Lifelines -- standards

[sailingharry]

So had a discussion with a fellow sailor this weekend.


I'm a fierce believer in standards. At the very least, I read them and consider them. I don't always follow them, but I do try. My view is that you can learn a lot of stuff through the school of hard knocks, you can make up a lot of stuff through common sense and observations, and you can get a lot of advice from like-minded individuals. But none of those give you the wisdom of a body of folks who look at actual incidents, look at actual forces/construction details/etc, and other focused consideration, that takes a great deal of time and resources to gather.


For example, what is a reasonable strength for a lifeline? How would you measure it? How many failures from actual incidents have you looked at, and assessed the materials and dimensions used? Few, if any, of us could dream up that sort of criteria.


I firmly believe in the efforts of ABYC. I equally believe in the efforts of World Sailing (the current name of the international racing organization) and the Offshore Special Regs.


So, what is this all about? We were talking about lifelines, and standards (height, strength, spacing, materials, etc) and I opined that lacking a "cruisers standard" I turn to the Special Regs as my baseline standard. She said "but what about ABYC?" uhhh...yeah.... uhhh....


So I pulled them up today. My copy of H-41 is July 22, so probably very close to current. To their credit, they do in some cases allow systems meeting the Special Regs as "exceptions" to ABYC standards, a position that I think is very accommodating and reasonable.


But to my dismay, there is ZERO discussion of materials or dimensions. In a way, this is good (the idea of "Performance Specs" vs "Prescriptive Specs."). But, their implementation is embarrassing. Their sole criteria is "take a 400lb static load without deforming or failing." Really? First, a 200lb crew member falling 4 feet to leward in a wave is WAY beyond 400lb. There is NO discussion about dyneema, or vinyl coated lifelines, or chafe protection, or maximum deflection, or any of the host of stuff that the Special Regs cover.


I'm just venting. I'm flabbergasted. ABYC is normally fairly thorough, but while they have just announced a revision on CNG systems (is any manufacturer still offering those?) they have all but ignored one of the most critical safety sytems.


Vent over....

[JPA Cate]

One way is to look for commercial venture lifeline standards here in Australia. Their lifelines are 3, not 2, and come up much higher on the legs than the American ones. Required for chartered boats, too. So, go world wide and see what other folks' governing bodies have come to.
Ann

[sailingharry]

Originally Posted by JPA Cate

One way is to look for commercial venture lifeline standards here in Australia. Their lifelines are 3, not 2, and come up much higher on the legs than the American ones. Required for chartered boats, too. So, go world wide and see what other folks' governing bodies have come to.
Ann

That is indeed another standard to look at -- and exactly my point about the value of standards.


I'm just amazed at the granddaddy of marine standards (with my American focused view of the world) completely ignoring the matter.


Oh... our boat is a North American boat (Canada, actually) and we have become so accustomed to our 30" lifelines that we feel insecure on almost any other boat we get on (Special Regs and ABYC require 24", which is about perfect to have you enter the water head first).

[rslifkin]

I agree with the comment on 24" vs 30" lifelines. I've got 30" ones on my boat and that's just high enough to use them as a handhold. 24" lifelines feel like a joke to me.

On top of that, mine are only along my side decks next to the deckhouse (powerboat), the bow and stern areas are solid rail. So the areas the have lifelines aren't somewhere that you could fall any distance against them as you're in a fairly narrow space next to them. On a sailboat, required strength would be higher, yet most sailboats I see have stanchions spaced much further apart than mine and lifelines no stronger than mine (mine are 3/16" stainless with a coating, at some point I'll switch to 5/16" bare stainless but all of the hardware needs to be changed for that).

[sailingharry]

Originally Posted by rslifkin

(mine are 3/16" stainless with a coating, at some point I'll switch to 5/16" bare stainless but all of the hardware needs to be changed for that).

That is an obvious upgrade -- except for the "gotcha." On sailboats, at least, where you have to pass through the stanchions, the fittings for the thicker wire won't fit through the holes. Yours might, but you need to look REALLY close. One solution is to take the stanchions with you, and have the fittings put on after running through the holes.

[rslifkin]

Originally Posted by sailingharry

That is an obvious upgrade -- except for the "gotcha." On sailboats, at least, where you have to pass through the stanchions, the fittings for the thicker wire won't fit through the holes. Yours might, but you need to look REALLY close. One solution is to take the stanchions with you, and have the fittings put on after running through the holes.

That's a good point. Even the current fittings won't pass through, so when I re-did the lifelines the last time I just bought a hand swaging tool and crimped them in place.

[sailingharry]

Double post....

[Dusty Mac]

Racers use the Offshore Special Regulations which outline lifeline specs for different conditions.

3.14 Pulpits, Stanchions, Lifelines
** 3.14.1 The perimeter of the deck surrounded by system of lifelines and pulpits as
follows:
** a) Continuous lifelines fixed only at (or near) the bow and stern. However a gate
on each side of a boat is permitted. Except at its end fittings and at gates, the
movement of a lifeline in a fore-and-aft direction shall not be constrained.
Temporary sleeving shall not modify tension in the lifeline.
** b) Minimum heights of lifelines and pulpit rails above the working deck and
vertical openings:
** i upper: 600 mm (24”)
** ii intermediate: 230 mm (9”)
** iii vertical opening: no greater than 380 mm (15”) except that on a boat with a
Primary Launch before 1993 where it shall be no greater than 560 mm (22”)
MoMu3,4 iv a boat less than 8.5 m (28’) LH may use a single lifeline system with a height
between 450 mm (18”) and 560 mm (22”)
** c) Lifelines permanently supported at intervals of not more than 2.2 m (7'-2 1/2”)
and shall not pass outboard of supporting stanchions
** d) Pulpit and stanchion bases permanently installed with pulpits and stanchions
mechanically retained in their bases
** e) The outside of pulpit and stanchion base tubes no further inboard from the
edge of the working deck than 5% of maximum beam or 150 mm (6”),
whichever is greater, nor further outboard than the edge of the working deck
** f) Stanchions straight and vertical except that:
** i within the first 50 mm (2”) from the deck, stanchions shall not be displaced
horizontally from the point at which they emerge from the deck or stanchion
base by more than 10 mm (3/8”)
** ii stanchions may be angled to not more than 10° from vertical at any point
Page 12
above 50 mm (2”) from the deck
** g) A bow pulpit may be open provided the opening between the pulpit and any
part of the boat does not exceed 360 mm (14”)
**
Figure 2 - Diagram Showing Pulpit Opening
** h) Lifelines may terminate at or pass through adequately braced stanchions set
inside and overlapping the bow pulpit
** i) When a deflecting force of 4 kg (8.8 #) is applied to a lifeline at the mid-point
of the longest span between supports that are aft of the mast, the deflection
shall not exceed:
** i 50 mm (2”) for an upper or single lifeline
** ii 120 mm (4 ¾”) for an intermediate lifeline
3.14.2 Special Requirements for Pulpits, Stanchions, Lifelines on Multihulls
Mu0,1,2,3,4 a) When on a boat it is impractical to precisely follow OSR regarding pulpits,
stanchions, lifelines, the regulations for monohulls shall be followed as closely
as possible
3.14.3 Spare number
3.14.4 Spare number
3,14.5 Spare number
3.14.6 Lifeline Specifications
Mo0,1,2,3 a) Lifelines of stranded stainless steel wire
Mo4Mu** a) Lifelines of either:
Mo4Mu** i stranded stainless steel wire
Mo4Mu** ii HMPE
** b) The minimum diameter is specified in table 8 below
** c) Stainless steel lifelines shall be uncoated and used without close-fitting
sleeving, however, temporary sleeving may be fitted provided it is regularly
removed for inspection.
** d) A lanyard of synthetic rope may be used to secure lifelines provided the gap it
closes does not exceed 100 mm (4”). This lanyard shall be replaced annually
** e) All components of the lifeline enclosure system shall have a breaking strength
no less than the lifeline
Mo4Mu** f) When HMPE is used, it shall be protected from chafe and spliced in accordance
with the manufacturer’s recommended procedures
** Table 8
LH Wire Min.
lifeline diameter
HMPE rope (Single
braid) min. lifeline
diameter
HMPE Core (Braid on
braid) min. lifeline
diameter
under
8.5m (28')
3mm (1/8") 4mm (5/32") 4mm (5/32")
8.5m -
13m
4mm (5/32") 5mm (3/16") 5mm (3/16")
Page 13
over 13m
(42' 8")
5mm (3/16") 5mm (3/16") 5mm (3/16")
3.15 Multihull Nets or Trampolines
Mu0,1,2,3,4 3.15.1 The words "net" and "trampoline" are interchangeable. A net shall be:
Mu0,1,2,3,4 a) essentially horizontal
Mu0,1,2,3,4 b) made from durable woven webbing, water permeable fabric, or mesh with
openings not larger than 5 cm (2”) in any dimension. Attachment points shall
be planned to avoid chafe. The junction between a net and a boat shall present
no risk of foot trapping
Mu0,1,2,3,4 c) solidly fixed at regular intervals on transverse and longitudinal support lines
and shall be fine-stitched to a bolt rope
Mu0,1,2,3,4 d) able to carry the full weight of the crew either in normal working conditions at
sea or in case of capsize when the boat is inverted.
3.15.2 Trimarans with Double Crossbeams
A trimaran with double crossbeams shall have nets on each side covering:
Mu0,1,2,3,4 a) the area formed by the crossbeams, central hull and outriggers
Mu0,1,2,3,4 b) the triangles formed by the aft end of the central pulpit, the mid-point of each
forward crossbeam, and the intersection of the crossbeam and the central hull
Mu0,1,2,3,4 c) the triangles formed by the aftermost part of the cockpit or steering position
(whichever is furthest aft), the mid-point of each after crossbeam, and the
intersection of the crossbeam and the central hull; except that:-
Mu0,1,2,3,4 d) OSR 3.15.2(c) is not a requirement when cockpit coamings and/or lifelines are
present which comply with the minimum height requirements in OSR 3.14
3.15.3 Trimarans with Single Crossbeams
Mu0,1,2,3,4 A trimaran with a single crossbeam shall have nets between the central hull
and each outrigger on each side between two straight lines from the
intersection of the crossbeam and the outrigger, respectively to the aft end of
the pulpit on the central hull, and to the aftermost point of the cockpit or
steering position on the central hull (whichever is furthest aft)
3.16 Catamarans
Mu0,1,2,3,4 3.16.1 A catamaran shall have nets covering the area defined:
Mu0,1,2,3,4 3.16.1
a)
laterally by the hulls; and
Mu0,1,2,3,4 3.16.2
b)
longitudinally by transverse stations through the forestay base, and the
aftermost point of the boom lying fore and aft. However, a catamaran with a
central nacelle (non-immersed) may satisfy the regulations for a trimaran
3.17 Toe Rail or Foot - Stop
Mo0,1,2,3 3.17.1 Permanently installed toe rail of minimum height 25 mm (1”), located as close
as practicable to the stanchion bases, around the foredeck from abreast the
mast
Mo0,1,2,3 3.17.2 An additional lifeline of between 25-50 mm (1-2”) high is permitted in lieu of a
toe rail on a boat with Primary Launch before 1984.

The full rules can be found here: https://www.sailing.org/tools/docume...ons20222023v2-[27823].pdf

Hope this helps.

[GordMay]

IMHO: Even a 30" high lifeline will provide minimum overboard fall prevention.

FWIW: CSA Standard Z797-18 Code load bearing and height requirements for scaffold* guardrails:
A top rail must be at least 0.9 metres [35 Inches] but not more than 1.1 metres [43"] above the surface of the platform*.
* Scaffold platforms are very stable work surfaces, compared to boast decks.

[thinwater]

For comparison to ABYC, read OSHA guardrail standards, 29 CFR 1929.29.


Like the ABYC standard there are only minimal discussions of materials, mostly materials. The strength requirement is only 200 pounds down or sideways, regardless of the height above the ground (fatal fall) (which does not compare dirrectly to the World Sailing method).


Same with grab handles 200 pounds.

[Benz]

This is where you can use a little imagination to achieve what you want without being a slave to someone else's arbitrary standards.
Ask yourself: "What do I want my lifelines to do?" and go from there.
If you want them to catch a body hurled from across the deck, you'll need closely spaced line/wires, and stanchions strong enough to take that load.
If you want them to steady you as you wobble forward in a lumpy sea, hunched over and clipped in (to something more centerline than a lifeline), you can get away with less.
If you want them simply to create a visual/tactile border for the edge of the boat (what most seem to be good for), you can get away with even less.
If you want them to contain small dogs and toddlers, you might want netting as well.

The wooden stanchions on my boat are extensions of the bulwark structure, and are strong enough to stand on (I often do, just to steady myself with the other foot on the cabintop), or wrap a dockline 'round for a quick brake. The lifelines are low, since I don't rely on them to keep me aboard, but are highly-tensioned 3/8" Dyneema, so they don't flop when I do grab them. Best of all, they fit the look and function of my boat, since I didn't go looking for someone else's standards when I made them--like the rest of the boat, I designed what met my criteria, and the whole is an expression of my idea of aesthetic and function.
Certainly you can look at others' boats for ideas: most designs don't happen in a vaccuum, but don't regret the chance to design and build something to your own taste.

[thinwater]

Originally Posted by Benz

This is where you can use a little imagination to achieve what you want without being a slave to someone else's arbitrary standards....

Standards can be a bit prescriptive, but they have the major advantage of being based upon a very large pool of experience. I used to work on several standards organization within the oil and refining business, and there were many standards that seemed pointlessly expensive, until you read the history of why it came to be. Often someone died. Taking this back to the topic at hand....


Tethers. They must hold a certain force but they must also pass a very specific drop test. Why? A number of cases where non-stretch tethers generated enormous impact forces and either failed or broke ribs. In both cases people died. Now they are safer.


The clip standard did not require a side load test. A clip failed under body weight, leading to a fatality. He was hanging over the rail from the clip, then it twisted and failed. The side load standard existed, but was only applied to climbing gear. Now we use via ferrata clips instead of Spinlock Race clips.


Jacklines are a specific strength because if they are any weaker they fail. Yes, there have been a few failures. Lifelines are the safe strength because, unsurprisingly, the force on a lifeline catching a body and a jackline are similar (horizontal fall plus wave force).



---


That said, your comments on thinking about the purpose are dead on.



Lets take that back to home. The railings on decks used to be horizontal. Now they have to be vertical so that little ones will not climb them. There is a maximum spacing (about 3.5 inches I think) so that little ones cannot squeeze between them. It sounds obvious in retrospect, but it wasn't.


This goes on and on with all sorts of things related to mechanical and electrical codes. Some you might figure out, but some you would miss. I would not want to live in a house built by common sense. In fact, the common sense builder will be drawing from codes (the components he buys and the things he has seen) whether he knows it or not.


---


Or as the saying goes, good judgement comes from experience, and experiences come from poor judgment. Same with standards.

[barnakiel]

Ours are mostly set up so that there is somewhere to hang the laundry.


Where I grew up sailing, boats had no lifelines. There were few accidents, as boats were sailed by sailors and fishermen, and not by many lay people.


My attitude today is to be be anal about my leash and consider lifelines more of a decorative value than a security element.


b.

[sailingharry]

Originally Posted by thinwater

This goes on and on with all sorts of things related to mechanical and electrical codes. Some you might figure out, but some you would miss.

I am engineer. Mechanical, but an engineer is an engineer -- we all have somewhat broken brains. In the late 80's, I came across a book called "The NEC Handbook." It contains the entire text of the National Electric Code (NEC). But heavily drizzled across the text of the code were many explanations of why the code was written the way it was. Fascinating stuff! I literally read it cover to cover. And then re-read the most gripping portions again. Michener will put me to sleep -- but the NEC Handbook I can't put down. Yeah, I'm an engineer.....

[HankOnthewater]

Hi Sailingharry, hmmm, I am not an engineer, although studied electronic engineering, did not complete that. Does that count?

I agree with the above posts that handrailing or lifelines on most boats are way too flimsy and/or too low. The requirement in Oz for commercial vessels is 800 mm (that is approx 32") for boats under 16 metres, and 100 mm (40") for larger boats.
https://www.amsa.gov.au/sites/defaul...ted-yellow.pdf
Hmmm, I thought it was 900 mm.......

I never really measured the height on my boat, but would be around 2600 mm/24"... too low. Would love to redo my handrailing, but that exercise would cost me too much (it is already solid handrail).