The Highways Department today said remedial works for damage to some ventilation fan components of the Central-Wan Chai Bypass & Island Eastern Corridor Link’s Air Purification System are expected to be completed by the end of April.

The department learnt last month the contractor had found some loosened or damaged bolts and blades at several of the system’s fans at the East Ventilation Building during an efficiency test at the end of February.

The operation of the system concerned has been suspended for safety reasons since February.

After inspection, it was revealed that seven of the 15 fans in the East Ventilation Building suffered from different degrees of damage including broken bolts and damaged blade edges.

The department suspects that the failure of the mounting bolts was due to problems in the re-installation of bolts when the contractor carried out adjustments to the fan blades.

The edges of some fan blades were also damaged as a consequence of loosened bolts.

Replacement parts ordered by the contractor from overseas have arrived in batches. The remedial works are scheduled for completion in the end of April.

Samples of the damaged bolts and blades were delivered to a local laboratory and the overseas fan manufacturer for testing and analysis.

The department noted that air quality monitoring results show no abnormalities in the recent air quality within the tunnel and in the vicinity of the eastern portal, and has submitted a report on the incident to the Environmental Protection Department.

It will also continue to closely monitor the progress of the remedial works, conduct a detailed investigation into the cause of the incident and hold relevant parties accountable.