Heavy Duty Winch Drum Torque

[llaren]

Good Day to you all,,
May I ask some question. I hope anybody can help me here. I confused to calculate Drum torque. Drum weight is 200Ton. Pull force at layer dia 5.6m is 20Ton. As my option, Torque is 20Tonx 2.8m= 549kNm..But I found 607kNm in specification. I can't clarify which one is correct. If I calculate drum torque, do I need to consider drum weight(200Ton) also or rolling resistance? Which formula is applicable ?
Thank in advance..

 

[PersonalProfile]

It almost looks like someone may have just added "10 % fat"?

Regards,
Lyle

 

[Newton1st]

They have probably have included a factor of safety + the weight of the drum

 

[chicopee]

The "fat" is for the acceleration ( inertia) of the load when it is about to be raised.