Just ordered my FATHOM!

[rddvet]

SR, Just to correct a minor point that you have alluded to. In that 1st stages were not necessarily easier to bring to market than an ultra-low WOB BOV. With the requirement for the 1st stages to be CE'd for 300bar oxygen use, this required significant in time and resources testing at bam.de in Germany. Not to mention a lot of explosively by fire destroyed 1st stages until the right combination of lube being Gleitmo 599 and HP seat material was determined. Whilst rebreather fires are limited, they are still a risk, that this work minimises.
The backup if the Apollo 1st stages failed was Apeks DS4s and both are CE'd for OSELs units per their testing but the Apollo 1st stages were just found to be a better engineered product, and still to this day the best available, with cost being irrelevant. http://www.deeplife.co.uk/or_files/DV_DL_ALVBOV_Breathing_Params_A3_100318.pdf


In addition to selling the DL designed Functionally Safe rebreathers, one of the reasons OSEL was set up was to support homebuilders and assist small scale manufacturers by offering professionally engineered components and sub-assemblies with the R&D and certification costs covered.
With that in mind, what is the flow orientation of the Fathom and bore size of the reinforcing rings molded into the FMCLs?
As I note it is currently supplied with a GG BOV and a factory upgrade with OSELs ALVBOV would significantly reduce the Fathom's overall WOB. If this is desired. It would also remove the need for a separate ADV and MAV.


Thanks SR. It's always good seeing warts and all reports from users. Some feedback is subjective and if the issue is a Functional Safety design requirement there is not much we can do about offering a better product that suits the individual but all feedback is noted and reviewed.


An interesting question noting Alex's expertise could just as easily be hired by the defense in the couple of cases he has been involved in to date. For some reason however none have wanted him to prove their units didn't have design defects and met the standards they were certified to, if so. With the multiple fatalites for the same root cause on certain units this is probably understandable. Note Case 1-10 in particular https://www.diversalertnetwork.org/medical/report/AnnualDivingReport-2018Edition.pdf

As there has not yet been a fatality on any DL designed rebreather across their Functionally Safe certified commercial, military and recreational units despite >10 years of use; you have raised a very interesting question. Which is also why DL don't yet report one in their accident list; however, it is a simple statistic that this will unfortunately alter at some point in the future. OSEL will then to the best of our ability for the rebreathers or components we have manufactured provide support to the divers NoK and provide direction/resources to enable independent inspection and testing of the units fitness for diving, ensuring chain of custody and evidence documentation is maintained. Backed up by provision of all of the relevant certification testing and documentation inclusive of FMECA and design validation testing etc etc. As a requirement of the Functional Safety certification all details of the fatality and investigation would then be documented in DLs accident list at Deep Life Design Team: databases and analysis of rebreather accident data

WOB is just fine. It ships with either a gg or dive soft bov or a gg dsv. Mavs and adv’s built into bov’s sucks.

 

[kensuf]

I did some playing around with the Fathom this week to get the backmount bailout configuration dialed in. It's effectively the same as my OC doubles rig now, but with a rebreather in the middle.

I'm using twin LP50's with LOLA valves and a manifold, then my regular OC backmount regs. Right post is 100% standard, 7' hose, wing inflate. Left post is standard short hose, pressure gauge, and DIL fed through a QC6. Oxygen is a 2L LP cylinder mounted onto the can with a standard pony mount (I'm using a Highland mount).

Test run was a 100 minute swim around Devil's Eye cave. It was absolutely stable and clean and when my dive was over, I simply had one trip out of the water. I'm looking forward to diving this rig off a boat next month, it'll also likely be my go-to bailout rig for teaching CCR cave moving forward.

 

[silent running]

SR, Just to correct a minor point that you have alluded to. In that 1st stages were not necessarily easier to bring to market than an ultra-low WOB BOV. With the requirement for the 1st stages to be CE'd for 300bar oxygen use, this required significant in time and resources testing at bam.de in Germany. Not to mention a lot of explosively by fire destroyed 1st stages until the right combination of lube being Gleitmo 599 and HP seat material was determined. Whilst rebreather fires are limited, they are still a risk, that this work minimises.
The backup if the Apollo 1st stages failed was Apeks DS4s and both are CE'd for OSELs units per their testing but the Apollo 1st stages were just found to be a better engineered product, and still to this day the best available, with cost being irrelevant. http://www.deeplife.co.uk/or_files/DV_DL_ALVBOV_Breathing_Params_A3_100318.pdf

Very interesting stuff, I didn’t know they were 300bar capable and I guess it stands to reason the standard is very high and barely achievable at that.

 

[Doby45]

I did some playing around with the Fathom this week to get the backmount bailout configuration dialed in. It's effectively the same as my OC doubles rig now, but with a rebreather in the middle.

I'm using twin LP50's with LOLA valves and a manifold, then my regular OC backmount regs. Right post is 100% standard, 7' hose, wing inflate. Left post is standard short hose, pressure gauge, and DIL fed through a QC6. Oxygen is a 2L LP cylinder mounted onto the can with a standard pony mount (I'm using a Highland mount).

Test run was a 100 minute swim around Devil's Eye cave. It was absolutely stable and clean and when my dive was over, I simply had one trip out of the water. I'm looking forward to diving this rig off a boat next month, it'll also likely be my go-to bailout rig for teaching CCR cave moving forward.

View attachment 525908

View attachment 525909

View attachment 525910

I take it your drysuit is coming off the tiny inflation bottle in the pic?

 

[CptTightPants21]

Looks good Ken. Do you have a picture from the top showing how much the O2 bottle adds to the profile?

Are you protecting the can in anyway with a cave shield or similar?

 

[kensuf]

Yes, that's a drysuit bottle.

No photos of it from the top right now, and I've got it stripped back down for my dives this weekend. I'll get some photos of it next month, but the profile with the 2L is pretty low. I was able to squirm through stuff that's pretty tight in 104's.

 

[rjack321]

Yes, that's a drysuit bottle.

No photos of it from the top right now, and I've got it stripped back down for my dives this weekend. I'll get some photos of it next month, but the profile with the 2L is pretty low. I was able to squirm through stuff that's pretty tight in 104's.

I'm using one of those mounts (in the same basic place) for a 13cf suit gas bottle behind 2 conventional 3L CCR bottles. Seems really big to me, but when the water is frigid (<5C/41F) and esp. when I am doing free ascents I tend to use a lot of suit gas. It is at least far more secure than my old Velcro straps.

 

[rddvet]

Yes, that's a drysuit bottle.

No photos of it from the top right now, and I've got it stripped back down for my dives this weekend. I'll get some photos of it next month, but the profile with the 2L is pretty low. I was able to squirm through stuff that's pretty tight in 104's.

I'd like to see those photos when you get them. I'd also be interested in seeing what the whole system weighs compared to a set of 85s or 104s. Is it a pain pulling it all apart? It'd be nice if the 50s could just slide off without having to take apart the lola valves

 

[rjack321]

Yes, that's a drysuit bottle.

No photos of it from the top right now, and I've got it stripped back down for my dives this weekend. I'll get some photos of it next month, but the profile with the 2L is pretty low. I was able to squirm through stuff that's pretty tight in 104's.

Can you reach the valve on your O2?

 

[kensuf]

Yeah, very easily. Not sure if I could if I was using 85's instead of the 50s though.