Don't understand your application, though what happens if (when) the power fails?

Suggest you consider a / some fail safe brake /s of some description.

Regards,

Lyle ■

TBS are normally used where blending of ore required. As it is a equipment to staging material another equipment for reclaiming the blended ore is mandatory. So some times the TBS Boom (which is not in O/P )will cross over the Reclaimer. To cross over -the non operating Boom have to be Luff up to 16-17Deg.to clear the Reclaimer. The boom in operation will be at much lower deg. thus the drive pulley C/L distance and level will very in respect to the angle of boom.So same drive for either boom is not fissile.

Regards,

ANM ■

It would be great if you could share out a bit more information about your application.

Nevertheless & assuming rope luffing: Pls. consult FEM II clause 4.2.2, you will see requirements towards rope safety levels. Assuming you have a twin rope system, your rope safety factor is half that of a single rope system --> thinner rope --> smaller drum --> less big & heavy gearbox + motor. Yes, there will be doubly the number, but there may have been reasons for that. Put it another way: If one rope / luffing system fails, the other one holds. Another bonus is, that rope change may be performed without a fixed setting up of the boom just using the other system to hold.

If you have two motors to a single gearbox, now that is uncommon to me, as you have another motor where another brake should have been. Does, if existing at all, this motor is running on standby or under load? However, two brakes per luffing system is surely the right way, and if possible one of them working on the drum itself.

Please, answer back to this forum.

R. ■

Dear Mr. Kundu,

in my opinion: An electric motor of customary dimensions / power is not that hard to obtain. Why not have a 24 h - delivery contact, or even a spare motor tucked safely into a shelf somewhere, secured from sudden disappearance? And when the day of necessity comes, a mechanic can replace any broken down motor quite swiftly, i think.

A in - place mounted secondary / backup motor will be exposed to environment and not getting better from that. Furthermore the live motor will have to turn the inert masses of the standby motor all the time, that makes up constant op. costs.

However, some clients / operators could be demanding extreme availability.

Last but not least: As mentioned earlier, a twin rope system would have very good availability + offering emergency op capabilities + very highly rated safety conditions.

In the end: An electric motor of sufficient quality (brand) + correctly designed power range will also have excellent availability characteristics... and it will be far from being the only source of trouble, if it comes to that.

So we arrive at last at the idea of a complete drive unit as a spare part against all odds.

R. ■