Ray Saunders was commissioned by Gastown businesses to build and install the clock back in 1977 as part of the area's revival.
It has been impressing tourists and locals with its steam whistles at Cambie and Water streets ever since, but it hasn't been the most reliable time keeper. So after 37 years of operation, the city asked Saunders to give the clock a refit.
The clock was taken down in October, and the $50,000 refit was originally scheduled to be completed by Christmas.
Saunders said the only other time the clock was taken down was when it was hit by a car and had to undergo a $20,000 repair. He notes the clock kept running despite the crash.
While the clock was away getting repaired tourists had to make do with a cardboard replica in its place.
When the clock is operating, Saunders said he still goes down twice a week to check on it and talk to people gathered around waiting for the whistles to blow.
"It is very gratifying to see how popular it has become. I just love going down there and talking to people... quite often I open the clock up and let them push a button and blow the whistle and it really blows them away."
While the Gastown clock was his first, Saunders has since created many other clocks for cities worldwide, including Whistler, Port Coquitlam, Indianapolis and Otaru, Japan.
He also made two other clocks in Vancouver, one on Main Street and the other in Queen Elizabeth Park.
"They are nice little icons for that area of the city."
Steam engine turning the gears
The clock is powered by steam from the city's downtown centralized heating system, which drives a piston inside a miniature steam engine inside the clock.
That engine in turn drives a series of ball-weights, chains and gears, which in turn drive a conventional pendulum, which in turn powers the clock's time-keeping mechanism that was custom-built in England based on an 1875 design.
But the clock is not entirely steam powered. It also has three small electric motors to help operate two internal fans, one of which blows the steam out the top, and another that controls the valves that play the tunes on the five steam whistles mounted atop the clock case.
The large central whistle, which was taken off the CPR steam tug Naramata, counts off the full hours while the four auxiliary whistles chime the Westminster Quarters every quarter hour. The number of chimes matches the number of quarter hours that have passed.