Yes it is, though it requires a few assumptions:

1. P=sqrt(3)*v*i*cos(theta)*efficiency

2. P=Te*s

Rearrange 2.

3. Te=P/s (power / belt speed)

Using:

4. T1/T2 = exp(u*theta)

5. T1=Te+T2

Rearrange: 5. and 6.

6. T2= Te/(exp (u*theta)-1)

You have Te from 3.

Assuming u and observing theta, you can calculate T2, from 6.

You can calculate T1 using 5.

Note you would have to apply some "starting factor" for Te when starting (and use the largest calculated T2).

Also note the actual T2 may be larger (or less..) than calcualted due to: subjective selection of u / theta, construction ambiguity, required for brakes that we are not currently aware of, control of transtion or curves etc, etc.

We would also suggest if using this approach you would use installed power rather than demand power. If it is to be used for critical applications (i.e. where there are significant safety or cost implications: belt selection, structural / civil design) you really need to validate the assumptions.

If this requires further clarification we would suggest it may be best not to use this approach.

Regards,

Lyle ■

Yes it is, though it requires a few assumptions:

1. P=sqrt(3)*v*i*cos(theta)*efficiency

2. P=Te*s

Rearrange 2.

3. Te=P/s (power / belt speed)

Using:

4. T1/T2 = exp(u*theta)

5. T1=Te+T2

Rearrange: 5. and 6.

6. T2= Te/(exp (u*theta)-1)

You have Te from 3.

Assuming u and observing theta, you can calculate T2, from 6.

You can calculate T1 using 5.

Note you would have to apply some "starting factor" for Te when starting (and use the largest calculated T2).

Also note the actual T2 may be larger (or less..) than calcualted due to: subjective selection of u / theta, construction ambiguity, required for brakes that we are not currently aware of, control of transtion or curves etc, etc.

We would also suggest if using this approach you would use installed power rather than demand power. If it is to be used for critical applications (i.e. where there are significant safety or cost implications: belt selection, structural / civil design) you really need to validate the assumptions.

If this requires further clarification we would suggest it may be best not to use this approach.

Regards,

Lyle ■

We note:

Becareful applying desing loads in the manner described here - i.e. assuming a tower mounted drive with the winch on the ground, the drive pulley and associated support may see T1+T1 (no torque as line pull is provided by other means such as a winch etc) in lieu of normal T2+T1 (+ torque). Hence the load question is still an issue.

You may be trying to achieve "average tension" in lieu of T1/T2.

It seems as though maybe the take length up may not be optimal. Designers generally make some allowance for elastic and permenant stretch (amongst other things).

The factor mentioned earlier referred to the increased torque relative to normal operation associated with starting, not the "spare capacity of installed power relative to demand".

Regards,

Lyle ■

We note:

Becareful applying desing loads in the manner described here - i.e. assuming a tower mounted drive with the winch on the ground, the drive pulley and associated support may see T1+T1 (no torque as line pull is provided by other means such as a winch etc) in lieu of normal T2+T1 (+ torque). Hence the load question is still an issue.

You may be trying to achieve "average tension" in lieu of T1/T2.

It seems as though maybe the take length up may not be optimal. Designers generally make some allowance for elastic and permenant stretch (amongst other things).

The factor mentioned earlier referred to the increased torque relative to normal operation associated with starting, not the "spare capacity of installed power relative to demand".

Regards,

Lyle ■