Lifting Out MOB Casualty Using Life Jacket Harness

[wrwakefield]

DH-

We have been experimenting with horizontal extraction methods for the MOB. While mocking up some portable rigs for doing so, I ran across MOB Lifesavers.

They use a two point lift: the MOB's chest harness [with an extension leash on the harness lift point] and a weighted, soft sling that fits behind both knees of the MOB.

On Edit: It appears the direction of pull [DOP] on the chest harness approximates the design DOP and likely reduces the loads on the crotch/thigh straps/buckles. [We are also evaluating better buckles for the thigh straps. e.g., parachute hardware.]





They also make a leash I have long been indending to fabricate. [To facilitate connecting the lifting line from the boat to the MOB.]



I have not yet ordered MOB Lifesaver products, but intend to. [Sans the multi-part tackle...]

I believe the MOB Lifesafer sling along with a MOB net/tarp device will be the final combo for us.

Thanks for sharing your practice outcomes. May you never need to use what you have learned in anger...

Cheers! Bill

[Dockhead]

Originally Posted by wrwakefield

DH-

We have been experimenting with horizontal extraction methods for the MOB. While mocking up some portable rigs for doing so, I ran across MOB Lifesavers.

They use a two point lift: the MOB's chest harness [with an extension leash on the harness lift point] and a weighted, soft sling that fits behind both knees of the MOB.

On Edit: It appears the direction of pull [DOP] on the chest harness approximates the design DOP and likely reduces the loads on the crotch/thigh straps/buckles. [We are also evaluating better buckles for the thigh straps. e.g., parachute hardware.]





They also make a leash I have long been indending to fabricate. [To facilitate connecting the lifting line from the boat to the MOB.]



I have not yet ordered MOB Lifesaver products, but intend to. [Sans the multi-part tackle...]

I believe the MOB Lifesafer sling along with a MOB net/tarp device will be the final combo for us.

Thanks for sharing your practice outcomes. May you never need to use what you have learned in anger...

Cheers! Bill

Thanks!


That extra sling behind the knees is exactly what we were thinking of.


Maybe we'll give that a try. A simple rope loop should do it.


We'll have another session in the next days and will report.

[ZULU40]

Originally Posted by Dockhead

Thanks!


That extra sling behind the knees is exactly what we were thinking of.


Maybe we'll give that a try. A simple rope loop should do it.


We'll have another session in the next days and will report.

I can think of something you might try


Similar 2 part lift, a simple snap shackle to the PFD and a sling under the legs. In this way you prevent the victim losing the PFD over their head, and the sling stabilise the shape of the lift. I guess it depends on the strength of the existing gear which might be an unknown, but it does save on tackle and is likely quicker to organise.


Another one I remember is using a sail. For us we would have to drop the main or mizzen pulling the sail out of the mast hanks on the way down. With the halyard still attached to the head of the sail the existing gear will pull a person up. Problem is the person rolls around inside the sail on the lift, and there is no easy access for us so its up and over the lifelines.

[hpeer]

Didn’t read the whole thread.

After reviewing the Lifesling reports of folks slipping out of PFD’s we sewed some crotch straps into ours. I used 1/2” nylon rope with a snap shackle. Won’t be comfortable but better than drowning.

I’m sure there are better methods; it is what we had available.

[tstano]

Have an old sail, tie the foot to two stanchions very tightly. Hang the sail over the side and into the water with your halyard on the head. Guide your victim onto the sail and pull up the slack sail. You now have your victim inside the sail alongside of your boat and you can continue to winch him aboard just like a hotdog in a bun. Make sure you have that foot tight or you'll drop him back into the water.

[estarzinger]

just as an aside - I tested various plastic side release buckles (the normal 'para-buckles') the good brands opened at about 95lbs, the cheap brands often failed at 25lbs, and if the good ones were not fully clipped both sides they would also fail at low load (this can happen if the user is not careful).

In commercial fall protection, the buckles should be able to hold 4000lbs, and there are metal buckles which meet that standard but I am not aware of any plastic ones.

You can also meet the 4000lb standard with various Dyneema joining solutions (soft shackle or if you need tension a lashing) between sewn loops in the two web ends.

However, if you beef up this week point, the question becomes what is the breaking strength of the next week point? IDK. You could make a very good guess with a close inspection of the rest of the system. As you know these were NOT designed to lift people, they were simply designed to stop the bouncy chamber from riding up over the head.

[ZULU40]

Originally Posted by estarzinger

just as an aside - I tested various plastic side release buckles (the normal 'para-buckles') the good brands opened at about 95lbs, the cheap brands often failed at 25lbs, and if the good ones were not fully clipped both sides they would also fail at low load (this can happen if the user is not careful).

In commercial fall protection, the buckles should be able to hold 4000lbs, and there are metal buckles which meet that standard but I am not aware of any plastic ones.

You can also meet the 4000lb standard with various Dyneema joining solutions (soft shackle or if you need tension a lashing) between sewn loops in the two web ends.

However, if you beef up this week point, the question becomes what is the breaking strength of the next week point? IDK. You could make a very good guess with a close inspection of the rest of the system. As you know these were NOT designed to lift people, they were simply designed to stop the bouncy chamber from riding up over the head.

mine has a shackle point on each strap, that is each side of the buckle
Perhaps its worth looking at that

[hellosailor]

Dockhead-
If you are looking for better plastic buckles, look for the "Fastex" brand. Those clips used to be called "Fastex" fasteners, the same way we refer to cellophane tape as "Scotch" tape.
Maybe this is part of why Crewfit (UK) use *two* crotch straps.

[steve77]

Originally Posted by Dockhead

Thanks!


That extra sling behind the knees is exactly what we were thinking of.


Maybe we'll give that a try. A simple rope loop should do it.


We'll have another session in the next days and will report.

You've got me thinking that the sling for the legs is a real good idea. I'm not sure about a simple rope sling, however. I can see this being difficult to get into while in the water. The retrieval kit from MOB lifesavers is weighted, and presumably the plastic pipe holds the loop open to make it easy to get the MOB into it.

I'm not sure I will purchase this kit, but it has some good features that I'm looking at.

Cheers!

Steve

[Timethief]

I always wondered if a hammock or one of those rope swing chairs - you know, one with the wood bar across the top to keep it open left to right with what looks like a macrame nightmare for a seat - could be used with the spinnaker halyard or line on the boom to get someone aboard. The $20 two person hammock I was looking at the other day is for a 500 lb pair of people - obviously should handle more. And I get to use them for hanging out on the boat! Maybe...?

[mowerandy]

Being over the side on a tether, sure beats bobbing around in the wake on a dark night, for my money. In the first scenario there is probably a better than 10% chance of survival....

Don't use plastic slide clips for anything that matters - some are impressive, and others with break or unlock without warning - I cant tell the difference to look at them. Replace them with metal carabiners/snap shackles (the other advantage of which is that the heavier snap-shackles will be very annoying dangling around your legs if you don't connect them - haha).

I think the thing with the life-sling is that they are so simple to deploy and get into in the water, and for their purpose they have sensibly assumed that the victim will not be wearing any harness at all. Climbing into anything more complicated, while swimming for ones life, is unlikely to be possible for most, especially kids or the elderly.

Lifting gear (mine is a 4 purchase block&tackle with snap-crabs both ends) and a mermaid catcher/heaving line (50m strong line with floats & snap-links both ends) live in the cockpit when under way. The long line is to attach to yourself, when you are the only other person aboard and the person in the water needs direct assistance.

[Dockhead]

Originally Posted by estarzinger

. . . As you know these were NOT designed to lift people, they were simply designed to stop the bouncy chamber from riding up over the head.

But if we're talking about the whole system -- its design brief is NOT indeed to merely prevent the "bouncy chamber" from riding up -- it's a SAFETY HARNESS after all -- its primary function is to arrest you from being swept overboard. If it's fit for purpose for that, shouldn't it be strong enough to also lift you out? The shock loads for the arresting function are surely bigger than the static load of being lifted out. I just don't understand any of this.

[hellosailor]

timethief-
You don't need a hammock. For many years it has been taught that you can use a sail, mainly the main sail, as a sling. The sail presumably already has been dropped before the recovery. Just get it over the side (halyard still attached) and position the MOB in the sail, then winch it back up. They'll be pulled over the rail and back on deck.

Dockhead-
Aren't we/you making the rash assumption that these vests HAVE been designed as an integrated system? As I recall it, in the 80's, there were no crotch straps on PFDs or life vests in general. The inflatable vests in particular were not USCG legal until the 1990's, although the UK did allow them earlier. But I don't recall crotch straps on any of that.
The crotch straps were added later, and I suspect that most vendors did not redesign an "integrated harness" using them, but that they simply added the optional straps to keep up with what the competition was offering. Without any real "design" effort going into rethinking the product.
I don't know how many times I heard other guys say "But doesn't that, ah, you know, hurt a lot?" referring to the crotch strap I had added. I've never been hoisted by it so I don't know, but I damn well don't want to all out of the PFD if someone grabs the collar to pull me up onto a boat. (Military style grab/drag straps not having made it over to the PFD market yet, which may be a good thing since they could also be an entanglement.)
Seems like one of those 20-20 hindsight design things.

[thinwater]

Originally Posted by Dockhead

...


1. STOP THE BOAT. By any means whatsoever – every second counts.


At the same time:


2. Simultaneously, another crew cuts the tether with his knife and frees the casualty.


10 | P a g e


Then follow MOB procedure as above, as quickly as possible. The casualty will likely need mouth-to-mouth resuscitation and/or CPR.


If you fall overboard still attached to the boat and somehow have any strength or consciousness, CUT YOURSELF LOOSE IMMEDIATELY using your knife."

I seriously doubt you could convince anyone to cut the crew loose in truly stormy weather at night. Not happening. Most likely, based on history, you will not see them alive again.



Instead, clip an extension (halyard or another tether) to the tether and cut the jackline. The crew will then drift aft, where they can more easily be recovered. Just as easy.

[Dockhead]

Originally Posted by thinwater

I seriously doubt you could convince anyone to cut the crew loose in truly stormy weather at night. Not happening. Most likely, based on history, you will not see them alive again.



Instead, clip an extension (halyard or another tether) to the tether and cut the jackline. The crew will then drift aft, where they can more easily be recovered. Just as easy.

That sounds good in theory, but they will be dead long before you can get a halyard up to them and hooked on. I doubt if anyone could last even a minute being pulled face-first through the water at speed, and the cases support this idea. Something like this happens every year in UK waters, and the casualty always dies.





My crew are required to use AIS MOB beacons on deck, so that's what we would put our faith in in such a case.



Instantly cutting them loose is the ONLY chance of survival in such a case.