[PSUBS-MAILIST] Original MBT vent?

[Jon Wallace via Personal_Submersibles]

I found this K-600 drawing (see attached image) of MBT vent valve dated March 23, 1976.  Rejected I suspect because it brought a water source into the cabin and offered multiple leak points.  The date listed on the drawing is interesting because even going back to the MK-III vessel which predates VAST, I'm seeing the traditional MBT vent valve outside the conning tower with just the valve stem protruding inside.  Was this something he considered an improvement that was rejected by the Norwegians?  Did it vent faster?  George, you left us with many questions.
Jon
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://www.whoweb.com/pipermail/personal_submersibles/attachments/20210609/9aa72b51/attachment-0001.html>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: mbt-vent.jpg
Type: image/jpeg
Size: 350314 bytes
Desc: not available
URL: <http://www.whoweb.com/pipermail/personal_submersibles/attachments/20210609/9aa72b51/attachment-0001.jpg>