Cruisers Forum
 


Reply
  This discussion is proudly sponsored by:
Please support our sponsors and let them know you heard about their products on Cruisers Forums. Advertise Here
 
Thread Tools Search this Thread Rate Thread Display Modes
Old 27-07-2019, 11:12   #136
Moderator
 
Dockhead's Avatar

Cruisers Forum Supporter

Join Date: Mar 2009
Location: Denmark (Winter), Cruising North Sea and Baltic (Summer)
Boat: Cutter-Rigged Moody 54
Posts: 35,035
Re: Preventer Rigging -- Lessons from the Platino Disaster

Quote:
Originally Posted by Breaking Waves View Post
. . . DH - jfyi - if you had a ketch, you probably would not have been flying the mizzen in those conditions (angles and strength). The main would be smaller, but still big enough on these size boats to create large loads. I would have preferred to have just headsails even/also with a ketch in this particular situation. net net - I'm not sure a ketch makes much difference to this particular case.

You're damn right I wouldn't be. And never have in a lifetime of sailing.


I will use the mainsail reaching in a F8 -- some good sailing possible like that. But I will not go down wind in F8 or above with the mainsail in use.



In such conditions the main is put away and the boom is secured with a pennant to the windward rail.


There's a reason why storm trysails don't use the boom.


Not just the risk of backwinding it, or dipping the boom -- you also sure as hell don't want the center of effort to be aft, in such conditions -- you want it as forward as possible. I don't even use the staysail -- I use a scrap of the jib, to keep the center of effort all the way forward.
__________________
"You sea! I resign myself to you also . . . . I guess what you mean,
I behold from the beach your crooked inviting fingers,
I believe you refuse to go back without feeling of me;
We must have a turn together . . . . I undress . . . . hurry me out of sight of the land,
Cushion me soft . . . . rock me in billowy drowse,
Dash me with amorous wet . . . . I can repay you."
Walt Whitman
Dockhead is online now   Reply With Quote
Old 27-07-2019, 11:32   #137
cruiser

Join Date: Jan 2012
Location: Pangaea
Posts: 10,856
Re: Preventer Rigging -- Lessons from the Platino Disaster

Rejoining the discussion for one final comment which I feel is vital.

Please everyone... read the entire report, much can be learned about cascade events such as this regarding equipment and human behavior. Nothing can be gained by endless speculation by those who haven’t even bothered to read the entire report.

Lots of valuable insight and knowledge in the report.... its not just about preventers or who thinks they have the best preventer, many, many equipment choices and decisions lead up to the disaster.

An absolute must read. https://www.maritimenz.govt.nz/comme...eport-2016.pdf
Kenomac is offline   Reply With Quote
Old 27-07-2019, 13:51   #138
Moderator
 
Don C L's Avatar

Join Date: Sep 2014
Location: Channel Islands, CA
Boat: 1962 Columbia 29 MK 1 #37
Posts: 15,068
Images: 67
Re: Preventer Rigging -- Lessons from the Platino Disaster

Quote:
Originally Posted by Hardhead View Post
I'm sure this is also a silly question - but couldn't an attempt been made to bring the boom under control, after the preventer failed, by drawing in on the mainsheet? Or was it that the hydraulic sail controls were smashed, and therefore, with the loads of that large boat, the main sheet could not be brought in otherwise? I know the mainsheet & traveler were pulled out eventually by the free slamming, but I thought maybe an attempt would have been made to draw in the main sheet before it was ripped out. Apparently, there were enormous issues in controlling the steering of the boat as well, and that must have prevented lessening the loads on the mainsail I would imagine.
Ordinarily, yes, but I think the situation was bad enough that they couldn’t do it or didn’t think of it, before things got worse.
Some other things: bigger boats tend to engender more confidence and security than they may deserve. Running downwind never seems as dramatic as even reaching in the same conditions so we may leave too much sail up for the conditions. And APs can seem infallible, or at least reliable. Those three to me seem to play the major roles here, less so the preventer, though it was inadequate, IMhumbleO.
__________________
DL
Pythagoras
1962 Columbia 29 MKI #37
Don C L is offline   Reply With Quote
Old 27-07-2019, 14:09   #139
cruiser

Join Date: Jan 2012
Location: Pangaea
Posts: 10,856
Re: Preventer Rigging -- Lessons from the Platino Disaster

All the answers are in the report, if only everyone commenting would take some time to actually read it.

The doomed yacht was on a steady and controlled beam reach, with a partially furled main... not running with the wind behind them... in 30-35 knot wind. Nothing out of the ordinary for a 36 ton sailboat, until the hydraulic steering leak caused an auto pilot malfunction.

A classic cascade effect... It’s all in the report.
Kenomac is offline   Reply With Quote
Old 27-07-2019, 14:22   #140
Moderator
 
Don C L's Avatar

Join Date: Sep 2014
Location: Channel Islands, CA
Boat: 1962 Columbia 29 MK 1 #37
Posts: 15,068
Images: 67
Re: Preventer Rigging -- Lessons from the Platino Disaster

Executive summary claims broad reach and gusts to 48kts stated too. I did not see where it says how much of main was up, have to re-check, but jib was already partially furled . In a “confused sea” hard to know how stable and steady she was.
__________________
DL
Pythagoras
1962 Columbia 29 MKI #37
Don C L is offline   Reply With Quote
Old 27-07-2019, 14:32   #141
Registered User

Join Date: Apr 2019
Posts: 1,432
Re: Preventer Rigging -- Lessons from the Platino Disaster

Quote:
Originally Posted by Kenomac View Post

The doomed yacht was on a steady and controlled beam reach,

hmmmm....NO... "sailing downwind on a broad reach2" and the report even defines that: "2'broad reach' is a course sailed further away from the true wind than a beam reach" - more specifically 120-degree apparent wind angle (thus deeper true angle - probably more like 140) with the wind continuously backing behind the boat. It is the exact sort of conditions where a boat can be squirly in ocean-sized waves and if being driven hard with can back a mainsail even with a working autopilot.

in 30-35 knot wind. Nothing out of the ordinary.

hmmm . . . . "gust noticed had been 48 knots." So a true gale, which they had never seen anything close to in this boat before.


A classic cascade event.

Yea, true, as with most incidents; As I pointed out in post above #1 crew/owners/Skipper not taking the voyage seriously. #2 poor seamanship with sail management. #3 Really **** preventer set-up. #4 super heavy boom, difficult to control after preventer failure, which rips the mainsheet hardware out of the deck to act as a flail. #5 Crew probably in shock after deaths.

breaking wave
Breaking Waves is offline   Reply With Quote
Old 27-07-2019, 14:44   #142
Moderator
 
Don C L's Avatar

Join Date: Sep 2014
Location: Channel Islands, CA
Boat: 1962 Columbia 29 MK 1 #37
Posts: 15,068
Images: 67
Re: Preventer Rigging -- Lessons from the Platino Disaster

I’d like to hear more about the AP, and it’s upgrades, from folks who have similar AP and similar boat. It seems that AP was overwhelmed by the conditions too, likely leading to the leak of hydraulic fluid.
__________________
DL
Pythagoras
1962 Columbia 29 MKI #37
Don C L is offline   Reply With Quote
Old 27-07-2019, 15:05   #143
Registered User
 
fxykty's Avatar

Join Date: Apr 2016
Location: SE Asia, for now
Boat: Outremer 55L
Posts: 4,130
Re: Preventer Rigging -- Lessons from the Platino Disaster

Quote:
Originally Posted by Don C L View Post
I’d like to hear more about the AP, and it’s upgrades, from folks who have similar AP and similar boat. It seems that AP was overwhelmed by the conditions too, likely leading to the leak of hydraulic fluid.


Ummm, read the report. Cause of the hydraulic leak was prior to the passage.

Gust of 48 knots does not mean the conditions were full gale. They were broad reaching in 30-35 knots of wind with commensurate sea state and they were experiencing gusts of up to 50%. Normal early winter conditions on the passage north from NZ and perfectly fine.

It seems they were over powered during the gusts and were too slow to reef down (probably because reefing would have been a pain on that wind angle and they were unwilling or delaying making a turn towards the wind to reef further).

But nothing that the autopilot couldn’t handle, until it lost pressure on one side. Had the autopilot been working fine there likely would not have been any trouble.
fxykty is offline   Reply With Quote
Old 27-07-2019, 15:58   #144
Registered User

Join Date: Apr 2019
Posts: 1,432
Re: Preventer Rigging -- Lessons from the Platino Disaster

Quote:
Originally Posted by fxykty View Post
Had the autopilot been working fine there likely would not have been any trouble.
Perhaps not at that instant.

It is common in incident investigation. You can conclude that this particular incident might not have happened if this particular thing (like the autopilot) had been fixed or changed or improved. But you also have to conclude that particular thing was not, in fact, the true root cause of the incident, and something else/slightly different bad would very likely have happened.

This boat and crew were 'an accident waiting to happen'. They were going to back that mainsail sometime, and it was going to break that preventer, and the weight of the boom was then going to rip the traveler out, acting as a wrecking ball, and be very very difficult to bring under control.

As you correctly describe the conditions should not have been unanticipated. But the crew had not sailed the boat in anything like them, were not taking it seriously enough, and the boat was not adequately prepped for it.
Breaking Waves is offline   Reply With Quote
Old 27-07-2019, 16:16   #145
Registered User

Join Date: Sep 2017
Posts: 1,075
Re: Preventer Rigging -- Lessons from the Platino Disaster

Fascinating report. One has to wonder if the attitude was too casual regarding the preventer rigging, not understanding the forces.
When racing downwing on a much smaller (35ft) boat, we would sometimes use human-preventers, leaning on the boom for short legs in rolling seaas with maybe 15-20 knots. Dangerous, sure, but also maybe breeding contempt for the exponential scaling of the forces on larger boats.

These points stood out to me in the report...

Equipment:

1. preventer at very bad angle - leverage multiplied forces more than 10 times
2. insufficient (and old, history-unknown) extender line connected to the preventer pennant
3. insufficient preventer extender connection method (2 bowlines, weakening line strength by 70%)
4. autopilot hydraulic leak (not detected)- no low fluid alarm in system
5. bad hydraulic ram installation with plastic block on un-reinforced GRP that partially failed
6. undersized padeye installed by mistake- installer even noted it looked too small

Humans:

1. bad call: large main, decent winds, on super heavy boom broad reaching in very confused seas
2. too much relying on autopilot in rough conditions
3. didn't notice that the crippled autopilot system was occasionally failing to hold course at times during 3 hours before accident
4. noted the preventer angle was not ideal but assumed they had to do it that way apparently due to pennant length
5. survivors collectively very surprised that traveller gave way on crash gybe, clearly not understanding the forces involved
cyan is offline   Reply With Quote
Old 27-07-2019, 16:41   #146
Registered User

Join Date: Nov 2005
Location: Ohio
Posts: 2,939
Images: 4
Re: Preventer Rigging -- Lessons from the Platino Disaster

Haven’t posted here in a long, long time.

That said. It’s foolish to push a large boat in heavy conditions with a small crew. A sixty some foot boat in 35 true will easily sail at 12 knots with just a staysail. No reason to push the boat unless it’s fully crewed with capable sailors.
Joli is offline   Reply With Quote
Old 27-07-2019, 18:15   #147
Registered User

Join Date: Aug 2012
Location: PNW
Boat: Bruce Roberts Ketch 40
Posts: 477
Re: Preventer Rigging -- Lessons from the Platino Disaster

This is food for thought regarding my own boat and considering unimagined possibilities for disaster.
Maka is offline   Reply With Quote
Old 27-07-2019, 19:07   #148
Registered User
 
DumnMad's Avatar

Join Date: Mar 2012
Location: Nelson NZ; boat in Port Stephens, NSW.
Boat: 45ft Ketch
Posts: 1,562
Re: Preventer Rigging -- Lessons from the Platino Disaster

Quote:
Originally Posted by Kenomac View Post
Rejoining the discussion for one final comment which I feel is vital.

Please everyone... read the entire report, much can be learned about cascade events such as this regarding equipment and human behavior. Nothing can be gained by endless speculation by those who haven’t even bothered to read the entire report.

Lots of valuable insight and knowledge in the report.... its not just about preventers or who thinks they have the best preventer, many, many equipment choices and decisions lead up to the disaster.

An absolute must read. https://www.maritimenz.govt.nz/comme...eport-2016.pdf
Thanks for the insistance Ken

Tragic.
My take;
If none had left the cockpit they'd all have been OK.
Being keen helpful types they tried to get to the wheel before the danger was fully appreciated.
If the wheel was in the cockpit they would have been OK.
DumnMad is offline   Reply With Quote
Old 27-07-2019, 22:33   #149
cruiser

Join Date: Jan 2012
Location: Pangaea
Posts: 10,856
Re: Preventer Rigging -- Lessons from the Platino Disaster

Copied from previous post by Breaking waves

The doomed yacht was on a steady and controlled beam reach,

hmmmm....NO... "sailing downwind on a broad reach2" and the report even defines that: "2'broad reach' is a course sailed further away from the true wind than a beam reach" - more specifically 120-degree apparent wind angle (thus deeper true angle - probably more like 140) with the wind continuously backing behind the boat. It is the exact sort of conditions where a boat can be squirly in ocean-sized waves and if being driven hard with can back a mainsail even with a working autopilot.

in 30-35 knot wind. Nothing out of the ordinary.

hmmm . . . . "gust noticed had been 48 knots." So a true gale, which they had never seen anything close to in this boat before.


A classic cascade event.

“Yea, true, as with most incidents; As I pointed out in post above #1 crew/owners/Skipper not taking the voyage seriously. #2 poor seamanship with sail management. #3 Really **** preventer set-up. #4 super heavy boom, difficult to control after preventer failure, which rips the mainsheet hardware out of the deck to act as a flail. #5 Crew probably in shock after deaths.”


Response:

I wrote “beam reach” in error, I meant to write broad reach. Otherwise, my assesment is accurate and I completely disagree with yours. I seriously doubt you read the entire report to come to your conclusions.

Had the hydraulic steering not failed, it’s highly unlikely any of the other cascade events would have happened, and the crew would have likely continued on a nice sail. The conditions were not out of the ordinary for a 36 ton sailboat to easily handle.

One of the many lessons I’ve learned from the report is to always have someone behind the helm, which is easy to forget under seemingly controlled cirumstances.
Kenomac is offline   Reply With Quote
Old 27-07-2019, 22:47   #150
cruiser

Join Date: Jan 2012
Location: Pangaea
Posts: 10,856
Re: Preventer Rigging -- Lessons from the Platino Disaster

Quote:
Originally Posted by Don C L View Post
I’d like to hear more about the AP, and it’s upgrades, from folks who have similar AP and similar boat. It seems that AP was overwhelmed by the conditions too, likely leading to the leak of hydraulic fluid.
Don,

I have a similar 36 ton boat, hydraulic steering and similar auto pilot. I’m trying.... but nobody seems to be listening, instead only criticizing and comparing the situation to smaller sailboats and their own equipment. I’ve already previously given up twice attempting to explain myself.
Kenomac is offline   Reply With Quote
Reply

Tags
rigging

Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes Rate This Thread
Rate This Thread:

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


Similar Threads
Thread Thread Starter Forum Replies Last Post
Advise for Preventer Line Size Firehoser75 Deck hardware: Rigging, Sails & Hoisting 28 08-04-2019 08:03
Preventer Rigging? Dockhead Deck hardware: Rigging, Sails & Hoisting 133 17-02-2016 23:36
Boom Preventer landonshaw Deck hardware: Rigging, Sails & Hoisting 107 07-05-2014 21:20
Rigging a Preventer LittleBubba Seamanship & Boat Handling 1 11-04-2014 19:13
Rigging Preventer smurphny Deck hardware: Rigging, Sails & Hoisting 5 11-03-2011 07:39

Advertise Here


All times are GMT -7. The time now is 06:13.


Google+
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2024, vBulletin Solutions, Inc.
Social Knowledge Networks
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2024, vBulletin Solutions, Inc.

ShowCase vBulletin Plugins by Drive Thru Online, Inc.