I got a Rockna today

[Cardinal]

Oh bugger. Should I go back and look for it?

At least you might tell us where it is so that we can anchor elsewhere. SW of the pier or NE of the pier?

 

[srm]

Had a similar experience many years ago with a 50Kg Bruce patent anchor on a fishing boat. Recovered a slab of rock about the size of a tomb stone plus a smaller rock acting as a wedge against the shank. Fortunately the winch was driven by a belt off the engine so no problem getting it all to the surface.

 

[jlavery]

At least you might tell us where it is so that we can anchor elsewhere. SW of the pier or NE of the pier?

About here (red anchor)

 

[Bouba]

Perhaps one of the rocks from ‘Rocky Area’ went for a little walk

 

[Cardinal]

Perhaps one of the rocks from ‘Rocky Area’ went for a little walk

Dragged out of position by another Vulcan

 

[AntarcticPilot]

Oh, duh - I was focussed on the lump of granite (at the time and when posting).

Go to the top of the class.

<pedantry>The rock around there is Olivine Basalt, not granite. Totally different stuff!</pedantry>

 

[jlavery]

<pedantry>The rock around there is Olivine Basalt, not granite. Totally different stuff!</pedantry>

Excellent! I was hoping to be educated/corrected.

 

[Bouba]

Excellent! I was hoping to be educated/corrected.

Then you have come to the wrong place

 

[Boathook]

Then you have come to the wrong place

The right place to be corrected but not necessarily in the right direction

 

[AntarcticPilot]

The right place to be corrected but not necessarily in the right direction

As in Eric Morecambe's response to André Previn "All the right notes, but not necessarily in the right order"?

To reassure others, my degree is geology and I checked the British Geological Survey app that gives access to geological maps for the UK!

 

[Cardinal]

As in Eric Morecambe's response to André Previn "All the right notes, but not necessarily in the right order"?

To reassure others, my degree is geology and I checked the British Geological Survey app that gives access to geological maps for the UK!

Did you check how close the nearest granite might be-from whence this rock may have been dragged?

 

[lustyd]

If you put a hinge on that anchor the head will tilt and the rock will fall off. CQRs have done this for decades, nothing gets stuck in a CQR, especially seabeds!

 

[Bouba]

This anchor thread is turning into an anchor thread

 

[jlavery]

This anchor thread is turning into an anchor thread

It's doomed.

 

[Fr J Hackett]

Can someone explain the setting process for the Rocna as from what I read it seems to imply that you do not set it in the "conventional" manner by applying gradually increasing power in reverse. I can only interpret the method as allowing wind and or tide to the work. Having managed in the past for more years than I care to think about to anchor with a CQR without loss of life or vessels I am becoming intrigued in a purely academic way of understanding the methodology and benefits of these modern anchors.

 

[jlavery]

Can someone explain the setting process for the Rocna as from what I read it seems to imply that you do not set it in the "conventional" manner by applying gradually increasing power in reverse. I can only interpret the method as allowing wind and or tide to the work. Having managed in the past for more years than I care to think about to anchor with a CQR without loss of life or vessels I am becoming intrigued in a purely academic way of understanding the methodology and benefits of these modern anchors.

My interpretation and use is to drop anchor to seabed, pay out 4xdepth as boat is taken down by wind, and  then apply power to dig in. If not enough wind, very gentle astern to draw chain out as boat moves.

Pertinent point being get scope out before digging in, and not dragging it along the bottom while paying out. (TBH this is what most of us have done with CQRs too, I reckon).

 

[Cardinal]

Conventional method seems appropriate in my experience. That would include extra care when there is believed to be kelp or similar on the seabed.

 

[AntarcticPilot]

Did you check how close the nearest granite might be-from whence this rock may have been dragged?

I admit I didn't. But "upstream" (glaciologically speaking) are the Cuillins, which are Gabbro (the intrusive version of Basalt). There are possible sources of granite, but there are far more sources of basic rocks. In that area, basalts and Gabbros are more likely. That isn't to say that Granite is impossible, and of course, in an anchorage there's always the possibility of a vessel discharging ballast stone which could have come from anywhere! But there's certainly no source very close, taking into account the direction of glacial flow.

But I meant my comment in a spirit of light-hearted pedantry, to uphold the reputation of the forum!

 

[Fr J Hackett]

I admit I didn't. But "upstream" (glaciologically speaking) are the Cuillins, which are Gabbro (the intrusive version of Basalt). There are possible sources of granite, but there are far more sources of basic rocks. In that area, basalts and Gabbros are more likely. That isn't to say that Granite is impossible, and of course, in an anchorage there's always the possibility of a vessel discharging ballast stone which could have come from anywhere! But there's certainly no source very close, taking into account the direction of glacial flow.

But I meant my comment in a spirit of light-hearted pedantry, to uphold the reputation of the forum!

This thread is becoming rather erratic

 

[jlavery]

This thread is becoming rather erratic

Nowt wrong with a bit of erraticism among friends.