|
|
22-07-2021, 11:20
|
#46
|
Nearly an old salt
Join Date: Jun 2009
Location: Lefkas Marina ,Greece
Boat: Bavaria 36
Posts: 22,801
|
Maritime NZ report into the loss of the yacht Essence, October 2019
Quote:
Originally Posted by blu3534
Could be that it's only rare because normal production boats don't often encounter such stormy conditions. I suppose quite a few such boats (with big windows) would sink after having fallen down 6 meters?
Mmh..., there's something wrong with your statement or else this accident wouldn't have happened. Flexing hull, big windows, storm boards not attached (and not quickly attacheable), no watertight bulkheads to contain the leak, life-raft torn away. -- This 47 and many other boats are built to a price tag. Nothing wrong with that, but there are consequences and one shouldn't praise well built strong when it clearly was inadequate.
(Also the crew was lucky that they got a replacement life-raft and that the helicopter came so fast, otherwise they would all be dead. A huge pity that the skipper couldn't enter the life-raft, I suppose he would still live if that had been possible. Very sad!).
|
I want to buy a 47 foot yacht for under 500,000 not under 1.5 million thanks
The Ocean range I know well, that boat is considerably stronger than the cruiser range.
It is a well built boat. It met a set of circumstances I suspect very few boats would have coped with . The conclusions of the report are highly speculative so you can’t really say it was hull flexing ( it’s based on a single crew members comments after several knockdowns )
Also the report draws attention to window securing systems that don’t apply to that ocean 47
As for watertight bulkheads. That wouldn’t have saved her as her main saloon flooded, and watertight bulkheads add significant cost and very little real utility on a 47 footer
In the end a good boat foundered in quite extreme conditions largely due to a series of increasing severe knockdowns each one no doubt damaging the yacht. I would have seriously questioned the decision not to stream warps if not a series drogue . Broaching in those conditions is extremely detrimental to your survival
I doubt few production cruisers could have withstood the punishment either
__________________
Interested in smart boat technology, networking and all things tech
|
|
|
22-07-2021, 11:41
|
#47
|
Registered User
Join Date: Mar 2007
Location: Santa Cruz
Boat: SAnta Cruz 27
Posts: 7,057
|
Re: Maritime NZ report into the loss of the yacht Essence, October 2019
I don't remember the specific complaints, but I remember the owner being disappointed with his new Bavaria. He would not have agreed that it was well built, even before it sank.
|
|
|
22-07-2021, 11:43
|
#48
|
Nearly an old salt
Join Date: Jun 2009
Location: Lefkas Marina ,Greece
Boat: Bavaria 36
Posts: 22,801
|
Maritime NZ report into the loss of the yacht Essence, October 2019
Quote:
Originally Posted by donradcliffe
I don't remember the specific complaints, but I remember the owner being disappointed with his new Bavaria. He would not agree that it was well built.
|
Where is that documented given the owners felt the boat was up for the predicted storm ! As documented in the report
For a Bavaria the Ocean range was very heavily built , I think Bavaria never really built them like that again
__________________
Interested in smart boat technology, networking and all things tech
|
|
|
22-07-2021, 12:08
|
#49
|
Moderator
Join Date: Jul 2007
Boat: Bestevaer.
Posts: 15,040
|
Re: Maritime NZ report into the loss of the yacht Essence, October 2019
Quote:
Originally Posted by Hesti
The report is good reading. Maximum wave hight at the time seems to have been 6 metres or more which is beyond the 4 + metres required for A rating. Flexing is mentioned several times in the report - well beyond standard requirements, the flexing may have been significant and actual hull or deck damage may have been well possible if it hadn't already occured, for example with stiffeners starting to delaminate or the sandwich starting to delaminate, which would reduce stiffness further.
|
Cat A standard certifies vessels as suitable for "significant wave heights above 13 feet". This is to elevate the standard above that required by Cat B classified vessels where the standard has upper limit of "significant seas to 13 feet" (my emphasis).
6m waves are, not "well beyond" the standard for Cat A vessels. This sea state is within the requirments of the standard.
An alternative definition reported of the Cat A standard is “category of boats considered suitable for seas of up to 23 feet (7 meters) significant wave height and winds". I am not sure what wording was on the certificate of the boat concerned, but irrespective, there is no indication the wave height was outside the standard of the boats certification, especially as the accident report indicates that at the nearest data buoy located in shallower water (where larger waves would normally occur) the wave height reached a peak of "just over five metres".
|
|
|
22-07-2021, 13:51
|
#50
|
Registered User
Join Date: Mar 2007
Location: Santa Cruz
Boat: SAnta Cruz 27
Posts: 7,057
|
Re: Maritime NZ report into the loss of the yacht Essence, October 2019
Quote:
Originally Posted by goboatingnow
Where is that documented given the owners felt the boat was up for the predicted storm ! As documented in the report
For a Bavaria the Ocean range was very heavily built , I think Bavaria never really built them like that again
|
The vast majority of boat owners don't publicly slag the boats that they currently own unless they are really pissed off--its bad for the resale value. As I recall, Stuart felt the boat was lightly built and required several modifications before it was fit for water sailing">blue water sailing.
In my case, I made several structural changes in the bow rebuilt the rudder and mast step, and replaced the standing rigging in my then 10 year old Beneteau First 456 before I set off RTW. The previous owner had upgraded the windlass, roller furling, mast, prop, rudder bulkheads, and electrical panel. We both did blister jobs, and I later replaced the fender washers on the deck cleats with real backing plates and upgraded the traveler. The 456 was one of Beneteau's first boats of that size, and I felt the rigging and deck hardware were much sturdier than similar boats and the whole boat was better built than subsequent Beneteaus.
I still feel that the Beneteau was not built to round Cape Horn, and I'm sure that Stuart felt the same way about his Bavaria.
|
|
|
22-07-2021, 16:35
|
#51
|
Registered User
Join Date: Feb 2007
Location: Gig Harbor, WA
Boat: Tayana Vancouver 42ac
Posts: 1,232
|
Re: Maritime NZ report into the loss of the yacht Essence, October 2019
Quote:
Originally Posted by Tillsbury
https://www.maritimenz.govt.nz/comme...22July2021.pdf
Looks like Maritime NZ is looking to insist that storm boards are fitted on large (>2sqft) windows for Cat1 now. Currently it's a requirement that they have them available.
Edit: scratch that, they've already changed the regs to require them to be fitted at all times:„
- 13.11 (K) Change from: Storm coverings are required for all windows more than 1852 cm2 (2sqft) in area „
- Change to: Storm coverings shall be fitted for all windows more than 1858 cm2 in area
Also tightened up the rules regarding the strength of attachment of the liferaft if attached externally to the boat.
As usual, a reasonably thorough report and a useful read, although nothing in there that wasn't expected. The reports noted that the storm covers weren't fitted, and it was impossible to do so after the window broke because fitting the covers required a drill. Something to bear in mind when sailing in a boat with this kind of huge window...
|
Thanks for posting. It is a very interesting read we all could learn from.
I won't second guess the report findings: this boat in this configuration operated by an experienced crew did not survive a storm of this magnitude; the options do not reveal themselves.
This is not the first case I have read of a boat with an large window (portlight/deadlight) area failing. A boat with excess window area design can be problematic for offshore passages and the manufacturing speaks more of marketing than meticulous design/practicality...not many buyers will know that.
"If anything is going to happen, its going to happen out there." -- Captain Ron
~ ~ _/) ~ ~ MJH
|
|
|
22-07-2021, 17:08
|
#52
|
Registered User
Join Date: Dec 2016
Location: Somewhere in French Polynesia
Boat: Dean 440 13.4m catamaran
Posts: 2,333
|
Re: Maritime NZ report into the loss of the yacht Essence, October 2019
not sure if i am misunderstanding the math, but i question whether a window of 1852cm2 (2sqft) is exceptionally large. we have 4 windows which are 90cm x 70cm (6300cm2) and another 8 which are nearly as large
but then we are a cat and don't have the same issues with knockdowns etc that monos have...
cheers,
__________________
"home is where the anchor drops"...living onboard in French Polynesia...maintaining social distancing
|
|
|
22-07-2021, 17:37
|
#53
|
Registered User
Join Date: Feb 2018
Location: In the air or on the water
Boat: Southern Cross 39
Posts: 207
|
Re: Maritime NZ report into the loss of the yacht Essence, October 2019
Quote:
Originally Posted by chrisr
...but then we are a cat and don't have the same issues with knockdowns etc that monos have...
cheers,
|
*Repeated* knockdowns.
|
|
|
22-07-2021, 18:32
|
#54
|
Registered User
Join Date: Oct 2009
Location: australia
Boat: adams 35
Posts: 103
|
Re: Maritime NZ report into the loss of the yacht Essence, October 2019
I would have thought that if you are going to build a monocoque structure such as a moulded fibreglass boat then the shell structure should have equal strength and stiffness. If you are going to cut a hole in it for a window then the fastening of window to hull (and the strength/stiffness of the window) should be as strong as the rest of the hull As there aren't any adhesives yet with this strength it would surely make good sense to increase the hull thickness around the window so it would not be able to flex thus no longer be a structural weak point.
Having addressed that weakness the next thing is the bonding. On an ocean going vessel the window needs to have a system which is both leak proof and mechanically sound. Windows being blown out shouldn't surprise anyone. Obviously the pressure of a breaking wave is massive, but so is the suction on the other side , or as in this case the internal pressure caused by the open hatch. Windows need to be held mechanically on both sides. If you are going to go into severe conditions, which 90% of us almost certainly never will, you need to have a boat without weak points. which large glued windows in flexible hulls certainly are.
|
|
|
22-07-2021, 19:27
|
#55
|
Registered User
Join Date: Feb 2015
Boat: Land bound, previously Morgan 462
Posts: 1,994
|
Re: Maritime NZ report into the loss of the yacht Essence, October 2019
Two thoughts: if there had been storm covers in place, they might have prevented a blowout. The installed port would have to not only break out of it's mounting, it would also have to push outward against the storm cover. Through bolting the storm cover, although it sounds rather drastic, might be required for ultimate protection.
Secondly, if the root cause of failure was losing the main hatch, keeping it in place and unbroken might have prevented the portlight blowouts. So a heavy hatch storm cover, through bolted well, might have prevented this kind of failure where the portlights blew out.
Any comments that the regulations for highest level certification might include storm covers for hatches as well as portlights?
__________________
No shirt, no shoes, no problem!
|
|
|
22-07-2021, 21:28
|
#56
|
Moderator
Join Date: May 2008
Location: cruising SW Pacific
Boat: Jon Sayer 1-off 46 ft fract rig sloop strip plank in W Red Cedar
Posts: 21,434
|
Re: Maritime NZ report into the loss of the yacht Essence, October 2019
Quote:
Any comments that the regulations for highest level certification might include storm covers for hatches as well as portlights?
_
|
In many vessels of this size the foredeck hatch is the only emergency exit forward of the companionway. Might think twice about rendering it inoperable with a storm cover.
Jim
__________________
Jim and Ann s/v Insatiable II, lying Port Cygnet Tasmania once again.
|
|
|
22-07-2021, 21:37
|
#57
|
Registered User
Join Date: Mar 2018
Location: New Zealand
Boat: 50’ Bavaria
Posts: 1,816
|
Re: Maritime NZ report into the loss of the yacht Essence, October 2019
Quote:
Originally Posted by Jim Cate
In many vessels of this size the foredeck hatch is the only emergency exit forward of the companionway. Might think twice about rendering it inoperable with a storm cover.
Jim
|
Good point Jim, but it looks like the regs now state that it must have one fitted if it's over 43cm square. Would be interesting to double check the definition of "window" in the regs
|
|
|
22-07-2021, 22:25
|
#58
|
Registered User
Join Date: Jul 2018
Location: NZL - Currently Run Aground Ashore..
Boat: Sail & Power for over 35 years, experience cruising the Eastern Caribbean, Western Med, and more
Posts: 2,129
|
Re: Maritime NZ report into the loss of the yacht Essence, October 2019
Quote:
Originally Posted by goboatingnow
I think it’s very difficult to use storm boards attached by a few drilled fittings to prevent a window from blowing outwards. Most likely the storm board attachments would pull out of the hull
For this to be effective would require the storm boards to have integrated backing pads in the grp etc
|
Well, of course. A few self tapping screws sure won't be sufficient. The only time I've seen that is when Florida homeowners put up some plywood in advance of a hurricane.
Normally proper storm board / storm shutter attachments are threaded holes that are part of the structure of the boat, and that accept machine screws. NB: be sure to use spring washers, loctite, or similar, as well as padding in between to prevent scuffs and scratches (well executed this can provide an additional water resistant seal too).
So structurally they should not much different to a winch mount, a headsail track, etc, none of which you expect to come flying off, even under extreme load.
As I have mentioned in other threads before, production yachts should just have them built in as standard since it's pretty easy to do as part of the normal construction.
For those concerned about appearances small plugs or trim can be fitted to tidy up the looks when not in use.
|
|
|
23-07-2021, 00:53
|
#59
|
Nearly an old salt
Join Date: Jun 2009
Location: Lefkas Marina ,Greece
Boat: Bavaria 36
Posts: 22,801
|
Maritime NZ report into the loss of the yacht Essence, October 2019
I think there are several interesting observations and they need to be asked even if unfortunately the skipper is sadly not around to enlighten us . Some of these were alluded to in the report
Why set off into a known storm the comment was made that the owners were comfortable that the boat could handle it. This seems strange in the light of comments on this thread
Secondly why try and run for cover bringing you into coastal waters and likely more violent wave action
Why no attempt to stream warps or a drogue. Why was that option, in the opinion of the remaining crew “ too dangerous “ and this on the face of repeated knockdowns. In my experience you must stop repeated knockdowns or you’ll loose the boat.
I experienced 90 knockdowns and they put tremendous strains on gear , interior fittings , mast , hull etc.
Why were the boards not fitted to the windows. Surely this is exactly why you have then. Storm boards on a locker are rather useless.
If you are experiencing repeated knockdowns surely it’s imperative to change tactics. In my opinion you are simply rolling die and eventually your numbers will come up.
I remain somewhat perplexed as to why certain decisions were taken or not taken. I appreciate we are not going to hear answer from the crew but it worth debating
For me it way too easy to blame the boat and smirk and walk away . Whether we like it or not these types of boats are crossing oceans and we need to discuss how to do it safely
Going on about RCD or classification societies is missing the point completely. There’s no indication these would have saved the boat.
__________________
Interested in smart boat technology, networking and all things tech
|
|
|
23-07-2021, 02:25
|
#60
|
Registered User
Join Date: Mar 2014
Posts: 987
|
Re: Maritime NZ report into the loss of the yacht Essence, October 2019
Quote:
Originally Posted by goboatingnow
I experienced 90 knockdowns and they put tremendous strains on gear , interior fittings , mast , hull etc.
|
Isn't that a bit much? Don't you consult MET forecasts? And/or respect good passage weather? Must be a dangerous area where you sail.
Considering that you talked about warps and drogues, why didn't / couldn't this prevent the 90 knockdowns? I would have thought, that your argument is, that Essence should have used these means to forgo (further) knockdowns.
But this is off-topic. One of the conclusions of the report is:
Quote:
Had storm coverings been in place, it is likely Essence would not have foundered
|
This is in contrast to waht you write: "For me it way too easy to blame the boat and smirk and walk away [snip] Going on about RCD or classification societies is missing the point completely. There’s no indication these would have saved the boat. "
|
|
|
|
|
Thread Tools |
Search this Thread |
|
|
Display Modes |
Rate This Thread |
Linear Mode
|
|
Posting Rules
|
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts
HTML code is Off
|
|
|
|
Advertise Here
Recent Discussions |
|
|
|
|
|
|
|
|
|
|
|
|
Vendor Spotlight |
|
|
|
|
|