Another very busy week here in Finike as we work our way through the last boat jobs that need to be completed before we can set sail (yes, we still refer to it as “sailing”) and finally put Turkey in our wake. In what feels a bit like some marine version of Groundhog Day (the movie), we thought we had left Finike for the last time about a month ago but life intervened with some new twists, quite literally. Christine “twisted” her knee and needed to go back to Antalya to get that operated on and when we first launched the Tender the overhead beam portion of the Davit Arch “twisted” and needed to be replaced. So we find ourselves back here in what was our home base for almost the past year to look after these and several other key items on our To Do lists. All working out very well as we know and like this area and have a good network of people we can call on to help find things we need which really speeds up the process and allows us to get these jobs done much faster than if we were in a new town.
Weather here continues to be outstanding and much “cooler” than past summers. Hottest we’ve been up to in the past few weeks is about 33-34C / 91-94F and nights have been down in the low 20’s / 70’s so makes for very pleasant evenings and sleeping and not too sweltering in the daytime though it does get toasty when you’re in the direct sun which I was for much of this past week and have the “farmers tan” to show for it. But we go for a swim in the ocean on the other side of the rock seawall behind us and that is a great way to cool down and good exercise for Christine’s knee which continues to improve and get stronger and stronger.
A good variety of jobs on the go this week including building DIY Paravanes, assembling and installing he new Davit Arch v2.0 and getting all its rigging in place. So let’s dive right in…………
Last week you may recall that I completed the rigging for the aluminium A-frames that fold out from each side of Möbius and have lines going down from their ends to a paravane of “fish” that glides about 6m/20’ below the water level. The rendering here is from when I was doing the calculations for line lengths so you are seeing multiple positions of the paravanes whereas there is only one on each side in reality.
Paravanes are know as a “passive” system to help stabilize the motion, side to side rolling in particular, of the boat in large seas and in rolly anchorages.
The other option is to use active stabilizers such as fins or gyroscopes which work very well and at more of a flip of a switch, but they require a lot of power, a lot of $$ and are relatively complex systems known to be quite prone to failures or at least a lot of maintenance and so we’ve chosen to go with all mechanical and very simple paravanes which are commonly used by commercial fishing boats.
Our intent is to use this paravane system for the next year or so and if we decide we want to change to active stabilizers in the future, the hull already has all the internal framing and watertight coffer dams which will make the installation of active stabilizers relatively quick and easy.
FWIW, if we were to do go with active stabilization today we would probably chose to go with the Magnus Effect type of stabilizers as these can be folded inline with the hull when not in use. This greatly reduces the danger of hitting something with the fins that permanently protrude out much further and can add some risk when in areas with lots of coral, rocks or ice. And who knows what new systems might be developed by the time we might be looking into active stabilization?
This is an example of the most commonly available paravanes from Kolstrand company and used by many commercial fishing vessels. Galvanized steel and work very well but very heavy and a lot of drag.
However, some fellow Canadian boaters have been having very good success with these DIY paravanes built using plywood for the horizontal wings and a metal T-bracket to attach to the line above and a lead weight on the front, so I’m going with this design.
Relatively low cost and easy to build and these will let me do a lot of experimenting in the next year of use to try different sizes of wing surface area, front weight, attachment line positions, etc. The ideal is to get the maximum roll resistance with the minimum drag.
Over on the always helpful Trawler Forum, a trawler owner “Cold Smoked” had provided some photos of this type of paravane he was building and
…. ended up looking like this.
This is an example off this same style on the trawler mv Hobo all rigged up and ready to be tossed overboard.
Here is a shot when this paravane is at work and helps to show you how the A-frame on this boat works.
With the Paravane A-frames all rigged, this week I started building the paravanes or “fish” themselves.
To my surprise, finding good plywood suddenly seems to be very difficult but on our trip to Antalya last week we were finally able to find a lumber shop that had some pieces on the side they were willing to cut for me.
I worked out my best estimate of the various dimensions and scale for what I think will be close to the Goldilocks size of paravanes for Möbius and got to work cutting the plywood.
My ever handy 18V Milwaukee router made it easy to put this bullnose profile on all the edges to help reduce the drag when these are flying through the water.
Two coats of white epoxy to make the plywood waterproof and easy to see when deployed. I’ll add a third and perhaps fourth coat tomorrow and can then start attaching the hardware.
Ideally I would like to have used a round lead fishing weight cut in half but could not find any here in Turkey so I’m going to use these large disc zinc anodes that I found in a marine shop when we were in Marmaris a few weeks ago. This one weighs about 7kg/15lbs and I will through bolt two of these to the bottom of the nose of the plywood.
Didn’t seem worth it to fire up Fusion 360 for such a simple bracket and fin so I just made this quick and dirty hand sketch as I worked out the dimensions and proportions for the T-bracket and the Tail Vane. I’m still tracking down someone in Antalya who has the AL plate I need and hope to have these here next week so I can finish building the fish for Möbius and start testing the whole paravane system out. Stay tuned as that happens.
As I do with so many other systems, my intent is to use these first fish as prototypes and spend the first year or so experimenting with them to find that sweet spot of best roll resistance with least drag and all the tricks to deploying and retrieving them. This design allows me to easily change the size and shape of the plywood wings as well as trying different amounts of front weights with the different zinc anodes I now have onboard. And I can try different attachment points of the line to the fish to get the down angle just right and I try out different positions at different boat speeds in different sea conditions. Should be fun and educational so stay tuned for more as I finish building and start using these paravanes in future blog posts.
Mr. Gee 3.0 First Oil Change
Mr. Gee has now been thrumming away very happily for almost 50 hours now so this week I did his first oil change to make sure I could get rid of any particles that had gotten flushed out after the last rebuild. He holds about 28 liters and I use a 24V transfer pump to make it very quick and easy to pull out all the old oil and then pump in all the new. Mr. Gee has the optional hand pump for removing the oil so the oil pan is all plumbed for this and I just push on a vinyl hose and use the transfer pump instead.
Gardner recommends oil changes at about 400 hours so should not need to do this again until next year but I carry an extra 50 liters of 15W40 oil and several new oil and fuel filters so I can change these at any time.
Captain Christine’s Tech World
While I was busy with all the mechanical work this week, Christine continued her non stop game of Whack-a-Mole as she gets our complex set of electronic systems for navigation and monitoring all working and playing nice with each other. Not something that lends itself to much in the way of photos but trust me she works harder than I do! As just one example of hundreds, this is the screen she uses in Maretron N2K View to create the oil pressure gauge with all its settings, color coding, warning light, etc. It is a super system for monitoring everything on board but you pay the price in both cost and time.
Davit Arch Beam v2.0
When we first launched the Tender several weeks ago the overhead beam of the three piece Davit Arch failed and so we needed to have a new one designed and built.
Fortunately Dennis, our awemazing Naval Architect at Artnautica in New Zealand, was kindly able to squeeze in my request to design this new version and have it fully tested by a structural engineer. As we had done with the design of Möbius, we were able to collaborate on the design via Email to exchange models and test results.
Dennis was able to use some structural engineering plugins with Rhino3D that showed the various loads in all locations and guide us through the new design. Then Dennis sent it to his engineer colleague Peter who did the full set of structural testing and gave it his OK.
All of this was then sent to Naval who also managed to squeeze building this new arch into their very busy schedule and had it build in less than a week. Next challenge was how to get this beam out of the Free Zone and trucked the 120km to where Möbius is in Finike.
As usual the solution involved hiring a customs broker, paying lots of fees and completing lots of forms but eventually the bonded truck showed up at Finike Marina on Monday.
Precious cargo inside.
And we soon had it out of the truck and onto the concrete behind Möbius.
The original two vertical legs of the Davit Arch were fine so it should have been a simple matter of bolting the three pieces together. However nothing with boats is ever easy and the new beam was 40mm too short. Grrrrrrr
So I designed some adaptor plates to get the vertical legs in the right position and Naval kindly sent up a small crew with a welder and we were able to build and weld in the adaptor plates on Wednesday.
With the new beam now fully bolted in place the next challenge was to get the new Arch lifted aboard Möbius, aligned with the hefty brackets welded to the deck and the 50mm OD SS hinge pins pushed in place. Fortunately crane trucks like this are ubiquitous in this area so Christine was able to quickly arrange for this one to show up.
Sure makes it easy to move heavy items from one spot to the next.
The fit is very close so it took some time to get everything lined up so the hinge pins would slide into place as you have to get the bored pin holes lined up within about 1mm or the pins won’t slide in.
But with some help by our local marina handyman Faik, we finally got everything lined up and the SS pins pressed in place.
And version two of the Davit Arch was now in place and ready to be rigged.
The rigging I had built for the first Arch had worked out fine but Dennis and I changed the Pivot Control Line blocks to be over on the far Port side (left in this photo) so that the angle the lines going to the beam were at the largest angle to reduce compression of the beam a bit. The lines you can see on the right going up the vertical leg is a 6:1 set of triple blocks which lead to the hand winch on each vertical leg. These lines lift the Tender Up/Down inside the arch to get the Tender up high enough to clear the deck chocks and the rub rail as it goes over the side.
The Pivot Control Line goes through this 3:1 set of blocks and then ….
……. over to the big Lewmar 65 electric winch in the centerline of the Aft Deck.
Davit Arch all rigged and ready for first test launch this coming week and I’ll bring you all of that and more in next week’s Möbius.World update.
And that’s a wrap for yet another week and almost another month! Thanks SO much for taking the time to join us and follow along on our adventures. Hope you will tune in again next week for the latest update and please continue to add your most appreciated comments and questions by typing them into the “Join the Discussion” box below.