Research on Conical Methacrylic Windows for 2000 m Deep Sea Research Submarine

Abstract

Observation windows for deep sea research submarine are indispensable for the manned deep sea survey, and the strength of the observation windows shoud be examined carefully to withstand pressure in the deep sea. The authors have performed some experiments to see the feasibility of observation windows for the 2000m deep sea submarine which is now under construction at their shipyard (Mitsubishi-Kobe), by adopting full-scale 90 degrees conical window made of methacrylic plastics. The results of the test and design concepts described in this report are outlined as follows; (1) Under the statical pressure test, a safety factor of six(6) has been ensured against collapse (crack observed) at maximum working pressure. Complete collapse has been observed at the pressure of 2350 kgf/cm^2. (2) Hydro-pressure repeat test of 500 times, thermal dymamic test, and creep test during life-support hours (80 hrs) have been examined and demonstrated. The results prove satisfactory in every respect and the design can therfore be applied. (3) The radial stress at the low pressure face and the axial deflection at the center of the low pressure face under the maximum working pressure were obtained and found to agree with the formulae.