The Journal of Explosives Engineering - May/June 2022 - 23

Cross Extra 40 per cent dynamite
in strength; stick for stick its equal
in execution in work for which it is
adapted; absolutely non-freezing and
non-headache producing; and there
are from thirty-five to forty more 1¼ x
8-inch sticks to the case!
The brand name " Dumorite " is
amply descriptive. " Du " for Du Pont,
and also for " do " takes on a double
meaning: " mor " is Rooseveltesque
for " more, " and the " ite " when
joined with the prefixed " r " rounds
out a name that listens well and also
describes the working qualities of
the product. In its broad field of use,
Dumorite-pronounced Do-moreright-goes
further and does more
work per dollar invested than any explosive
now offered for sale.
Chemists have been working on
this explosive since 1919. Four or five
hundred experimental mixtures were
prepared and tried. Twenty mixings
were made on a plant scale basis. One
compound after another was brought
to the test before the class of explosives
called Dumorite met their rigid
standards.
But the experimental work did not
cease there. Approximately 15,000
test shots of the product have been
made to determine its action under
varying conditions. It has been subjected
to temperatures lower than 40
degrees below zero; it has been submerged
in water for hours at a time;
it has been checked for possibilities of
deterioration in storage, subjected to
friction and many other tests in various
sections of the country under very
diverse climatic conditions. Its performance
in both laboratory and field
indicates a wide range of adaptability
for most all kinds of open work and
for some underground mining operations
where permissible explosives are
not required.
Dumorite is not represented to be
a perfect explosive for all purposes.
That type has not yet been made, and
probably never will be. But for certain
kinds of agricultural and industrial
blasting work, its performance, stick
for stick, is just as satisfactory as other
explosives now used, and there are
more sticks to the case, aside from
the other superior qualities we have
mentioned.
Specifically, this new explosive is
well adapted for blasting stumps,
boulders, and holes for planting trees;
May/June 2022
but it can also be used satisfactorily for
dry ditching by the electric method. It
is not, however, sensitive enough for
ditching by the propagated method. For
all agricultural purposes except the last
mentioned, Dumorite has been thoroughly
tested and found highly satisfactory.
In
the industrial field it has proved
practical for open-pit mining and some
classes of underground mining. It is well
recommended for quarry operations,
railroad and highway construction, and
excavation work of all kinds. Experts
who have supervised test shots made
in quarries, open-pit iron mines and salt
mines report that where the preliminary
work has been properly done, the
results have been satisfactory, and that
Dumorite shots have been accompanied
with less smoke and fumes than when
other explosives were used. Also, where
objection has been raised against some
explosives because of a noted tendency
to discolor the material blasted, it is observed
that where Dumorite has been
used no discoloration or stains have
been apparent.
So far Dumorite has been referred
to as the brand name for this group of
new explosives, which has been subdivided
into four commercial kinds-Dumorite
Nos. 1, 2, 3, and 4. Each one is
recommended for special kinds of work.
For example, Dumorite No. 1 is recommended
for quarries, construction and
agricultural uses. Dumorite No. 2 is better
adapted for blasting hard rock and
hard ores where the ventilation is good.
Dumorite No, 3, otherwise known as Pacific
Stumping Powder, is made especially
for stumping purposes in the Pacific
Northwest and for use in that territory
The Journal of Explosives Engineering
alone. Dumorite No. 4 will probably be
used most extensively in bituminous coal
mines where a permissible explosive is
not required and where large production
of lump coal is desired.
In these Dumorites are blended, in
proper proportion, the propellent qualities
of colloided guncotton, along with
the smashing, shattering characteristics
of nitroglycerin dynamite. The former
develops its energy with a shoving or
pushing force; the latter acts as a violent
disruptive force. How to combine explosive
materials possessing these qualities
to form a chemically stable compound
of good working properties has been
a problem. But the solution has been
found and it has added another chapter
to the achievements of Du Pont explosives
chemists.
The Du Pont Company has led the
field in explosives research and invention
in this country ever since E. I. du Pont
de Nemours built America's first powder
mill in 1802. For many years, research
chemists employed by the company
have studied actual mining, quarrying,
stumping and other operations with a
view to developing types of explosives
best suited for each kind of work. As a
result, many of the notable advances in
explosives manufacture have been developed
through their painstaking efforts.
In mentioning Dumorite as the latest
achievement, it may not be amiss to refer
briefly to some of the earlier ones.
In black powder manufacture the Du
Pont Company was the first in America
to produce nitrate of soda blasting powder
on a commercial scale. This improvement,
made nearly a century ago, has
meant a tremendous saving to powder
users, just as Dumorite will mean a great
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The Journal of Explosives Engineering - May/June 2022

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