Chimney stand-up was “forewarned”…

Blasting company reacts angrily to rival’s chimney blast failure.

Here at DemolitionNews, we walk a very fine line. We consider ourselves to be of and for the demolition industry and, when push comes to shove, our default reaction is to always come down on the side of the demolition contractor. But what do we do when one company highlights the failures of another? We can’t take sides and, frankly, although we write about this subject on a daily basis, we’re not sufficiently expert to comment on the technicalities of a specific contract.

So instead, we have decided (on this occasion) to simply publish a full and frank letter we have received from Robyn Rushforth at Precision Demolition Company Ltd that suggests that the failed blast at the Cemex works in Rochester last Sunday was not just predictable but entirely according to precedent, a fact that Rushforth highlights with a 25-old video clip.

Once again we would reiterate that we’re not taking sides in this debate, nor are the views expressed necessarily those of DemolitionNews. However, as a news resource of and for the demolition industry, we believe that this is a debate that should be aired publicly to hopefully prevent a recurrence of this partial stand up:

“…The failure of this chimney to collapse properly is a sad reflection on the way some elements of our industry presently work.

PDC were asked to look at this chimney and to quote for the explosive demolition. During our inspections we noted the thickness of the wall of the chimney. The position of the door in the base of the stack with respect to the direction of fall, this was pointed out as being of major significance. These two features alerted us to the fact that this stack did not lend itself to what may be referred to as traditional ground level preparation. Simple ground level preparation of chimneys introduces uncontrollable risks at the best of times but in this case was most certainly not a safe way to proceed.

We explained to the main demolition contractor in our quotation letter to them how the stack could be prepared in order to reduce risk of heel failure to an absolute minimum and also attached a sketch and a marked up photograph showing what would be required to achieve a safe and complete demolition. This was followed this up with verbal explanations of our proposals on numerous occasions.

In our presentation entitled ‘The evolution of Explosive Demolition’ at the Institute of Demolition Engineers seminar in Leeds in March this year we showed a video of a chimney failure in 1984 (see below) and explained in detail the causes and consequences of heel failure during chimney demolition. We then explained how this can be avoided by designing the geometry of the pre-weakening and charging pattern. We even showed photographs of how we presently prepare reinforced concrete chimneys in the light of what was learned in 1984.

What happened on Sunday was forewarned as predictable and should never have been allowed to occur.
The demolition industry in general likes to think of itself as being forward thinking, developing new safer systems of work and then here we are using practices that were out dated 25 years ago!

Whilst we appreciate that in this day and age all costs need to be watched by contractors it is most disheartening that technical information provided free of charge is disregarded and that subcontractors are selected on bottom line price with little or no regard to their technical merit…”

Robyn Rushforth
Precision Demolition Company Ltd

Barking B Short from Mark Anthony on Vimeo.