Elevator Modernization at Gloucester Tower

Mitsubishi Elevator Hong Kong, Co., Ltd. was tasked with modernizing the vertical transportation in this 43-story Hong Kong commercial complex.

Mitsubishi Elevator Hong Kong, Co., Ltd. was tasked with providing elevator-modernization solutions to Gloucester Tower, a 43-story class-A commercial building located among Hong Kong’s The Landmark commercial complex. The building’s elevator system consisted of 18 traction elevators installed in four zones. The units, in operation since 1979, had a 2400-kg capacity and were capable of traveling at speeds up to 6.3 mps.

Innovation and Technology

A heavily trafficked area, elevator usage in Gloucester Tower is high, which led to the property management’s concerns over the effects modernization work would have on building traffic. Machine-room floors were fully occupied by the large, existing gearless-traction motor. Replacement of the traction motor would have greatly impacted building operations. Alternatively, Mitsubishi planned an on-site motor overhaul to minimize traffic disruption, with the operation equipment upgraded instead of completely replaced. In addition to upgrading the existing control to a variable-voltage, variable-frequency drive, the conventional group control was upgraded to a Destination Oriented Prediction System (DOAS) with card reader, destination floor indicators were modified, and the car frame was extended to 2,700 mm to create a higher ceiling.

Installation Method and Overlay Technique

To minimize disruption, the modernization work was divided into three major steps. Step one consisted of the overlay, a critical element requiring a link between the existing system and new DOAS. The overlay can apply the new dispatching system and immediately improve the entire system. In step two, individual elevators were isolated for modernization work without reducing overall performance. The newly modernized unit could then be integrated into the group as the next unit was isolated and upgraded. Once modernization was complete, step three, which consisted of the on-site machine overhaul, went into effect.

Challenges

One week after upgrading Zone D, a group of four elevators, property management received complaints about the system’s abnormal and inefficient operation during lunch peak. Upon reviewing the traffic data, a reason for the operation problems could not be pinpointed. After several on-site studies by the engineering team, it was confirmed that some abnormal behavior existed. Daily and weekly on-site observations continued during morning, lunch and evening peak times. At midnight, the investigation continued as Gloucester Tower became a testing tower for running simulations to obtain on-site traffic data. Utilizing the results, the system’s accuracy and efficiency was improved by implementing countermeasures week by week until finally accepted. Modernization at Zone D and, subsequently, other zones could then continue.

Advanced Technology

A remote elevator monitoring system known as MelEye, which provides property managers a user-friendly interface for monitoring, scheduling and controlling elevator use was installed. Using MelEye, all essential elevator information, such as traffic data and operation status, can be monitored in real time. Property managers can also schedule elevator use and control the floor access authority incorporated into the elevator card-reader system. In addition to MelEye, an LCD multimedia car position indicator was installed inside the cabins. Information such as stock indexes, weather and building details, and advertisements can be displayed onscreen. 

Gloucester Tower’s elevator modernization occurred over a three-year replacement schedule, with the project completed in December 2010. After Mitsubishi’s modernization, average wait time improved overall traffic by 80% and achieved a 30% energy savings from regenerated power.