TM 10-4320-345-13
2-11. ASSEMBLY AND PREPARATION FOR USE - cont.
(8)
To construct a spacing triangle, obtain a piece of paper, transparent sheet, or cardboard thick enough
to be used as a straightedge. Then proceed as follows (refer to figure 2-9).
(a)
Divide the horizontal base of the triangle into spaces on the same uniform scale used to divide the
base of the ground profile graph. Mark off spaces along the triangle base to at least 39,000 ft.
(b)
Divide the vertical, left-hand edge of the triangle into spaces on the same uniform scale used to
represent elevation changes on the ground profile. Mark off spaces along the vertical side of the
triangle as follows:
(1)
Zero represent the elevation of the pumping station.
(2)
The upper left-hand corner represents 300 ft above the pumping station.
(3)
The lower left-hand corner represents 600 ft below the pumping station.
(c)
Draw a straight, diagonal line from the 300 ft mark on the vertical scale to the 39,000 ft mark on
the horizontal scale. This line will form the hypotenuse or long side of the triangle.
(d)
Make sure all lines have a straight edge, cut the triangle along the three sides drawn (horizontal,
vertical, and diagonal).
(9)
Using the ground profile and pump spacing triangle, determine the location of the first boost pumping
station as follows (refer to figure 2-10).
(a)
Place the pump spacing triangle on the ground profile.
(b)
Aline the vertical side of the pump spacing triangle with the vertical (elevation) side of the ground
profile, so that the zero mark of the spacing triangle is on the lead pumping station mark of the
ground profile.
(c)
Make sure the horizontal side of the spacing triangle is exactly parallel with the horizontal base of
the ground profile. Horizontal spacing marks on both the pump spacing triangle and ground
profile should be exactly alined.
(d)
Mark the point at which the hypotenuse (or long side of the spacing triangle) crosses the ground
profile. This will be the location of the first boost pumping station.
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