How to break rocks underwater

[Honkey3k]

Morning,

Last summer I found a honey hole while sniping. There was a 'V' shape that the side of the river ran through and I was able to pull out a few grams of gold while digging down into this 'V' formation in the bed rock. As I dug down I found a 3ft wide x 2ft long x approx 8" thick rock that is blocking the center of the 'V' (thats what she said). I had a 4ft pry bar but was unable to move the rock. The location makes it particularly difficult to get to since I have to dive down about 4ft to get to the area to work. This summer I'll bring a come along down with a strap to see if I can break it loose.

Do you guys have any recommendations on how to break larger rocks underwater?

 

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[mikep691]

Best bet IMO is to use an old tire chain and a winch. You can get old chains on any highway where the snow flies. Seems some truckers can't put them on right. A come along may not have the strength to move larger rocks. Dig around your boulder as best you can, then give it a yank. It may dislodge and you'll be able to pull it out of your way.

 

[dave wiseman]

Use a single jack and a gad or moil on one edge...or if you just want to move it try to lift one edge a bit and keep adding smaller rocks underneath.Not much fun getting pinned under a big slab as happened to me in the late 1970's.A weight belt will make you less buoyant.

 

[ratled]

"Best bet IMO is to use an old tire chain and a winch. You can get old chains on any highway where the snow flies. Seems some truckers can't put them on right. A come along may not have the strength to move larger rocks. Dig around your boulder as best you can, then give it a yank. It may dislodge and you'll be able to pull it out of your way."

+1 on mechanical advantage. A rock that small could be moved with a come a long and maybe even a 5' bar.

 

[Reed Lukens]

Sounds pretty small from your dimensions but still, you can easily drill and blast any size rock out of your way. An underwater battery powered sds plus and one charge with a sierra blaster is simple.

 

[mytimetoshine]

Drill and winch.

 

[Honkey3k]

Sounds pretty small from your dimensions but still, you can easily drill and blast any size rock out of your way. An underwater battery powered sds plus and one charge with a sierra blaster is simple.

I was unable to break it loose with a 4ft breaker bar and 3lb sledge. What is an SDS?

 

[Honkey3k]

Drill and winch.

Under water drill? Link?

 

[jcc]

SDS refers to the drill bit end fits into an SDS chuck I am guessing.

Underwater drill on ebay shows Nemo Power tools to 164 feet starting at $800 or so.

I might buy an SDS chuck, a harbor freight pneumatic drill (consider it a throw away) and haul in a gas powered air compressor, might be cheaper, depends on how easy the site is to get to.

Sounds like fun.

 

[BLK HOLE]

Are explosives out of the question?

 

[arizau]

Just thinking out of the box here.....might you be able to fit a small hydraulic jack under the rock? A few strokes may loosen it up enough so you can move it out of your way.

Good luck.

 

[arizau]

Are explosives out of the question?

It is probably a trout stream so yes. On the other hand......be sure and set a seine down stream to collect all the fish.

 

[Reed Lukens]

https://www.amazon.com/sds-plus/s?k=sds+plus

 

[Reed Lukens]

The Sierra Blaster is made in Oroville, you should call them.

 

[N-Lionberger]

Reed you can run a sierra blaster underwater?

 

[Reed Lukens]

Reed you can run a sierra blaster underwater?

yup

 

[Honkey3k]

There is no way to wrap anything around the rock that is stuck. It is wedged in such a way that the force of the rock was pushed and is practically seamless with the bedrock on each side. Obviously I can see there the two rocks meet and touch but I cannot get any tools in between. I need to crack the edges / center somehow. Ill look into the Sierra Blaster but a come along and strap arent going to do it unfortunately.

 

[RTR]

some ideas here https://diy.stackexchange.com/questions/6961/is-it-ok-to-use-pneumatic-tools-underwater

 

[Bejay]

If you cable pull it be sure to drape blankets over your cable (in the air) it will make it so if the cable snaps it won't whip lash back to you...a very dangerous situation! We use a "geared" big hand boat crank and have chains and a webbed boulder draped puller.

Bejay

 

[N-Lionberger]

On page 34 of Advanced Dredging Techniques volume 2 it describes opening a boulder bound hole, tight packed rocked that cannot be grabbed by a sling. It talks of using a slide hammer to drill a hole to attach a modified eye bolt. An A frame hoist is used to yank the rock up and out.