Azimuth Conversion to CCR

 

Here is a quick overview of the conversion of my azimuth to CCR.

 

Design Philosophy

 

Being a Mech Eng, I felt very comfortable with a mCCR. Also felt that the simplicity and reduction in number of failure modes compared to eCCR provided a much higher level of overall system reliability. 

 

Also having a DIR back ground (Eh!) I wanted to aim for a unit that didn't clutter the chest and was similar in general layout to my twins, and while CCR, had little reliance as possible on electronics

 

The design was never supposed to break new ground, in fact the opposite, it was to use established techniques and parts to produce a 100m capable unit at moderate price and lowest possible risk regarding techniques and parts to the end user. The aim was to produce a well finished unit that had high system reliability, easy to maintain, and easy to travel with in the South Pacific region. 

 

Principal Design Outcomes Desired

 

·         Disassembly using no special tools.

 

·         One handed gas controls. (on right side with PO2 on left arm allowing correction of PO2 while watching outcome)

 

·         High reliability factor.

 

·         Recoverable after a partial flood of the exhalation CL (simulated removal of mouth piece with closing it)

 

·         ADV and manual dil addition functions

 

·         Off board plug in dil option for deeper dives

 

·         Reduced weight compare to original Azimuth (target under 30 kg compared to about 42 kg for my unit originally)

 

·         Designed to be capable of 100m dives if I ever decide to do one. The loop is assumed to be able to do that based on the Azi AF version which uses the same scrubber etc

 

·         Sensor calibration to be able to be done in free air. Makes life easy.

 

·         OC DSV

 

·         Designed to be easily maintained and completely field serviceable in remote locations. ADV is aqualung 2^nd stage components, DS4’s are easy to service, and hose can be adapted from standard scuba hoses. The unit can be safely dived on 2 PO2 metres, with all other components easier to repair and adjust as required than a KISS classic

 

Major Components Added to Unit

 

·         ADV – inspiration after market unit fitted with new adapters to mate to Azi CL and hoses.

 

·         Dil manifold for the supply of all dil  (OC bailout, ADV, manual dil add and wing)

 

·         Gordon Smith Kiss valve for O2 addition

 

·         Gordon Smith Triple PO2 readout (from sports Kiss) run from 3 K1D sensors mounted in the inhalation CL via a p-port using a Dave Sutton style sensor probe

 

·         1.9 L (13 cu ft) AL tank for O2

 

·         2.7 L (19 cu ft) Al tank for Dil

 

·         Back plate and wing to replace original mares wing and harness. Wing is an older halcyon 50 lb wing

 

·         Constant volume type dump valve/OPV in exhalation CL.

 

·         Replaced original MR-12 valves with DS4’s. Smaller/lighter and have standard din connectors

 

Major changes includes changing the original 4 L 300 bar steel tanks for AL (mainly to reduce weight), with the 2 Al tanks, with O2 being assessable from the right hand side, and the Dil tank being reversed and assessable from the left hand side of the unit. This is to prevent accidental closing of the wrong valve in time of need.

 

Changing the tanks required modification to the chassis to fit them, and reinforcing the shell were I had removed structural elements.

 

Gas Control Systems

 

I have used the original mares dosing block as the manual Dil addition button. Really is a waste of the great system, but allows addition of dil by pressing on the lever.  Nice and easy way to do it, just hit it with the palm of your hand.

 

Since the gas controls are all located together I wanted different actions to differentiate them from each other in times of stress. O2 is a button as per the kiss valve activated with my thumb, Dil is a lever action (palm of hand press on chest) and the shut of for the ADV (for use when at the surface want to flush with O2 and in case the ADV has a problem) is a slide control. Very hard to mix them up in practice.

 

All are located high on my right chest, opposite the power inflator for the wing.

 

Aim was always to leave my chest area as free as possible and being able to run stages etc with minimum clutter in that area. Hence back mounted CL design chosen as basis for conversion.

 

Gas Addition Points

 

The O2 feed is just prior the exhalation Counter lung. This allows maximum mixing time before reaching the sensor.

 

The ADV is located between the inhalation CL and the DSV. So that If I ever collapse the loop, the system can be effectively dived OC and will provide gas. The original Azi internal CL springs to maintain a gas path are also still in place to counter this possibility

 

Manual dil is feed directly into the inhalation CL, for 2 reasons, fastest response to PO2 spikes and to see senor response to dil flush. The Dil is feed into the old gas feed point for when the unit was SCR..

 

Outcomes

 

To date I have dived the unit to 43 m with the longest run time 60 minutes.  Unit is actually now slightly negative in water after the weight reduction, with final weight about 32 kg fully loaded. Trim is good being basically dead flat.

 

I haven’t tried recovering from a partial flood as yet, but not expecting it to be as successful as hoped. Due to placement of valve is not ideal for water removal. It should work, but some water will end up in the second water trap in the scrubber. But thinking a flood of about 1.5 litres will be able to be drained before that happens.  Flood is drained by position body with a heads up 45 degree angle and tiled slight right side down and purging loop with dil to force water out OPV in bottom of CL.  This is to allow for recovery from accidental loss of the DSV in water

 

While the unit uses all standard scuba hose fittings, some are custom length, so had to use reusable hose ends that do require some tools to get apart. Other than that standard strip down for cleaning  is as per azimuth, and tank, scrubber and counter lung removal for cleaning takes 3 minutes (longest time is spent unscrewing the 300 bar din connectors on the valves).

 

Unit is very simple to maintain and check between dives. You can see any water in the CL between dives and remove it if required in less than 2 minutes.  All parts are easily assessable, the only hard one is the OPV can not be adjusted underwater by the user, but can be by your buddy if required.

 

To date have not fitted the off board dill system, but that is a 15 minute job, really just run hose and plug into manifold and add check valves to on board dil supply to manifold. Same with OC DSV, waiting to see new jetsam unit before buying one.

 

Short Comings

 

The length of the cables to the PO2 monitors is a little to neat. Could do with being about 5 cm longer to prevent any strain being put on them (mainly when putting fins on). Need to see if I can re wire the metres of whether it’s in the too hard basket to do.

 

ADV install wastes a bit of inhalation CL space, Really would be better if I could of used Bob Howells original ADV for the Azimuth, as the angle of the hose adapters better suits the layout than modifying an inspiration ADV. If I can ever find one at a reasonable price would look to change it

 

Still have some tidy up work regarding hose routing and securing hoses in the gas addition area (get rib of the black tape and have a mounting plate to secure the hoses to). But other than that happy with unit to date. Also a bit more reinforcing of the shell to be done.

 

Unit design was really an extension of Philippe Gerin's conversion. Aim was to make it a fully complete CCR from all points of view, a specially regarding build quality and fitness for purpose of the various parts used.  In this case all basic parts have already been dived to excess of 100m by others and are certified as such by the respective component OEM's

 

Concerns

 

Haven’t  flooded the unit and seen what the buoyancy is like and whether the wing will lift it . Think it will sink like a lead balloon.  

 

Cost of Conversion.

 

All up the unit has cost me about the same as a classic kiss in total.  I paid $3300 AUS for the azi 2^nd hand originally. Plus about $3500 Aus in parts and tanks. On top of that I spend 2000 Aus on a lathe and tooling to make various parts. So all up it cost about $9000 Aus. but to do again would be around the $6K mark

 

For that I got a unit easier to strip and maintain than a classic kiss, with manual dil addition, some flood recovery ability, and a more reliable ADV ;-).  On the down side the K1-D’s have a shorter sensor life so higher operating costs than a classic kiss ad the unit is slightly larger over all, but easier to get on and of the boat due to the azi handle.

 

So where to from here?

 

Dive it, get the off board dill system plugged in and eventually the OC DSV.  Fix a few minor bugs in the tanks positioning, Reinforce the shell a bit more to get rib of one area or weakness, remake the manifolds (rotate 90 degress and shorten for better hose routing), and get the final manifolds chromed plated

 

But I did have a good look at an Optima recently, so might go ECCR yet

 

ADV	BACk On	Dil manifold and hose routing
back on ready to dive	Exhaltion CL with DUMp vavle fitted	Overview
Fron on showing backplate, wing and harness (all Halcyon)	Gas Controls, manual Dil, O2 and ADV flow stop	Gas controls and O2 gauge (dil gauge is on left hip as per twins)
Back with CL's and scrubber removed	LH side	O2 addition point in loop
O2 valve access	OPV / dump valve location in shell between back plate and chassis	PO2 displays - Sports Kiss
RH side	Cl installed with sensor probe fitted via P-port	Sensor probe - another Dave Sutton imitator ;-)
Side view	Tank arrange (valves are halcyon double valves split and capped)

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