On the morning of Friday, June 11, lightning struck an oil tank
belonging to the Tidioute and Titusville Pipe Line, at Titusville,
Pa. The fire thus kindled, raged until Sunday night, consuming 200,000
barrels of oil, crude and refined, and destroying property to the
amount of $1,500,000. The most appalling feature in this fire was the
successive "boiling over" of oil from burning tanks of the liquid.
To empty rapidly a tank containing 20,000 barrels of oil, while the
latter is on fire, is no easy matter. The pipes connected with the
tanks were utterly inadequate to remove the oil rapidly enough to rob
the "boiling over" of its terrors. A happy thought suggested itself
on Friday to Mr. D. R. Herron, of the Titusville Battery. Obtaining
permission, Mr. Herron brought out one of the Parrott guns of the
battery, loaded it with solid shot, and began firing against the
three-eighths iron sheets of the distant blazing tank. The first
shot glanced, but subsequent volleys pierced the shell of the tank,
releasing a large quantity of oil that otherwise would have fed the
flames. The battery then moved on to the Emery tank, also burning, and
lastly to the Acme tank. Large rents were made in all these, and the
liberated oil ran harmlessly down into a stream. This novel target
practice greatly shortened the duration of the fire at these tanks,
and so drained them that the flames died out for want of fuel, and no
"boiling over" resulted.
The peculiar attraction for lightning which these iron oil tanks
appear to possess has been several times referred to in our columns.
Whenever a thunderstorm passes fairly over one of them it seems to be
devoted to destruction. Millions of dollars' worth of property have
thus been destroyed. No practical safeguard has yet been suggested.
Ordinary buildings, when properly provided with rods that are
well grounded in the earth, are comparatively safe from lightning.
Structures made of iron and simply resting upon the earth, without
rods, are also exempt from electrical damage. Such structures always
present a continuous body of conducting material for the free passage
of electricity to earth. Why is it, then, that iron oil tanks form
such conspicuous exceptions to our common experience with lightning?
Rods put on other structures save them; but rods have been put on oil
tanks, masts with rods have surrounded the tanks, but the tanks were
exploded by lightning all the same.
We will repeat a possible explanation which we have heretofore given.
From every oil tank, according to our theory, there is a constant
escape of light hydrocarbon vapor, which forms a permanent cloud or
column, rising to a great height above the tanks, far above any
rod that could be erected. This vapor rod is a conductor, which the
lightning naturally follows, sets on fire the vapor, and explodes the
tank.
A column of heated air or vapor rising from a chimney is well known
to be a conductor for lightning; the rise of hydrocarbon vapors is
illustrated by the balloon.
If the theory we have outlined is correct, the remedy for the
electrical explosion of oil tanks is to be found in such a treatment
of the oil, or such a construction of tank, as shall prevent any
escape of the light vapors.
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