Reply
 
Thread Tools Display Modes
 
Old 08-15-2014, 06:02 PM   #201
Master and Commander
 
markpierce's Avatar
 
City: Vallejo CA
Country: USA
Vessel Name: Carquinez Coot
Vessel Model: 2011 Seahorse Marine Coot hull #6
Join Date: Sep 2010
Posts: 10,251
That was the lightship we sailed around on the annual "Lightship Race" in the sixties. However, in relation to the small boats we use, that mushroom is small.
__________________
Advertisement

__________________
Kar-KEEN-ez Koot
markpierce is offline   Reply With Quote
Old 08-15-2014, 06:23 PM   #202
Scraping Paint
 
City: -
Country: -
Join Date: Oct 2007
Posts: 13,748
My understanding of how a mushroom anchor works is that, assuming it is large and heavy enough for the job, it continues to bury itself into the bottom as it "works" from the pulling of the vessel attached to it. So the more it gets pulled and jerked on, the deeper it digs itself. I would imagine that when a lightship like the one in Al's photos had to come in for servicing, it was a hell of job getting the anchor out of the bottom.
__________________

Marin is offline   Reply With Quote
Old 08-15-2014, 07:16 PM   #203
Master and Commander
 
markpierce's Avatar
 
City: Vallejo CA
Country: USA
Vessel Name: Carquinez Coot
Vessel Model: 2011 Seahorse Marine Coot hull #6
Join Date: Sep 2010
Posts: 10,251
They probably just took their time, oozing through the mud.
__________________
Kar-KEEN-ez Koot
markpierce is offline   Reply With Quote
Old 08-15-2014, 07:59 PM   #204
Guru
 
Nomad Willy's Avatar
 
City: Concrete Washington State
Country: USA
Vessel Name: Willy
Vessel Model: Willard Nomad 30'
Join Date: Oct 2007
Posts: 13,705
Marin wrote;
"So the more it gets pulled and jerked on, the deeper it digs itself."

As far as I know every anchor acts in that way. Probably the best way to set ... a long line of little jerks.
__________________
Eric

North Western Washington State USA
Nomad Willy is offline   Reply With Quote
Old 08-15-2014, 08:15 PM   #205
Guru
 
psneeld's Avatar
 
City: Avalon, NJ
Country: USA
Vessel Name: Freedom
Vessel Model: Albin 40
Join Date: Oct 2011
Posts: 15,861
Mushrooms are considered permanent anchors because they dig in further no matter which way the pull as opposed to the anchors most people lie to for a temporary time.

Anchor - Wikipedia, the free encyclopedia

Mushroom anchor[edit]


Mushroom anchor on the lightship Portsmouth in Virginia.


The mushroom anchor is suitable where the seabed is composed of silt or fine sand. It was invented by Robert Stevenson, for use by an 82-ton converted fishing boat, Pharos, which was used as a lightvessel between 1807 and 1810 near to Bell Rock whilst the lighthouse was being constructed. It was equipped with a 1.5-ton example.
It is shaped like an inverted mushroom, the head becoming buried in the silt. A counterweight is often provided at the other end of the shank to lay it down before it becomes buried.
A mushroom anchor will normally sink in the silt to the point where it has displaced its own weight in bottom material, thus greatly increasing its holding power. These anchors are only suitable for a silt or mud bottom, since they rely upon suction and cohesion of the bottom material, which rocky or coarse sand bottoms lack. The holding power of this anchor is at best about twice its weight until it becomes buried, when it can be as much as ten times its weight.[17] They are available in sizes from about 10 lb up to several tons.
psneeld is online now   Reply With Quote
Old 08-17-2014, 11:51 AM   #206
Guru
 
kthoennes's Avatar
 
City: Sioux Falls, South Dakota
Country: USA
Vessel Name: Xanadu
Vessel Model: Mainship 37 Motor Yacht
Join Date: Oct 2013
Posts: 857
Then there's taffy mud, like the mud along Turnagain Arm along the Seward Highway - that mud eats tourists once in a while. They don't respect the mud (despite the warnings) and then the tide comes in...

I put myself through college working for my dad's commercial diving company. No glamorous deep sea work, no, lots of shipping terminal, piling, power plant, and dam jobs - and mud, mountains of mud. We'd use 6" trash pumps to pump mud out of cooling water intake canals, cooling towers, buried cables, clearing underwater valves and machinery and trash racks. Did that for about five years. Felt like I pumped enough mud the fill the Grand Canyon. We had a lexicon for mud. Baby s--- mud (we liked that, easy to pump). Stick-mud was the worst, mud with sticks in it. Jammed the pumps if the sticks were big enough, if you let them get sucked into the intake. Yes, mud is fascinating stuff. Once in a while too we'd strike a vein of mud that would smell so bad you'd almost throw up in the helmet - I always wondered if those spots were from things like dead cattle or large animals that sank to the bottom and decayed into mud themselves after a few dozen years. Ah yes, mud. Mud paid for a good portion of my college degree. Where would I be now without mud.
kthoennes is offline   Reply With Quote
Old 08-17-2014, 05:01 PM   #207
Moderator Emeritus
 
jwnall's Avatar
 
City: St. Marks, Florida
Country: US
Vessel Name: Morgan
Vessel Model: Gulfstar 36
Join Date: Sep 2012
Posts: 3,621
Quote:
Originally Posted by kthoennes View Post
Then there's taffy mud, like the mud along Turnagain Arm along the Seward Highway - that mud eats tourists once in a while. They don't respect the mud (despite the warnings) and then the tide comes in...
I've seen that mud, and last time I was in Alaska a tourist did indeed get stuck in it (but they got him out). Oh well. Helps the gene pool to lose people like that.
__________________
John
jwnall is offline   Reply With Quote
Old 08-24-2014, 09:00 PM   #208
Guru
 
READY2GO's Avatar
 
City: Marathon, Florida
Country: USA
Vessel Name: Walkabout
Vessel Model: 1989 Sea Ray 380 Aft Cabin
Join Date: Jan 2012
Posts: 521
Brian,
When will the test results be posted.

Thanks
__________________
"Whenever you find yourself on the side of the majority, it is time to pause and reflect." Mark Twain

www.mikeandsharondunsworth.blogspot.com
READY2GO is offline   Reply With Quote
Old 08-25-2014, 06:01 AM   #209
Senior Member


 
City: Fort Lauderdale
Country: United States
Join Date: Apr 2013
Posts: 156
Quote:
Originally Posted by READY2GO View Post
Brian,
When will the test results be posted.

Thanks
I think we will post the charts this week and possibly the videos from all 4 days on YouTube.

Regards,
Brian
Anchor Brian is offline   Reply With Quote
Old 08-25-2014, 07:40 PM   #210
Guru
 
Nomad Willy's Avatar
 
City: Concrete Washington State
Country: USA
Vessel Name: Willy
Vessel Model: Willard Nomad 30'
Join Date: Oct 2007
Posts: 13,705
You Tube .... kinky stuff then eh Brian?

I was wondering too but didn't want to be the first one to ask.

Thanks READYTOGO.
You were ready eh?
__________________
Eric

North Western Washington State USA
Nomad Willy is offline   Reply With Quote
Old 09-04-2014, 06:29 AM   #211
Senior Member


 
City: Fort Lauderdale
Country: United States
Join Date: Apr 2013
Posts: 156
12 Anchor Performance Charts - Chesapeake Bay Testing

I have attached a 12 page PDF file with the performance results from the Chesapeake Bay soft mud bottom testing in August.

I welcome your comments and questions.

Brian
Attached Files
File Type: pdf Chesapeake Anchor Holding Power Test.pdf (1.15 MB, 758 views)
Anchor Brian is offline   Reply With Quote
Old 09-04-2014, 06:48 AM   #212
Guru
 
psneeld's Avatar
 
City: Avalon, NJ
Country: USA
Vessel Name: Freedom
Vessel Model: Albin 40
Join Date: Oct 2011
Posts: 15,861
wow...gonna generate a lot debate and discontent with those resuts.

some will say just not possible....or usable info....

but pretty much what many experienced people would have/did guess(ed).
psneeld is online now   Reply With Quote
Old 09-04-2014, 07:02 AM   #213
Guru
 
Forkliftt's Avatar
 
City: Biloxi Mississippi
Country: USA
Vessel Name: Patricia Louise II
Vessel Model: 1983 42' Present Sundeck
Join Date: Oct 2007
Posts: 2,433
Quote:
Originally Posted by Fortress Anchors View Post
I have attached a 12 page PDF file with the performance results from the Chesapeake Bay soft mud bottom testing in August.

I welcome your comments and questions.

Brian

Nicely done Brian.


1983 Present 42 Sundeck
Twin Lehman 135's
✌️
__________________
Steve Point Cadet/ Biloxi, Mississippi USA
*Present 42 twin 135 Lehmans
Forkliftt is offline   Reply With Quote
Old 09-04-2014, 07:42 AM   #214
Guru
 
ranger42c's Avatar
 
City: Maryland
Country: USA
Vessel Model: 42' Sportfish
Join Date: Aug 2013
Posts: 3,156
Brian, now I really wish you had been able to include a SuperMax in your tests!

Regards, -Chris
__________________
South River, Chesapeake Bay
ranger42c is offline   Reply With Quote
Old 09-04-2014, 10:42 AM   #215
Senior Member


 
City: Fort Lauderdale
Country: United States
Join Date: Apr 2013
Posts: 156
Quote:
Originally Posted by psneeld View Post
wow...gonna generate a lot debate and discontent with those resuts.
No doubt. As previously discussed, all of the anchors were challenged in this soft mud bottom, and many rarely, if ever, achieved significant holding power.

I hope to post videos of footage from all 4 testing days shortly (uploading now), during which Chuck Hawley, formerly the VP of Product Testing at West Marine, will be doing the play by play (or more accurately, the pull by pull).

Quote:
Originally Posted by Forkliftt View Post
Nicely done Brian.
Thank you!

Quote:
Originally Posted by ranger42c View Post
Brian, now I really wish you had been able to include a SuperMax in your tests!

Regards, -Chris
Yes Chris, I suspect that it would have performed better than many of the other anchors included in this test.


Please find below a link to a Dropbox folder if you would like to view images that were taken during the testing:

https://www.dropbox.com/sh/vkl9ekrm5...pxF4HhWqa?dl=0
Anchor Brian is offline   Reply With Quote
Old 09-04-2014, 10:51 AM   #216
Guru
 
Nomad Willy's Avatar
 
City: Concrete Washington State
Country: USA
Vessel Name: Willy
Vessel Model: Willard Nomad 30'
Join Date: Oct 2007
Posts: 13,705
The Rocna isn't a mud anchor but I didn't know it was that bad.

Look at the Mantus. The amazing thing is that it almost never fell below 300lbs of tension. Amazing. One may be able to say it's the most dependable of the lot. All the other anchors failed at some point except the Mantus.

And the Danforth. What Danforth was it? That firms up what a lot of skippers think .. that the Danforth is a good HIGH performance anchor. 1938 design.

The older designs did well considering completely unlike any other anchor test I've seen and that's what I was expecting and wanted to see. Other anchor tests seemed to be saying your older anchor is next to worthless and you better get a new one ....mine!

The Boss did extremely well and for a roll bar anchor the Supreme held up fine.

But this is a mud test as far as I know and many will poo poo it as not applicable to most anchoring situations. However I anchored many times on the BC Coast w an anchor that such a wide fluke tip I assumed it wouldn't set in anything but mud but it set every time. Must be a lot of mud up there.

THANK YOU BRIAN .. and Fortress.
__________________
Eric

North Western Washington State USA
Nomad Willy is offline   Reply With Quote
Old 09-04-2014, 11:13 AM   #217
Grand Vizier
 
Delfin's Avatar
 
Join Date: Jan 2010
Posts: 2,487
Quote:
Originally Posted by Fortress Anchors View Post
I have attached a 12 page PDF file with the performance results from the Chesapeake Bay soft mud bottom testing in August.

I welcome your comments and questions.

Brian
Outstanding work, Brian, thank you and your company very much.

I'm sure you will clarify how you characterize the different datum, for example, that you didn't keep dropping in the same spot into a sea bed disturbed by the prior drop.

What day did the cable break on the FX 37 45 deg? If not day 1, then what do you think is going on with the FX on that day?

Prepare yourself for the inevitable comments that Chesapeake mud is atypical of anchoring conditions.
__________________
Delfin
"Dad always thought laughter was the best medicine, which I guess is why several of us died of tuberculosis." - Jack Handy
Delfin is offline   Reply With Quote
Old 09-04-2014, 11:48 AM   #218
Guru
 
healhustler's Avatar
 
City: Longboat Key, FL
Country: USA
Vessel Name: Bucky
Vessel Model: Krogen Manatee 36 North Sea
Join Date: Oct 2009
Posts: 4,178
Such an interesting comparison. Graphed as it is, one can almost sense what is happening during the pull. It could be deduced that in a storm situation, the Fortress may become a sacrificial anchor in that kind of mud. Would a limitation on the degree of fluke angle have helped? The most experienced Manatee cruiser we know of with 24 loops and four down-island voyages carries a 150 lb. Danforth on his bow as his storm anchor. Looks like an educated choice.

Thanks to Brian and Fortress.
__________________
Larry

"I'd rather be happy than dignified".
healhustler is offline   Reply With Quote
Old 09-04-2014, 12:13 PM   #219
Senior Member


 
City: Fort Lauderdale
Country: United States
Join Date: Apr 2013
Posts: 156
Quote:
Originally Posted by manyboats View Post
The Rocna isn't a mud anchor but I didn't know it was that bad.

Look at the Mantus. The amazing thing is that it almost never fell below 300lbs of tension. Amazing. One may be able to say it's the most dependable of the lot. All the other anchors failed at some point except the Mantus.

And the Danforth. What Danforth was it? That firms up what a lot of skippers think .. that the Danforth is a good HIGH performance anchor. 1938 design.

The older designs did well considering completely unlike any other anchor test I've seen and that's what I was expecting and wanted to see. Other anchor tests seemed to be saying your older anchor is next to worthless and you better get a new one ....mine!

The Boss did extremely well and for a roll bar anchor the Supreme held up fine.

But this is a mud test as far as I know and many will poo poo it as not applicable to most anchoring situations. However I anchored many times on the BC Coast w an anchor that such a wide fluke tip I assumed it wouldn't set in anything but mud but it set every time. Must be a lot of mud up there.

THANK YOU BRIAN .. and Fortress.
Eric, concerning the Rocna, everyone aboard who was familiar with this anchor was surprised by the results. We suspected that if the Rocna landed on the roll bar or side in this soft mud, then it would not orient the fluke in the downward position as it was being pulled along....it would just slide through the soft mud in that fixed position.

Regarding the Mantus, I think it is important to keep the test results in perspective. According to the Mantus sizing guidelines, the 45 lb model tested is for boats 40-45 ft.

Per the Horizontal Loads Table that is published by the American Boat & Yacht Council (below), in 30 knots of wind a 40 ft boat of average beam & windage will have 1,200 lbs of load against it. For a 30 ft boat, it will have 700 lbs of load in that wind.

The Mantus held above 700 lbs during 3 of the 5 tests, but it ended at less than 500 lbs three times.

The 35 lb Danforth Hi-Tensile® model was tested.

Concerning the Boss and Supreme, once again, check the Horizontal Loads Table for a comparison with the results that the anchors achieved, and then the holding power that is required for the boat sizes in varying wind speeds.

The Boss had one pull where it achieved a good reading, while three pulls were minimal and well below 200 lbs for the last half of the testing, which is comparable to the readings that we had just pulling the 45 lb weight.

The Supreme broke free and never regained tension after it had peaked loads of 700 and 800 lbs, and it ended four tests at less than 400 lbs.


And I appreciate the thanks as well!

Brian
Attached Thumbnails
Click image for larger version

Name:	Safe Anchoring Guide.jpg
Views:	86
Size:	196.1 KB
ID:	32623  
Anchor Brian is offline   Reply With Quote
Old 09-04-2014, 12:29 PM   #220
TF Site Team
 
Bay Pelican's Avatar
 
City: Chicago, IL
Country: USA
Vessel Name: Bay Pelican
Vessel Model: Krogen 42
Join Date: Oct 2007
Posts: 2,781
I am a great fan of my Rocna. The only time it did not set was in soft mud in Lake Worth. But then I had a hard time getting my Bruce to set and finally gave up.
__________________

__________________
Marty
Bay Pelican is offline   Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off





All times are GMT -5. The time now is 06:08 PM.


Powered by vBulletin® Version 3.8.8 Beta 4
Copyright ©2000 - 2017, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0
Copyright 2006 - 2012