Certain safety precautions must be taken by all demolition contractors while working on top of these structures. Indian demolition contractors tend to neglect safety and this may lead to loss of life and property. Apart from the usual safety measures to be adopted, like fall protection, PPE, lifeline, anti-vertigo measures, mock up training, teamwork etc., there are also few environmental factors to be considered. For example, the working conditions at a height of 100m will be entirely different from those at ground level as even a highly skilled person can falter when working in heights.

Before a person is deployed to work in the high location spot, the following must be ensured:

1. Health condition, in that the operative must not have vertigo or high blood pressure and be tested for balance.

2. Vision test.

3. Good communication skills.

4. Must be equipped with proper PPE.

5. Must carry all necessary tools and equipment required to complete the work.

6. Must never work alone. 

7. Have a handsfree walkie talkie with speaker.

8. Must know what the day’s work consists of and be well trained for the job (cannot learn on the job at that height).

9. The management must have a mock-up made to explain the exact work.

10. Must have a first aid kit at all times at the high working level.

11. Must not be allowed to carry a mobile phone.

Environmental factors

At a height of 100m, the wind speed can reach 100km/h, especially during monsoons in India. At this height, no one must stay at top. All tall structures like chimneys, cooling towers etc. will sway during high wind which may cause fear amongst workers and lead to a loss of balance. Thunderstorms are also a dangerous time to be at the top. If a thunderstorm is expected, no one should be allowed to work at the top of a structure. In important demolition work, it is better to install a pre warning system that can alert on an incoming thunderstorm.

Lightning

Lightning is the most dangerous enemy when working in heights. Usually, when old tall chimneys are to be demolished, there will be no lightning arrestors (LA) in the top. The old ones may not work as someone would have either stolen the copper conductors or they might have fallen down. Under such conditions, when a worker is on top of these structures and there are no taller structures around, the worker can become a lightning conductor. By this I mean when there is lightning along with a thunderstorm, the lightning may be attracted, with the worker acting as a lightning rod. Also, if the worker is holding an electrical tool like a chipper, this may also be the reason for the lightning to be attracted. Lightning usually carries a very huge electrical current and intense heat which is rarely survived if a person is struck. This means that it is always better to immediately come down to a lower level before a thunderstorm.

For such high demolitions, I recommend that the contractor install a temporary LA with a 50mm2 copper down conductor cable with proper earthing running from the top till ground level. This should be positioned at least 2m above the tallest person working at that height. This temporary LA should be gradually lowered as the structure is being demolished. Vertical reinforcements of a structure can also attract lightning; hence, these rods must be cut as soon as they are exposed.

I hope the above tips will be followed by all demolition contractors.

Wishing you all safe demolition.