Bang on! Twin towers fall to a perfect blast

Varying Amount Of Explosives For Cascading Effect

- Aditya Dev

Noida: What does it take to raze 30-storey buildings rising over a cluster of societies with pinpoint accuracy? A study of the structures, their distinct features, a calibrated use of explosives and preparations for months to make sure the entire exercise was backed by science and was ultimately safe.

The masterminds of the demolition told TOI on Sunday that the biggest challenge was to bring down the towers without damaging nearby apartments, the nearest just 9 metres away. The recognition that thousands of houses were at stake was what drove the implosion blueprint, said Joe Brinkmann, the director of Jet Demolition and architect of the blast design.

Experts analysed the buildings and realised they were stronger than 30-storey structures would typically be — partly because construction in an earthquake-prone zone (Noida is a Seismic zone 4) requires foundations to be sturdy, and also because the towers were originally to be 40 storeys high.

A test blast in April also gave them an idea of the strength of the columns in the towers, Apex and Ceyane. A decision was taken at that time to use an additional quantity of explosives, and change the blast design, now including more floors in the plan. And so, the quantity was finalised at 3,700kg of explosives across 9,642 holes in the columns of both the towers.