Residents will have to wait for almost a month before they can again match their watches with the landmark clock on the Old Secretariat tower that stopped functioning three weeks ago.

A team of engineers from the Calcutta-based firm Anglo Swiss Watch Company inspected the clock earlier this week and detected damage to its pinion and several other parts.

Executives from the watch company claimed that the firm was involved in clock manufacturing and repair since 1908, and looks after the maintenance of clock towers in Bhagalpur (Ghanta Ghar), Shimla (clock tower on Mall Road), Calcutta (New Market) and Amritsar (Golden Temple) among others.

The team assured building construction department officials that the secretariat clock could be repaired and ruled out any need to replace it with a digital one. However, the repairs would be done in Calcutta for around three weeks, giving it a 100 year lease of life.

Building construction department officials intend to make the clock functional before the commencement of the Assembly monsoon session on July 29. A senior official of the department said: "Anglo Swiss Watch Company engineers would need to take the pinion and several other parts of the clock to their service station in Calcutta and repair those in three weeks."

Supratim Chatterjee, an executive in the maintenance wing of the company, said an estimate of charges for the clock repair would be submitted to the building construction department in a few days. "We have expertise in repairing clocks fitted on towers and we would be able to repair the clock on the secretariat tower as well. While the pinion would be repaired, few other spare parts would be replaced with newer ones," he said.

One of the finest pieces of Churchill pattern of clock towers, such clocks have a patterned round face and larger digits than usual in India, the secretariat clock was fitted in 1924. Gillett and Johnston, clockmakers from Croydon, England, made the clock.

Originally, the clock tower was 198ft high but a part of it fell off in the 1934 earthquake, reducing it to its present height of 184ft from the ground up to the lighting conductor.

Sources said around Rs 50,000 was sanctioned annually to maintain the clock. Employees have to climb 276 steps to wind it and maintain it.