Pony bottle Alternative air source

-



a pony bottle (left) attached larger cylinder


a pony bottle small independently filled diving cylinder, of few litres capacity, forms part of extended scuba set , fitted own independent regulator. in emergency, such exhaustion of diver s main air supply, can used alternate air source in place of controlled emergency swimming ascent. key attribute of pony bottle provides totally independent , redundant source of breathing gas diver. pony bottle specific configuration of bailout cylinder.


configuration — in pony bottle system back-up regulator complete diving regulator (first , second stages, , submersible pressure gauge) on separate cylinder not intended use primary breathing gas during dive. provides totally redundant emergency air supply. size of pony bottle cylinder smaller of primary scuba cylinder. should provide enough breathing gas make totally controlled return surface, including required decompression stop or safety stop planned ascent. required pony cylinder capacity depend on profile safe ascent surface required particular dive plan. pony bottle used sport diving may 6, 13 or 19 cu ft in usa, while 2 litre , 3 litre common sizes in europe. deep, technical diving or wreck diving, 30 , 40 cu ft (4 litre , 5.5 litre) cylinders used. pony bottle minimum requirement doing solo diving, has no alternative source of air in form of buddy s available tank , octopus regulator if dive depth diver not able safe free ascent. in scientific diving operations, pony bottles can standard part of tethered scuba diving operations diver solo connected surface communications equipment.


there several options mounting of pony bottle. common way pony bottle carried fixing side of primary (back gas) scuba cylinder straps or clamps, may include quick-release system (as in above picture). common alternative slinging between 2 d-rings on diver s scuba harness or buoyancy compensator.


choice of pony bottle size — function of pony bottle provide source of breathing gas controlled , prudent ascent surface in emergency situation, volume must sufficient purpose. when doing no decompression diving, total reserves of breathing gas must still sufficient supply 3 phases of ascent:



at end of time pony bottle should still hold enough gas provide sufficient pressure smooth flow regulator first stage.



the table above constructed show gas consumed in such scenario – 2 minutes @ depth bailout , preparation ascend, safe rate of ascent 5 meters followed 3-minute safety stop. calculations based on heavy breathing rate of 30 litres per minute , initial tank pressure of 150 bar (2,200 psi). in particular scenario 3  litre pony sufficient diving @ 20 meters not 30 meters. these values may vary depending on diver , other circumstances. diver selecting pony bottle can such analysis his/her own breathing rates, cylinder pressure used, , required ascent profile, or take professional advice on selection. since monitoring of remaining air key safety issue during dive, submersible pressure gauge attached pony bottle regulator should readable @ time during dive.








Comments

Post a Comment

Popular posts from this blog

Mobility.2C training and insignia Impi

-
zulu warrior in full regimental regalia, carrying large isihlangu war shield. c. 1860. upper body covered in cow tails, kilt of spotted cat, genet or civet skin , shins decorated cowtails. elaborate headdress consists of browband , face-framing flaps of leopard skin band of otter skin above. there multiple ostrich feather plumes , single upright crane s feather. shaka discarded sandals enable warriors run faster. move unpopular, objected killed, practice concentrated minds of remaining personnel. zulu tradition indicates shaka hardened feet of troops having them stamp thorny tree , bush branches flat. shaka drilled troops frequently, implementing forced marches covering more fifty miles day. drilled troops carry out encirclement tactics (see below). such mobility gave zulu significant impact in local region , beyond. upkeep of regimental system , training seems have continued after shaka s death, although zulu defeats boers, , growing encroachment british colonists, sharply curtailed r...
Read more

Expenses controversy Ian Gibson (politician)

-
in may 2009, gibson became embroiled in mps expenses scandal detailed daily telegraph, reported claimed flat in daughter lived rent-free before selling half market value. subsequently, barred standing in next general election disciplinary panel of labour party. believing after panel s decision position untenable , resigned mp (by traditional procedural device of becoming crown steward , bailiff of 3 chiltern hundreds of stoke, desborough , burnham), thereby forcing by-election. resultant by-election won chloe smith, conservative party candidate, majority of 7,348, reversing previous labour majority of 5,459.
Read more

11th century parish church of St Leonard Hythe, Kent

-
st. leonard s church shelf containing skulls in ambulatory below chancel, commonly inaccurately described crypt. the large 11th century church hill; tower @ eastern end destroyed earth tremor in 1739 , restored in 1750. chancel, 1220, covers processional ossuary (a bone store, more commonly found on continent) lined 2,000 skulls , 8,000 thigh bones. date medieval period, having been stored after removal, make way new graves. common in england, bones dispersed, , rare collection. several of skulls show marks of trepanning. 1 of 2 surviving ossuaries in england; other in holy trinity church in rothwell, northamptonshire. other curiosities worth looking for. on pillars on south side of nave medieval graffiti depicting ships. vestry door, on north side of nave, unlocked; open see fine norman doorway. has been suggested this, in late medieval times apparently on outer wall of church, once internal wall, earlier norman church stage higher hill. make existing chapel of st edmund (or north tra...
Read more