle times and volume of material moved, hourlyproductivity was calculated. Each cycle consisted of an 80 ft (24.4 m)slot, a 20 ft (6.1 m) transfer segment (tractors were shifted from1st to 2nd speed forward), and a 60 ft (18.3 m) carry. The difficultyof building stockpiles with the same dimensions in every test couldcause inconsistent cycle times. Therefore, dump times wereomitted to reduce variables.

The tractors were operated in 2nd gear at the beginning of eachdoze segment and downshifted to 1st gear in order to fill the bladecompletely and climb out of the slot. The tractors were downshiftedfrom 2nd to 1st at the operators discretion. At the 20 ft (6.1 m)transfer segment, both tractors were shifted from 1st to 2nd speedfor the carry, dump, reverse, and first portion of the doze.

Slot Dozing

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ProductivityThe following table shows the cycle times, volume of materialmoved, hourly productivity, and fuel efficiency of both tractors.Cycle times are expressed in hundredths of a minute.

Slot Dozing TestD8R %

D155AX-5 D8R AdvantageDoze Time .56 .47 16.07

Transfer Time .14 .12 14.30

Carry Time .23 .21 8.70

Return Time .35 .34 2.90

Total Time 1.28 1.14 11.00

Cycles/Hour 46.88 52.63 12.30

BCY/Cycle 8.38 8.01 (4.42)

BCM/Cycle 6.41 6.12

LCY/Cycle 10.48 10.01

LCM/Cycle 8.01 7.65

BCY/Hour 392.85 421.57 7.30

BCM/Hour 300.50 322.10

LCY/Hour 491.30 526.83

LCM/Hour 375.51 402.62

SAE LCY Capacity 11.50 11.40 (1.0)

LCM Capacity 8.79 8.72

LCY/Cycle as a % 91.13 87.81of SAE Capacity

Gallon/Hour 14.88 15.36 (3.2)

Liter/Hour 56.32 58.14

BCY/Gal 26.40 27.45 4.0

BCM/Liter 5.34 5.54

LCY/Gal 33.02 34.30

LCM/Liter 6.67 6.93

When compared to the Komatsu D155AX-5, the D8R:

moved 7.3% more LCY (LCM)/Hour

was 16.07% faster in the doze segment

shifted from 1st to 2nd forward 14.30% faster during the transfersegment

was 8.70% quicker during the carry and 2.90% faster returningto doze

Overall, the D8R averaged 12.30% more cycles per hour comparedto the Komatsu D155AX-5. The D155AX-5 moved 4.7% moreLCY (LCM) per cycle than the D8R, but was 12.3% slower.

Test DescriptionThe tractors backfilled two trenches each. Average trench lengthwas 200.83 ft (61.21 m), average depth was 11.10 ft (3.38 m), andaverage width was 5.4 ft (1.65 m). Both tractors were operated in1st forward and 1st reverse because the doze and reverse distancewas only 25 ft (7.62 m).

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Trench Backfilling

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ProductivityThe following shows the cycle times, volumes, hourly productivity,and fuel consumption of both tractors. Cycle times are expressed inhundredths of a minute.

Trench Backfilling TestD8R %

D155AX-5 D8R AdvantageDoze Time .21 .21

Reverse Time .15 .14 6.70

Total Time .36 .35 2.80

Cycles/Hour 166.67 171.43 2.90

BCY/Cycle 15.89 15.94 0.30

BCM/Cycle 12.15 12.19

LCY/Cycle 19.86 19.93

LCM/Cycle 15.18 15.24

BCY/Hour 2,648.39 2,732.59 3.20

BCM/Hour 2,025.04 2,089.73

LCY/Hour 3,310.07 3,416.60

LCM/Hour 2,530.05 2,612.59

SAE LCY Capacity 11.50 11.40 (0.09)

LCM Capacity 8.79 8.72

LCY/Cycle as a % 173.00 175.00of SAE Capacity

Gallon/Hour 18.45 18.74 (1.60)

Liter/Hour 69.83 70.93

BCY/Gallon 143.54 145.82 1.60

BCM/Liter 29.00 29.46

LCY/Gallon 179.41 182.32

LCM/Liter 36.23 36.83

When compared to the Komatsu D155AX-5, the D8R:

made 2.9% more cycles/hour

moved 0.30% more material/cycle

The D8R was therefore 3.2% more productive than the D155AX-5in the trench backfilling application.

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Test DescriptionA hill climb test was performed to compare the drive trainefficiency of both tractors. The test course was 50 ft (15.24 m) longwith a 30 degree slope. Both tractors were timed as they climbedthe test course. The hill climb test times are expressed inhundredths of a minute.

Test Results

When compared to the Komatsu D155AX-5, the D8R was:

27.30% faster in 2nd gear

41.67% faster in 3rd gear

The D8R has superior drive train efficiency capability due to asuperior torque divider.

Hill Climb

Test DescriptionBoth tractors were driven forward in 1st gear at high idle and thenturned as sharply as possible. Both operators tilted the blade tomake a mark on the ground that could be measured.

Maneuverability

Hill Climb TestD8R %

D155AX-5 D8R Advantage2nd Gear .22 .16 27.30

3rd Gear .36 .21 41.67

Test ResultsThe blade turning clearance of the D155AX-5 was 26 ft (7.92 m)and the blade turning clearance of the D8R was 25 ft (7.62 m).The D8R has a shorter turning clearance measured at the endof the blade of one foot. Overall, the D8R has 3.8% bettermaneuverability than the D155AX-5.

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FeaturesMajor features that impact performance, operator comfort, andtractor durability include:

3406C Engine The D8R has a 55% torque rise, which helpsit push loads faster in 1st and 2nd gears.

Torque Divider The D8R torque divider transmits 70% of itshp/kW through the converter and 30% direct, which means morehp/kW is available at the ground. The D155AX-5 seems to havea much softer torque converter, which is probably why its cycletimes are much longer.

Fully Suspended Undercarriage (U/C) The D8R bottomrollers and idlers are free to move up and down. This meansevery shoe and grouser bar can remain in full contact with theground, providing superior traction and stability. The D155AX-5has a partially suspended U/C because its front idler and rearsprocket cant move up and down to form a ramp for climbingrough ground.

The Caterpillar D8R fully suspendedU/C can conform to rough groundconditions for improved traction,stability and operator comfort.

The Komatsu D155AX-5 has limitedbottom roller movement.

The information contained herein is intended for circulation only to Caterpillar and dealer employees whose duties require knowledge of such reports and isintended exclusively for their information and training. It may contain unverified analysis and facts observed by various Caterpillar or dealer employees. However,effort has been made to provide reliable results regarding any information comparing Caterpillar built and competitive machines. Effort has been made to use thelatest available spec sheet and other material in the full understanding that these are subject to change without notice. Any reproduction of this release without the foregoing explanation is prohibited.

TEXR0319July 1999

www.CAT.com

1999 CaterpillarPrinted in U.S.A.

Undercarriage Rollers Both tractors have a track length of126 in (3206 mm). However, the D8R has eight bottom rollers,while the D155AX-5 has only six bottom rollers. This meansthat the Komatsu may have reduced roller life.

We weighed both tractors at the proving ground and found theD155AX-5 to be 4,900 lbs (2223 kg) heavier. Both tractors hadSU blades, differential steering, cab and air, and multi-shankrippers. The Komatsu weighed 89,650 lbs (40 665 kg) and theD8R 84,750 lbs (38 443 kg). The D155AX-5 has 12 bottomrollers that support 89,650 lbs (40 665 kg). Each roller mustsupport 7,471 lbs (3389 kg). The D8R has 16 bottom rollers thatsupport 84,750 lbs (38 443 kg). Each D8R roller supports 5,297 lbs(2403 kg). Less weight (29%) compared to the D155AX-5.This means less wear on the D8R rollers.

The D155AX-5 bottom roller spacing is 3 inches (76 mm) longerthan the D8R and the bogie spacing is 2.5 inches (64 mm) longer.This wider space between rollers may allow the track shoes toback bend, which could explain why the D155AX-5 is roughriding compared to the D8R. The D155AX-5 may also havereduced traction in rough ground conditions because of thewider roller spacing.

Tag Link The blade tag link design moves the blade 5 in(127 mm) closer to the front of D8R compared to the D155AX-5.There is more tractor weight on the blade for greater penetrationforce for quicker blade loading in hard ground.

ObjectiveDateLocationField Data ByWritten ByTest Tractor SpecificationsTest SiteSlot DozingTest DescriptionProductivityTrench BackfillingTest DescriptionProductivityHill ClimbTest DescriptionTest ResultsManeuverabilityTest DescriptionTest ResultsFeatures