Town Hall’s chamber of secrets

Once you enter the southern gate of Town Hall, opposite the Assembly House, you can walk up the stately steps to the balcony, craning your neck to marvel at the massive white Grecian columns, and be greeted by our old friend, the Krupp Gun, which used to be housed in New Market till five years back serving as the best signpost for the directionally challenged shopper.

Or, you can do what Mamata Banerjee did a few days back after the launch of the Kolkata Museum of Modern Art (KMOMA), and explore a hidden treasure of Town Hall. Here’s how.

Turn left, take a little path skirting bushes and leafy plants and turn left again. Walk down the short flight of steps and turn right. A little ahead, you will face a black gate of cast iron. Pause for a moment, for the gate is two centuries old. Well, actually much of Town Hall is 200 years old, the construction having started in 1807 and completed in 1813.

The gate parts to allow you into the underbelly of this majestic building designed by Colonel John Garstin. This is the basement of Town Hall, a series of arched, interconnected tunnels, the brick skeleton of the walls exposed, no plaster, no smooth finish. There is little natural light, so we wait for our eyes to adjust to the dark. Two of the chambers have concealed LED lighting in blue and red. Work is on in the other four. The 200-year-old bricks are rough to the touch, a little damp in places.

High on Harry — Potter, the boy wizard, that is — we are immediately transported to the Hogwarts Chamber of Secrets. We almost strain our ears to catch Nagini the snake’s scratching whisper in Parseltongue. We half expect Tom Riddle to emerge from the dark cavern in front of us.

Dipankar Sinha, the director-general (town planning) of the Calcutta Municipal Corporation, points to little droplets of water on the low ceiling of one of the passages in between the tunnels. He and his team are busy making the basement “habitable”.

We worry about the damp. “But that’s the reason the tunnels were built. If we plaster up these walls, their very purpose will be lost. The bricks have been left exposed not just for aesthetics or historical sentiments,” says Sinha.

Er?

“Back then, there was little by way of waterproofing. The bricks in the tunnels are exposed to let the walls breathe. The moisture that rises from the ground evaporates through the walls, thus the upper structure is spared the damp. This delays the decay of a building,” explains Sinha.

Wow!

To help the walls breathe better, Sinha and his team have tried to improve the ventilation in the basement, which covers between 7,000 and 8,000sq ft. That explains why our nostrils couldn’t detect the musty smell that one would expect in a place like this.

Sinha describes this kind of a basement as a “barrel vault”, so called because it resembles a barrel sawn in half, vertically.

The first time in recent memory when people entered the basement was in the late ’90s. In fact, Sinha and The Telegraph correspondent Deepankar Ganguly were the first ones to venture down, armed with flashlights and thick boots, not knowing what creepy-crawlies lay within.

After the initial rediscovery of the basement, or dungeon as it was being called then, nature was allowed to reclaim it. Around two-and-a-half years back, work started again.

The first task was to clear the mud, filth and vegetation that had risen almost waist high within the tunnels. Next, the grounds near the doors and windows of the tunnels were cleared, to allow in more air.

Two mechanical fans were placed to improve ventilation. The flooring was haphazard, a little patch of brickwork here, some limework there. So the floors were paved uniformly. Keeping the bricks exposed, the mortar in between was strengthened through a process called “pointing”. That’s basically applying cement and admixture.

In one of the tunnels, a large crack runs through the length of the ceiling, where bits of iron are wedged in. “This is possibly a fault with the original plan of the structure and the iron was used to rectify it. We didn’t tamper with it. If the building has stood steady for two centuries, who are we to mess with it?” says Sinha.

Interestingly, the original plans of Town Hall show that the tunnels were not completely below the ground level. But over time, the road level has come up, first when the road was metalled and then because of layers of pitch laid every few months.

This is, however, Calcutta’s second Town Hall. The first one, which housed the courthouse, stood where St Andrew’s Church stands now. Thus the name Old Court House Street. The first Town Hall was built in 1729 and the structure was severely damaged in 1737. It was pulled down in 1792.

The present Town Hall authorities are in the process of deciding how best they can utilise the underground tunnels. In April 2010, the basement was inaugurated as an exhibition space, where sculptures were showcased.

“This can be an excellent place to house sculptures and artefacts. The humidity rules out a painting exhibition, though,” says Sinha.

The other idea is to host a sound-and-light show. Sinha would like the people of Calcutta to suggest other options.