Another Lift Incident – Cargo Lift Petaling Jaya

This safety alert is issued as a result of several lift incidents which are relatively similar that occurred within the Klang Valley within the past 4 months. The most recent incident happened late January 2011 involving a cargo lift at a manufacturing plant in Petaling Jaya.

The cargo lift was used to move a series of equipments over a period of a few days, from level 4 to level 3. The equipments vary in sizes, but most of the time the cargo lift may fit up to 4 units of the equipments at a time. At the time of incident the estimated load was about 2100 kg, inclusive of 4 workers (estimated at 60 kg each). The cargo lift was designed for 2000 kg loading capacity with a 2:1 roping system. The overload limit switch was located at the termination point for the lift hoisting ropes inside the lift motor room (Refer Figure 1).

During the time of incident, as the fully loaded cargo lift arrived at level 3, the cargo lift door and landing door opened for a few moment. Suddenly it started to descent and the lift car door started to close. One of the worker (closest to the lift car door) started to climb out of the lift by using the 3 level landing floor as leverage. The cargo lift continued to slide down and the worker had no mean to free himself safely. Eventually the cargo lift slammed the buffer and the victim was found on top of the lift car with serious injury (Refer to Figure 2).

Suggestions:

1. Every inspector and Lift Competent Person should be reminded that an overload limit switch is the first line of defence for a series of several safety devices for lift. With the device working as intended, it should provide a fail safe lift operation. However, more often than not, the average lift user uses the overload alarm indicator as a measure on loading capacity and fit for use. When the lift failed to detect the overloading condition at regular intervals,it will create a series of unsafe act and unsafe condition which will eventually lead to the unfortunate accident.
2. Lift maintenance company must ensure that the overload limit switch is maintained and calibrated periodically, especially if the device is known to have low accuracy. The lift is not supposed to be operated if the device is found to be defective and in need for replacement.
3. The user must know the limit of the total load that they can carry and not to rely fully on the alarm to be activated. A gross weight label/indicator on each load or cargo would be a good practice and may help the worker make a quick calculation how much load are they dealing with.
4. Should the lift car malfunction, the passenger should remain calm in the lift car and not to do anything which will place himself in danger. The emergency button inside the car operating panel can be used by the trapped passenger to raise an alarm if the lift malfunctions. Please remain inside until help arrives.