elephant trunk drain on a sib?

kelson · 15 January 2009, 17:30

I have a zodiac futura mk2. I operate in areas with large shifting surf (overhead sized breakers) and try to be prepared for the possibility of getting swamped. When heading out to serious surf or over a bar I move my battery up on top of my bench and strap it down. My electrical connections are all tucked up as high as possible in my console. I have a bucket for serious bailing, but the small drains installed on my zodiac sure don't suck water out very fast and are prone to getting clogged. I was considering installing an elephant trunk drain on my transom. Overkill? If the motors still running it would be nice to get water out of the boat fast. Anyone install one on a sib? Was it worthwhile?

engarom · 15 January 2009, 17:59

I have an old Avon SIB and it has elephant trunk drains on the transom.
I thought Zodiac did the same on the F470 - F550 SIBs.
I think you can even remove the bailers on the transom on some models and make some elephant trunk drains. The water pressure keeps the trunk closed

m chappelow · 15 January 2009, 19:21

my little 3 .4 metre has 2 -4inch ones ,they work great i can fill the boat the the top of the sponsons and it will empty it underway in moments ,they do still allow a little water back in if they are left in the closed upright setting as they act like a funnel if spray gets kicked up ,but nothing to worry about ,the small zodiac diaphram type only seem good when new and are forever leaking and soon get glogged up with weed ect,even just one small elephants trunk type would make a difference and you can thread a chain through the hole if you want to stop the boat getting stolen .

jyasaki · 15 January 2009, 20:27

Rescue SIB (about a 10 foot Zodiac) at Pt. Lobos State Park (California, USA) had a pair of 4" trunks.

Never saw the boat in action, but the ranger said the trunks worked quite well.

jky

prairie tuber · 15 January 2009, 20:32

Hi Kelson,

The 2 scuppers on my SIB are also 4" diameter, but are located a little higher up on the transom than the ones on Mart's boat (not sure what the rationale for that is). They are held in the up position by a simple hook (on the transom) & loop (on the trunk) system. So far, the only time I've needed to use the scuppers was this past summer when I had completely swamped my boat by stuffing the bow hard at the bottom of a large set of rapids. With the trunks lowered the water drained out (to the bottom of the scupper hole) in a matter of seconds. The remaining 1 1/2" of water gets pumped out with a manual bilge pump.

m chappelow · 15 January 2009, 22:23

,

yours do seem higher up than most but i had a humber 16 ft and they were high on that too ,my trunks are kept up by pulling a thin cord and a clam cleat on the inside of the transom with a plastic stopper ball to stop the cord i going through the small hole in the transom ,,though i have seen them kept up with just small velcro patches , i like the frilly bits on yours lol, regards mart.

jyasaki · 16 January 2009, 16:59

On my RIB the trunks are controlled by cords; they feed through the transom, hit a pair of clamcleats, and are stopped by a 3" long piece of PVC pipe (rather than a ball as on Marts) that also makes a nice grab handle.

jky

kelson · 16 January 2009, 17:17

Thank you all for the great responses. I particularly appreciate the pics posted by m chappelow and prairie tuber. Locally I don't not see many elephant trunk drains in use and there is a lot of skepticism regarding their value on a small vessel. The members of this forum are a creative and adventuresome lot! I am doing my best to prepare for the worst since I choose to flirt with disaster. I appreciate the guidance.

Nasher · 16 January 2009, 17:57

I like the frilly bits on prairie tubers trunks.

Very twee.

Nasher.

m chappelow · 16 January 2009, 18:11

if you want to see how good they are in practice have a look on youtube and type in D CLASS LAUNCH RNLI you will see why they are the best type .

prairie tuber · 17 January 2009, 01:34

What can I say, I'm a frilly sort of guy.

I believe the frilly ends to help keep water from coming back into the trunk by helping to keep the trunk flat if water pushes back against it.

Mart from your pictures it is obvious that you have a very well built SIB !

m chappelow · 17 January 2009, 19:56

Quote:

Originally Posted by prairie tuber

What can I say, I'm a frilly sort of guy.

I believe the frilly ends to help keep water from coming back into the trunk by helping to keep the trunk flat if water pushes back against it.

Mart from your pictures it is obvious that you have a very well built SIB !

its basicaly an avon 3.4 the RNLI beef them up themselves at the inshore lifeboat centre at cowes on the isle of wight this is where all the institutions inflatable boats are built sibs and the ribs ,the elephant drain trunks are fitted ,extra wear patches are stuck on ,the valves are recessed , the floorboard is made one piece with bottle screw tensions and the equipment bags go on, and a closed foam mattress goes to sit on , the sausage flexi fuel tank is fitted down one side, they then go back every year for a close inspection , first the boats are put on a jig to see if the tubes out of shape then if it needs any thing it gets it regardless , pic of the bow and bottle screws and when i first picked her up

ggoemer · 24 June 2009, 10:18

I have a bombardc6 & really need to come up with a bilge system. I was hoping not to take off the motor as its a 4stroke & the bolt hole have been siliconed & painted & I need a motor hoist.
Anyway would it be possible to make the 4 drain plugs into elephant trunks or are they to low ?

m chappelow · 24 June 2009, 10:53

Quote:

Originally Posted by ggoemer

Anyway would it be possible to make the 4 drain plugs into elephant trunks or are they to low ?

i once put a small diameter trunk on to one ofthe existing drain holes on an old zodiac,just pushed out the old diaphram unit and sleeved in a stainless steel tube leaving about and inch to sleeve the trunk tube over ,only problem was it was a bit too close to the engine leg and prop ,but it still worked ,

prairie tuber · 24 June 2009, 12:54

Slightly OT but,

Mart,

Would you know where I could get a pair of those bottle jacks? I have a 27 old Zodiac GRII with 3 alluminum floor boards and the 2 front wood floorboards, but the thrust board is no longer attached. I have no desire to go through the aggravation of trying to re-glue the thrustboard in place, and am thinking that using bottle jacks instead (with at thicker front floorboard) would work well.

jyasaki · 24 June 2009, 16:40

PT: Do a search for turnbuckles.

jky

m chappelow · 24 June 2009, 17:48

Quote:

Originally Posted by prairie tuber

Slightly OT but,

Mart,

Would you know where I could get a pair of those bottle jacks? I have a 27 old Zodiac GRII with 3 alluminum floor boards and the 2 front wood floorboards, but the thrust board is no longer attached. I have no desire to go through the aggravation of trying to re-glue the thrustboard in place, and am thinking that using bottle jacks instead (with at thicker front floorboard) would work well.

HI P/T, i re thrust boarded a zodiac with no problems, as long as the fabric flaps are still there to stick to ,.with the bottle screw system the boat is tensioned up far better than with a thrust board ,but not sure if it would work with multi boards ,but as jyasaki said they may call them something else over your side of the pond, you might have luck finding them on farm machinery or able to modify some off a large sailing boat ,best of luck ,mart

nexus · 09 July 2009, 16:48

I have 2 of these drain tubes on my achilles and they are a total pain in the ass. when i lower them they never actually drain any water until i reach over the transom and straighten them out and kind of pinch them to make them round again (instead of flat). when they are just lowered the outside water keeps them pinched flat and nothing drains. once opened they work superbly but its not as easy as it should be.

any ideas?