Thinking of designing a high-tech dredge head for use in Nome
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Fleng
19:22:56 Tue
Feb 14 2012
Thinking of designing a high-tech dredge head for use in Nome
I'm a professional engineer in Florida with some experience in developing high-tech devices. I'd like to bounce some ideas off of the board for possible use in Nome. Anyone interested?

peluk
20:00:59 Tue
Feb 14 2012
Re: Thinking of designing a high-tech dredge head?
Fire away!

dredger
02:25:07 Wed
Feb 15 2012
Re: Thinking of designing a high-tech dredge head?
:welcome::smile:

Fleng
15:15:19 Wed
Feb 15 2012
Thanks for the welcome
Is there interest in a crawler? I can envision a powered creeper with a vortex suction system and working either untended or guided by a diver. It seems like the amount of work, wear, and tear on a diver to drag around a 6-10" dredge head would limit his ability. If a system were designed to take only up to 10% mud could this be helpful? How important is a divers ability to see the gold?

LipCa
16:38:05 Wed
Feb 15 2012
Re: Thanks for the welcome
isn't there already one? I thought I saw a news shot on one...

In fact, here's what I saw:


http://www.persistenceexploration.com/Gold_Dredging_Nome_AK.html

peluk
18:51:43 Wed
Feb 15 2012
Re: Thanks for the welcome
There has been a dredging operator using a remote vehicle for many years in Nome.It is a successful operation.
The site LipCa has referred to is also using a remote vehicle but they are just getting into it.

I'd bet that when the South African outfit that bid on offshore leases starts their operation they will use a remote vehicle as well.I say that because about two years ago,I saw what was being used for diamond mining by a South African firm.It may have also been used for gold recovery.It was a ship with a well and the tractor was put down through the well.The material looked like it was brought aboard and worked below decks in the ship.

Fleng
19:07:42 Wed
Feb 15 2012
Good link
ROV's are definietly all the rage as they chart the Titanic and other areas on the sea floor not normally accesible to divers. What I'm proposing is more like a sea floor vacuum cleaner that takes stress off of the diver by powering the head like a self-propelled lawn mower. The idea is that the dredge head doesn't have to be lugged around on the bottom and can navigate over modest formations. Part of the design is the ability to adapt to uneven conditions.

Some of my questions include:
1) Would there be interest in "farming-out" the technology for a share of the profit?
2) What would be some "wish-list" items for a new design?
3) What kind of safety features might improve diver safety?

AK_Au_diver
05:24:27 Thu
Feb 16 2012

Most ROV attempts have failed, the owner of the only one that is turning a profit took 15 years in Nome to get to that point, and he came into it well funded.

I don't know if the Persistence made enough last year to cover fuel; I think they have another couple years to become profitable, and while this was their first year in Nome, it was year three of four of working on it.

The biggest problem still is finding ground to work on that is good enough.

Anglo Gold Ashanti will likely bring up a crawler, they are a huge company, they spent $7million on leases and plan to take 5 years to design, permit, and build their ROV. And they already operate ROV miners in other parts of the world.

Fleng
17:36:21 Thu
Feb 16 2012
Dredge head design
Anglo Gold sure seems like a giant. They don't show any current operations in Nome but with 20 locations around the world and $1bil spending last year they could get into the business as big as anyone. The Persistance looks interesting as they are small enough to be hungry. Thanks for the tip.

I still think that an ergonomic design would improve the divers lot. I'm going to proceed on the assumption that if I would be lucky enough to design a better mousetrap good things could happen.

For starters, should Mod 1 connect to a 8" hose?

dredger
01:59:34 Thu
Feb 23 2012
Re: Dredge head design
Hey Fleng,

Just thinking about ya dredge head,

And no prob at all, i agree,

"I still think that an ergonomic design would improve the divers lot. I'm going to proceed on the assumption that if I would be lucky enough to design better mousetrap good things could happen".

Mate, I would suggest you need a lot of time on the suction nozzle to see for yourself, what bedrock shape problems your dredge head ( or diver helper ) will encounter, thin crevices, fat crevices, the list is endless, to say nothing of dredging in a manner that keeps the workface water clear with good visibility,

Another line of thought
"an ergonomic design would improve the divers lot”. so as a possible line of thought???, first build something that improves the divers work, in fact helps the diver dig crevices a lot faster, move rocks a heck of a lot faster, increase production by presenting the suction nozzle with fewer oversize rocks,

Then when that works, the diver can control the ??. digging head, remotely, and stay on the surface, so the suggestion there is to keep the diver dredging and controlling the head, until it works properly, then make it remote,

A question here is if you are designing a dredge head, would you have to design it especially for beach, and have a different design for river dredging, ??. Please consider the natural bedrock formation/erosion of both beach, and river, and where would placer bedrock formations/erosion fit between them??.

I was thinking something like this in scale relative to the diver, small lightweight, maybe 3 times bigger, and stand stretched out may 20-30 feet,

:smile:

Digging arms or legs around this scale,



With maybe one these cutter heads on a extra arm, ?? If you were dredging in placer in New Zealand, maybe on the beach, ?? Were the top bedrock layer is a sticky clay, feet deep, but really necessary, ??.



Another extra 2 arms fitted with a fingered clam shell concept, for picking up and removing rocks away from the immediate work face, ?? 6 foot wide, and another 2 arms the that are adjustable but mainly work at brushing over size rocks to the side, and run all the time, spread 25 foot range,
Another arm for a good ripper tyne, capable of ripper out rocks from crevices, and soft and faulted/cracked bedrock, :confused: basically with the robotic movement as a human arm, 4-6 arms / legs, dream on, but I have to go, I think it could be constructed, and operated by one diver , and could be better operated by a dredger, with experience at dredging and operating, backasap,
:smile:


dickb
05:40:40 Thu
Feb 23 2012
Re: Dredge head design
Why does everyone want to re - invent the wheel. The best dredge is already being used up there. Just need a different hoe to work as a dredge. The hoe that he is using is for digging holes and the dipper isn't long enough to get into deeper water. A drag line or clam bucket would work, but the loses in the bucket would be greater. The longer dipper with a smaller bucket would just the ticket to dig the sand and small boulders.

Look here.

http://www.youtube.com/watch?v=Lp2TSFezMUg&feature=related

http://www.youtube.com/watch?v=J2oZtbOTLEg&feature=related

They already use them for dredging harbors all over the states.

Dickb

Fleng
19:05:17 Thu
Feb 23 2012
Re: Dredge head design
dickb- Don't want to reinvent the wheel-thats what this post is about. I'll check out the youtube videos when I'm not at work-blocked.

dredger-Love the Transformers reference. My 5-year old nephew is a hopeless fan. If I built his second retarted cousin Larry- He'd be hooked for life!

I see a separate designs for sand/beach and rock/rivers. Churning appears to be a bad thing for diver's visibility. A system of rollers and cutting teeth working in conjunction with a suction head is probably a good direction.

dredger
22:41:21 Thu
Feb 23 2012
Re: Dredge head design
Hey Fleng,

I agree mate, this not about 60 ton Excavator,

I am focusing on a diver mounted and operated robot,some points of focus,

(1)I can envision a powered creeper/ "crawler" system guided or operated by a diver.

(2)""""""""It seems like the amount of work, wear, and tear on a diver to drag around a 6-10" dredge head would limit his ability"""""""".

Been working on a post, will post soon, back,asap.







dredger
01:10:16 Fri
Feb 24 2012
Re: Dredge head design
Dredge crawler, Sorry, my mistake, too much to do and no time,

I did not see that my scale picture was not posted, sorry,

This is the size arm or around this size is what I was suggesting, and please note, The idea is that the suction nozzle would be attached at the rear, and the small robot, perhaps looking like a cockroach, or big ant, would work at the face under water, with the diver seated or positioned up front and on the back of the robot, perhaps a clear plastic pressurized bubble, or perhaps a bubble with heated water for the diver in cold applications, also please note, the focus,
Is there interest in a crawler? I can envision a powered creeper guided by a diver. It seems like the amount of work, wear, and tear on a diver to drag around a 6-10" dredge head would limit his ability.

To stop sea water entering the hy oil system, all ram and servos would or could be fitted with an extra set of seals that creates a sealed pressurized air pocket in front of the original hy oil seals, and still allow some air to be sucked into the ram or servo, which happens anyway, force water away from the seal with a low air pressure seal, hy tank and hy-drive unit on boat topside, ,

The body of the cockroach or beetle shaped to contain ballast tanks, to raise the robot to the surface, the ballast tanks are filled with air, and once the robot has settled on the bottom, the ballast tanks could be re filled with concentrated pre processed black sands, to add weight to the crawler,
Beetle Body length 8-10 feet, wide,6 feet, with all arms and stabilizer legs folded back into and under chassis/frame, shell.
Weight, ?? ˝ ton to ton, and constructed to be lightweight, and strong, 15hp motor,
So 7 legs, rear legs are basic stabilizer concept,( back hoe arm ) next 2 legs are same are opposing and adjustable, being a 4 leg base with skid plates as feet, , front 2 legs are more like hands with clamshell clamps, 3 finger, and 2 fingers that when closed form a roughly flat shovel , for brushing away oversize in crevices, also have a swivel or twist 120 degree,
I would suggest this type of robotic dredge diver concept would result in a lot of “older dredgers “being perfectly cable of doing long days of dredging, I also suggest this robot concept would be suitable for any bedrock bottom (except NZ clay, too deep.) Under water or above water, ??> I am suggest this concept would also work on dry or damp alluvial gravels, not hard rock, but i only just thought of that,
So this is incomplete, lots more, but I got to go, dredger.


militaryman168
03:16:57 Fri
Feb 24 2012
Re: Dredge head design
J/w was reading the website for persistance. Is there a reason they are only doing 40 to 60' deep? Id assume they could well surpass that. Possibly something limiting on thier design/build?

peluk
03:30:50 Fri
Feb 24 2012
Re: Dredge head design
It doesn't appear that either of the two Youtube films are showing a dredge working in material similar to the ocean bottom here.
The first film looks like a hoe simply relocating material from one barge to a larger barge.
The second is working in muck,not hard packed clay.
That cutterhead Dredger submitted might be a worthwhile consideration.It would eat up the clay ahead of the suction and it would contain material in a cut as it eats.

Plugups might be a problem.Right now,Pomarenke's excavator is slowed down considerably when it brings up clay in large chunks.The fact that the clay is only a layer is in your favor.After passing through it,the bucket again is more appropriate.Then when schist is encountered,the pendulum swings back in favor of that cutter design.

I don't know if they are encountering schist bottom where they are but it sometimes pokes up out of the sand here and there along the front of Nome.It may be beyond his reach so far offshore with that excavator.

shaftsinkerawc
05:44:24 Fri
Feb 24 2012
Re: Thinking of designing a high-tech dredge head for use in Nome
I liked the cutterhead drawing also with the suction nozzle. Thought the cutter needed to turn in the opposite direction to keep from jamming on a large rock. It would still loosen/cut material and throw oversize away from the nozzle. Has to use a lot of fuel and time to lift an excavator bucket or clamshell all the way from the bottom to the box and back down again.

Fleng
20:45:58 Fri
Feb 24 2012
Re: Thinking of designing a high-tech dredge head for use in Nome
shaftsinkerawc- Power/fuel use will be key to an efficient design. Sending the sand/ore up via a suction hose is a hard solution to beat. I hate the idea of a bucket full of flour gold being rinsed out in the 20' trip to the surface. A cutter that could be reversed might help plugups.

peluk- Schist is certainly going to wear on a cutting head and could clog the system. A way to sort out that material may be worth looking into.

militaryman168- Persistance hasn't responded to my email but I see that they are hiring hydraulic engineers. My guess is that the pressure at 50' is over 20/in sq my have overtaken their seals.

Fleng
21:06:27 Fri
Feb 24 2012
Re: Dredge head design
dredger-
Love the beetle idea. Bio-designs can be very effective. Bringing older dredgers back to work is part of the design goals (fifty-something here). One nice thing about hydraulic design is that the seals are calculated to not leak at surface pressures. At depth you have a counter pressure which reduces strain. The stress isn't reduced however and the epa won't be happy when pressure cylinders start leaking. Sending up concentrated ore via an air ballast system is brilliant. I thought of running a density separation stage at the sea floor as a concentrator and filling buckets which could be sent to the surface w/o the diver via a balloon which could be refilled with a standard hookah when full.

peluk
22:56:06 Fri
Feb 24 2012
Re: Thinking of designing a high-tech dredge head for use in Nome
Fleng,my guess is those are bolt-on cutters which could be easily replaced.I don't know what hardness schist is but my guess is that those teeth would bust up great quantities before showing wear.Frost buckets are used on hoes when encountering schist bedrock as far as I know.Those cutters look even more agressive and they have a water lubricant under water.

If the wheel operated in a reverse direction away from the suction, it would flip clumps of gold bearing clay and rocks surfaced with clay away from the suction intake.After viewing with a camera,possible upgrades such as a bar or two over the intake might help.

Shaftsinker,I'd bet the cost of fuel would be offset in bringing such a large quantity of material to the surface in one swoop as opposed to the material brought up by a suction head.Maybe the delay in processing that large quantity through the grizzly and trommel would negate that speed advantage however.

Maybe that cutter could have a ripper precede it to indicate too much resistance(as with an oversized obstruction)and thus give the operator time to take evasive action.


dredger
04:44:42 Sat
Feb 25 2012
Re: Dredge head design
Hey Guys, too much too fast, hahaha, no time, so here we go, we are still talking about excavators "and" Bio-designs, so,

The beetle design, please note, the robot would not walk and climb like a beetle, ok scenario, I catch a roach and super glue his Back" legs stiff, then super glue the next set of legs under him and tucked away, leaving his front legs free, he can still move around and nearly run,and can be made to back up with rear skid feet, that is the idea, except on the robot the front legs will have the similar movement as human arms, 110 deg twist,
the rear four arms are used as stabilizers, while the front two legs/arms are digging, ( also please note, the no7 leg/arm would be located in-between the to arms,at the head, this arm is fitted with a ?? 24" ripper tyne, I have the idea, or line of thought, that , the diver will control the left robot arm, with the full length of his hand and arm, giving a 9 function control, centre ripper arm has 9 function control, and right arm also has same, but, but, we have three robot arms, and only two arms on a diver,< so the centre arm would / could accept either the left or right diver arm, Allowing the diver to pick up rocks in the left hand and use the right hand to control the ripper tyne, especially the revolving angle of the ripper tyne,
:smile:
The scenario could be the diver is clearing rocks with both robotic hands, and uncovers a good crivice, the crevice is on a ?? 10-15 degree angle, so the diver settles the left robotic arm, and changes his left arm to the centre, ( ripper tyne )9 function control, and uses his right arm to continue clearing with the right handarm, and left arm/hand to rip out the crevice,quickly and effectively, left robot arm remains settled, and unused, or as a stabilizer against opposing forces from the ripper arm, if you know what I mean, ??.

All three diver controls would be air over hy,

Please note, the concept is to take the work load off the diver,

Please note the u-tube with the excavator digging on bottom and loading barge,with what appears to be good gold,

I think we are all worried about gold be washed of the bucket as the bucket is brought to the surface, I would suggest fitting a lid for the bucket, so that when the bucket digs the materials it closes on the lid, it is a fixed thumb concept, I would suggest anywhere a excavator digs in this manner, there should dredge following to caver any gold not picked up or lost while digging and raising the bucket,
Peluk, after seeing the u-tube and seeing the gold in the mud i would suggest the above cutter head would be the most efficient way of dredging those type of mud and gravels, an observation was to position the the head just below water level and run the head at 100rpm, as expected the force threw out water front back and down, 500 hp at 100rpm, I lowered it down and it was the same, I brought it back up to about 2' below the surface, then i started the 500hp dredge gavel pump, and ran the cutter head at the same time, and noted that the suction completely overcome the force on the water that the revolving head created, in fact float some and debris floating in the hole were drawn in steadily, until they got close and accelerated very quickly, so my observation was there is plenty of suction around the head,

Please consider the water spinning in and with the head, 100rpm, being dragged around by the teeth, high velocity, nothing stops it except a 100 of cable wrapped around, with suction, opposed to the muddy bottom seen being dumped in the u-tube, I would suggest most mud would be affected by the spinning water, sand gravel rocks to break up a lot of clay as a face, ??.

And at a guess I would guess and say the cutter dredge could do the same area 1/3 the time, with a complete back sweep dredge symmetrically controlled by computer and GPS<,I would then dive the area with a 10" dredge, just to see if and why something was missed, fine or cause, ??.

Only problem is positioning the dredges cables, the cables must at least be anchored at or above water levels, ( not anchored 30' blow the surface,), big problems there, anchoring of the ocean floor would angle the cable down and pull the side down, slow production ect, angle the cutter head badly, cutting across the face might be reduced from secs per yard to min per yd, solution might be to anchor three large boats, then pull the dredge off them, :confused:

So, I am pretty convinced the direction of rotation is correct, and will try and post,


shaftsinkerawc
16:43:31 Sat
Feb 25 2012
Re: Thinking of designing a high-tech dredge head for use in Nome
I still feel that reversing the cutterhead direction would leave you loosening material to be sucked up and not force feeding or jambing a big rock. Once digging in a hole any material thrown would just slide back down waiting for the suction pickup.

peluk
22:15:21 Sat
Feb 25 2012
Re: Thinking of designing a high-tech dredge head for use in Nome
Shaftsinkerawc,it may be that what you say is what would actually happen.As dredger describes this cutter,it operates at 100RPM which would probably not toss rocks as much as i first imagined,but merely displace them.The whirling small debris is eventually drawn in.In either rotation,it looks like it could pulverize clay.
I wouldn't be a candidate for its use.I'm just wondering about its capabilities in Nome where it would be in at least 10-12' depth in the offshore dredging.

I wonder how it would do mounted on a barge like the one shown in "Bering Sea Gold" series with only one spud used as a pivot on the stern instead of two which limit the movement.
The anchoring would have to be kept as simple as possible,isolated from the cutter and preferably dependant only on the barge for positioning and removing.

I'm in way over my head but it is an interesting design. I have seen the cutter heads currently used by the Corps of Engineers laying on the dock and they really do take a beating.

dredger
12:20:46 Sun
Feb 26 2012
Re: Thanks for the welcome
Hey guys, just got photobucket working, yahoo. it is working "weird " though, :confused:

Shaftsinkerserawc, mate, I might now be able to do a little drawing that may help. :smile: everyone,

Peluk, :smile:, I think the cutter head is exceptional in specific situations, very specific, I suggested a cutter head dredge is or could be suitable for the slurry or gold bearing materials show on above u-tube, and in the use I was employed to use it for, that was grinding soft sand stone off hard sands and well suck up nice white sands on beaches, but never rocky situations like a rocky riverbed, or most probably NOT Nome Beach, my line of thought when I posted that picture, was a scaled down attachment, for the SCALED DOWN bio-robot to handle heavy sticky clay bottoms like in New Zealand,

Another point is I suggested and posted a full size cutter head for the area shown in u-tube, but it would have to be attached to specific dredge and operated in a specific manner, to achieve extremely high production rates, Multiple spuds could work but not as high production rate, ?? back asap,


peluk
21:04:48 Sun
Feb 26 2012
Re: Thanks for the welcome
No Phil,I wasn't thinking of its application on the beach.An excavator would leave it in the dust.My thoughts were for offshore work for a dredge where clay was encountered.
The hardpacked clay offshore sits atop a pay layer.There are reputed to be more gravel clay layers beneath that but good pay lies beneath the first,for starters.

This is one reason an excavator mounted on a barge is doing so well just offshore now.He's really the only one capable of getting through this clay layer.I visualise a pass with the cutter head to pulverize the clay and leave a vulnerable trench full of waiting material,flip up the cutter and follow with the suction head if that is an improvement.'Improvement' meaning that there would be less possibility of clogging.I didn't realize it was so vulnerable to rocks.

dredger
22:47:04 Sun
Feb 26 2012
Re: Thanks for the welcome
33333, Sorry, mate I meant off shore, and you are right about the rocks, it will throw most anything back, but :confused: say six foot deep of rocks, You might be wasting time,??, deeper in rocks and forget it, but, judging all the dredging u-tube I seen of dredging off shore, you never know, and a cutter head could have suction fitted for the dust, big advantage of using the sucker too, is the dust and gravels are removed, from the oversize rocks and rock piles, making the piles easier to force back,

A quick suggestion here is, as you may know a wide bucket is hopeless at cleaning or picking up gold in a thin crevice, and very slow on hard pan, and just as a preliminary test, and if they have not already got one, try a ( quick change )ripper tyne, ?????, just to get through it and have a look, ??. A cutter head can also be quick change, hy-hoses r quick change too, 2 mins,


I have always wondered if the excavator guys up there, excavator clears a patch, and then do they dredge that patch or area, :confused: I would be grateful if you could find out, please,

Anyway, I have some?? Pictures with arrows,: smile: concerning some other points of interest, back asap.


peluk
23:50:48 Sun
Feb 26 2012
Re: Thanks for the welcome
Generally I think it is safe to say after an excavator works an area,he is off to another.Dredging would be done by a friend perhaps if the person requested that permission.From what digs I've seen,the water level would not support a dredge floating but maybe a setup like you had with the dredge on land would work with one of those blaster/suction heads for sucking off bedrock.

I know of a dredge here that followed an excavator after the area was flooded but it did not pay.

The "frost bucket" used here is a narrow bucket with a crescent shaped face and teeth like Eleanor Roosevelt.Note:I can say that because prior to braces,I looked the same way.Unlike Eleanor however,I could not eat an apple through a picket fence.I digress.... On the beach,a square faced bucket would be used first to make a wider trench and hopefully avoid sloughing to some degree.That should take care of the pay on the bedrock then the frost bucket would come into play.

The ripper tyne would be a rarer bird for the average cotracted hoe owner.If a scratching with the frost bucket proves the need for one,they can be found here.

dredger
00:33:02 Mon
Feb 27 2012
Re: Thanks for the welcome
Mate, something I have always wanted was to see a lot of excavators with sealed pivot bushes, working in fresh water washes the grease out, and that is a pollutant, salt water must be a killer, repairing worn-out pins and bushes are a pain and a waste of time and money, so about 13 years ago, ( bit foggy now ), I fitted sealed bushes to the pivot points on the bucket,

Trick is it was so cheap to do, cause i used a seal bush bottom excavator track roller off a 60 ton excavator, please note, all the time the full weight of the machine can tortured one roller, all day long, beautiful,

These are only small rollers but the shapes are the same to carry and guide the track chain,



white lines shows 1/4 of 60 ton roller welded into dipper arm, also u can see where cut and flaten the sides so it would fit better,


dredger
00:39:17 Mon
Feb 27 2012
Re: Thanks for the welcome
Brown lines show, saddle mount for the rollers welded on a standard Hogan quick hitch, Yellow lines and obvious cracks show caps, 4 x bolts per cap, I built the ?? Adaption myself, had the saddle and caps laser cut, and machined, ?? about $600, all up, 13 years ago,
Red line shows oil plug, also water/oil contamination check plug, and please note I use my scope to check lub and hy-filters, for metal, rather than wait till it blows up, , no greasing required last 13 years, and I am not scared to work them hard,
Bolts came off 60 ton excavator slew ring, free,
2 points if interest are, 1 pins and bushes are easerly tuned to extend life, 2 is to fill the two bolt holes in the roller shaft with e-poxy and smooth off so as not to damage the seals while assembling, that idea cost me a extra set of seals,
I would suggest Nome excavators could be fully fitted with sealed rollers, with air press sure line fitted inside the dipper, easy,
Blue lines show ends of roller shaft,

pink lines show the distance between the pins, my conversion gave a few extra inches separation, but I not have noticed the difference, and the next bucket will be designed shorter, no prob,


dredger
02:45:48 Mon
Feb 27 2012
Re: Thanks for the welcome


Yellow line at the back is 8' grader blade, mostly out of sight,
Pink line is ripper tyne, ripper tooth is facing other way,
Red line is 7' long sucker nozzle, green line shows where pin fits,
Blue lines show 1, 6" dredge suction pipe, and 2 other blue line show position of high pressure jets, 2 other jets cannot be seen either, I will do a sketch of the angles of the high pressure jets, this is a proto type, that was tested on a 6" dredge, and worked really well, observation was ,

Sorry peluk, gotta run,phil.


dredger
05:33:15 Mon
Feb 27 2012
Re: Thanks for the welcome
Mate, I think this is what alot of your excavator guys could use on u hardpack false bottoms, just use about 7,000 psi pumps on the jets,x 4.

Just dig out what ever the way u r doing it, and quick change to a dredge tied to the excavator,

I tested this sucker nose thougherly and was going to suction the bottom of my holes after digging them out with the bucket,and maybe find crevices or hard pan, ( and it is hard pan, too not so much clay, but still cemented,)that the bucket missed,

ok, hope you can see the fine coloured lines, blue x 6' suction pipe , please note the 6' pipe stick out a few inches,
testing,

dredger
06:46:28 Mon
Feb 27 2012
Re: Thanks for the welcome
444444 Red Lines show the quick change screen/s, this screen over feed the dredge too much, observations were, this overloaded the sluice if moved around to quickly, part of the observations were to overload the dredge in a controlled manner to access the dredges recovery / failure, times,
Yellow lines show 2 of the 4 jets, just above the jet nozzle pipe flares to 2" to 4 into manifold then 3" single to pump, strong pressure, jets are directed to touch in line, the centre of the six inch pipe, just below and outside the screen, observations under water or on rocks and clay above water level, around test sites, showed very powerful blaster, 8hp x 350 standard pump, ??. it would be my intension to increase high pressure pump to around 7,000 psi, 8'to 10"dredge,

Another realization during testing was that the operator with experience of digging and sucking the hole, already has a good mental picture of the hole before diving and actually seeing bedrock, ect,

I suggest a operator with experience could easerly find and blast out and suck up very hard pan, and feel his way to bed rock, please note the feel of the nozzle or tooth touching or forcing it way though over screen size rocks and bedrock, or just sucking and feeling a very big rock, is easy,

testing,


dredger
07:19:06 Mon
Feb 27 2012
Re: Thanks for the welcome
top figure and black arrow show direction of suction, and six inch removable jet tube, dark blue lines show high pressure pipe, light blue shows direction of water jet, also removable,

3 sketches in yellow show nozzle direction ( retracting and extending the hoe within easy reach ) are movement that would slid the rounded nozzle over bedrock and give good feel to the operator for hard pan or bedrock, while forcing oversize rocks out of the way,

Double the length of the sucker nozzle for extra reach,
:smile:

dickb
17:22:34 Mon
Feb 27 2012
Re: Thanks for the welcome
Hi peluk:

"This is one reason an excavator mounted on a barge is doing so well just offshore now.He's really the only one capable of getting through this clay layer."

From what I see on TV,I think that the hoe that is on the barge is too small to dig deep enough. The two videos show excavators with longer booms and dippers. That allows them to dig deeper than the Christine Rose. My guess that is why the barge has to only work in shallow water. The bucket just can't reach below the clay in deeper water. A trommel on the barge might help break up the clay also.
JMHO

Dickb

Fleng
19:10:30 Mon
Feb 27 2012
Re: Thanks for the welcome
Phil-
While high pressure blasting might help dislodging placer, it seems like it might also push it out of the way of the dredge head suction. Of course there will be a large percentage of the high pressure fluid that will end up in the suction tube as well. The answer must be a balance of these two effects. Your combo nozzle looks like it would work well for crevices and rocky areas while the suction bucket seem better for a smooth sand bottom.

peluk
21:06:58 Mon
Feb 27 2012
Re: Thanks for the welcome
dickb,it is a fact that the Christine Rose is limited in digging depth.I've heard the owner is planning on putting a larger excavator aboard that barge or another one.However,in one of the scenes in the "Bering Sea Gold" series,you can here Shaun(his son)saying something like 'Dig shallow that's where the pay is'.

There is plenty of good pay in shallow water right in front of town...in some areas.I can't swear to this but I believe there is a trommel aboard that barge.This is why I wonder why it doesn't get more exposure on the film.
I don't think I've seen one shot yet of wwere the material goes after the hopper.

If an excavator with longer boom and dipper were used,it would appear the current deck space would be too cramped and a longer barge would be called for in order to load the hopper.No?

Dredger,if I see the barge owner or his son,I will refer them to your photos and suggestions.His line is busy right now.I'm also going to ask around about just how much I can expect from a frost bucket on schist bedrock.A lot will depend on how the schist is layered.I've seen verticle layering just off the beach.I think horizontal layering would lend itself more easily to a frost bucket.
I've seen big excavators slamming away at schist with a ripper tooth and it is a long task usually done in tandem with a cat and a ripper tooth.In a sand trench,it would bring down the walls and the tooth's impact would be cushioned requiring changeout to a bucket.

You're talking 'underwater' and I'm going back and forth with the offhore work in progress and the onshore plans I have.I'll get out of your hair.



dickb
18:20:32 Tue
Feb 28 2012
Re: Thanks for the welcome
Hi Peluk:

I agree that they don't give much air time to the operation on the CR. Looks to me that they empty into a wash hopper that may run into a vibrating grizzly, then turns to port into a sluice box, then overboard on the port side.

I'm wondering why, that in all the cleanups shown, all we see is say 1/8" down to about 20 mesh. Never anything larger and/or smaller. I suspect that all the numbers that they are posting are phony anyway!

The only hard thing I come away from watching both shows is that it takes big capital to finance a money making mining operation, and it's a lot more than luck that fills those pans.

Hope you have a good season this year.

Dickb

peluk
01:10:06 Wed
Feb 29 2012
Re: Thanks for the welcome
Thanks Dick...and to you the same.By the way,I saw an invitation from an outfit that had planned on coming up to Nome with a cutterhead dredge.The invitation was for investors.This included a rundown on what type of gold the Bima(monstrous offshore bucket line dredge) was running into when it worked in the Nome area.

The information is over on the AMDS Prospecting Forum.Just scroll down the threads to the one on the Bima.
The information stated the coarsest gold they ran into was 15mm or about 5/8ths inch.Average cubic meter held 824mg. Highest was 1.120grams per cubic meter.

I'll try to get over to the CR when I get some wheels and take a look at their layout.I thought I saw a trommel mounted on board at one time.



homestead54
18:41:32 Thu
Mar 1 2012
Re: Thinking of designing a high-tech dredge head for use in Nome
design of a cutterhead and how it could work in nome and rivers in alaska with perma-frost- and different types of material.- you can contact me at homestead54@hotmail.com
I have tested many rivers and creeks on this-nome have not tested yet- but look at what is there- and have ideas to imnprove recovery of fine gold without lost of horse-power or incresing it.

klondike_jake
02:32:12 Wed
Mar 7 2012
Re: Thanks for the welcome
a side by side hydraulic setup operated remotely via camera.one operating 12 inch nozzle the other operating hydraulic grabber for sweeping away the bigger rocks.then some way to unplug the s.o.b.use like an exstenda hoe arm the size of a track hoe say Hitachi400.

Fleng
17:33:44 Mon
Mar 12 2012
Lots of good ideas
dredger-
I like the idea of pressure sealing the joint bearings of the shovel from seawater. Probably need to do the same thing for the hydraulics or I'm never going to get an environmental permit. I'm going to try and fabricate something in the garage that I can test in the creek and work down to 30 feet.

Fleng
19:53:08 Tue
Aug 21 2012
Re: Lots of good ideas
I came across some plans to build a backhoe for $2500. Hope to incorporate some of the suggestions into a submercible version.

http://www.millerwelds.com/resources/communities/mboard/showthread.php?130-My-Homemade-Backhoe



thegoldgopher
17:53:14 Wed
Aug 22 2012
Re: Thinking of designing a high-tech dredge head for use in Nome
Am working on patented concept that may apply to your project. I can be contacted at thegoldgopher@gmail.com

Please contact if interested.

Steve

jcazgoldchaser
08:51:25 Thu
Aug 30 2012
Re: Thinking of designing a high-tech dredge head for use in Nome
http://www.youtube.com/watch?v=tAa2Df2mifU


http://www.youtube.com/watch?v=FlUmJSWtdqc

http://www.youtube.com/watch?v=VTKJy5wRdz0


http://www.youtube.com/watch?v=Sxn8ZWAwzWo


Diamond_digger
20:36:46 Sun
Oct 21 2012
Re: Thinking of designing a high-tech dredge head for use in Nome
Hi,
I was playing around with the same idea but just a cutter head is not going to do it.
The way I see it there is two options. A cutter head connected to a large suction hose 15 odd inches wide the cutter head must be mounted on either a crawler or a very large hydraulic arm.
On the barge you will have to put a serious trommel/classifier on as a first stage reception unit for the gravel with the big stones being sucked up.
Then you have to move the gravel on a conveyor belt to the standard wash plant.
However in order for the unit to work in winter time it must be fitted with tracks as well as hydraulic movable flotation pontoons. So that the pontoons can be moved out of the way so that the unit becomes a crawler and can move around on the ice. The cutter can then cut through the ice as you go and mine.
It is an idea lol will surely be expensive!
My 2p's worth barring inflation
Andy
(Lets face it, it would be one heck of a machine)



Thinking of designing a high-tech dredge head for use in Nome
http://bb.bbboy.net/alaskagoldforum-viewthread?forum=2&thread=1383
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