Not strictly under water but.... I have a fire fighters BA set with two SABRE 200 bar tanks. Its in perfect condition and tested, I intend to use it in bad air situations underground.

Q. what's the situation on charging the tanks?
Q. Does anyone in the Mendip area have the ability to re-fill tanks?
Q. Is this the same type of tank/connection used by diving equipment?

I look forward to various posts about how scary this sounds  :ras:

.        That damn micro dot gets everywhere!

Hughie said:

.        That damn micro dot gets everywhere!

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Hows yer hole?

c**tplaces said:

I look forward to various posts about how scary this sounds  :ras:

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Wow! that sounds really scary!!!

There is a sough in Derbyshire full of bad air that I've always wanted to go up, and needed this sort of stuff. It's expensive to buy though....and heavy.

Bear in mind if you are working hard (climbing/crawling etc) you will empty it fairly quickly!

If the cylinders are in test you should be able to get them filled at most diving shops.
If they are not tested you will have to get them filled by a local friendly diver who has access to a compressor.
You can get them tested although some diving shops may be a little scared of them as they look different to normal diving cylinders, I have a mate who experienced this recently. I have recently had four ex-ba-set cylinders, with Sabre taps, tested no problem but I did go direct to the test house.

As for how long they will last, that depends on how big they are. This will be stamped on the cylinder probably, depending on the age of the cylinder, as the water capacity i.e. WC7l ;- water capacity seven litres. You must then multiply the capacity by the pressure to get the free air available i.e. 7x200bar = 1400l of free air and if you have two then 2800l of free air. Its probably advisable to apply the cave diving rule of thirds to the sets use in a cave so you will have to divide 2800 by three = 930l. You can test your breathing rate in a non-toxic environment but as a rough rule of thumb work on 25l/min. 930/25 = 37min on your way, 37min on your way out, 37min in your back pocket. But try not to drain them completely as the air delivery system may not work on the final dregs of your tank pressure. Also this method relies on you breathing both cylinders, if they are manifolded then thats not an issue, if you are breathing off both independantly you will need to swap from one to the other regularly to ensure that both are functioning.

The fitting on your sabre taps will, more than likely, be a standard DIN fitting and therefore compatible with scuba sets. Ex ba cylinders are used all the time by cave divers, I have six of them.
Old ba sets never die they just go cave diving!

If you ever think of getting rid of the set give me a shout! I would be interseted to know what size the cylinders are.

AndyF said:

c**tplaces said:

I look forward to various posts about how scary this sounds  :ras:

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Wow! that sounds really scary!!!

There is a sough in Derbyshire full of bad air that I've always wanted to go up, and needed this sort of stuff. It's expensive to buy though....and heavy.

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Bear in mind if you are working hard (climbing/crawling etc) you will empty it fairly quickly!

We used it in a low roofed colliery a couple of weeks ago, three of us each with a BA and spare tank and one of us with a gas monitor.
We had visited the place twice previously and found oxygen down to 14.5% after the 1st fall, you don't have long at that Oxygen level.
Having obtained BA sets from Ebay for a splendid price of £40 including 2nd tank (both tanks ready filled)  we visited again.
This colliery has a low roof at about 4.5 feet which makes walking round with a tank on your back hard work, several serious falls had to be negotiated which gain is extremely difficult with that amount of kit.
Being in-experienced with BA sets we set a strict policy of exiting immediately when the 1st tank was used.
Tanks last more or less exactly 45 minutes despite the exertion and wandering around stooped over.
At the point that I changed tank Oxygen was down to 10.5% and changing the tank was an exhausting experience, a few minutes without the air supply made life very difficult
We had 90minutes in the mine beyond the 1st fall where barely 5 to 10 minutes were manageable without the kit, unfortunately a deeper visit requires more tanks (perhaps 5 each) which brings with it even more complications.
I'm sure Darkplaces can display a couple of photos from the trip report if anybody wants to see them?
In short, wandering around underground with BA kit is bloody hard but the rewards are high, you simply get to see what otherwise is impossible
Tanks are Sabre 9litre 200bar.

Oh forgot to add, tanks are alloy with composite, have stickers on showing test, some just still within the two years some just past

Not making a judgement either way on what you are saying, but imagine the field day the press and HSE would have if you were unlucky enough to have a big problem, and it then came out that your tanks were past their test date 

Peter Burgess said:

Not making a judgement either way on what you are saying, but imagine the field day the press and HSA would have if you were unlucky enough to have a big problem, and it then came out that your tanks were past their test date 

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if it reached that stage Peter that would be by far the least of our worries :-\
In that particular environment there is no margin for error (never tried cave diving but I don't imagine its much different)
Also with this particular location if an accident were to happen then it would probably mean rescue would be impossible so nobody would ever know the tanks are out of date anyway

Fair enough, except the 'evidence' is on this forum for all to read!!!!

Peter Burgess said:

Fair enough, except the 'evidence' is on this forum for all to read!!!!

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Fair point

Good effort!

I would say that, and I am thinking as a diver here, that breathing one cylinder down and then changing to the other seems a bit risky. What would you have done if you failed to attach the second cylinder or that cylinder did not function?
Also, your strategy of exiting when the first bottle was used does not leave you any margin for dealing with problems, a further collapse, someone taking a fall etc. (thats where the thirds rule is helpful)

Sounds like you had a good trip anyway and your all allive

Thanks very much Johnny, its a learning curve which is why I posted here to learn as much as I could.

The DIN connection, would that be the tank being a female screw connection into which the male screw goes in. (no giggling everyone please) with 'SAS LTD TESTED 01/04' so out of test.

I assume then these tanks should be tested every 2 years?
Do cave divers have two of everything when they dive?

Jagman said:

We used it in a low roofed colliery a couple of weeks ago,...  <snip>

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Thats a great story, taking mine exploration to a new stage IMO. Love to see some photos from that.

Be careful of flammable gas in coal mines though.

Yes Darkplaces the female threaded port on the cylinder tap is the DIN fitting. You can also get yoke fittings which have a flat face and o-ring but they are not prefered in cave diving as they are not considered as robust as DIN.

Steel tanks should have a visual inspection every two years and a hydraulic test every five years, not sure about composite cylinders.

Cave divers do usually carry two independant sets and breath off both regularly to ensure they are functioning. One of the reasons for using thirds is if one set goes down you have some margin in the other set to get you home.

The trip report is only visible to registered c**tplaces members. The pictures can be seen here;
http://www.c**tplaces.co.uk/phpBB2/album_personal.php?user_id=307

Note the use of air monitor, the yellow thing on the left shoulder.
Yes its all a risk but not reckless.

Thinking about Johnnys post.. Ideally to carry both tanks as autonomous systems, would make things a lot easier if the full face mask was replaced by just a mouth peace. Both carried in something like a rucksack!

Good pics, looks like an enjoyable trip.

You could bolt the two cylinders together, side by side, and mount them on your existing backplate. I have noticed allot of backplates with twinning bands on e-bay recently.

Hmm I have been looking at ebay stuff, it looks like the standard connector is a clamp type, not the same as my screw in connector.
The connectors; http://www.c**tplaces.co.uk/phpBB2/album_page.php?pic_id=8907

c**tplaces said:

Hows yer hole?

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Going ok.

Johnny said:

Good pics, looks like an enjoyable trip.

You could bolt the two cylinders together, side by side, and mount them on your existing backplate. I have noticed allot of backplates with twinning bands on e-bay recently.

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We did think about this but the big problem is getting through the falls sections as is, another tank on your back would make it more or less impossible, both cylinders were checked to be working and charged before we went in.
We decided due to the particular hazards that in this mine half way point was cylinder change as the major hazard is a shale collapse about 50 yards in from the entrance, (we failed to reach the signposted egress because of a fall that could not be negotiated with the BA), had this run while we were in the mine then survival was unlikely anyway we simply would not have had sufficient air supplies to dig it out.
While tank changes were done the other two men on the trip stood by, if necessary a short spell of breathing could be had from another's system, we practised the tank changes several times before hand to ensure we could do it right 1st time.
Gas levels were carefully monitored all of the time, no explosive gases were present just very low oxygen levels.

The risk factor was high, but calculated as well as possible :-\