Abstract:
Tests were conducted on a full-scale model of the emergency
forebody release used in the deep-diving submarines ALVIN, SEA CLIFF
and TURTLE. The model was machined from metal to the same dimensional
tolerances as the prototype. Resistance strain gages, attached
to the model, permitted measurement of forces on component parts of
the device. Of primary concern was the bending stress which might
be set up in the release operating shaft when the submarine is submerged
in an inclined position. Tests were arranged to simulate three possible
conditions of loading of the release device at a 30 degree vehicle list
angle: case (1) righting moment of inclined forebody resisted by release components only; case (2) righting moment resisted by release
with assistance from lower guides; and (3) righting moment resisted
by couple set up by release and rubber support ring. Test results show that shaft bending stresses (for ALVIN) are high (200,000 psi)
for the case (1) condition, lower (400,000 - 90,000 psi) for case (2)
and essentially zero for case (3). The conclusion is that the present
forebody release design is adequate for all submarine attitudes
encountered
in normal operation, provided the vehicle has been assembled so
that contact between sphere and rubber ring is assured at all times.
