Most of the visible changes this week of July 23-27, 2018 took place up at the bow though there was also lots of work going on inside as more of the thick hull plates on the bottom of the hull (currently the top in its upside down position) were pulled tight against the framework and tacked in welded in place. Weather here cooled off nicely at the beginning of the week and temps are down to the mid 30’s during the day and dipping into the high 20’s a few nights so makes for very pleasant weather for our early morning workouts and sundowners out on the porch and pool at our apartment. But things continue to go hot and heavy with Team Möbius as Project Goldilocks continues to make great progress so let’s get to showing you that now.
With the title providing some clues can you guess what this is??
That’s right, this is Möbius’ nose cone! Or at least that’s what we are calling it.
A few more clips from the Rhino model to bring this all into focus before I take you through the real thing. This clip off the model looking at the front Port side. Nose cone in blue.
Here is what it will look like when you are standing up on the anchor deck area.
You can see how the deck in this area is recessed and angled steeply as it goes forward to the nose cone which serves two purposes; a strong centered fair lead for the nylon snubber line to travel though from the Samson post out to the anchor chain and to provide a good drain for all the water and muck rinsed off the chain as the anchor comes aboard.
The nose cone started out as a 300mm/12” diameter cylinder of solid aluminium which was first bored out to an inner diameter of 120mm/5” and then machined to taper out to a diameter of about 150mm/6” at each end.
This created a very smooth curve on the inside a bit like the inside flared end of a trumpet with large radius blends around the outer ends to provide a very smooth surface for the nylon snubber line to bear against as it stretches in and out while we are on anchor.
As you may recall from a previous post the snubber line acts as a shock absorber as the boat tugs against the anchor with wind and waves thanks to the stretchy characteristic of 3 strand nylon line.
We spend the majority of our life aboard at anchor so this is a very important feature we use almost every day and night. The snubber line also eliminates the rattle of the anchor chain in the bow roller as it is isolated from the boat by this length of nylon line.
My hand will give you a sense of scale.
Burak pulled some 2D templates off the 3D model which Uğur and the team used to trace the complex curves where the surrounding plates support the nose cone and it was soon tacked in place.
If you look closely (click to enlarge) you can see how the snubber line has a nice straight line through the middle of the nose cone to the Samson post it is tied off on.
Once everything is all lined up and tacked, Sezgin is called in to do the continuous welding
With all the welding finished on the inside this large collision bulkhead,,
the Starboard hull plate can now be fitted. The Port side has already been fully plated so there is no access to the inside to weld this Stbd plate so these rows of slots have been cut to expose the underlying flat bar like the one you can see here running parallel to the upper edge of the hull plate.
The hull plate is checked for precise position and then tack welded through the slots.
A length of flat bar is tacked to along the upper edge of this first plate to keep that edge perfectly straight when the next 10mm hull plate is welded where they butt together.
The 10mm plate is soon all tacked in place and ready for the final 15mm / 5/8” thick “ice plate” is welded in place to complete the bow plating.
What is this guy doing over on the Starboard side of the bow? That upper 15mm plate wasn’t quite up tight against the underlying flat bars under those slots so Uğur and I where deciding how best to pull the plate in tight before it was welded. A U shaped bridge made out of thick aluminium plate was welded to the 25mm Stem Bar up top and the 15mm plate below so that a hydraulic jack could push the bow plate the last few mm to be tight against the flat bar and it was soon tacked to stay there.
Meanwhile over on the middle section of the Port side Enver and Umit have been working on getting the 12mm plate carefully fitted in place and tacked to the inner framework.
These thicker plates with their complex 3D curves require careful work to trim them to fit just right with no gaps where their edges butt together and their inner curved surfaces are laying tight against the frames. All in a days work for talented and persistent Team Möbius.
Next week the attention will shift to the Starboard side plating some of which you see here with their edges all nicely beveled in preparation for being welded together.
Mehmet is a true worker bee as he works non stop to clean up all the tack welds with wire wheels and rotary bits prior to Sezgin coming along and laying down the final welds which Mehmet then needs to thoroughly clean again for their final finish.
Throughout the week the humm and crackle of the MIG welder is our ever present background music as Sezgin welds and welds and welds.
Not to be outdone by the work of mere mortals, Mother Nature topped off our busy and productive week with flair and Christine and I had the perfect view from the balcony of our nearby 9th story apartment for the truly awemazing sight of the total eclipse creating this extremely rare blood moon.
And so another week has zipped by and here is the time lapse video summary for you to enjoy.
Amazing progress and love how her lines are beginning to take shape!! Terrific craftsmen!
Thanks Sue, we too are very happy with the progress and how she is shaping up. It is about three years now since we first started down this path and with the wonders of 3D modeling and rendering in many ways Mobius has felt very real to us and we don’t even need to close our eyes to walk through her, however there is still a difference between virtual and real so we have been enjoying that transition as her shape and scale emerges a bit more every day in very real aluminium. We can not say enough good things about the whole Team Mobius here at Naval Yachts, from the two brothers Baris and Dincer who created this rapidly growing company to each of the people you are seeing in the posts doing the construction out on the shop floor and people like Burak who is constantly working on details in the models and coordinating all the ordering and scheduling. And this is “just” the metalworking guys, wait till you see what the others who will join this team add to the equation with all the systems installation, cabinetmaking, electronics and so on.
You and Bob have designed and built your share of homes and planes and such so you know this experience very well yourselves. Some stages seem to go very quickly and the progress is very visual and obvious. Other stages seem to take forever and not much seems to be changing. The details and decisions every day can seem endless sometimes and yet we wouldn’t really ever want it any other way and the end results are only able to bring us the joys they do because of all the blood, sweat and tears that we put into these projects. Do keep a visit in mind so you can come see this for yourself and let us share some of both this experience and this fabulous part of the world with you.
Hope to see you soon??!!!
“The nose cone started out as a 300mm/12” diameter cylinder of solid aluminium which was first bored out to an inner diameter of 120mm/5” and then machined to taper out to a diameter of about 150mm/6” at each end.”
Caught ya. I knew you were using solid aluminum chunks and machining away the stuff you didn’ need. lol
I am constantly in awe of the volume and quailty of work being done by the very small in number welding crew!!! I keep telling myself, “John, do you realize what that crew is accomplishing?”
Are you getting a feel if that is the optimum size crew for the task, taking into account their very extra ordinary capabilities.
Gleefully guilty as charged John. I’ve been working with metal most of my life and one of the most powerful aspects of metal is how many ways you can work with it. You can do additive things like welding, even 3D printing of more and more metals. You can work it like clay with things like forging and wheeling. You can fabricate new assemblies by bolting parts together. You can turn it into a liquid by melting it and pouring it into any shape you want with molds. You can bend and shape it cold or hot. And as you noted you can do subtractive machining on lathes, milling machines and shapers.
I loved introducing my students to this marvelous world of metal when I was a metalworking teacher for many years and I continued my love of working with this, and pretty much all other materials to build and make things right up to this day.
A large part of what motivated me to take on the very daunting Project Goldilocks was the opportunities and challenges this gifts me with to work with so many different materials, and so many people, on such a grand scale. And when she’s done she becomes my magic carpet ride to eXplore the world and be our full time home. Pretty hard for a “maker” like me to beat that combination!
Ah, a “fabricator”. It is interesting how the role of a “fabricator” has evolved with the introducition of information processing technology. From another field, the Shelby Daytona Coupe in many ways marks a demarcation from a fabricator’s product to that of the engineer and fabricator, and now adds the technologist who can create “design” alloys.
Interesting question about work crew size John. Based on the progress so far I’d say that for this stage of the build it is a Goldilocks or just right sized team we have here. There would be a lot of different factors that would go into defining what an optimum sized crew would be but I quite like the current size because it seems to be just right for the ebbs and flows of the work load. There are days when you could put more people to work but there are other days when you have more than enough so having more all the time would not be very effective I don’t think. The scenario will change in the next few months as we are able to start having different kinds of crews working simultaneously on things like systems installations, interior cabinetry, plumbing, electrical and so on.
We have a significant advantage with staffing flexibility here in the Antalya Free Zone in that there are so many different shipyards within a few blocks of each other and so there is this overall pool of people with as you put it “very extra ordinary capabilities” for all of the shipyards to draw upon in a very “on demand” and “just in time” way. As best as I can tell most of the skilled workers here “float” between companies and projects rather than being employees of any one company. As you can appreciate this kind of flexibility is fabulous to have at our avail and seems to be a very win-win situation for both the projects and the people.
This was one of many key factors which drove our decision to choose to build Mobius here in the Antalya Free Zone and do so with Naval Yachts and that decision has been confirmed and validated more every day we’ve been here.
couple of questions
What were the design decisions that led going from twin engines to one?
Bow design. These passagemakers appear to be designed to operate well in a following sea. The bow is faster than the stern. The problem arises that you have to have enough boynacy in the bow to keep the stern from driving the boat into a submarine. The bow has to come up. Very subtile shaping of the bow is required. How’d you handle that?
Hi John. A decent answer to your question about single vs twin engines is deserving of its own post which I’ll do my best to write up in the next few weeks and for now I’ll just list the main points of our rationale on deciding a single main engine and prop system was the best for us. For clarity and convenience and because this really does need to be thought of as the whole propulsion system from engine through to propeller, I will use the term “single screw” to refer to the entire propulsion system of a single diesel engine driving a single gearbox, prop shaft and propeller, and “twin” to mean two of the same complete propulsion systems.
Let me use my last point above to start by saying that this choice of engine/propulsion systems is an extremely personal decision because our lives at sea are very dependent upon this system. This goes in part to the overall confidence we believe every crew needs to have in their boat before they can or should go to sea. As with most things about our design then I want to stress that these are our personal reasons and what makes sense, works best and fits best with us and our use cases. Every other boat owner needs to make this decision based on their own equally unique situation.
Secondly I should note that our journey to this decision was an extremely educational one and a long one which we worked on somewhat constantly for over a year. Several times along the way we thought the decision was clear but upon further reflection, discussion and research we moved on and eventually decided a single engine and propulsion system was best for us. This decision is a very big factor in the overall hull design so once made it is very much fixed and not something we can change in the design but in the year or so since we made it, this decision to go with a single engine/prop has been confirmed in our minds many times as we have learned more, spoken with owners of all different configurations and delivered several boats with different setups.
The decision on engines/propulsion systems seems to come down to four options:
* Single screw: one main engine and one prop system.
* Single screw with an additional independent power source (hydraulic/electric/diesel) able to be connected to the same (single) prop system.
* Single screw with a second “get home” engine/prop system
* Twin screws: two equal diesel engines each driving their own gear boxes, shafts and props.
Of these four we quickly ruled out the middle two. The independent power source able to drive the same prop system does not provide any solution for the loss of use of the prop system and has other cons for us and the “get home” system would only seem to make sense as a refit to an existing single engine boat. With a new build it would not seem to make sense to put in a seldom used “get home” system so you would go with twins. That left us two choices and your question; single or twin?
Defining further, the problem to be solved here, the scenarios we are concerned about are:
* Loss of engine power due to fuel or cooling related problems.
* Loss of engine power due to other mechanical problems or failures; seized or stopped engine, etc.
* Loss of propulsion system due to failure of prop shaft: seized/turned cutlass bearings, shaft seal leakage, broken shaft, etc.
* Fouling or breaking of propeller; logs, coral, rocks, line, cable, nets, etc.
Lastly and perhaps most importantly for this discussion and decision, the primary goals need to be clarified. In our case it was to have a propulsion system (engine through to propeller) which would have:
* the least likelihood of failure in the first place,
* the highest likelihood of being able to resolve the failure
* the ability to drive the boat at 5 knots or more for at least 1000nm in typical open ocean conditions.
The key factors in our decision to go with a single screw were as follows:
* Single engine/prop boats are by far the most common amongst groups like commercial fishermen who’s both lives and livelihood depend upon their boats getting them there and back. We spoke with and spent time with many of them and their consensus was clear, singles were the most likely to do the job best.
* I can’t be sure of exact numbers and they certainly are changing, but I would guess that by far the majority of world cruising boats, sail or power, are still using single screws and the number or reports of situations where these singles have failed and having a twin screw boat would have prevented this seem very, very small. Catamarns and twin screw preferences but much of the buying public are changing these numbers but the data an experiences we have to go on now are predominantly single screw boats and the probability of loss of the propulsion system is very low.
* Christine, who was an equal voting member in this 2 person decision, had a bit of an Aha! moment when she realized that almost every sailboat goes to sea with a single propulsion system, otherwise known as their mast & sails. While most sailboats do have a diesel engine these can not really be considered a “get home” solution as they have neither the power nor the fuel capacity to get you out of trouble or “home”. This didn’t make the decision or us but it did add a useful perspective for us two former single handed and single engine sailors.
* One of the more interesting and surprising things we learned was that twin screws have an increased likelihood of being fouled compared to singles. This was often sited by the commercial captains we spoke to and while somewhat more complex the basic reason is that with two counter and outboard rotating propellers (top of blades rotate outwards) create a kind of suction zone below them which tend to pull debris, lines, nets, etc. into the props. Not going to be something that happens too often but was a factor to consider.
* Twin screws have literally twice the number of moving parts and things to go wrong. The counter argument for twins is of course is that if there is a mechanical failure it is likely to only affect one and you still have the other to keep you going. So this is not a “safety” issue so much as a maintenance and repair factor.
* In the majority of scenarios we could imagine that would cause loss of power such as bad fuel, fouling, etc. it is most likely it would take out both engines as often as just one.
* While we will and do gladly pay for safety related equipment, we did add to our discussion and research, the initial costs and ongoing maintenance costs of these different solutions. We do this by first taking costs out of the equation entirely and see what our answer is and then add the cost factor back in and see if our choices would change. Twins more than doubled both sets of costs as well as the amount of maintenance time which is a factor because my maintenance staff is the guy I see in the mirror!
OK, let me try to bring this to a conclusion with a few more related factors in our decision making process:
* DRAG: from props, rudders, etc. Not a huge difference but more drag from twins
* PROPELLER/RUDDER PROTECTION: Twins with props and spade rudders on the side loose the protection of the keel and skeg.
* STEERING SYSTEM: Affected by single/twins as twins would most likely have twin rudders.
* DRAFT: Less with twins but we nullified this by using a prop tunnel.
* CLOSE QUARTER MANEUVERABILITY: Twin props and rudders, if spaced well apart provide distinct advantages in turning in close quarters. We will counter this with a bow thruster, CPP prop and oversized rudder.
* FUEL BURN: Twins would be slightly less efficient fuel wise.
* ENGINE ROOM: Twins would require a larger engine room or at least take up more space.
So what is our “get home” strategy?
* PREVENTION: Well designed propulsion and steering system which reduces probability of an unfixable failure to a very low, though never zero, number. Super reliable Gardner engine and Nogva CPP gearbox, shaft & prop. Closed loop keel cooling, Alfa Laval fuel cleaning system, gear not impeller based sea water pump for wet exhaust, dual sea chests for sea water intake, etc.
* MAINTENANCE: Well maintained system with all work done by myself. Single screw commercial boats have this as their strategy.
* WORKSHOP: Well equipped Workshop with all the tools, spares, equipment to resolve most any problem including set of four CPP prop blades.
* TENDER asa TUG: Another whole post at least but our tender will be diesel powered and will have a rig to attach it to the rear of Möbius to power it in an emergency fail situation.
* KITE w/ AutoPilot (eventually). Not currently ready for prime time nor affordable for our size of boat but getting closer all the time.
Well as usual I have added more proof, not that it was needed, to just how brevity challenged I am and I will still write this up as a whole post to cover more thoroughly in the coming weeks. Until then I hope this gives you and others reading an overall sense of why we have chosen to go with a single screw setup with a Gardner engine and Nogva CPP prop system. In the end, a well maintained single screw setup with a well equipped workshop and parts department is what we feel is the best Goldilocks just right setup for us.
As to your question on bow design I will let Dennis chime in if he has time with the expert answers design wise.
A well behaved boat in following seas (surfing) was definately one of the design criteria we set for Dennis and while none of us will know till we get out on extended sea trials in some big following seas, we think he has delivered on that very well. Very subtle shaping of the bow as you noted and as you’ll read in this weeks post I also noted some of the other factors which give us a bow with the combination of superior wave piercing as well as good lift as forces try to drive the bow down.
Our “empty ends” design helps with this and at the bow we have the first meter of the hull being a completely welded shut air chamber and then the next 3 meters being a relatively empty forepeak storage area. In many ways we have designed this XPM boat to use our integral fresh water tanks as movable ballast so we have the ability to adjust the amount of water in the large forward sets of tanks (3875L/1020 USG) and the aft water tanks (1435L/380USG) on either side of the Engine Room. We will primarily use this water ballast to compensate for the fuel as it is used up but we can also use it to adjust the ride and attitude of the boat for different sea and weather conditions.