The Editor, Sir:

I have read with dismay about the suspension bridge (not 'huge swinging bridge') between Broadgate and Mahoe Hill in Saint Mary, where your writer describes the fall of the bridge as a "freak accident". As an engineer, when I saw the photos of the fallen bridge, I immediately concluded that this was not an accident, but rather an inevitable occurrence.

Corrosion

Why should I say this? I say this because I see the extent of the corrosion of the suspension bracket and steel corrodes when exposed to the oxygen in air and moisture.

Steel, if it is to last, must be protected from oxygen and moisture. How? By priming and painting the clean steel. This puts a barrier between the steel and the elements and slows down the corrosion so that the bridge will last a long time.

However, paint does not last forever. Therefore, it has to be replaced if the bridge is to last for generations and even generations to come. If you let the protective coating be penetrated and corrosion starts, it costs more to chip off, or sandblast off the corrosion, to the underlying steel.

If you don't quickly remove the corrosion, you will rapidly lose the bridge, as happened here. This costs many, many times more than the regular inspections, cleaning and painting as required.

Typical behaviour

This is typical of the Jamaican government. Have the bridge opened with much fanfare. Do not spend the pittance to maintain it.

Then with many crocodile tears flowing, amidst the weeping, wailing and gnashing of teeth of the relatives of the injured (and maybe, dead) say that it was a 'freak accident' and commiserate with them.

In 1997, when I took some photos of the old Spanish Town cast iron bridge for the cover of the Jamaica Institution of Engineers Journal, I was shown severe localised corrosion of the newer steel bridge by a passerby while I was walking back to my car.

On the side closer to Spanish Town, at the bottom of the second (if my memory serves me rightly) diagonal brace, the bottom flange of the bridge channel member was entirely corroded away, and the top flange was about a third gone, beside the pedestrian walkway.

Was there more corrosion underneath? I'm not sure. The bolts nearby didn't look too hot either.

Another disaster waiting to happen

So, I immediately reported it to the then Ministry of Works over the phone, and then in writing. There was even a visit of a Ministry person to my office (to look at my photos). Want to bet that any repairs have been done to this day? (A combination welded and bolted repair would be relatively simple.)

That's not a bet I'd make.When will it fall? I'm not sure, but it's inevitable at this rate. Hopefully, no one will be on it when it does. All of this, while the Government wastes a few more billion dollars per year.

Why not send a reporter to confirm my observations? It might prove interesting after all these nearly 10 years.

I am, etc.,

HOWARD CHIN

hmc14@cwjamaica.com

Member, Jamaica Institution of Engineers

President, Jamaica Welding Institution