<div dir="ltr"><div>Are you sure you are interpreting the rules correctly Alan? The only rule I can find in GL requiring a hatch equalization lock is the following:<br><br>Part 3, Chapter 1, Section 3<br>"2.3.1 Diving bell hatches and mating devices which are not sealed by pressure are to be fitted with a locking mechanism which prevents opening under pressure. The locking mechanism is to be so designed that the correct closure position is clearly apparent before pressure is applied."<br><br></div>This only applies if you're building a diving bell, recompression chamber, or diver lock-out. In that case having the hatch open under pressure would result in an explosive decompression, instantly killing everyone involved in a nasty way. I would guess that this rule was implemented in response to the Byford Dolphin accident (<a href="https://en.wikipedia.org/wiki/Byford_Dolphin">https://en.wikipedia.org/wiki/Byford_Dolphin</a>) where that exact scenario happened and would have been prevented by a pressure activated hatch lock.<br><div><br clear="all"><div><div><div class="gmail_signature"><div dir="ltr"><div><div>Thanks,</div><div><br></div><div dir="ltr">-River J. Dolfi<div><br><div><a href="mailto:rdolfi7@gmail.com" target="_blank">rdolfi7@gmail.com</a></div></div></div></div></div></div></div>
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