What is behind the Sigma lift incidents and why did HDB restrict Sigma from tendering new projects in 2015?
Sigma has been installing lifts in HDB estates for the past 10 years. Out of the approximately 24,000 lifts in HDB estates, about 3,500 are Sigma lifts. The overall performance of Sigma lifts has generally been comparable with other lift brands.
However, for a HDB tender awarded in 2013 to install 469 lifts, Sigma was unable to adhere to the contractual timelines of installing the new lifts. Hence, in Oct 2015, HDB restricted Sigma from tendering for new HDB lift contracts to ensure that the company focused its resources to fulfil its contractual obligations.
The tender restriction is part of HDB’s quality management system to ensure that contractors are able to deliver to HDB’s standards and contractual requirements. This process applies to all HDB contractors who do not meet contractual requirements.
Subsequently in 2016, HDB also observed a higher-than-usual breakdown rate in lifts from this batch of 469 Sigma lifts particularly in their first year of operations.
The issues with this batch of Sigma lifts are different from typical lift faults or incidents, which usually involve older lifts, from a variety of lift brands, and which are largely maintenance-related.
For the 469 Sigma lifts, investigations by HDB and independent Authorised Examiners revealed that the design and installation of the lifts complied with prevailing codes and standards; however, the doors and sensors were more susceptible to misalignment from knocks from heavy and rough lift usage, which typically takes place during the first year of operations from renovation and moving activities.
HDB has since instructed Sigma to rectify these issues and to carry out improvement works to ensure that the lift doors and sensors operate smoothly. HDB has also issued stern warnings to Sigma, and is closely monitoring the performance of its lifts. Both Sigma and its parent company have channelled more resources towards addressing the issues. In particular, Sigma has undertaken the rectification works progressively, and this has resulted in some observed improvements in lift performance. HDB will continue to hold Sigma accountable for its performance standards, and the tender restriction on Sigma will continue until they meet the required standards.