NEIEP Mechanics Practice Exam

If a hoist machine roped 1:1 is capable of running at 650 fpm with a capacity of 4500 lbs, what would the capability be if roped 2:1?

1. 650 fpm at 4500 lbs

2. 325 fpm at 9000 lbs

3. 180 fpm at 10000 lbs

4. 900 fpm at 4000 lbs

The correct answer is: 325 fpm at 9000 lbs

When a hoist machine is reconfigured from a 1:1 to a 2:1 rope system, there are changes in speed and capacity due to how the rope’s mechanical advantage operates. In a 1:1 configuration, the hoist can raise a load directly, meaning the speed of the hoist is equal to the speed of the load being lifted. In this case, it operates at 650 feet per minute (fpm) with a maximum capacity of 4500 lbs. However, when the system changes to a 2:1 configuration, the effective capacity doubles, but the speed is halved because the rope system involves more lengths of rope to lift the same load. In practical terms, with a 2:1 rope system, the hoist can lift twice the weight, therefore the capacity increases to 9000 lbs. Simultaneously, because of the halving of speed due to the additional rope lengths involved, the new maximum speed is reduced to 325 fpm. Therefore, in a 2:1 configuration, the hoist operates at 325 fpm with a capability of 9000 lbs. This outcome aligns with the available choices, confirming that the correct answer integrates the fundamental