both engines dow

Ezgoing · 03 December 2008, 23:12

http://www.youtube.com/watch?v=zZ3tk...eature=related

!!!

Chris · 04 December 2008, 10:50

Very intersting and useful, certainly got me thinking as well.

Just ordered a drogue off ebay

JSP · 04 December 2008, 11:14

I've never seen drogue's used and I could see exactly what they where doing in the link. I don't mind putting the dunce hat on and asking what they do?

Lewy · 04 December 2008, 11:27

Quote:

Originally Posted by JSP

I've never seen drogue's used and I could see exactly what they where doing in the link. I don't mind putting the dunce hat on and asking what they do?

i imagine they could prevent the craft from broaching but only if the drogue had been at the limit of its tether. In the case of this boat i'd imagine they just dropped it over the side and it took awhile for it to have any effect.

why do you think both engines stalled and then only one restarted?

JSP · 04 December 2008, 11:38

Looked to me like both engines went under.

Thanks lewy, so does a drogue course drag or something?

Lewy · 04 December 2008, 11:53

Quote:

Originally Posted by JSP

Looked to me like both engines went under.

Thanks lewy, so does a drogue course drag or something?

it works like a parachute for the water but with a smaller hole to allow water to pass through it. it enables the boat to more or less keep its heading into the on coming waves when tethered to the bow. its often used on the stern aswell. i know yotties use them quite alot!!

codprawn · 04 December 2008, 13:49

Also known as a sea anchor but some people would argue that they are different things.

When you are in the mille of the Ocean and water depths are 12,000' it's a bit difficult to anchor. By using a large parachute type device you get the same effect as being at anchor although you will still drift slightly. If you engines have died it will hold you into the wind and waves so the bow can ride the waves. You need a very long rope for this to prevent the anchor coming out of the waves.

A drogue is pretty much the same thing but smaller. You use it at the stern to prevent surfing down waves and the boat broaching.

I carry one as they roll up so small.

codprawn · 04 December 2008, 13:58

Looking at this brilliant video though it makes me wonder

Did they use a drogue or sea anchor?

I doubt it somehow. A situation like that is NOT the place to use one. If you are in danger of being swept onto the shore in shallow water you use an anchor - a proper one!!!

ILBs are rigged for very fast anchor deployment and have a big winch in front of the console to get it back in again.

Lewy · 04 December 2008, 14:44

you can see when the drogue properly works 1:46 secs into the film. prior to that i guess they were paying out the warp and then they got hit by a wave that probably swamped the boat but took them the correct distance from the drogue.
what length of tether do you have on your one codders?

Jono Garton · 04 December 2008, 15:19

A "Sea Anchor" is a great bit of kit in situations like this connected to the bow, by personal experience I found that a "Sea Anchor" recommended for a 30ft Yacht is not suitable for a 5.5m - 6.5m RIB, I now use one recommended for a 50ft yacht with 5 x the boats length of warp.

It could also be used as "Drogue" with a displacement boat or semi displacement boat being towed from the stern with a 2nd line (tripping line) in a following sea to stop the boat broaching.

Jono

Jono Garton · 04 December 2008, 15:21

Quote:

Originally Posted by codprawn

ILBs are rigged for very fast anchor deployment and have a big winch in front of the console to get it back in again.

Which ILB is that then?

chewy · 04 December 2008, 15:22

Quote:

Originally Posted by codprawn

Looking at this brilliant video though it makes me wonder

Did they use a drogue or sea anchor?

I doubt it somehow. A situation like that is NOT the place to use one. If you are in danger of being swept onto the shore in shallow water you use an anchor - a proper one!!!

ILBs are rigged for very fast anchor deployment and have a big winch in front of the console to get it back in again.

The sea anchor will hold you head to sea, a drogue is deployed off the stern to slow your speed.

The reason the sea anchor was deployed was to hold the boat head to weather, it can be deployed loads quicker as its already tied off in the bow, all you do is open the lid and throw it over the side prefrably running through the fairlead.

If the crew had used the anchor they may not have got a bight and the boat end up ashore, it takes longer to deploy the ground anchor. Atlantics don't have a winch to recover the anchor, it needs pulling in by hand where it is coiled on the drum mounted infront of the console.

The crew were trained for what happened and recovered the situation.

codprawn · 04 December 2008, 15:49

I apologise - I thought the drum could also be used as a low powered winch - ie - a giant fishing reel.

Lewy · 04 December 2008, 15:54

Quote:

Originally Posted by Jono Garton

A "Sea Anchor" is a great bit of kit in situations like this connected to the bow, by personal experience I found that a "Sea Anchor" recommended for a 30ft Yacht is not suitable for a 5.5m - 6.5m RIB, I now use one recommended for a 50ft yacht with 5 x the boats length of warp.

It could also be used as "Drogue" with a displacement boat or semi displacement boat being towed from the stern with a 2nd line (tripping line) in a following sea to stop the boat broaching.

Jono

whats the physical difference between a sea anchor & a drogue? could not one desigh do 2 jobs?

Jono Garton · 04 December 2008, 16:01

Quote:

Originally Posted by Lewy

whats the physical difference between a sea anchor & a drogue? could not one desigh do 2 jobs?

No physical difference apart from the lines attached. Yes it could do 2 jobs, this is what we do on our All Weather Lifeboat which can only do 17 knots.

However on a rib there is no need to use a Drogue. A rib can normally be in much more control in a following sea staying on top of the wave and not letting the wave go faster than the rib.

Jono

chewy · 04 December 2008, 18:16

Quote:

Originally Posted by codprawn

I apologise - I thought the drum could also be used as a low powered winch - ie - a giant fishing reel.

No worries mate, all the reel has is a handle which goes directly into the middle of it meaning its not geared at all.

If you have a look at the other vids from the same user they is one of the Atlantic smashing into the tractor during a net recovery!

Jono Garton · 04 December 2008, 18:31

From memory Rye Harbour was the biggest single loss of RNLI lives in the 1930's, their boat capsized on the Harbour Entrance and all the crew were lost.

JSP · 04 December 2008, 20:31

Thanks for the explanation lads!

So when equipping out my next boat and remembering room is important would I be best just getting a sea anchor or sea anchor and drogue?
Quality info

teampulsar · 04 December 2008, 20:32

Wondering why an Atlantic was out in this sea state and dunking the engines like this.

Is this standard training, or were they on a rescue?

Seems odd to do this to such important kit, having said that, it shows clearly the benefit of a sea anchor.

Great video and very informative.

TP.

willk · 04 December 2008, 20:38

So, cat and pigeon time. Can a large plastic basin/drum/bucket with an appropriate hole in the bottom be used as a sea anchor? Just asking...