Paul C's Inspiration BMCLs

Paul C’s Inspo with Back-Mounted Lungs
By Paul Channing


Pictures say a thousand words, so I’ll keep it brief. I designed and fabricated a stainless steel box that sits snugly between the box/ wing and the backplate:


The unit sits 50mm back from its original position. The s/s box provides a useful means for stowing various bits and pieces out of the way:


This shows a suit inflate bottle (just), snorkel (don’t ask), a big spidge bag and an emergency blob all tucked away and readily accessible. This works for me as I have found that when gas-diving, the quantity of ‘things’ I like to carry can breach a critical point – now I don’t look like a Christmas tree..!! Excuse the rubbish in the background btw.


Standard Inspiration lungs are used for both ease and to keep the cost down, albeit with a few bits removed:


Now for some pictures of me looking silly, diving at 1 atmosphere


How it sits to my right:

How it sits to my left:


Putting stages on is very simple as I can see what I’m doing:


For the extra bits and pieces that I need for gas diving, a Joey Pouch, clips from the bottom of the backplate to the waist-ring. All my equipment goes on the right, gas to the left and a Q40 shines directly over the handsets to the right – just like good old OC


As I’m right handed – all the gear is accessed with the right hand. The left stays with the torch and reel – making easier work of the task loading on descent/ ascent – i.e. no need to swap hands to get to kit. You can see how the box doesn’t dig-in to my arse at the base:


A view from the left shows the profile of the lungs:


Valves are accessed without any noticeable difference:


Short of a slave, maintenance doesn’t get much easier than this



No Manual O2??

In the above photos there was no way of manually adding O2, however this has now been remedied:


I considered various designs and believe this one to be the most simple, elegant and cost effective. The buzzer tucks-in nicely behind too.


The design uses standard APD fittings throughout, making replacement straightforward. I have added a water-trap to the ADV T-Piece and had a ‘converter’ made to marry the O2 add to the T-Piece. The only physical change to the T-Piece was to plug the hole:



Detail and Thoughts

• Diluent flushes can be facilitated via pressing the ADV diaphragm.
  
• The lungs remain effective water traps
  
• WOB is, as far as I can tell, no different, but this may be because of the profile of the lungs and the fact that we breathe ‘off the top’ of them - I don’t dive on my back so I haven’t had ‘hamster cheeks’
  
• The position of the lungs has done two things:

• The T-pieces are further apart – before I always felt quite encumbered and wrapped-up, but now I feel I have much more freedom – not so tight or restrained. However, the lungs can be threaded over the harness if desired and returned to their original position.
  
• The position of the lungs seem to put me in the water much like a wing i.e. horizontal, this is in spite of running minimum loop volume.

• The dump valve toggle is extended to sit over the shoulder and actually dumps better when horizontal due to its upward facing position.
  
• The lungs are, to an extent, protected, certainly more so than before.
  
• Maintenance is an absolute joy.
  
• The S/S box creates a relief at the base, so the unit no longer digs into my arse - no more lower back ache on long dives!
  
• Kit can be stowed more effectively, making better use of that little more space.
  
• Kitting up and putting stages on is greatly improved.
  
• The backplate and harness can be removed independently of the s.s box and transferred to OC - much like the KISS (not that I would of course )
  
• The pressure gauges are a typical scuba length (whatever that is) and are there for the convenience of pre-dive checks – otherwise I’d use button gauges.

It seems just like OC diving - an unencumbered clear chest with good access to what I want. However, I can’t crush the lungs anymore for diluent or O2 flushes, but it works quickly enough nonetheless, and hey, gas is cheap right!

Please feel free to ask any questions and discuss HERE

Regards

Paul Channing