Winch Drum Torque calculation. 2

[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..

 

[MintJulep]

Yes, consider the mass. Acceleration.

Yes, consider rolling resistance.

 

[Cockroach]

There are losses in the system due to friction, bearings and mechanical linkages with pins for example. Perhaps buddy simplified by putting in a correction factor, 10% in this case.

Not uncommon, just a guess.

Kenneth J Hueston, PEng
Principal
Sturni-Hueston Engineering Inc
Edmonton, Alberta Canada

 

[chicopee]

An extra 10% added to you calculated value of 549kNm. 607kNm makes sense