The heat wave continues both weather wise and Möbius progress wise this week and here is your summary of all that has gone on. After cooling off slightly last weekend with daytime highs down in the mid to upper 30’s (90’s F) they climbed back up throughout the week and we were up to 41c/106f yesterday. Suffice it to say that we are getting VERY good use out of the lovely big pool we have at our apartment and doesn’t take long to get well cooled. As I sit and type this on Saturday (July 14, 2018) the forecast is for 40-41 high today so I’ll write this in between trips down to the pool if you don’t mind.
Fortunately there are shower facilities for everyone inside the Naval Yachts shipyard so most of the team is able to cool off and clean up at the end of a hot day which helps make it all quite workable and this is very typical weather for July and August here in Antalya so they are all quite used to it. Undeterred by the weather everyone on Team Möbius just kept on going and more great progress was made throughout the week and just before I dive in with all the photos, if you check the daily count meter at the bottom of the blog you will notice that today is the 100th day since construction on the hull began. We could not be more pleased with the progress and the results from this incredible team which Naval Yachts as surrounded us with. Now, on with the show!
Let’s get the title’s fuelishness out of the way first with my way of showing you the beginning of building our Day Tank. It is called a Day Tank because this is the tank which holds the daily diesel supply Mr. G (our Gardner 6LXB engine) needs when we are underway.
Word of Warning; this fool will pop up again in the video at the end of this post!
As you’ve been seeing in previous posts, the rest of our tanks are all below the waterline and integrally built into the framework of the hull for added safety and keeping all that weight down as low as possible. These lower integral tanks hold about 14,000 litres/3700 USGals and each day we will fill up the Day Tank by pulling diesel from those big tanks. The Day Tank holds about 500L/132 USG and we anticipate our maximum fuel burn rate to be less than 20L/5.3USG per hour so this tank should have enough fuel for more than a 24 hour and 250nm day on passage.
This was the very beginning of prepping the plate for the Day Tank and other new parts earlier this week.
The most visible change on the hull this week was the addition of the final aft section of the eXtreme Keel Bar. This is the Before shot of the aft end of the hull…..
….. and this is the after shot with the Keel Bar set in place.
Enver and Umit are making sure this section of the Keel Bar is precisely positioned just right prior to tacking it in place.
Sezgin, in blue, is of course welding non stop all day every day trying to keep up as the rest of the team add more and more parts for him to weld.
You’ve seen the forward sections of this 25mm thick Keel Bar being fitted in previous weeks including the truly eXtreme bow section where the Keel Bar curves through 90 degrees to go all the way up to deck level and form the Stem Bar and sealed collision crash bulkhead.
This aft section now completes the placing of the Keel Bar.
This quick clip of the model will help put this into perspective for you. The dark green is the beefy Keel Bar you see in the photo above.
If you are wondering, that section in the middle of the Keel Bar and down by Enver’s knee above, with the thin vertical connectors are just temporary to keep everything aligned. That gap is where a large thick walled AL tube will be welded in place to house the propeller log tube and shaft for the Nogva CPP prop system.
Standing inside the Workshop and pointing the camera forwards along the side of the Keel Bar you can see where the prop tube fits once those spacers are cut out.
This perspective also clearly shows how the Keel Bar fits into the slots cut into the transverse frame #20 and where that prop shaft tube will pass through.
All this will be fully welded up once we have all the other parts of the hull framing and hull plates in place to create an extremely robust aft end.
Moving the camera just forward of Frame #20 you can see how the rest of this aft section of the Keel Bar continues forward and is captured and precisely positioned by the slots in Frames #19 in the foreground, 18 and 17 which is also the WT Bulkhead between the Engine Room/Workshop area and the Guest Cabin aka Christine’s Office.
Turning around 180 and looking aft at Frame #20 again this shot might help complete your visualization of this area and how the framing all comes together.
If you look closely (click to enlarge) on either side of the center Keel Bar those sloping lengths of 25mm AL form the beds for mounting the main engine and CPP servo gearbox. Thicker than needed in the eXtreme to fully support the engine and gearbox but we have supersized these engine beds because one of the ways to reduce vibration and noise is with mass, and these are eXtremely massive because we want an eXtremely quite boat.
While I am inside let me show you around some of the different interior spaces on Möbius so you can see how those look from the inside right now. Be sure to check out the video at the end for an even better tour of the inside areas.
It is a bit of a challenge to visualise these interior spaces at this stage of construction so I’ve done this quick and dirty clip of the upside down hull all stripped away to show the main spaces.
This is looking aft through the door into the Workshop/Engine Room we just left and now standing inside the Guest Cabin/Christine’s Office.
Moving aft and turning 180 to stand beside that doorway above and look forward, this shows the rest of the Guest Cabin/Office. All upside down of course but you can start to get the idea of this nice big space.
In both pictures looking up you can see the ever present integral fuel tanks and all their baffles and get a sense of how this grid construction of the tanks creates such an eXtremely rigid and strong hull bottom. Just wait till we get the 12 and 15mm hull plates welded on there!
Stepping back into the Workshop and looking forward through the Workshop door will give you a better view of the length of the Guest Cabin and the doorway leading out of the Guest Cabin “up” into the main part of the Pilot House, the SuperSalon.
The SuperSalon is our main living area with the Galley, Dining, Lounge and Main Helm station all wrapped in 360 degrees of glass. The above deck superstructure which is below this area will be added after we flip the boat right side up next month so right now it is a bit difficult to visualise this great room but if you look back at the labeled clip of the 3D model above I think you will get the basis layout.
Here we are standing near the aft end of the SuperSalon in what will be the Galley and looking towards the forward end of the SuperSalon and this will give you a bit of as sense of the size of this room.
The floor is overhead and the massive frame #13 in the foreground on the right forms the support for the superstructure which will go on after we flip the boat next month.
These two beams in the bottom foreground provide the support for the forward end of the Pilot House/SuperSalon where the main Helm Station will sit.
What you see looking all the way forward in this photo and the one above is Frame & WT Bulkhead #4 at the front end of our Master Cabin.
Popping back outside you can see that Sezgin and the other welders have been busy welding up the first two rows of hull plates.
Uğur and Umit are carefully wedging this intersection of hull plates so they are all flush before Sezgin comes and welds them up.
Welding all done, fairing bars removed.
This is standing about mid ships on the Port side looking forward and you can just see the anchor roller assembly at the very far end.
Saving the best for last, yesterday the latest truck load of aluminium parts arrived with all the pipes and 3D curved hull plates.
These various size pipes will soon be fabricated to form things like the big foldable arch, the paravane A-frame booms, stanchions, rudder tubes and prop shaft tubes.
The curved hull plates are the most exciting, at least for me and these next few shots are from the bending shop in Istanbul a few weeks ago.
This is still one of those processes which has yet to be automated and remains a very rare and highly skilled all manual task so these guys are in very high demand, but Burak & Dincer were able to convince them to send us these 4 shots as they were bending our plates.
The shop in Istanbul which does this amazing 3D curving of the plates had a very big job that was scheduled prior to ours so we have had to patiently wait for them to bend all our bottom hull plates and truck them to us.
Difficult to capture but this shot will help you see the complexity of these 3D curves as they were bending this plate.
Back to real time in Antalya, the forklift soon had all the curved plates off the truck……
….. and into the shop floor behind Möbius. Even though it was late Friday afternoon, the boys wasted no time unstacking these very heavy thick plates to get at the first one and starting prepping the edges so they can hoist it up on top of the hull framework and tack it in place next week.
My hand and thumb will give you a sense of the size of these 12 and 15mm plates.
The numbers you see are part of a grid which is used to align a series of templates the bend shop makes up from the 2D drawings Burak sent them which they lay on the plate at these points to check that the curves are just right.
As you can see these are very complex 3D or undevelopable curves to match the sleek curves of the bottom surfaces of the hull.
As these get tacked in place in the next 2 weeks all those slippery curves of the hull will very visibly emerge and you won’t need any imagination to see this sleek slippery hull.
So that’s the week that was July 9-13, 2018 here at Naval Yachts and the building of Möbius. The summary video compilation is below and will help put all of the above together for you.
Thanks for taking the time to follow along and remember to add your questions and ideas in the Comments section below.
Short version of the question – why the keel bar?
Long version – why use a keel bar to solve what problem and/or provide what capability?
Longer version – what other solutions did you consider and why did you discard them?
Interesting question as usual John.
Short answer: Rigidity, Reference and Ice
Longer Version: Doing my best to start with a blank slate and try to make no assumptions or carry forward any “momentum of tradition” I did look into various forms of hull designs when we were first getting started. The so called “origami” technique of having almost no framework and bending intricately cut straight plate into the outer hull shape was perhaps the most novel and interesting and a technique that is being used by some commercial as well as more DIY hull builders. You are probably aware of the amazing sv Seeker project also known as “the boat the internet built” is using this technique to build an 86ft steel junk rigged sailboat that will be offered for research scientists to use when it launches and has become quite the YouTube sensation and has been great fun and learning to follow along with.
However for Möbius both Dennis and myself found that a combination of both transverse and longitudinal framing tied into an overly large central keel bar offered the optimal option for both construction and then strength once built.
Design and Construction wise, having that big central reference point to tie all the frames into and ensure the accuracy of the “kit style” CNC cutting we did provided a lot of benefits including time saving, more ensured accuracy, less prone to human errors, etc. Strength wise in addition to the strength of this skeletal backbone style we have, we will leave the 25mm keel bar proud of the hull panels by a good margin so that it would be the first point of contact in most situations. One or the many attractions of going to both power and to this style of boat was how much it increased our options for high latitude sailing. Much higher speeds in much larger weather windows compared to our previous sailboat opened up much more of the world for us and so we see some ice in our future. We have no interest in being an acutual ice breaker we did want to design and engineer Möbius such that she would never be broken by ice and that we would have full confidence spending time in single digit latitudes some of the time.
It isn’t a direct consequence of going with a keel bar based framework but based on my 12 years sailing and maintaining our steel sailboat I learned the benefit of having a grid like framework tied to a central keel bar on a metal boat in that it was relatively easy to cut out the hull plate material between one or more areas framed by the stringers and frames and weld in a new one. On our almost 25 year old steel boat this was required due to internal rusting rather than collisions or scrapes but it could apply to our new aluminium boat if we are unfortunate enough to strike something really big and hard that might require such drastic measures.
I’m certainly no naval architect or engineer or anything remotely close to that John so these are simply my logic and conclusions from talking to many such experts and using my experiential learning from the past.
I think I follow.
How about the same questions for the “shark fin like” protrusion?
Always a tension between directional stability and maneuverability?
Impact on rudder size?
Not really much debate or question for us when it came to the “shark fin” or keel on Möbius. We had to have one to protect the prop and rudder in any case and so the key decisions were based around choosing the best foil shape and otherwise shaping this into the hull for minimal resistance and optimizing water flow patterns for the prop, rudder and prop tunnels.
I don’t see much in the way of “bugs” or drawbacks with the keel given that you have to have something to enclose and protect the prop shaft, prop and rudder and as you noted it adds to some directional stability as well as a bit of roll attenuation. It is small enough that I don’t see there being much reduction in maneuverability given the size of our prop and rudder.
The only influence on the rudder size was in how deep to make the rudder so we have kept the bottom of the rudder a bit higher than the very thick bottom plating of the keel so it will take the brunt of any encounters with the hard bits in the oceans we travel. We have also designed the bottom 1/4 or so of the rudder to be purposefully “weaker” than the rest above so that it can take a good licking and the rudder keeps on ticking functionally.
You seem to be making very good progress Wayne and thank you for sharing the weekly updates.
Could you answer a few questions about the use of bare aluminium?
Firstly is there a choice of alloys to use? Which one did you pick and why?
Are you leaving the deck and coachroof unpainted and uncovered? Is it slippy under-foot when wet? And have you considered what temperature the outside deck would reach under say the Turkey summer sun. I met the owner of a dark grey colored GRP motorboat and he couldn’t walk on it bare foot in the sun! Might aluminium be the same?
Are you making the trims from aluminium too? I think Dashew has moved to aluminium stantions etc and gone non-stainless externally. Does this mean things have to be chunkier? And are things like cleats fabricated/welded not bolted on accessories?
I guess all aluminium will oxidise, but I have noticed some boats (a ferry recently in Malta was horrible!) have a very visible oxide layer which has a slight smell on hands etc. How is this dealt with – or is it in the choice of alloy?
I think you can guess where I am going with this. Painted aluminium is a no for me for corrosion reasons. I am just establishing the draw backs of bare aluminium???
Hi Nigel, glad you are enjoying the blog and appreciate you taking the time to follow along and post questions like this. It is work to create the posts but I enjoy it and get lots back from folks like you plus I want to be adding value back in to the “net” overall as I have benefited and continue to do so from so many other people who take the time to articulate and share what they are doing. We all benefit and all play a part and I’m happy to do mine.
There are plenty of marine grade Aluminium alloys to choose from however in reality my experience is that once you have a given application you are shopping for then the choices become very small and obvious based on industry “best practices” that are quite clear after the thousands of boats which have been built out of AL over the past many decades. The benefit of all this experiential learning and all the time in the water which has gone by to provide real world data and insights is what those of us building anew with AL can take great advantage of.
In our case we had the significant added advantage of the combined expertise of Dennis our designer out of NZ and Dincer and his team here at Naval Yachts. They got to know Möbius very intimately as well as our use cases so they were able to provide great advise and again, the decisions are pretty clear and easy once you have all these parameters to enter into the decision making.
It is also important to understand that you would never likely build the whole boat out of just one allow as they all have their specific pros and cons so once you know the details of each AL part you can make the call on the allow. AL hull plates that will have a lot of welding and be immersed in sea water and potentially have a likelihood of high abrasion from groundings for example would call for a different allow than would our rub rails which are going to require some relatively small radius bending to make them. Stanchions and railings and the arches we are building would be yet another use case that would call for yet another alloy.
I found this very brief overview of the primary allows on the Sunshine Metals site that you might find useful.
On Möbius we are using 5083 H321 for the hull plates, frames and stringers. For tubing we are using 6063 T6 for pipe which will be welded on the interior edges of stringers and such to create a soft edge and good hangers and then 6082 T6 for stanchions, arch, railings and the like.
Deck will be coated with something and right now most likely a Treadmaster like material which you glue down but also researching some of the paint on coatings specifically made for deck non skid such as KiwiGrip. Christine and I have spent most of our time in the tropics, Fiji, Caribbean, Marshall Islands, Polynesia, etc. so we are VERY familiar with the incredible heat absorption of deck materials. Some of the key things we learned on our last boat which was all steel was that having super well insulated below decks made a HUGE difference (we had 4″ of spray in foam on that boat, and the other key was colour of the paint or material. Anything but the purest white you can find get’s amazingly hot from the heat absorption of that colour. Even the slightest tint of ANY colour will heat up drastically more than pure white. And even finding “pure” white takes a bunch of research because what you need to find out is if there is any black based pigment mixed in there as there often is in most “white” paint blends to take off that blinding white colour. There is some good discussion on I think the Sailing forum discussing this, I think on the huge thread of the couple who was having a 49′ Besteavar AL boat built and there was some specific brands and colour names of white paint and charts of their heat absorption rates that would be helpful if you wanted to go that route.
For the decks of Möbius I think we will most likely end up with a Treadmaster like material and get it in white, though true Treadmaster is no longer available in white for some reason. These glue on materials are a vinyl like material and is about 3-4mm thick so in addition to the good non skid surface and the pattern of groves, this material is itself a bit of an insulator which doesn’t tend to transfer or retain heat. In any case be clear that you MUST put something on top of the bare AL decks or any other surfaces you walk on as they will burn you otherwise.
As for your questions about other parts on the exterior we have a list of “banned” materials on the exterior which include paint (non skid being the exception), SS or wood. Partly esthetics as we are very purposely going for a very utilitarian and quasi military don’t mess with me look so “bling” is banned. But low maintenance is another top priority so that accounts for these “banned” materials and the overall way we are constructing this boat. So yes, this means that we are using AL for pretty much everything on the exterior with the exception of the window glass and the Dyneema lifelines. For the most part going with all AL has not required us to design parts which are much “chunkier” than SS or other materials, at least not that you can see. The stanchions for example are about the same OD as we would have specified where they to be SS but their wall thickness is much greater but you can’t see that. I’ve also learned the value of having thicker things and mass in general for the reduction in noise and vibration transfer so the “chunkiness” can be a feature not a bug in the right places.
We will be CNC machining the cleats and they become integral parts of the hull by extending deep below the deck level, slotted around frames and thoroughly welded throughout. Bolt on exterior items are kept to a minimum and where we do use them they are made by welding an AL disc that has threaded holes in it to create a blind threaded hole on the deck because one of the other big items on the banned list is any penetrations of the hull. I’m still debating as to whether to make the few railings we have bolted on or welded on but if we go with bolted on they will all do so with disc flanges welded to the bottom of each railing tube with holes in it to match the blind threaded disc welded to the hull below it. No portholes or other openings in the hull sides for us thank you, no threaded fasteners of any kind penetrating the deck and so on. I’m designing our own hatches for example which we will fabricate here from CNC cut AL plate and the frames will be welded to the deck so we don’t have any fasteners and sealant to deal with. No through hulls either, we will use welded in place sea chests for all intake and exit of sea water, grey water and black (when at sea of course).
Like all materials aluminium is not all fabulous features and does have some “bugs” inherent with it. Oxidation is one that is a bug and a feature to me. The feature part is that AL Oxide creates a very hard durable surface coating on AL which keeps it very resistant to any corrosion from sea water and the like and tends to be quite “non stick’ in terms of dirt and growth. However as most of us know or have seen, this non stick feature becomes a real bug when you want to apply paint or adhesives to AL. The AL oxide forms almost immediately, has a “non stick” feature even for welding which is why you see us cleaning the AL parts just before they go into the hull to be welded so that these surfaces are clean of any oxide coating where they are going to be welded. So you can paint and stick things to AL with fastidious cleaning and then immediate coating and GreeNaval paints all their GN line of hybrid boats which are all AL and their finish is mirror like and amazing. BUT as you have seen anytime that painted surface is penetrated with a scratch or a crack, water will quickly start to slither its way ever inward and creates an oxygen starved wet environment which means that you don’t get oxidization you get poultice corrosion which quickly eats the AL and creates that white dust or toothpaste like stuff you see oozing out of those damaged areas and continuing to grow.
The other “bug” which you refer to is that some of the AL oxide does rub off and quickly turns your hands and feet black as it sounds like you discovered on the Maltese ferry. We are very conscious of this and will take a number of steps to minimize it on Möbius. Deck won’t be much of problem as there won’t be much in the way of exposed AL to walk on as it will all be covered by non skid material of some description. For other parts like hand rails that you touch regularly we will have those anodized so they and your hands stay clean so in the end I think we can really minimize this blackening aspect of AL. I have not read if one alloy of AL is any better or worse than others for this but I don’t think you would choose to use an alloy for this reason if it would compromise its other strength and benefits for those parts. For me then I take the approach of being aware of this blackening aspect of AL and figure out ways to minimize or eliminate it. You’ll have to ask me in a year or two how that worked out but again, there are a LOT of AL boats out there and it does not seem to be an overall or unsolvable problem.
I hope this comes across as intended Nigel. Not meaning to be defensive or say that AL is “the best” material or one with no drawbacks or faults. It is the clear winner for us in so many ways and we are liking it more every day working with it here as we build Möbius. I think the best way to treat any material you have on a boat is to be aware of its less appealing aspects, bugs and drawbacks and then do our best to work around these. So far in my experience there are good work arounds to all the faults of AL and the benefits far outweigh these and make it an excellent material for boat building in general.
Might be of interest to you and this point that I just read the latest issue of Professional Boat Builder magazine ** and it is all on AL for boat building because they are getting so many requests over the past 5 years for more articles on this material. When you add its excellent machinability and weldability and the exponential growth and features of CNC cutting and machining which make customized one offs no more costly than other materials or methods, I will be surprised if AL does not become the material of choice for most boats other than large production runs and I think this has already happened in the ship building industry.
** I recommend Professional Boat Builder magazine to anyone interested in boat building AND all the more enthusiastically with their recent decision to open up their entire back issue archive free of charge. I bought every back issue a few years ago and am very happy I did and I applaud their decision to support the industry even more by opening their entire archive for no charge. Worth checking out.
Thank you for your long answer Wayne. Lots of interesting info in there and I will check out Professional Boat Builder.
Choice of deck covering is hard. If you go with kiwigrip, presumably you would prime and paint first and then you are into the bubbling paint territory that you want to avoid. If you choose Treadmaster, then I guess you can get unseen corrosion under ?
I know that yacht masts are anodised to make them look smarter and stay nicer to handle. I have not seen it done but I suppose its electroplating in a chemical bath of some kind. Is it still possible to weld an anodised part? If not, I guess its use is limited to bolt on things.
I have noticed that sport-fishing boats, for example, seem to use a shiny aluminium for their tuna towers and biminis etc. This seems to stay nice, maybe its a special alloy as I cant think they get those structures into an anodising bath somehow!
In passing, I think it would be nice to have a finished boat renderings, elevations and a general arrangement plan on the website homepage to give a frame of reference. Would that be possible?
Unfortunately for you and others here Nigel long answers are all I’ve got! Do check out PBB when you have time, free subscription that only takes a few minutes if you like what you see and as I mentioned they now make their entire archive of back issues available online for no charge.
Another resource you might want to check out is the Attainable Adventures blog at morganscloud.com. John and his wife Phylis are long time sailors on their 54′ aluminium sailboat and he runs this subscription based web site that is another excellent source of good first hand information on many valuable topics including how to maintain aluminium boats, electronics, batteries, and so on.
You have it quite right about the dilemma of putting any coating on aluminium decks, either paint or glued on material open up the possibility of entrapping water under them with no oxygen which quickly leads to poultice corrosion. Paint has the quasi benefit of showing such damage more easily than glued down material but requires more maintenance to keep up. The flip side of that is that if/when you needed to replace the non skid treatment the painted on method is a bit easier to remove than the glued on material, however it probably is a wash over the long term as the Treadmaster like material or synthetic decking choices typically seem to last a good 20 years. Either method of creating non skid decks works though and the key is extremely careful surface preparation and application.
As I said right now we are leaning more towards the glued down approach as it offers a bit better non skid especially in freezing temps and snow apparently and also likely to be a bit more feet friendly in tropical sun conditions being a bit of an insulator itself. Stay tuned as the construction continues to see what we end up doing.
Anodising is pretty much the same methodology as chrome plating in that it is an electro chemical process. My understanding is that the companies which make anodised arches and the like use anodized tubing which they carefully bend and then weld up. In the weld areas there is debate amongst the manufacturers as to whether is better to leave the welds bare or cover them with either clear lacquer or paint. The other option is to have the whole assembly powder coated which is also an thermo process of spraying electrostatically charged paint (in powder form) onto the aluminium. It is thicker than anodising but can chip under some circumstances.
We won’t use much if any of these coatings on Möbius but I keep them in mind for things like a few hand holds or other places where we would be literally handling frequently and having the black oxide become annoying on our hands.
You are not the first to ask for more drawings and renderings and GA’s and we are working on getting more drawings, models and renderings of Möbius up on the site and just this week Burak created a nice little 3D model in HTML that Christine is now working on adding to the blog. You will be able to manipulate this 3D model on the screen to explore the boat a bit better that way. I’ll see if I can put up a post this weekend that has more of the GA drawings, profiles, etc. In the interim, if you go back to one of the first posts called “Project Goldilocks: Mission Impossible or Just Right” there is a rendering and a top and side drawing at the end of that post. Working on getting you more ASAP.