survival boat

Some further thoughts on the design mechanics of a flotation collar. If inflatiable it would have to withstand far greater plunging stress loads than the tube shaped sides of a life raft. A plunging collar has to carry a great percentage of the weight (moments) of the dingy plus occupants. Other than a mesh(net) co-coon type fastening system I see nothing else that would have some cushioning (give) effect to reduce the stress of where it is fastened to the dingy. Rigid mechanical fasteners would be under great stress and very subject to literally being ripped off. Even if a mesh co-coon were used the mesh knots would have a tendancy to chafe the rubberized coating on the floatation tube.So this possibly leaves only one reliable solution as mentioned above that the floatation be encased, and a flare shaped under profile to shock absorb the plunging craft and it's cargo. Possibly constructed from closed cell foam encased with a thin layer of kevlar reinforced resin(weight saving) and fastened by formed flanges using a combo of mechanical as well as glassed into the hull sides and gunnels. The other problem here is, a rigid collar adds volume to the craft and takes up valuable deck space on smaller mother ships. Towing is not a good option as towed dingys has shown a low surviveability rate in storms. However if the mother ship can warrant the stowage space a lifeboat containing a life raft would be a nice option.

 

Actually, like escaping fire, it is better to have several options. Yes, a dingy, a raft, suit, life vest, floats. When shiitt happens you go for whatever is closes to you and jump. When the ship sinks hopefully everything else floats to the top and you gather your stuff. And make sure your dingy or raft is not tied to boat too well. When in a hurry to get off boat, especially in a gasoline boat, you don't have time to launch anything. That is why mothership should be properly equipped with bilge pumps, fire sprinklers, and stuff to plug holes, etc...

 

In addition to my post above As Michael has pointed out is the very very important hypothermia factor. This warrants a sturdy tent like structure with superstrong zippers and snaps. The ideal frame I think would be a simple set up of off the shelf fiberglass rods simply formed into an arch and locked into receiver holes in the gunnels. The other important item(s) would be a couple of high volume permanently installed manual whale pumps plus a small watermaker. Since this is a rigid craft anyone have any ideas on a simple safe heating system--might as well go for the works since we're this far into a survival machine.

 

Great info....and Viking, I would think my heating system would need to be geared toward the most likely cold weather/waters to be used. It would be unnecessary and overkill to carry diesel heater suitable for artic conditions if the worst you'd ever get caught in would be a winter off the Carolinas.

A tent structure, there is an insulated material used in camper tops that is two layers of material with a snadwich of insulation. It would certainly be bulkier than a single layer, but it may be worth it. A clear top with a second darker interior layer might help with some solar gains and sufficient for mild cold weather.

Doesn't the interior size of the living compartment have a great deal to do with any heating requirement, I know that in a snow cave in 50 below weather that several candles can warm you up. Clothing seems to be the most important issue for protection from the elements.

Throwing out a vision just flashing before me, what about a boat that had basicall two hulls, that bolt along the gunnels, in good weather and warm climates the boat would fit inside the "other" outer hull, for bad ather, that outer hull could be brought up on top of the inner hull, forming a hard shell overhead and use a canvas/plastic back at the stern???? This would fully encapsulate you if necessary in a hard shell if thought to be needed.

 

that's right but my bump on a piece of plastic floor(which is probably wet as well) floating on the ocean surface is definitely not the solution, so another good reason for a survival tender with foam buoyancy which will also act as a thermal layer.

 

Worth developing the idea I believe. Still wanna do something with solar panels and lithium batteries.

 

How about seawater batteries instead of solar panels? Should be more rugged/reliable/practical for a power source.

The craft itself might be made to automatically deploy in survival raft mode in case of bad weather. Then possibly be reconfigured while occupied to a streamlined shape suitable for easy propulsion when conditions are calm....

P.

 

First i must explain: Having survived two horrifying mothership ordeals it drove home the challenge of survival at sea. I have read alot on the subject, problems encountered and some prevenative measures. I am also in the planning stage for a small but effective survival craft. I think this a very important subject which has not been given it's proper coverage on the forum and commend the OP for the discussion opportunity. I keep going back to the egg shaped idea but I am fully open to the OP's approach if for nothing else to acquire more space within. Ok-no heating system other than heat loss prevention thru out the whole system--I.E. survival clothing-double walled craft with a close cell (very important) core. Bilge pump (s) to get rid of any water that might accumilate inside the hull. This has been a big problem of past survivors.The other big problem often recorded was salt water irritated buttock and leg sores from chafing due to sitting on the a not so comfortable surface. While this might seem frivilious believe me it is not. The resultant infection has greatly hindered survival or outright caused deaths. Might i make a suggestion here to include some soft yet water resistant padded cushioning say in the form of the old lifesaving floation cushions in the cockpits of many boats. My thinking here is a survival craft that has to be occupied for two weeks or more before rescue occurs. Like it or not ( i see the head in the sand appraoch is still alive and well on this subjec) sharks are and were a big scarey problem encountered by by long term survivors in life rafts.(read the reports) The electric fields generated by salt water batteries are a no no thus the prev. idea of a small manual generator to re charge survival electronics. The idea of a hull shell within a hull to be flipped and fastened is just too time consuming-complicated and adds extra top weight thus degrading the overall stability. A light weight vinyl impregnated top, zipper-rope tie combo fastened with a fiberglass rod frame is easy to store within the craft-simple to erect after the fact. The survivors do not have to get out into the water to erect it as you would have to do with the prev. idea. It is not guaranteed that the survivor (s) would exist in numbers or in experience to accomplish this where as with the fabric system a surviving woman/son/daughter/ inexperienced man could figure it out. Especially if survival instructions were posted some where within the craft. The idea of snaps -rope ties in additon to zippers is -- The zippers will provide a fairley water tight seal but are prone to failure (pull apart) under pressure thus the idea of rope ties to prevent too much stress on the zipper. Anyhow just some further input and ideas I thought I'd throw out there--Geo.

 

Geo:

What about mesh netting seats/hammocks suspended to keep you just slightly off the floor? This might reduce chafing sores and any impact of bumping jolts from sharks on an inflatable survival raft. Just empty/mop up periodically; the mesh dries out quickly if it is splashed/gets wet. There will always be some puddles that a bilge pump can't get to and a manual one doesnt help much with big leaks. Also the survivors get weaker and less alert to leaks and puddles as time goes on operating at 24/7. You will be essentially marinating in a microbial soup which gets more toxic as time goes by, unless you can clean up and dry out periodically. Sharks can probably smell the decay for miles...

The zipup cover could be made of heat absorbing/retaining material, which gets heated by the sun, yet is ventilated by opening some zippers. The cover might be designed to catch and store rainwater in a bladder under the mesh...

The egg shape has proven itself in records set by the tiny boats. Some that survived storms were no more than a large bobber with a hatch top, big enough to hold a single man, yet with enough topside to stand and even lie down on a hammock- for some designs...

P.

 

on a small craft FIRST you need to design an effective tender to use everyday..after you have a useful design , then you may ruggedized or customize for emergency use.

All this talk of liferaft tenders makes me laugh. A seaman like tender to lay a kedge anchor in a gale is what will save your life.

 

Michael--I agree as I posted prev. a tender modified for survival could never match a proper liferaft for survivorability. I would hazard to guess only about 50% of the craft out there (coastal and near blue water cruisers) carry a liferaft. Boaters with sufficient funds to properly equipt their vessels forget that, not everybody can afford to purchase and maintain inspections on these expensive lifesaving devices. Most carry life jackets but again i'd gamble that a scarey percentage of those are not of proper size and in good condition. I'm as guilty as anyone, for the first 20yrs. sailing i didn't carry a life raft and many of my trips were blue water. I can't recall even seeing a lifejacket in our fishing vessels and dories in the early days. The point here is most drag along a dingy so why not discuss designs or modifications to maximize it's use as a life saving device especially for those without liferafts on board. It's not a subsitute but it's better than nothing for those boaters in the REAL world who can't afford the PROPER "Thing" as we say. The other spinoff of this discussion is, many of the suggestions and ideas can also be applied for use in a liferaft. If for nothing else it generates awareness, preporation, and what to expect, all good survival tools to have under one's belt in case that dreaded situation ever arises. Floating around, freezing to death,exposed to preditors in the open ocean is no cake walk so I say let the discussion on the OP's topic continue. It has my full attention and i am making notes
Portacruise -maybe some sort of hammock could be set up for one or two people but it would require some unique engineering in the small space available.-- I like the idea of your heat absorbing cover especially for cooler climates and of course a rain water collection system which I seem to recall are included in most liferaft kits if not it should be part of the grab and run survival kit aboard the mothership. I see you've been reading survival stories-- I.E. the mess that can accumilate in the bottom of a liferaft or bilge of a lifeboat over a very short period of time. Might be a good idea to include some large freezer zip lock bags as well as garbage bags to safely get rid of human excreations that occur mostly within the first week without attracting those beasties. Possibly a good idea in the South African crusing grounds of the OP Taniwha

 

If I had to abandon ship into a tender I would prefer to be jumping into a 13 ft boston whaler.

I dont agree with any of this inflatable or flotation collar stuff.

Start with an appropriate size, beamy, blunt end design....build lightweight,,,sglass over foam core...double up on the core and laminate at the INNER gunwale. Hang the thwarts from the inner gunwale. Make the hull unsinkable and self bailing when unloaded.

Instead of a keel use two full lenght hand rails on the bottom for lateral resistance.

Mold a luft tape track into the bottom inside edge of the gunwale to secure a. INTERNATIONAL ORANGE boat tent.

rig the tender with a lightweight 5 hp engine on a folding transom so the the engine folds into the tender to shorten its footprint for storage.

Heavily fender to bow fo push boat duty.

 

ok your aloud to laugh.
(thats sometimes why we do it)

I have 4 pool noodles in the hull of my rowboat.
{under the (air-tight) floor board}. my thought is if, after a catastrophic situation there would be pool noodles everywhere! (kidding really)
however, it is plausible.

In truth, they are there in-case of hull damage.
1 pool noodle = 90 to 130 Lbs support.
x 4 = approx. 400lbs. (boat weight 130 lbs.)
thus it becomes a raft.

I do realize it is simply a rowboat, but I believe the application could work.
Bataans #12 reminded me of what I had done.
a little more chance of survival.

 

I saw a BW 13 with a sprit rig pretty far forward once. He used the outboard for a rudder and often sailed downwind to the beach for afternoon beers from his anchored out boat. The sail was large and the boat scooted right along.

 

BATAAN nice boat!
i like to keep it simple too.
simple and neat. small tho