Life Raft siting on transom rail any Pros or Cons

[sailingrbg]

Can anyone advise on the following, I currently have a valise Life raft but due to the fact that I keep it down below on a 27' yacht it does take up a bit of space, to this end I am considering going for a canister type and to mount this on the transom stainless steel rail, my questions are as follows

1. While the transom rail looks quite substantial how do I know if it would take the weight of a canister life raft @ about 30Kg

2. With the outboard engine 13.5kg and the life raft @ 30Kg on the other side over the rear stern does this mean that I will have to compensate for additional weight in the bow in the from of added chain

3. I notice that sometimes when motor / sailing that the exhaust outlet is sometimes beneath the water my main concern is that placing this additional weight right at the rear may mean the exhaust outlet could be much nearer waterline or partially submerged, would this constitute any problems?


Any thought or suggestions gratefully received

 

[ChrisE]

Regarding 1, you might like to consider what we did which was to have a couple of legs made for the cage that bolted onto the transom. The legs take the weight of the cage and l/r.

Regarding 2, I would be disinclined to put more chain up the front as weight either end will cause your boat to hobbyhorse in a sea. We reduced our chain from 100m to 30m to reduce this effect.

Regarding 3, I'm no expert but our exhaust is under the water more than it is above and the engine doesn't seem to suffer from it.

 

[jamesjermain]

I concur with Chris. The balance that has to be struck is between speed of deployment, space below decks and balance of the boat.

To be honest, on a 27 footer I thnk the weight on the transom added to the weight of the outboard is going to be bad for performance and sseakindliness. Adding extra weight to the bows would only make maters worse.

This might be an acceptable sacrifice if there were no alternative place for the raft. How much space do you have on your coachroof? A simple wooden cradle, or even four eye bolts would be enough to secure the raft on deck where its weight would be neutral and you could heave it over the side quickly. If the raft was to be permanently mounted there it would need to be in a canister because a valise would take in water with time.

 

[Bajansailor]

Is 44 kg on the stern really going to have such a significant effect on performance and seakindliness? This is the same weight as one rather small crew member sitting in an aft corner of the cockpit.
I think that the weight of a typical crew complement (say 3 people at 65 kg each) sitting in the cockpit while sailing will have a much more profound effect.

I do agree absolutely though about not adding weight in the bow to compensate - bad news! Our boat had 5m of large stud link anchor chain lurking in the bottom of the anchor locker when we acquired her - I could only assume that this was to 'balance' the weight of the diesel genny shoehorned into the aft peak locker. Generator was flogged off, solar panel acquired instead, and the studlink chain was put to useful service as part of the mooring.

Just being pedantic, which will have more overall effect (eg from a stability point of view) - having the liferaft canister relatively low down but on the transom, or relatively high up on the coachroof amidships?

 

[Stemar]

I'm not adventurous enough for it to be an issue for me, but I've heard a number of well-documented tales of liferafts on transom mounts suddenly not being there any more when it gets really nasty, just when you're most likely to need a raft. If you think you're ever likely to be out in such conditions, could you find room in a cockpit locker? It would still be easily accessible, but less vulnerable to a pooping.

 

[flaming]

I once saw a photo of a boat which had been dismasted in heavy seas. The family crew were then forced to work very hard to cut the rigging free and patch the sizeable hole in the hull as the mast had fallen on the pushpit and smashed the liferaft into the sea, where it had inflated amid a tangle of broken rigging and been punctured.

One incident admitedly, but I've always been nervous of pushpit mounted life raft stowage ever since!

I don't however think that there is a magic answer of where to mount the liferaft. For any given location there will be horror stories of people who couldn't get at it when they needed it.

But the performance issue is an interesting one. At 27 feet you are likely to hobby horse and pitch quite dratically anyway when punching into a nasty head sea. Anything that enhances that cannot be ideal. And definitely do not add weight to the bow!

 

[Phoenix of Hamble]

As I sail regularly with the family, I discounted the coach roof mount, as with the weight of a typical liferaft, I seriously doubt SWMBO would be able to pick it up and throw it over the side.... and certainly my kids wouldn't be able to.

Mine is on the transom rail.... admittedly, a bit bigger than 27', but in my mind the only viable option for a family crewed boat....

I tie the painter to the boat, so that in the event of the liferaft being swept off the rail by a wave or the rail being taken away itself, then it will still be with the boat.... I also have a hydrostatic release to be fitted shortly....

My youngest also likes to helm as much as he can... he's only little, and as it is struggles to see over the companionway.... a liferaft on the coachroof would spoil his forward view yet further, and make him less likely to be either safe on the helm, or in the worst case, willing to take the helm to start with...

Also, looking at pictures of dismasted boats, then very often the coachroof is a tangled mess, and I fear accessibility of the liferaft...

Finally, and not a major justification, but none the less relevant, the coach roof is popular sunbathing space....

 

[Phoenix of Hamble]

One other point, highlighted to me as part of the RNLI sea safety check (well worth doing), is to make sure that the cannister is mounted on the rail with the gas cylinder at the bottom... the cylinder forms a substantial percentage of the overall weight of the assembly...

Not only does it prevent the liferaft sitting with the weight of its cannister on top of it between service intervals, but also significantly reduces the turning moment forces involved by keeping the weight low down, and hence less stress on the rail

 

[matt1]

I can no longer find the MAIB report on the Beneteau which lost a liferaft when it was washed off the Pushpit, but there was a comprehensive and scary report on there some time ago! Since reading that and having personally been pooped by a wave off Finistere I would not fit a liferaft to the transom/pushpit. Also on modern boats the pushpits look quite flimsy and thin

 

[Phoenix of Hamble]

IMHO, a case of balancing risks..... far more likely to have the rigging fail, than have the pushpit washed away.....

And secondly, the chances of a liferfat being washed away by being pooped are IMHO far far less than the chances of a big green one over the bows washing a coachroof mounted liferaft away....

 

[photodog]

We just did the same thing, removed our liferaft from the locker and I went through the same process as everyone else has commented on!!

It would have been cheaper to put it on the pushpit, but I was very keen to get the boats balance right, and have been trying to get weight out of the ends to this effect....Dont underestimate the effect a load of weight on the stern in a smaller boat will have on balance!

(It allows me to continue to feed my burgoining waist line without being detrimental to SOG.)

Just getting it on deck is a big safety improvement, and I think that the coachroof was on balance a better spot for us, but you need to look at the design of your boat and have a good think about how difficult it would be to launch from the coachroof, versus the stern. (Were would you rather board the raft from?)

As a aside I traded mine in, and including the £780 liferaft, very tidy looking liferaft cradle, installation, cost was £600 (old raft only cost £480 and needed a service next year.)
As the service next year would have been about £175 or so I figure, the actual upgrade cost was only about £200 (Not including the mounting etc) and its in theory a better raft...

Boatenomics in action.

 

[Robin]

[ QUOTE ]
And secondly, the chances of a liferfat being washed away by being pooped are IMHO far far less than the chances of a big green one over the bows washing a coachroof mounted liferaft away....

[/ QUOTE ]

Absolutely. I've been pooped but once in 35 years and then in a small boat and it did no damage. I've had solid water over the coachroof and solid waves breaking over it in bad weather in many boats many times over the years. I have never lost a mast either, but if it did go, we have a very solid stern gantry that would protect the raft anyway!

Our raft is in a vertically mounted pushpit cradle and could be released instantly by the weakest of crew one handed if needs be. I wouldn't put it there perhaps on a really small boat especially a narrow sterned one but I would still worry about it being on the coachroof, even if I thought SWMBO could launch it from there over the rails if push came to abandon ship.

 

[sailingrbg]

Thanks to all that contributed

You have all given me some food for thought. I have noticed that my lightweight frame (NOT) when siting at the rear of the cockpit with a few others on board find that the engine exhaust outlet is under the water and I probably weigh at least 3 liferafts (+). I do not notice any significant performance problems (all be it at 27' it is not a blue water fast yacht) .
While there is probably room on the coach roof mounting it there would dramatically reduce visibility forward for SHMBO when on the helm, is there anyway of finding out whether the existing rail will take the additional weight?.
My yacht is a Leisure 27 and as such while now over 28 years old is pretty substantially built. Additionally I currently have 25m of chain along with the same in warp but perhaps for the West Coast of Scotland more chain may be advantageous in the bows?


Many thanks Again for all contributions

 

[Robin]

Most pushpit rails are made from the same size tubing anyway I believe.

As far as weight up front is concerned or weight in the ends I don't think it is always a problem or if it were is noticeable on a cruising as opposed to race boat. Years ago I owned a Trident 24 which had a skinny back end (a full compliment of drinkers in the cockpit would have the drains putting water back) yet I added a brick sized chunk of lead ingot up in the bilge in the bows which significantly improved the upwind performance. The Trident also carried a 25lb CQR and 25m of chain. Mind you it probably only balanced the excess carried back aft by the skipper. 25m of chain is probably a normal length but we carried double that on our last boat (W33 and heavy) AND went up a size to 10mm as well without a noticeable problem. Our current boat carries 60m of 10mm chain up front which allows all chain rode in pretty well any depth/weather we care to anchor in, even though we do have another 50m of anchorplait as well.

 

[matt1]

hmmm, Can you put it in the cockpit well with a grating or the like over the top?

Personally I like the idea that it is fixed to the structure of the boat with nice big backing plates, rather than bolted to metalwork. Almost certainly when your boat was designed the designer and the maker of the Pushpit would never have designed things thinking a 30-40kg liferaft would be fitted to them in the future. That's not to say it's not strong enough, though. FWIW I was in a 43' oceanis (the same sort that was rolled in Biscay and lost it's liferaft) and in fairness there was no great damage but I'm sure that if we had a liferaft on the rail it would have taken the brunt of the force of the wave. If you want to see what happens to pushpits and stanchions, look at the pictures of the Fastnet aftermarth - many bent just under the force of waves (without having anything fitted to them). Also take a look at the liferaft cradle itself - how strong is it? does it have hinged joints etc.

I wouldn't be overly concerned about ease of launching - on the basis that I only ever plan to step into or upto the liferaft rather than down to it from the deck!