the total strain on rigging linea and even on the balloon itself becomes
excessive. With the thin polyethylene film of' the General Mills' balloons,
such a wind force causes the balloon first to billoW, sail-like, as ih Figure
25, then to tear.
To eliminate surface failures on days when the wind is not calm, the
following release technique is employed: The equipment train is laid out
parallel to the wind direction, with the balloon in the lee of' a large build-
ing and the other components stretched out downwind. The central portion of'
the balloon rests on a platform balance and the lower portion rests on a
sloping eleven-toot table whose top is level with the platf'or.m and whose
bottom rests upon the ground. The upper portion of the balloon usually
lies on another table, level with the platform. Except tor this upper
portion, the balloon is held down on the scales and sloping table by bags
of sand and lead shot. In addition, one sand bag is fastened to tile lead
thimble of the balloon by a short line which is kept taut during inflation.
This layout is shown in Figure 28.
When the balloon iS inflated, it is held down at the "Weighing-off'
scales by the shot bags. Fersonnel requirea tor the launching consist of' two
men at the hold-do'W!l shot bags (who lift the bags at the release signal), one
man near the large sand bag (who cuts the line to the load thimble when "tile
balloon rises above him), one man at each piece of' sensitive equipment on the
train (to support and protect the equipment until it is airborne), one man
at the lower end of the hold dowr1 line (Who fires the cannon severing the
last line whe~ the gear is all safely lifted).
If each operation is performed When the balloon is directly overhead
and if the train has been accurately laid out downwind, the entire train is
sent off with a minimum of oscillation of the load. Figure 29 shows successive
positions of the balloon and gear during release.
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