It is Eid al-Fitr here in Turkey right now which is a major 4 day holiday celebrating the end of Ramadan, the Islamic holy month of fasting so it as a three and a half day week with a half day on Thursday. After 30 days of dawn to sunset fasting you can imagine the joy and celebration going on over this long weekend. It is a time when families traditionally get together to mark the start of Eid with a lavish meal and we are delighted that Dincer and Baris have made the journey up to their original home town of Çanakkale which is at the far western end of the Sea of Marmara with Istanbul over on the far Eastern side. Enjoy your family time Baris & Dincer!
People who have jobs involving a lot of physical labour are exempted from the fasting so our crew were still able to have their tea breaks and lunch and keep up their fabulous progress on Möbius. I’ve talked in previous postings about our use of the “empty ends” design for Möbius which allows us to have as long as possible waterline for maximum hull speed and efficiency but keep the interior just right sized for us by leaving the two ends of the boat, bow and stern, relatively “empty” non living space for storage, propulsion and other systems equipment. This week the focus was on framing in these two empty ends of the boat by erecting the frames at both ends and connecting them up with stringers and baffles for the tanks. The week may have been short on days but it was long on progress with TWO exciting milestones; the final Frame was erected on the jig and our first 2 hull plates were tacked in place! Many more milestones to come but I’m getting ahead of myself so let’s jump right in and let the pictures do all the talking as I take you through all the progress from June 11th through 14th, 2018.
As you may recall from last week’s post, this is what the aft end framing looked like. The Engine Room Enclosure begins at Frame #17 seen at the left and the rest is all for my amazing Workshop. All the frames are in, the longitudinal stringers have been installed in their matching slots and everything is precisely tacked in position.
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f you click to enlarge this photo you can see the lengthways running engine beds up at the top which have been fabricated from very beefy 25mm plate flanked by two large water tanks on each side within the hull as elsewhere on the boat.
All of which set the stage for THIS!
The very first hull plate is lifted into position
and Umit tacked it in place to the stringers and frames.
Frames are notched where the lengths of plate meet up to allow for a continuous weld which will be done once all the plates have been tacked in place.
The next day a second 6m/20ft length of 6mm plate could be tacked in place in front of the first.
and I can now sight down these two hull plates and use my AI (Augmented Imagination) to visualise the sleek slender shape of our hull. It is difficult to see in these pictures with just these two upper plates but there is a nice compound curve to these plates as they move aft and begin the narrowing of the hull aft.
This subsequently set the stage for positioning the aft transom plate and tacking it in place.
The rectangular opening on the right will have a watertight door on it and is our HazMat locker for safely storing things like fuel, welding gas, propane and anything else that we want to keep safely outside of the boat but in a dry secure space.
The opening where Enver and Umit are standing is another WT door in and out of the Workshop and Engine Room areas.
Here is a shot looking aft inside what will be the Workshop and Engine Room enclosure with the HazMat locker on the left, entrance door on the right. Keeping in mind the boat is upside down right now you can join me in imagining this great space.
Umit who is about 190cm/6.2ft will give you a sense of scale in this space and you can start to see the prop tunnel shape when those upper curves in the frames are plated in.
Moving forward to the mid sections of the hull, the tank assembly which you saw lifted into place a few weeks ago is now being framed in and the margin plates installed which form the top of the tanks where they intersect the hull plates.
On the right here we see the bulkhead which separates our Master Cabin on the left from the Galley and Basement areas to the right. There is a “void” in here to form an air space between the fuel tanks in the floor on the right and water on the left and here you see the stringers being tacked into place. Up at the very top, soon to the very bottom when we flip the hull right side up, you can also see the big thick 25mm Keel Bar which travels all the way from stem to stern and forms a super strong backbone for the whole boat.
I have previously noted some of the various ways which wedges are used to put aluminium pieces into perfect alignment and here you see that same Keel Bar and this wedge being used to align this joint which will soon be fully welded to form a single bar.
Panning over and out a bit above our Master Cabin shows more of the stringers and baffles forming the underfloor integral tanks.
Looking aft you can see how the gridwork of baffles and frames for all the integral tanks are mostly in place now.
What you can’t see as well are the nautical miles of welding in place along all every edge of these baffles. This is one of the spools of AL wire for one of the MIG welders and they go through several of these a day now. All of this just a warm up act for the truly long lengths of weld which will begin once the hull plates are tacked in place and this giant jig saw puzzle of a hull has been fully assembled.
Continuing our way forward this is Frame #4 on the left which is the WT Bulkhead separating the forward end of our Master Cabin from the Forepeak storage area and you can see Uğur up on top tacking the margin plate in place.
Back up on top this forward looking shot shows the framing pretty much complete under our Master Cabin and a view of the Forepeak area where we are headed next.
Back on the ground and looking towards the bow we see all four frames that make up the bow.
If you’ve really been paying attention to these posts this is the first time we’ve seen Frame #1 in place which is the last frame to be added so another welcomed milestone this week is having ALL the frames now in place which is overly exciting for your reporter here!
Next week when everyone is back and fully fed, the framing in will continue as will the addition of more plates so the hull will soon take on more and more of its shape for you.
For now though, here is this week’s compilation of sped up video clips I took throughout the week.
My sincere thanks for taking the time to join us on this journey and be sure to add your questions and suggestions in the comments box below.
– Wayne
Fascinated by your posts Wayne – thanks for sharing. Dennis H pointed me here as I have an interest in building this type of boat one day to replace my Ocean 71 ketch.
One question – you refer to tack welding all the time. Is the plan to tack the boat together and then go back for final welding? Is everything accessible when you do that? I am thinking bottom of tank baffles. Back of frames etc.
Hi Nigel and welcome aboard. Your Ocean 71 is a beauty. Never been fortunate enough to be onboard one but have had several anchored near us in the past to get a better look and we certainly liked what we saw. Hope our blogging the experience of designing and building Möbius provide you with some helpful ideas as you consider building once yourself one day and don’t hesitate to put in questions along the way or send me an Email whichever you prefer. Things are certainly busy here but I’ll do my best to get back to you as quickly as I can.
To your question about tacking, you have it right that the general idea is to tack everything together first and leave most of the continuous welding to the end. This is key to taking maximum advantage of the accuracy of having all the parts CNC cut and Dennis has added this feature to the overall design by having most parts be interlocking. If you look over some of the previous posts you will see how things like all the stringers fit into slots cut into the parts they intersect with and how the massive Keel Bar fits into slots cut into each bulkhead and frame. Even in spots where there are two pieces which butt up against each other there is often a tab cut into the end of one and a slot in the plate where it joins. In other cases the CNC has etched lines and marks into the plates so that the locations for each part are all clearly and accurately laid out. This interlocking feature along with lots of careful measurements with the laser sighting tool ensures that the parts all match up with the design and we get a very true and fair hull.
And you are quite correct that we also need to take welding access into account with this process. As you are seeing in the construction so far the welders are taking advantage of the good accessibility as it occurs and so places such as where the baffles joint the frames and the stringers are now being fully welded up. The tanks for sub assemblies which in turn are located by the stringers and margin plates so the self correcting nature of this “interlocking kit” approach is maintained. One of the trickier places as you noted is welding the bottom edges of the tank baffles to the hull plates and in this case the spacing of the baffles has in large part been determined by allowing enough space for the welder to reach down to the bottom. MIG welding has the benefit of having a relatively small “gun” at the end with a light trigger on it so the welders are able to run the gun at arms length relatively easily. Though I’m very glad it isn’t me doing all these nautical miles of welds!
In other places a key technique called “slot welding” is used where elongated slots are cut into plates such as tank tops that are last to be welded into the tank assemblies. These slots align with flat bar running along the top edges of the baffles and frames and allow the MIG welder to fill these slots with AL that is then ground off flush and the weld pretty much disappears. You will see these rows of elongated round end slots in some of the panels sitting alongside the boat right now and then late in the hull building process I will show this in more detail. Hope this answers your question reasonably well and if you scan through some of the previous posts the pictures will do a much better job of showing this.
Thanks again for the interest and please jump in any time with more questions as they come up.
– Wayne
Hi Wayne and Nigel too,
How weird a coincidence is this. I’m avidly following this fascinating blog as I dream of someday moving up to an FPB or one of these boats. The coincidence is that I cut my teeth sailing before the mast as crew on an Ocean 71. A wonderful boat, and a great couple of years, that I will never forget.
Welcome aboard Dave. I’ve been using serendipity and synchronicity as guides most of my life and speak to this often so no surprise with all the overlaps and connections that you are finding here and glad to see these forces still working so well. I noticed you were on the Attainable Adventures blog as well the other day so more examples of the overlapping interests and people here.
Christine and I are also long time sailors and never thought we would be doing this but once we first started to talk about it the more intriguing it became and as with most changes in my life I reach a point where I can’t learn anything more and follow my curiosity any further from research and vicarious experiences and so just go for it, jump into the deep end of the ignorance pool and start learning experientially. This is how I got into sailing initially and we reached the same point with this consideration of voyaging under power and decided that we needed to bite the bullet and set off to design and build this new boat. In addition to the amazing adventure of designing and building a new boat, one of the biggest aspects of voyaging under power that is calling our name the loudest is the entirely new set of challenges this provides us with. We were definitely not tired of sailing and are fortunate enough to be in very good health in our mid 60’s now and had thought that we’d continue sailing the world for the foreseeable future. But the opportunity to see more of the world and to have all these new challenges which so few others have faced beckoned so compellingly that we said “Lets do it” and that’s what you now see us doing.
Great to have you along for the ride and please don’t hesitate to add your ideas, questions and the like in the comments here as these conversations and discussions are so rich in value to all of us and is the primary reason for creating this blog. Thanks.
-Wayne
Hi Wayne,
Exciting to see the progress, it’s getting easier to discern the boat to be!
I’m curious about a few aspects:
1. I’m assuming that the (exposed) windows in the SuperSalon allow a view both when seated and standing. Given the safety requirement that’s apparently expensive in both the financial and the weight-above-the-waterline sense. What material(s) and thickness(es) did you land on?
2. I’m guessing that the two accommodation spaces in the hull (having no windows in the hull) will have at least one hatch each, with possibly the workshop as well. Are you going with a hatch with a window (allowing light to enter even when closed) or solid aluminium hatches (which are probably easier to make safe, and isolate)? Apparently mounting them slightly heightened helps with keeping the water out as well?
3. In a future post, could you post an accommodation and deck plan?
If these questions front run a post, please disregard.
Good questions Carl and I’ll answer as best I can right now.
1. Yes one of our design criteria was to have 360 degrees of views, whether sitting or standing in the “SuperSalon”. We had 270 degrees in our previous boat with her raised salon and loved it so an enhanced version of this was a “must have” for the new boat. Adding self righting as another must have requirement from our sailing days this meant that the glass has to be quite thick and thus heavy. There are standards and formulas for calculating the glass but in general the windows, glass, frames, etc. need to be the same or greater strength as if the surrounding AL plate. In our case the glass will be laminated from 2 panes of tempered glass with each one like to be the same thickness of about 12-15mm. We are still working with the glass suppliers right now to work out the exact design and thicknesses but this is close to what I think we will end up with. I am also considering a double paned setup with a gap between like in house windows as this would help out quite a bit with the heat transmission through the windows but we need to see if we can find a supplier who can make these that would be up to the required specs and guaranteed to not ever have the seals leak. I suspect we will end up with solid glass though.
One related factor you might find interesting is that we are also exploring options for the film we will most likely put on the inside of the glass to reduce the amount of solar heat coming through all this glass. There are some very high performance clear films for this and one fascinating characteristic several of these have is that they provide an unbelievable amount of shatterproof protection. We already have very good protection by laminating two panes of tempered glass but this unexpected and added protection of the film will help increase our SWAN factor very nicely. I will write up more about our glass decisions and installation as we get to it in the construction.
2. Lighting is another key feature we have learned to appreciate and value in our boats and it too is one of the key characteristics of our design requirements. We decided to go with no windows anywhere in the hull partly out of safety being the highest priority and partly because we are rarely in the two rooms below deck, our Master Cabin and the Guest Cabin when it is daylight and so views per se are not critical. LOTS of natural light however is a requirement and as you guessed that means these cabins will have several large hatches to let in plenty of light as well as equally critical fresh air. I am currently designing the hatches as we will make them ourselves here because I have yet to find a hatch which has all the features and strength I want. Like you it sounds we too have learned that raising the hatch frame well above the deck helps to reduce water intrusion especially on the hatches on the foredeck which are often subject to high volumes of green water in high seas. We will fabricate the hatch frames in the hull from thick wide flat bar that we can roll bend with large radius corners and then fully weld into the deck so there are no fasteners, no sealants and no leaks. I am designing these frames to protrude well above and below the deck itself. Above the deck to create a bit of a damn or wall to deflect any large waves washing over and below the deck to get down flush to the ceiling panels to aid in trimming them out with solid wood.
For the lids my current thinking is to CNC machine these out of very thick 25-50mm AL plate with a recess for 15-20mm laminated glass to be sealed in place. Plastic lenses seem to craze very quickly whereas the glass will stay clear throughout its long life and by utilizing the same standards as the salon glass windows we can ensure they are plenty strong enough. Such construction would make these lids heavy but I think we could easily incorporate some compressed gas struts into the design to deal with that. I have similar thoughts as you mentioned to the benefits of having solid AL hatch lids so I’m playing around with some ideas of how to incorporate an additional AL plate cover for the hatches in the forward deck area which could be installed when heading out on long passages or when nasty conditions are headed our way. But I’m not sure it is worth the trouble and will try to make the regular glass based lids extremely robust and waterproof in all conditions. To help these forward hatches stay well sealed when being hit with those big green waves coving over the bow sometimes, I think we will also weld in some “damn walls” as a first line of defense by taking the brunt of the force of these waves. These damn walls would simply be wide AL flatbar bent into a U type shape wrapping around the front and both sides of each hatch spaced about 50mm way from the outer hatch lid edges for plenty of drainage. However I will test our hatches when they are first installed with good blasts from a fire hose and see if we’ve come up with a hatch design that stays fully sealed in such high pressure situations to see if these additional defenses are needed.
3. Working on finalizing deck plan drawings and will post when we have them. In the interim, if you check out the section profile drawings in the “Extremely Baffling” post you will get a good idea of the layout. We really liked the “down/up/down” arrangement on our previous boat with the two cabins being down a few steps from the salon so we are going with a similar layout on Möbius. The Galley, Dining area, Lounge and Helm station are all “up” and constitute what we are calling our SuperSalaon and then both Cabins are down 4 steps from there. Galley is aft Stbd with dining table in front of that and the access way and lounge chair area to Port. Drawings to follow soon.
-Wayne
If my math works correctly, the plating is slightly less than 1/4 inches thick. Curious about what kind of point loads that can take from things like inadvertant grounding or stricking something floating out there like a log, etc. Is there an intent to add a “grounding” plate to the bottom for purposeful grounding to dry out the bottom?
Hi John. Hull integrity is certainly right up at the top of our priorities list as it is so key to our overall confidence in passagemaking on this go anywhere boat. We are coming from a very well built steel “tank” in the form of our previous 52′ Canadian built motorsailer so we have learned from lots of experiences with “things that go bump in the night” and how important plating thicknesses is and why we love metal boats.
Switching over to aluminium and a completely different boat, we spent a lot of time working with our naval architect and engineers to develop the just right plating combination for our new boat and it ranges from 6mm at deck level up to 25mm at the keel.
There are a few renderings in some of my past posts which show the various thickness plates in different colours that will make this quite clear and varies as follows:
• 6mm (0.24″) from deck level down 1m
• 10mm (0.4”) down to about 350mm above the WL
• 15mm (0.6”) for first 4.3m of bow
• 12mm (0.47”) remaining length from WL to Keel Bar
• 25mm (1”) Keel Bar from upper deck at bow to end of swim step.
No “grounding plate” per se as we have not designed for “drying out” situations with no active stabilizer fins at launch and a single rudder/prop setup and frankly not a feature we see much use case for.
The Keel Bar will be left proud of all the deck plates so it will be the first point of contact most of the time and this along with the very generous plate thicknesses should keep us very well protected in any situations we have encountered or can imagine. Logs and such will present annoyance rather than any damage and about the only thing which we can imagine is a mostly submerged container which depending on where, what speed and how we hit it would have the ability to puncture the hull. However, with the 25mm Keel Bar and 15mm plating for the first 4.3m, the crash bulkhead and everything below the WL being tankage we think we are as well prepared for the unexpected or unthinkable as is possible to be.
Hope that helps answer your questions and thanks for contributing.
-Wayne
Thanks
I guess the keel bar will help a slight amount with resisting wind driven drift also.
As to drying out, different strokes for different folks. But I definately agree that “with no active stabilizer fins at launch and a single rudder/prop setup” drying out is not an option.
Quite right John, the “trick” for each of us is to figure out what is just right for us and have the boat which fits these criteria and use cases. We considered having this drying out option but just didn’t have a good cost/benefit ratio for us. I think that if you live in or regularly cruise in areas of the world that have the tides and bottoms that make drying out possible then this could be nice option but we have rarely been in such areas and wouldn’t likely take advantage of it even when we were. We talked to others with boats that do have this option and it seemed like it was one of those things that sounded like a good idea but after years of use almost none of them could remember doing it. The ability to settle onto the bottom and remain fully upright appealed to us and we would have been happy to have it as a consequence of having say twin rudders, sturdy stabilizer fins or bilge keels but we have decided to have none of those so drying out is an option we knowingly give up with those decisions.
For maintenance of the hull below the waterline our preference is to use our electric “hookah” for things like cleaning the bottom and have come to almost “like” doing so as we can usually find some nice lonely little bay to do this and enjoy the fitness routine of being down there for a long time. Having a clean bottom and prop makes such a difference to the efficiency of the hull so we have made it a habit to do a good bottom scraping with plastic scrapers after we’ve been sitting for a long time and are about to head out on a longer passage. In addition to the hookah we bought some of those big plastic clamp on suction cups with handles that the glass moving people use and just clamp on these instant hand holds to the hull and scrape down a large radius area around that and then just unclamp, move and reclamp for the next area. And the other helpful trick was to make up some ankle weights out of bicycle inner tubes and plastic mesh tubes filled with lead shot. We strap these to our ankles to help keep us vertical in the water and not always floating up horizontal as we work and makes it all go much faster and easier.
We’ll make the call before launch but one option we are seriously thinking of is using CopperCoat for the bottom paint. Given our preference for hand scraping the bottom and not having to haul out and remove/replace the bottom paint every year or two this option is very appealing. We have talked to owners who have done this to their boats and seems to have been working quite well and holding up to the advertised claims of effectiveness and long lifespan of 10+ years. So that’s the quick update on our construction and plans for the hull, thanks for asking.
-Wayne
This does not apply to your current construction but I’ve always been facinated by nickle copper alloys for hull construction
https://www.copper.org/applications/marine/cuni/properties/corrosion/corrosion_resistance_and_antifouling.html#90-10
https://www.copper.org/applications/marine/cuni/applications/hulls/performance_corrosion.html#Table1
Cu-Ni is a fascinating material and it was on our list of materials when we first began researching the best material to choose when building this new boat was an early idea. It dropped of our list mostly because it was still too unproven and too many possible problems that could arise with dissimilar metals, welding, etc. and the cost/benefit ratio wasn’t high enough for our use case. Appreciate the links and reading more about it. The option of covering an existing hull with Cu-Ni foil is an interesting option that I could see becoming more popular as bottom paints become less and less effective and concerns for their harmful effects grows. For Mobius as I mentioned I think that using a copper based paint on the bottom might be a good fit for us and we are looking into that more. Seems to be proving itself over the past 10+ years on other boats we have talked with and our designer Dennis put this on his LRC58 “Koti” and it has been working very well.
duplicate ?
https://www.copper.org/applications/marine/cuni/applications/hulls/performance_corrosion.html#Table1
Apparently having a FAT FINGER USER PROBLEM
Excuse the possible duplicates
https://www.copper.org/applications/marine/cuni/applications/hulls/performance_corrosion.html
While we’re waiting, check out this site:
https://www.hullvane.com
Does the Hull Vane appear to be applicable to your hull design?
“For a 25 m vessel, this means a speed range from 6 to 21 knots”
Although you are in the 6 to 11.5 knot range, the lower half, it is definately in your speed range.
Fun bit of synchronicity as I had watched a YouTube video on that Hull Vane last week and it sounded very interesting. From my very small bit of research so far I think it could quite possibly deliver some good benefits for these XPM style boats so I’ll be looking into it more and thanks for sending the note. Nice thing about AL construction is that it makes adding something like a Hull Vane relatively quick and easy so would not be a problem to install. I assume that Hull Vane would do the engineering calculations for you so I’ll look into that and will be interesting to see if having a prop tunnel with that different stern wake presents a problem for the Hull Vane. We are all about efficiency so if a hull vane was able to improve the overall efficiency of the hull through the water, reduce motion and fuel burn that could help make such an addition pay for itself over time. And we certainly like KISS items (Keep It Simple & Safe) so the no moving parts and simplicity of this design add to the appeal. Thanks John.
my pleasure