|
|
Post by Dredger89 on Apr 10, 2012 21:53:11 GMT 12
|
|
|
|
Post by caminoz on Apr 11, 2012 15:47:31 GMT 12
Thanks for putting those photos up . It looks fairly simple although its not something i would want to get wrong as i don't like the thought of getting steamed alive .
How much is it worth ? is it mild steel , stainless or alloy? also would it be worth using a pressure relief valve somewhere along the line or is that surge tank enough
|
|
|
|
Post by RKC on Apr 11, 2012 16:47:07 GMT 12
|
|
Deleted
Deleted Member
Posts: 0
|
Post by Deleted on Apr 11, 2012 16:53:13 GMT 12
A filter, a surge tank, we use a 4-5 liter one, and a tap in the line at your hip. One you can operate easily with dive gloves.The big surge tank cools it a bit but lessens the chances of a steam burn. We also just have a hose stuffed down your long john part of your suit heading towards your more tender bits/ If it all turns to custard you can just rip the whole thing out. Have to be careful too after you restart the motor after a break. To Cam if you get to the point of needing a relief valve it maybe too late. Cheers
|
|
|
|
Post by GeoffS on Apr 12, 2012 14:25:21 GMT 12
Subject: The Exotic Life of the Modern Day Gold Miner
Date: 24 March 2012 11:37:10 AM NZDT
With the water being rather cold we have heat exchangers on the motors which pumps water through the exhaust system and you can regulate the heat of the water that pumps thru your wetsuit.....so this is where the **** hit the fan!!!. I was doing the afternoon dredge in swift water with warm water flowing via a small clear hose jammed down inside the wet suit and after much after thought I can only assume that in the swift water I was rolling the rocks behind me and one of those must have cut off the flow from the heat exchanger which is fine but what happened the water in the exchanger was heating up and when I pulled the hose free this released boiling water into my wetsuit. This would have to be the most severe pain I have ever experienced, I would not wish it on anyone nor would I wish too experience it again. Here lies the difference between Logic and Panic....the logical thing to do would have been to remove my facemask and find the offending hose and isolate it, but because of the severity of the pain you are pulling at anything and trying to rip the wetsuit off which is an impossible task at the best of times. Lucky for me D...... was nearby and heard my screams and rushed over to turn the motor off....all in all this probably took about 10-15 seconds but long enough to do the damage. As I removed my wetsuit I could feel the burnt skin tearing away. Straight away D…. realized we needed to get to a hospital asap so by this stage I had removed my suit and all I had on was a pair of shorts, So I soaked my tee shirt in cold water and we headed up to get cellphone coverage, this took about 20mins as the pain on the bumpy road slowed us down but not much. At the top, once we got coverage we phoned for a helicopter....it was about this point that I started to go into shock. Emergency services despatched a helicopter from Queenstown and an Ambulance from Cromwell. About 30mins later the Ambulance was first to arrive, much to my relief. They got me on a stretcher and were trying to give me morphine but I was in shock and shaking uncontrollably but managed to hold it together long enough to get the morphine in. As I started to calm down slightly I could hear the chopper arriving so I said to get some video footage, but as I remember saying that I slipped back into shock again. I can only imagine that I far more resembled a trench compactor than a Hobbit. Anyhow after what seemed about 30mins they finally had me settled enough to fly me to Dunedin Hospital, although my blood pressure was 225 over something and I was still burning one second and freezing the next. From the time of the accident to taking off to Dunedin was about 1 1/2 hrs, I have to say it would have been the worst 1 1/2 hrs of my life.
The flight to Dunedin took about 45 mins and they kept pumping morphine into me but it didnt seem to be doing much until I reached Dunedin and once in the hospital I felt much more relaxed and relieved.
05/04/2012
Hi Geoff, Yes you can post that letter on forum, or at least the part of the letter that relates to my burns. If it can save someone else from going thru this then great. Today is 3 weeks since my accident and I am still in hospital and have just found out this morning that I will need skin grafts, so not in a happy space. The last 3 weeks has not been easy to say the least, I will add a photo taken 3 days ago that you can publish as well if you want. As I said if your article saves someone else from this then its worth while.
|
|
|
|
Post by GeoffS on Apr 12, 2012 14:36:15 GMT 12
Picture missed from previous post. I do hope that this is read in the spirit it is intended and that it is to help prevent this ever happening again to anybody. Geoff Strang Attachments:
|
|
|
|
Post by Dredger89 on Apr 12, 2012 21:39:54 GMT 12
Talked in depth to Terry Stapp who made my heater! He is the most well known of USA dredgers that builds and uses Hot Water Heaters while dredging! I spent around 1 hour talking with him on safety when using the heaters! He told me he has been using heaters for over 40 years & not been burnt! I know of other dredge operators that have not but also some that have! I think sometimes some people have a very poor knowledge & grasping of the essentials! It is extremely important to have a quality built heater! I have seen some very poorly built & poorly maintained gold dredges! Owners of poorly maintained equipment most likely will have a dangerous heater! With a heater a filter is an essential item, to be effective it must be serviced, i.e. Kept clean, the filter assembly i have has a see through housing, Terry,s notes say CHECK EVERY HOUR & clean to remove organic debris!  Working underwater concentrating on all the things a dredger must do, it essential to be constantly aware of where your hot water line enters your suit? If you feel a sudden change in temp RIP IT OUT! A surge tank is also a good idea as it provides more volume and should aid in sensing a dangerous rise in temp? On Terry,s Heater there is a mixing valve with a settable temperature so if the heater outlet water temp increases the valve opens allowing cold water to flow, cooling the heated water! One should never throw rocks on to hot water hoses, thus kinking the line and restricting flow! Having a hose that floats like your air line keeps the hot water hose out of the danger zone! |
|
|
|
Post by RKC on Apr 12, 2012 22:34:37 GMT 12
G'day cobungragold,
I've always had non-kink hoses on the HWS I've ever used. Non-kink hoses have a thick wall and the thick wall has the added advantage of floating. The hose you are using looks as if it might kink or collapse, so take care with it.
Its rare to hear of dredgers being burnt these days because of more readily assessable information available now through the Internet that can inform anyone of such things as the use of filters and surge tanks.
I only hope the tragic story Geoff has related will remind everyone on this forum to take care with HWS and use all the safety gear. HWS are an essential piece of equipment for all professional dredgers in New Zealand.
Regards,
Rob (RKC)
|
|
|
|
Post by Dredger89 on Apr 13, 2012 16:25:44 GMT 12
Looked at my hose seems like it would be very difficult to kink it, not sure if it floats, will be attaching to my air line anyway! ;D
Rod
|
|
|
|
Post by RKC on Apr 13, 2012 16:53:05 GMT 12
G'day cobungragold,
Attaching your HWS hose to your airline is a great idea! It will also assist in preventing the hose getting in the way and being dragged ahead of you by the current.
I thought I had some photos of my old HWS hose, but they are nowhere to be found. The HWS delivery hose I used was a common white washing machine hose ... so if anyone is making a HWS and wants some hose it can be easily sourced (even in NZ). The thick wall on the washing machine hose has an added advantage of providing some insulation. When I used to dredge in Otago with snow falling about me, the water would cool noticeably from where it left the heat exchanger until it got to me in my wet suit as the air temperature got lower. I once tried wrapping some aluminium foil (as sold in supermarkets) around the hose and it did help.
Another reason for using a HWS is that by keeping the divers body warm it might help in preventing arthritis. Yes, arthritis! Arthritis can appear in a gold divers hands, and has. Its all theoretical on my part, but seems a reasonable theory to me to blame the cold on causing the arthritis. One well known Kiwi dredger can no longer dredge at all because of bad arthritis. Arthritis only impacts professional dredgers as they are the only ones who work long hours fully submerged in cold water, through Autumn and Spring, and even into winter for some dredgers.
Regards,
Rob (RKC)
|
|
|
|
Post by goldkiwi on Apr 13, 2012 18:02:39 GMT 12
That is a bad burn. Are you still in Dunedin hospital, I'll drop in for a yarn, give me a name and ward etc.
After many years of experimenting with the HWS arrangements, I came up with this set-up;
Must use a re-inforced hose, 3/8" we found was best to keep the speed of water flow up and good temperature as we had about 15 metres of hose in the water. A filter between the pump and a surge tank in the water is a must. My 8" dredge comfortably supplied two divers with hot water and air. The water temp was adjusted on the dredge.
In the morning when starting up we waited for the water temp to settle and pushed the hose up the rear of the vest and stood there looking like the Michelin Man steaming away before jumping in nice and toasty warm in 4-5 degree water.
Both air line and hot water hose were taped tightly together to a safety line from the dredge to the diver. This also prevented the air line or hose from kinking. The line and hoses were adjusted at the dredge end and at the diver so the weight was on the safety line and not the hoses.
The safety line was connected to a U shaped hook that slipped over your weight belt with the air line over a shoulder and the hot water hose tucked up from behind under the dive vest.
The secret to any hic-cup in the water with either the hot water or air line, was immediately drop your weight belt that pulled the hot water hose out and possibly your mouthpice if thats what you wanted and left you free to float back to the surface.
We used this many times and found we never got into difficulty.
From 15 years of dredging I never had one problem with the HWS.
The air line kinked on me once as I had that secured to another belt and could not release quick enough so changed that to a loose fitting as described above.
Ray
|
|
|
|
Post by roughau on Apr 13, 2012 19:33:49 GMT 12
Hi Guys.
Gold Kiwi is on the mark here.
I spent my time on the bottom of many Oil rigs and Pipelines etc. Deep Sea is rather cold so heaps of warm water (not hot) is pretty essential when you are in 600 ft of seawater working.
Normally this is supplied by a larger diesel fired heater with bulk flow and protected by numerous solenoids, temperature cut outs etc.
Flow to the diver is normally thru a very thick walled, but soft, flexible 1/2 inch hose. This is not normally reinforced, but it is bundled into the main umbilical, which is made up of Gas flow supply, Gas return for recycle hose, communication line, Numo hose is normally 1/4 in and is open ended for accurate depth reading, Camera video lines and power for cameras.
This makes a very bulky and unkinkable umbilical, which is normally attached to the Divers harness at the right hip.
The Bulk flowing warm water hose is attached by a large, approx one inch Hansen Quick Connect, and has a dump valve at this attachment, which is built into the Divers Hot Water Suit.
The Divers Hot Water Suit is made of heavy duty nylon lined Neoprene and is quite stiff and bulky. From the inlet point, at the dump valve on the right hip, numerous built in small hoses channel the water around the suit to many outlets as well as small extension hoses that protrude into the boots and gloves.
Its kinka nice to be toastie warm at 600 foot.
Temperature adjustment is primarily by manipulating the dump valve and adjusting the flow. Alternately, the Diver can whinge and moan to the Supervisor, who will hound the System Tech to adjust the temp at the boiler.
I got quite a surprise when I seen the garbage, cheap, clear plastic, crap tubing that Terry Stapp is selling with his dodgie unit. Quality unkinkable Hose is essential, unless you like Hospitals.
When Gold Dredging, there is just as much chance of the umbilical becoming fouled, as there is in Commercial Diving.
Do not take the risk. Tape, or heat shrink, good quality hose into a safe floating umbilical bundle and be very, very conscious of where this is floating at all times.
As Kiwigold suggests, I do not see anything wrong in attaching the umbilical to the Weight belt, but if you do this, it should be attached with the two biggest Carabina's that you can find.
One carabina should be permanently attached to the Weight belt by a small lanyard, about 300 or 400 long. The other carabina is fixed on the umbilical end. By attaching in this manner, either carabina can be released, and by having two, they can be very easily located, when in a panic
Simple commercial diving common sense.
CHEERS
JET
|
|
|
|
Post by goldkiwi on Apr 15, 2012 11:32:43 GMT 12
Dive at 600', havent done nothing like that, no room for mistakes there. You wouldnt want to be claustraphobic.
Bundling the air line and hot water line together with the safety line means the hoses will float anyway which is most important. Cant have the lines looping around rocks on the bottom.
|
|
|
|
Post by lloyd2234 on Apr 19, 2012 23:41:31 GMT 12
G'day Guys, Sorry to hear about another dredger getting burn't, I hope you get well soon.
I was burn't severely about 20 years ago. It was the first time i'd used hot water and i had no idea about how dangerous it can be. In my case i would have been f$#$# if i'd gone into shock as my mate had dropped me off out in the bush. It was close to a 50 km walk out for me. The fist 2 hours being the worst. 1 month in hospital and a bunch of skin grafts and i was ok.
Anyway, Not being one to give up i talked to a few people and i re'rigged my hotwater and was back in the water within the next month.
There are a few ways your hotwater can overheat but bassically its because the flow has been stopped, allowing what water is left in the water jacket or copper pipe to turn to steam. Here is what i do now, and i've never had a problem sinse. The first thing i did was install a self cleaning filter. If your pump has an oulet for a blasting hose. "mine is a 1" outlet. i have a red rubber washer that has a fine wire mesh in the middle. I think they use them for washing mashines. Anyway, you can buy them at any hardware. I've inserted it into the fitting that screws into the outlet on my pump. If you look inside the main outlet on my pump you can see the wire mesh, (filter) protruding slightly into my pump. In other words, its self cleaning. From my pump to the water jacket. The hose is secured very well with non kinking airline. After the water pump i've attached the tap to regulate flow. After the tap my hose is not clamped on. Its a resonable fit but definately can blow off if any presure builds up. My hose is non kink that comes to me and secured to my arline. Heres the other important bit. I use a small length of copper tube jammed into my water line and i have a thin piece of airline that i piut down the back in my longlohns. Then i put my wetsuit top on. After i have my wetsuit top on there is a few inches of this small diameter line sticking out of the front of my wetsuit just below the weightbelt. I simply plug them together. I must stress here. DO NOT USE AIRLINE FITTINGS. You will not get them apart quick enough in an emergency. I know of one dredger that was burn't useing airline fittings quite a few years ago, then a friend of mine got hit last year. Same thing, Used airline fittings to connect up. Problem was, he was down 16 feet when it happened and he accidentally disconnected his airline. He then had to waste valluable time just trying not to drown. He latter told me. He had the dredge in storage for a while and thinks that a wasp might have laid a nest in the line. He plugged himself in without testing the water flow.
If anyone is vaguelly interested, i could take some photo's and put them up next time i'm in town.
|
|
|
|
Post by caminoz on Apr 20, 2012 18:43:20 GMT 12
Hi lloyd , Im interested in the washer filter you speak of that protrudes into the flow of water from the pump if you have time some photos would be great , this is not something one would want to get wrong .
|
|
