Soviet Union
Soviet IP-4M Rebreather
Manufacturer: NPO
Model: IP-4M Rebreather kit
Country: Soviet union / Russia
Year: 1988
Production run: 1980s - still in use
Replaced: IP-4
Condition: New / Unissued surplus
Size: 2 (medium)
Price: £50 + £12 postage
Availability: Extremely rare
Source: private collector
Shipped from: UK
What's in the package?
- Rubber face piece
- Protected fixed hose
- 2 X oxygen generating canisters
- Aluminium storage case with air bladder
- Ballistic outsert eye pieces
- 1 X set of anti-fog stickers
- 1 X spare voice diaphragm
- 1 X spanner
Well what a stroke of luck! What were the chances of coming across an IP-4M?
The name won't mean much to a lot of people but for the gas mask collector it has to be one of the most elusive to find, especially in its complete form.
The face piece can be bought on its own from certain places online but it's often the haversack and oxygen generating canisters which are hardest to source.
The reason why this IP-4M came up for sale was because a serious collector was selling all of his stock. He cited a change of interest in his hobbies and thought he might sell up and do something else. His collection was impressive with many gas masks I hadn't seen before including this one.
The seller had priced this kit at £65 + £12 postage which seemed OK but after negotiating I managed to buy it for £50 + the postage. It's probably the most I have ever spent on a gas mask/rebreather but it is very rare and it does come complete with an extra canister. It seems a good investment.
What do we know about the IP-4
The IP-4 is a closed circuit rebreather system capable of operating in zero oxygen situations. It has the ability to generate its own oxygen whilst scrubbing unwanted CO2 at the same time.
The Soviet union were pioneers of the self contained chemical reaction rebreathers. The IP-4, IP-4M and the IP-5 are perhaps the best known models. - all of which are hard to find on the surplus market.
The exact details concerning the identity of the manufacturer and years of production are vague.
Some have suggested that the IP-5 rebreather was a direct replacement to the IP-4M but this is not the case.
Both models work on the same principal but differ in their application.
The IP-4M was designed for general emergency work whilst the IP-5 was designed as an underwater escape mask for tank crews and a stealth divers mask.
Click HERE to see my original IP-5 rebreather review.
Although the IP-4M was an innovative design it was not adopted by any of the other warsaw pact countries. Quite surprising.
Other than a handful of facts the IP-4Ms true story is an enigma.
The face piece
The IP-4M face piece is made from a single piece of thick rubber and has a rubber head harness. A mask that is very reminicent of the soviet GP-7 and PMK masks which were appearing towards the end of the 1980s.
It features two triangular eye pieces which look to be made from a coated steel or zinc alloy.
At the front of the mask is a round rubber voice diaphragm which sits behind a plastic cage.
Underneath this diaphragm is the all important hose input which carries inhaled and exhaled air in and out of the mask.
This rebreather system was not designed to be used as an underwater rescue aid as was the IP-5. One main reason for this was the design of the face piece.
Was this design robbed from the americans?
United States M4 lightweight service gas mask
It's easy to notice the similarities between the IP-4M and the ancient US M4 from 1942. The face piece section is almost a straight copy if you ignore the larger nose piece. It has the same triangular eye pieces often found on old American masks and it has a similarly identical-ish voice diaphragm piece around the mouth.
Compared to the original IP-4
When the Soviets replaced the original IP-4 with the IP-4M they only really changed the design of the face piece while the oxygen canister and bladder haversack seems to have been left unchanged.
The main differences between the face pieces is blatantly obvious. A complete switch from a GP-5 round eyed hood design to something like an american M4 (as previously mentioned).
This could be considered an upgrade by some and a hindrance by others. Opinion is sometimes devided on which Soviet mask style is the best.
Many prefer the GP-5 all over hood style as it offers the best air tight seal whereas some say the strap system has its other benefits.
The inside of the face piece is well made and well designed. Although it doesn't incorporate a Tissot anti-fogging system it does has an inner nasal cup to help channel the warm air away from the eye pieces.
The IP-4M also has an inner mask or overlapping section which helps to make a better air tight seal.
When it comes to securing the mask to the head a series of rubber straps are moulded into the rear of the face piece. Much like the GP-7 and PMK these have numbers on them so the wearer can taylor an exact fit time and again. no need to readjust every time.
Overall it's a good quality face piece. No complaints here.
The oxygen canisters
Not to be confused with regular gas mask filters, these oxygen generating canisters provide the essential air required for work in low or zero percent oxygen levels situations.
regular gas mask filters require a minimum level of oxygen to operate despite what nasties it can protect the user from. No oxygen means suffication so gas mask filters have some limitations.
Spin the plunger to active the canister
The IP-4m canister is cylindrical in shape and has a hose port at each end.
As well as a hose port on the canister top it also has an activation plunger which is wired tied until it is needed for use. The canister weighs around 2Kg and is noticeably heavier than the haversack frame it is mounted to.
Although this canister doesn't contain any cancer causing Asbestos it isn't exactly risk free either.
Like the IP-5 canister it's likely to explode or produce some nasty toxic alkaline solution if the contents come into contact with water. Not something you want to think about if you plan on using it.
The best advice for the user is treat it with respect or don't use it at all.
How it works
Canister is mounted on the top of the haversack
A rebreather canister has the ability to sustain the user with fresh oxygen within a closed system regardless of whats going on outside.
other rebreather systems use an oxygen tank worn on the users back to provide the fresh air but the IP-4M and IP-5 system work by way of a chemical reaction.
The IP-4 canisters works by first connecting the bladder hose on the right hand side. Then the hose from the face piece is attached to the left side canister port.
The big black screw plunger is then turned counter clockwise and depressed to start the process.
A small amount of air is then required in the system to kick start the process.
Carbon dioxide expelled by the user is then scrubbed essentially by a chemical reaction involving sulphuric acid and potassium superoxide. The result is fresh oxygen recirculated into the face piece and so on until the canister is depleted (you can tell I'm not a chemist can't you!)
The IP-5 system is almost identical to the IP-4 in the way it works it's just a different shape.
Bladder and overflow valve in the bottom of the bag
These russian rebreathers can withstand a 0% oxygen situation for quite a long time. arguably longer than an average scuba diving tank.
According to the paperwork this canister will last:
- 30 mins under a heavy stressed load
- 60 mins under normal energetic work load
- 180 mins when the user is resting - essentially sat on their arse.
Quite impressive! I believe the IP-5 canisters have a similar run time to these despite them appearing to be larger in size.
Accessories
Outserts for placing over the eye pieces
For a little bit more eye protection the IP-4 kit comes with a pair of ballistic outserts. Basically a couple of toughened plastic lens that fit over the existing glass ones. They are a pain to get on due to the tight fitting of the rim rubber. I must admit they do look good when properly fitted.
And no, this mask is not suitable for air soft activities despite the double glazing and tough look.
Anti-fog stickers, spare voice diaphragm and a spanner
A nice surprise at the bottom of the kit bag were these little extras. The usual round anti-fog sticker tin, a round tin containing a spare diaphragm membrane and a proprietry adjustment tool presumably for tightening the hose connections?
Instruction leaflet/Service record
It's all in Cyrillic text but nevermind - it's a historic document
This page features the inspection signing
You know when you get a complete kit when they leave the paperwork inside.
This service booklet is very similar to the IP-5 in terms of layout and content.
Granted I can't make much sense out of it being solely written in cyrillic text but It's essential for collecting purposes none the less.
Overall this is a most unusual looking kit. I think perhaps its the fact that the box haversack thing has to be worn on the front of the users chest. It reminds me of something from a 1950s science fiction movie.
It's a really well made piece of equipment which I am happy to have gotten my hands on.
Rating: 5 out of 5 ✅✅✅✅✅
The price may be off putting compared to other Soviet Rebreathers but is justified when the availability of this kit is considered. You just don't see these things for sale.
These russian masks were well made and unique in design.
An absolute must for any gas mask collector in my opinion. A fascinating historical piece. I won't be parting with this any time soon.