Titan CCR

The Titan CCR From BubbleSeekers
By Ron Micjan





Recently at Inner Space 2006, Tomar Gross and Larry Shreve unveiled their prototype eCCR, the Titan. The units design is pointed at the recreational CCR market and hits the target rather nicely. Keep in mind this unit is the first generation pre production and as such is not in a finished condition. This may remind some of the state of the original Optima CCR and that cleaned up nicely. The unit is quite compact and its size and weight certainly lend it in the direction of the traveling diver. Weighing in at a lean 49 lbs including steel 13cf cylinders and full Extendaire scrubber, it is a breeze to throw on and go diving. A single back mounted counter lung keeps the chest area clear and all fittings inside the housing.


Lets Get Into How It Works

The gas flow is American conventional, fresh gas comes over the divers right shoulder and into the injection moulded DSV, through the mushroom valve to the diver and back out through another mushroom valve and over the divers left shoulder. There is a bulkhead fitting on the housing of the unit that connects the exhale hose with an extension hose that feeds the exhaled gas into the bottom of the scrubber canister, which is a modified Extendaire scrubber system. The Extendaire system is orientated in a vertical fashion, and this placement has not been tested for duration as of this writing.


This is the view from behind the divers left shoulder with the cover removed from the unit, showing the bulkhead connector with the extension hose attached. The breathing hoses on this prototype are of 1” ID, I have been informed that this will be moved up to 1.25” in the production unit.


Here is the Extendaire canister out of the unit, notice the extension hose fitted into the bottom of the canister, the three sensors installed into the mixing tower, the rectangular plug near the top facing lid, (ready for an ADV) and the two quick connect fittings on the side of the top of the canister (bottom of the picture) for plumbing in O2 and diluent.


Back To The Gas Flow…

After the diver’s exhausted gas enters the bottom of the scrubber, it is fed into the solid Extendaire scrubber cartridge and the CO2 is removed. At the top of the scrubber, installed into the lid, are two solenoids, one for oxygen and the other for diluent. The diver can fire either solenoid from the handset to add either dil or O2 and the computer can fire the O2 when it decides the loop needs it. The gas then travels up into the mixing tower and into the counter lung, which is affixed to the top of the scrubber housing by a threaded nut and sleeve, similar to how the Classic Kiss Rebreather attached the CL to the head. The O2 sensors are located in the top of the mixing tower, inside the counterlung. The last path is from the counterlung to the inhale hose through another bulkhead connector on the housing.


The housing is manufactured from vacuum formed ABS plastic and is quite light. Four stainless steel locking latches hold the back cover onto the main unit and can be touchy to fit up as the ABS flexes.


Counterlung is made from a food grade poly and has three fittings in it, the bulkhead that feeds the DSV, the fitting that threads onto the mixing tower, and an small OPV (over pressure valve).


Ok, Lets Go Into Some More Detail

At the top of the scrubber housing we mentioned some solenoids, take a look at how they are situated.


I am told that the right angle swivel fittings thread directly into the solenoid bodies to help prevent leaks into the housing. The solenoids are rated for 500,000 cycles and these exact units have been going strong throughout the testing and building process. The oxygen solenoid is protected from debris by a 60 micron filter that is fitted between the QD and the 90 deg swivel. The wiring from here heads out to the HUD and the computer through two bulkhead connectors, shown below.


You can also see here the detail of the base of the mixing tower and the nut to hold the counterlung in place. The holes in the mixing tower are where the gas from the solenoids gets mixed with the returning gas from the scrubber while entering the counterlung.


The hoses are made to be just long enough to reach the proper fitting, so no mixing up dil and O2. Regulators are from XS Scuba.

The two cables from the top of the scrubber housing go to the computer handset and the HUD controller, lets look at the HUD first.


This is the HUD controller, a simple black box, potted, with an internal non replaceable battery. This will be changed to a unit with a replaceable or rechargeable battery for production. The single piezo button controls power as well as a calibrate mode. The unit can only be calibrated in oxygen and will show cell failure (by continuous alternating color flashing) if calibration is attempted in air. The unit reads the millivolt output of the sensors from the tower (the HUD controller is wired in parallel with the computers sensor input using high impedance Op-amps so each sensing device will not interfere with the other by pulling a load on the sensors.)

A long push on the button will toggle power to the HUD system. While on, three quick pushes will enter calibrate mode and will store the “divide by” values to convert the raw millivolt output of the sensors into a more useful number, PO2. This value is then converted into a HUD readout of 3 flashing LED’s. The LED system is similar to other HUD systems, notably the Will Smithers system of 1.0 = one orange flash per sensor, anything above 1.0 providing a green flash per sensor, example 1.1 is one green flash per sensor, 1.2 is two green flashes per sensor. Any value below 1.0 is represented by a red flash and one flash per each point below 1.0, example .9 = one red flash, .8 = two red flashes. The improvement here is that the HUD display has 3 tri-color LEDs, one for each sensor. Instead of one LED handling all three sensors with a pause in between, this display shows us data continuously from all three cells. The HUD is a stand alone piece and the only commonality between it and the computer is the three sensors.



On To The Computer…


The computer is a two button, 3 line display with a menu system and built in mixed gas decompression. The display here shows, across the top line, Depth, Bottom time, Stop Depth and Stop Time. The second line shows the three PO2 values of the three sensors. The bottom line shows what mode the computer is in, either OC or CC, then the gas mixture it is using to calculate decompression, the No-Decompression Limit in minutes (basically a countdown before deco) and the Time to Surface, which calculates in ascent time plus all required deco stops between where the diver is in the water column and the surface. The buttons are “Menu” and “Confirm” and allow scrolling through the different menus, including “Turn Off”, “Calibrate”, “Dive Setup”, “Dive Log”, “System Setup”, and inside those menus are “Define Gas” and “Auto Setpoint” adjustments which allow the computer to automatically change setpoint based on what depth the diver is at. Also are backlight adjustments, time and date, etc. Personally I would rather see three buttons, which would allow backing in and out of menus rather than getting bounced out and have to cycle all the way around if you pass a desired menu or miskey. This system, manufactured for the Titan by SRI, is designed with wet switches, to turn on the unit once it is in the water, as well as lock out menus that should not be used while diving, such as calibration and power off. The two blue LEDs at the top of the display show when the solenoids are being fired, either by the computer or by the diver. This is a feedback system from micro switches in the solenoid itself that show if the solenoid physically moved, not just if the voltage was applied, but doesn’t, however, confirm that gas was injected, just that the solenoid opened. LED’s light blue if diluent is injected and green for oxygen. The next photo shows the divers interface to the solenoids, the left, blue button is for diluent, the right green, for oxygen, following the standard for lean left, rich right.


Another feature of the computer is the wet mate connector that fits the unit to the rebreather. Shown below.


The computer housing has two internal batteries, which are recharged through the wet mate connector with a separate charger. The batteries are of a Lithium Polymer technology. There are two, one exclusively to fire the solenoid and one to run the computers power needs.


Good Stuff

Nicely put together size wise and overall platform, takes any BCD and harness with no mods. Industry standard cylinders and regulators assure you wont get stuck somewhere with no spares. Having deco info on your CCR controller is great, the ability to take the same dive computer on an OC dive and keep all your tissue numbers is better still. Rechargeable batteries in the handset insure that the diver can’t screw up the computer seal by trashing the O ring in the battery housing. Extendaire cartridges are becoming more popular and Micropore will ship anywhere so you can have your scrubber at the dive site when you get there. Ease of scrubber change out, no granules or associated packing headaches. Gas injection on the handset, neat idea, lift your arm up and hit the button, no grasping for buttons on your chest or valve hanging off somewhere else.


Not So Good Stuff

I’m not sure the wet connector on the computer will survive repeated connections, especially in a salt water environment, there was some corrosion on the connector when I looked at it. Larry mentioned they were looking for a better connector, hopefully not Fischer. Not being able to manually inject O2 or diluent (dil side would be fixed with the ADV) with a non electronic pushbutton. There are too many failure points between the buttons on the handset and actually getting O2 into the loop, switches, battery, wiring, QD on the handset and the solenoid itself. If the cable gets unplugged, you lose all control of the rig on your back. I wonder what the controller would do with your deco if all sensors went to zero’s?

The HUD LED’s are very small and might be difficult to see, I understand that if the PO2 drifts into a bad mix, the LED’s get brighter in response. Although the Extendaire canister system has lots of benefits, duration and cost versus granules are not two of them. I believe, for the market this unit is aimed for, the Extendaire system is still an advantage though.

I hope this gives the reader a good overview of what could be a great new system. Time will tell and we will keep you posted. Any errors or omissions are most certainly mine, contact me if you have any questions about the article, contact Larry or Tomar at bubbleseekers(at)hughes.net They are located in California.

Ron Micjan
1 June 2006

www.tmishop.com


Discuss this article HERE