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Explosive situation

If Controlled Demolition Group managing director Charles Moran ever doubted the need for armed guards during his preparations to blow down two tower blocks in Puerto Rico last week, the discovery of a corpse in the next door block changed his mind. Moran had been warned that the area of San Juan where the blocks were located was notorious for drug-related violence, and that guards were essential to protect both Controlled Demolitions four strong team and the 100kg of explosives that would be used for the blow down, but he was not expecting 400 heavily-armed police, 80 of them on horseback.

Then, during the three days the team were on site, the body of the murder victim was found only a few metres away. Until then, Morans only real worry had been the massive reinforcement in the 22 year old 16 storey blocks. He says: We were expecting heavy reinforcement because wed been told the buildings had been made strong enough to resist hurricanes.

But whoever designed it must have had shares in a steel company Ive never seen such an over-designed structure.

In one of the key areas Moran encountered a cage of 40mm steel bars with only 12mm gaps between them. Normal explosive demolition techniques were impractical, and there was no alternative but to painstakingly break out concrete and cut through the bars one by one.

Areas like these on two floors on each block were cut out and propped, while four floors were pre-weakened. This was to be Puerto Ricos first ever blow down, and Moran faced constraints from other blocks only 10m away. And the main post office was just across the road, with a roof completely covered in solar panels, he adds.

A local team had prepared the structures ready for the team from the UK to fix and connect the explosives. In all, some 1,500 non-electric detonating charges were used.

In the event the blocks imploded and fell without a hitch, a tribute to the experience the West Yorkshire-based company has built up on projects all over the world. It will be a long time before Moran forgets this job, however.

It was quite a contrast to the UK, he reports. Normally it takes ages to evacuate neighbouring properties, but here the police stormed into them and drove the occupants out at gunpoint in no time at all.

By contrast, a planned blow down later this year in the former notorious troublespot of Beirut, Lebanon, should seem relatively straightforward.

Reader enquiry no 807

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