Table A5. Sample input and output of CRM-1 (snow)

Table A3. Traction and motion resistance multipli-

Table A4. Vehicle weights supported by various frost

ers for wheeled vehicles on thawing sandy soils.*

depths.

Soil Type: SW

Wetness: Wet

Vehicle: Wheeled

Weight on wet ground

Weight on dry ground

Thaw depth (cm)

Traction multiplier

Resistance multiplier

Frost depth (cm)

(MN)

(lb)

(MN)

(lb)

1

1.0

2

0.0003

77

0.0001

31

2

1.0

5

0.0022

483

0.0008

197

3

0.88

2.6

10

0.0086

1933

0.0035

787

4

0.77

5.4

15

0.0194

4350

0.0079

1770

5

0.73

6.96

20

0.0344

7734

0.0140

3147

6

0.68

8.1

30

0.0774

17401

0.0315

7082

8

0.66

9.0

40

0.1376

30935

0.0560

12590

10

0.64

9.5

50

0.2150

48336

0.0875

19672

12

0.636

9.9

15

0.63

10.0

20

0.63

10.0

*The same multipliers are obtained (with warnings) for

clayey soils and tracked vehicles. A multiplier of 1.0 is

specified for rock, water and pavement and for all dry

(with warning) or moist soils.

Table A5. Sample input and output of CRM-1 (snow).

Example

1

2

3

4

5

Input

Modeling option*

1

3

4

Vehicle†

M113

Snow Base Code**

1

3

4

Snow depth (cm)

15

12

Snow type††

7

6

7

RCI

--***

--

Snow density (g/cm3)

0.2

--

0.2

Slope (degrees)

0.0

30.0

0.0

Output

Vehicle speed/wheel speed

0.975

0

0.974

0.964

0.941

Rut depth††† (cm)

9.0

0.0

7.2

Gross traction (N)

44134.3

39207.1

29692.1

16741.3

Total resistance (N)

5585.4

57631.6

3903.5

5464.8

5275.1

Drawbar (N)

38548.9

18424.5

25788.6

24227.2

11466.2

Drawbar coefficient

0.370

0.177

0.248

0.233

0.110

Notes

*Modeling option 1 is snow analysis, 2 is freezing/thawing soils.

†Requires a vehicle data file name.

**Snow base codes (the material underlying the snow):

1--superhighways/primary roads.

2--secondary roads.

3--off-road terrain/trails/strong frozen ground.

4--ice (if snow depth is <1.0 cm, then ice only).

5--unfrozen soil (requires RCI).

††Snow type:

6--disturbed (more than four vehicle passes or a prepared snow road).

7--undisturbed snow.

***Input not required with the previous specified input.

†††Total vehicle sinkage.

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