On what type of machine does re-roping occur most frequently?

Re-roping occurs most frequently on overhead drum machines due to their design and operational characteristics. Overhead drum machines utilize a drum that winds and unwinds the hoisting cables, which leads to a significant amount of wear and tear on the ropes over time. This wear necessitates periodic inspection and replacement of the cables, a process known as re-roping.

In contrast, hydraulic machines operate using fluid pressure to lift the elevator car and do not rely on cables for vertical movement; therefore, they do not undergo re-roping. Geared machines have a different mechanism involving gears to operate the hoist, which may still require maintenance but not as frequently as re-roping. Direct drive machines, which are known for fewer moving parts and a more straightforward operation, also do not require re-roping in the same manner or frequency as overhead drum machines.

Overall, the mechanics of overhead drum machines make them the most prone to needing regular re-roping to ensure safety and efficient operation of elevator systems.