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is approximate , because it does not take into account the deformation of the

tires or the possible weight shift of the operator . But experiments in the

McKinley case demonstrated that the tilt would occur between 18 and 20

degrees .

The accident occurs as the operator enters a terrain where the ground

slopes suddenly to one side . The manual recommends ' that to avoid the flipover , the operator should lean uphill . This is actually not too difficult to understand or to do if there is sufficient time to assess the problem . 10

ver

is particularly difficult , however , if the terrain changes suddenly and if

this is combined with a requirement to turn the vehicle .

Turning

Figure 5 illustrates the ATC 110 in a full ( 90 degree ) left hand turn .

The minimum turning radius for the ATC 110 ( shown on the drawing ) is 1 . 9

meters . Applying this , the angle at which the front wheel is rotated for the

sharpest possible turn is a shade over 30 degrees . ( See Figure 5 ) .

Figure 6 illustrates the centrifugal forces that will be acting

separately on man and machine ( see top view ) .

The actual force is in each

case proportional to the mass of the object ( vehicle or man ) , to the square of

the speed , and inversely to the turning radius .

In the lower right hand

corner the effects of the weight forces and the centrifugal forces are shown .

It is evident that the weight forces w tend to stabilize , while the

centrifugal forces F tend to turn the vehicle over with respect to the tilt

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