How does Robert Frost create tension in the poem "Out, Out—"?

In Frost's poem, "Out, Out--," there is an underlying tension between machine and human.

One interpretation of Frost's poem "Out, Out--" considers the year in which it was written, a time when boys were losing their lives to the machinery of war. The technology of war was tearing limbs from young men, depriving them of the vigor of their youth, if not their lives. Perhaps, then, in this poem Frost imitates the dichotomy of man and...

In Frost's poem, "Out, Out--," there is an underlying tension between machine and human.

One interpretation of Frost's poem "Out, Out--" considers the year in which it was written, a time when boys were losing their lives to the machinery of war. The technology of war was tearing limbs from young men, depriving them of the vigor of their youth, if not their lives. Perhaps, then, in this poem Frost imitates the dichotomy of man and machine in war, one that is certainly unfair when the "man" is still but a boy.

The tension of this poem is first expressed with the personification of the saw; that is, Frost affords the saw the powers of a living creature, thus equalizing it as a potential adversary to the boy, just as in war. It is an aggressive creature, too, that works ever so swiftly: 

The buzz saw snarled and rattled in the yard
And made dust and dropped stove-length sticks of wood,...
And the saw snarled and rattled, snarled and rattled,

Clearly, the saw's aggression is expressed when it "Leaped out at the boy's hand, or seemed to leap—" severing his hand.

The onomatopoeia of "buzz" and the sound words in the above lines create a certain tension, as well. For, the saw makes aggressive and disturbing noises with the snarling and rattling sounds. Also, the alliteration of "dust and dropped" and "saw snarled...snarled," which speeds the line, suggests a certain danger for the boy.