The Advantages of Twin Keels

I found an interesting article (ok, maybe not interesting) relating to the advantages of Twin Keels on the Interweb, the very obviously naned - The Advantages of Twin Keels, I'm not going to bother re-producing it - I just thought I would put it on here in case anybody was interested.

I've had a quick read of it and some of it doesn't really apply to the Jedda - but some does. I suppose the main thing, which we have known all along is the fact that when you are heeled over the leeward keel becomes more vertical and achieves greater depth and stability, while the windward keel creates downward lift increasing righting moment. The Jedda does have a noticeable sweet spot when heeling  that is greater than many small yachts, I suppose this goes someway to explaining why...???...well, maybe...

I know that was an exceptionally interesting summary - I just thought seeing that Maggie is a twin keeler, the article should be referenced.

'til next time...happy sails...

How the swing keel operates and replacing the gaskets on the keel control rods

I've just remembered the other reason why I didn't sail Maggie between late October and Christmas - I was out for a quick spin to try out my new GPS in about a 10kt SW-W, below is the track - jeez I love the novelty value of this thing!

OK, so it doesn't look like the most exciting sail - but due to the strong current running and the variable wind, our speed relative to land was between 0 and 2kts heading south and between 6 and 8kts heading north. The south bound trip took the best part of 2 hours and the return took 20 minutes!

Before I set sail, I noticed that of the cabin lockers had a little bit of water in it - oh well, so I bailed it out and set  off, assuming that the water was just from a leak through the cabin top somewhere. Upon returning I thought I should check to see if any water was in the locker, well we probably had about 5-6 litres. On closer inspection it appeared that we had a leak where one of the keel control rods passes through the hull. OK, looks like I've got a project!

So here's a basic run down on how the swing keel mechanism works. The keel winch handle, located between the outboard gear control arm and the red tool box, is the only bit of the mechanism that you generally need to worry about. What is interesting, is that most of the swing keel Jeddas have the keel winch handle in a different spot!

The handle is connected to a drum (I think - Mental note to self : crawl into that little space and see how it works!!) which is in turn connected to a cable. The cable is then connected to a control rod on each side of the yacht, via various sets of blocks.

The rods (1 per keel) pass through the hull, as shown

The rod is connected to the keel, and raises and lowers the keel as pulled and pushed - I haven't seen the exact configuration of this bit as it is all glassed in and the fewer holes in the boat the better!!

Anyway back to the leak and replacing the gasket...

Step 1: Lower the keels slightly so they rest on the trailer. This will release the tension from the cable.

Step 2: Undo the "D" bolt thing connecting the rod to the block

Step 3: Undo the thumb screw and then remove the big "O" ring thing, remembering to measure where it came from so you can put it back in the same spot!

Step 4: Remove the steel plate and rubber gasket and remember where you put the nuts - I screwed them back on so I wouldn't loose them!

Step 5: Acquiring the gaskets. The gasket is heavy duty rubber about 6mm thick which the local Clark Rubber store had to purchase at minimum meter lengths. The roll was a perfect width for two gaskets, and if I remember correctly I have enough rubber left for another 6 gaskets. The best part was it was only $20!

Step 6: Drilling the holes in the gasket. I used the steel plate as a template for the locating of the holes. The smaller holes were drilled with a standard 6mm (?) drill bit. However, drilling a hole in thick rubber which was going to fit snugly around a 25 mm (maybe 1inch) stainless steel rod took some thought. Initially a machinist who worked with belts and the like was considered, but then once I realised how much excess rubber I had I thought I could experiment. So the winner was making a template out of ply - using a 24mm spade bit on the drill, clamping the rubber between the template and a baking piece of ply and using the spade bit to drill the rubber - worked on absolute treat!!

Step 6: Put the whole lot back together with a bit of Sikaflex between the steel plate and the gasket and the gasket and the hull and Bob's your Uncle no more leak!

So I finally get back down to the boat for the first time after replacing the gaskets and have a look in the cabin locker which had been collecting water and see a nice dry locker...well, actually no - it's got water in it! Well, fancy that (or words to that effect)!!

Looks like the water is coming from above not below - well...maybe...the side...hmmm... looks like it's time to check the window seals and maybe the hull to cabin connection behind the rubber bumper...

Alternatively, I just go with Plan B - heaps of silicon sealant and a bilge pump!!

Stay tuned....

The current set up

Just a brief run down on how Maggie is currently set up.

Sails:

The main sail has a bolt rope on the foot and slugs on the luff. The main is reefed by a roller reefing system around the boom. I have generally had problems getting a good shape to the sail once reefed - however I may have just been provided with a solution by using the topping lift to keep the boom level - I'll have to play around with this out next time I go out. Another minor issue is that the vang can't be used when reefed - i have a bit of a thought on this but i'll have to check it out before making a tool of myself with a really bad idea!!

When I got Maggie she had a jib furler fitted - it was however on BACKWARDS!! So that was soon rectified. The next dilemma was that the furling line wouldn't all fit within the drum - so I replaced the 6mm line with 4mm Spectra - OK now we're getting somewhere. The furler was still struggling, so after pulling it apart and seeing how much of a dogs breakfast it was inside I decided it was time to go.

So now the headsails are all hank on. The headsails we have on Maggie are a Genoa - about 140%, a Jib - about 100% and a smaller Storm Jib.

One of the things on the list (for when I remember where I put my bottomless bucket of cash) is to get a kite - the big question is where to go conventional or asso???

Running Rigging:

As with all small yachts the "How many blocks, cleats, lines does one want / need to control stuff" dilemma exists. I've tried, and am still trying, to find a balance between which lines need to come back to cabin top cleats - thereby accessible from the cockpit - and which lines can terminate sooner and will require a walk to adjust. I'll start from the bow.

Headsail controls - the jib halyard runs back to a cleat on the cabin top, i've got a jib downhaul just to give the headsail a gentle reminder how to douse when it gets a bit stuck - this also runs back to the cabin top (mostly because it uses the use furler hardware) and the jibsheets obviously run back to the cockpit for trimming.

Mainsail controls - Although the mainsail halyard runs back to a cabin top jammer - it's lack of length dictates that the winch on the mast is used when required, the boom vang doesn't have any associated hardware and just connects between the mast base and boom when required - the main reason for this is that with the roller reefing main the vang can only be used when we are flying full main, a fairly poor excuse for an outhaul exists on the boom - however the age and decrepit nature of the main (once again where's that bucket of money!!) means outhaul tension has little value,the topping lift runs to a horn cleat on the mast - however since my discovery regarding the reefing of the boom - this may need to be altered??, and the mainsheet and the mainsheet traveller control line are both obviously in the cockpit - although they both have enough length that I can happily sit on the cabin top ready to ease or dump the main as required!

Maggie has three winches. One on the mast for the mainsail halyard, one on the cabin top for the jib halyard and the third attached to the front of the mainsheet traveller for the jib lines, as below.

Many people find the winch in this position awkward - I don't mind it. The line runs from the block, through the eyelet, to the winch and then cleats on the opposite side - it means not having to go too far to leeward when trimming the jib.

We also have blocks and cleats for a kite - but haven't bothered to go down that path yet...as mentioned before.


Toys / Extras: 

One of the greatest conveniences for anyone who does solo sailing is almost certainly an autohelm - I was lucky in that Maggie came with a Raymarine ST1000plus Autohelm. It gives you heaps of freedom to relax and not worry about holding the tiller the entire time - although I must admit once the wind comes up I still enjoy being in control. I was again lucky in that the autohelm has a set of controls on a length of cord making it possible to change course from anywhere on the yacht. However, my favourite feature has to be the autotack - which takes you through about 100deg. It makes solo tacks really easy!

GPS/plotter - The GPS is great. One of the advantages of it as i see is your ability to see how much headway you are making. Western Port, where most of my sailing is done, is strongly tidal and currents of to 2-3kts are not uncommon and when you only do 4-5kts most of the time you can go nowhere or even backwards fast, particularly in light air. The plotter is currently just clamped onto the rope bag - however plans are afoot to build a little swing bracket to attach just inside the companionway.

UHF and Marine radio

AM/FM radio tape deck - needs upgrading to one with a USB jack.

I think that is about it - I will add anything else I can think of at a later stage!

Oh Yeah, as you could probably see in the previous photo, the iron topsail is a 8hp Yamaha outboard in a well, which pokes out like this.

As you can see the rudder can be raised for storage. And as you can also see, it needs to be sanded and re-painted...boring!

And finally, James making sure the lifeline padding works.

Yep, all good!

The techncial stuff

For those of you who are interested in the technical stuff about the Jedda 22, here it is:

HULL Material GRP

LOA 6740 mm (22 ft)
LWL 5756 mm (19 ft)
Beam MAX 2081 mm (7 ft)
BM RATED 1940 mm
MASS 1510 kg

DRAFT approximately 600 mm (fixed) or 1200mm (swing)

INT BALLAST 204 kg
KEELS MASS 318 kg (fixed) 338 kg (swing)
TOTAL BALLAST 522 kg

AUXILIARY POWER
Outboard, Diesel, Outboard in well, (7.5 or 8hp)

SLEEPING ACCOMMODATION
1 double V berth - if you are shorter than me 
2 single berths

GALLEY
Metho 2 burner stove, sink, shelving.

TOILET
Porta Potti under V berth

STORAGE
Under bunks, side pockets, anchor locker, cockpit lockers

SAILS
Main 8.4 square metres
Genoa 13 square metres
Spinnaker 35 square metres

RIG TYPE
Single spreader, non tapered, mast head, LOA 7.3 metres

KEELS
Twin swing bilge keels, (patented action, 20 turns to lift)
Total weight with mechanism 338 kg.
Or Twin fixed keels

What is Maggie and why write about her?

I suppose for my first blog i should write a little about Maggie. As you have probably noticed from the main picture, Maggie is a yacht - a Jedda 22 trailer sailer (TS) to be exact.

The Jedda 22 was designed and built by Ozzie Whittley in the 1970's. I'm not exactly sure how many were made - but quite a few are still about now. They were built on the shores of Western Port in southern Victoria. The Jedda was built to meet the requirements of the JOG (Junior Offshore Group) class and, along with many other trailerable yachts of this vintage and class, is somewhat heavier than the more modern style of TS.

Also worthy of note is that the Jedda is a twin keel TS - either fixed of swing - which is a bit of a rarity in Australia.

Maggie is the only yacht I have owned, having got her in 2002 about the time of my 30th birthday. Claire - the Admiral - will gladly tell everyone that Maggie was my 30th birthday present! Over the past 7, or so, years I have done a bit of tinkering with the way Maggie was set up and even sailed her occasionally, this has been a bit hard over the last 5 years with the crew arriving - but hopefully they'll start to get into it soon!! When I bought her she was apparently owned by an elderly gentleman who was planning to sail her through the Pacific Islands - luckily his family stepped in and the yacht was put up for sale.

I suppose the main reason for my ramblings on here is that very little information on the Jedda exists on the interweb and I thought that it would be good to get it out there, along with the good - or otherwise - times spent on Maggie.

Stay tuned and hopefully i'll be back soon!!