This post covers the fist two weeks, April 2 – 13, 2018  with an overview of the very beginning of building the hull for our new 24m expedition Passagemaker named Möbius.  Before we can build the hull we need to build the jig that holds the hull as it is being built and that’s what I’ll do my best to summarise below.

**  For those of you who prefer or have less time I have compiled a video of these past two weeks and put it at the end of this post., so you can scroll down to the bottom to see those now if you’d prefer.  Please be forewarned though that I’m new to video and not had much time for editing so far so they are pretty rough but hopefully add to the text and pictures here to give you a better sense of this project.  I’ll work on my videography skills as time goes on and thanks for bearing with me.

PGL sketch 67This is what Möbius would look like naked.  That is if you stripped off all her outer skin by removing all her hull plates.  Easy enough to do in the 3D CAD model as shown here by simply turning off some layers and this lets us see her lovely “bones” in the form of all those transverse aluminium frames and the interlocking longitudinal stringers which provide the just right combination of maximum strength and rigidity and minimised weight. 

*  Click on any image in any post to see them full size

With all the AL hull plates welded in place, which vary in thickness from 6mm at deck level and increase through 10, 12, 15 and 25mm as you move down towards the center keel the hull becomes about as bullet proof as possible.  Much more about the hull plating in future posts as the purpose of this post is to talk about the jig which is the first thing being built because it is the jig which will hold all those frames in just the right position as this skeleton of interlocking frames and stringers is assembled and the hull plates are welded on.

PGL sketch 67 - invertedGiven that the hull will initially be built upside down it will look more like this and it may help to keep this image in mind as you read through the rest of this post and see the jig being assembled in the coming days.  Note however that the Pilot House structure which sits up on top of the deck will be built separately off to one side and then lifted up onto the completed hull after it has been flipped right side up.

The purpose of this jig is to provide an accurate base upon which to erect and assemble the hundreds of CNC cut aluminium ** parts as they are assembled pretty much like a “big boys” Erector or Meccano set if you’re old enough to have such fond memories of building things with those kits like I do. Or you can think of it like those large 3D jig saw puzzles of things like dinosaurs and such.

** Yes, this is the right way to spell aluminium but I’ll often just refer to it’s elemental symbol of AL as aluminium is element 13 on the periodic table. It seems that Sir Humphry made a bit of a mess of naming this new element, at first spelling it aluminium (this was in 1807) then changing it to aluminum, and finally settling on aluminium in 1812.

Hull structure details AnnotatedThe internal framework consists of transverse FRAMES spaced about 1 meter apart and then longitudinal STRINGERS which fit into interlocking slots cut into the frames to tie it all together.

Different builders and welders have different preferences for building hulls and as is most common practice the experts on Team Möbius prefer to start building the hull upside down.  Reasons for this upside down beginning are many and include making it easier to accurately position all the vertical frames in just the right spot along the 25mm center keel bar which starts way up at deck level of the bow and continues all the way down and back to the very aft end of the hull at the swim step.  With these frames erected and locked in place on the jig, the longitudinal stringers which in most cases run the entire length of the hull, will slide into slots along the edges of the frames. 

PGL sketch 68As each interlocking stringer is slid in place the whole skeletal framework aligns itself more and more precisely due to the self correcting nature of this technique.  Yet another benefit of accuracy and time savings achieved by building the virtual boat in 3D CAD and then feeding this data to the CNC plasma cutter.  Once this underlying framework has been assembled and mostly just tack welded together it will be double checked with laser sighting levels, transits and lots of measuring to ensure it is completely true to the 3D model. 

Being upside down it will be easier to position the precut and shaped hull plates and weld their outer seams.  At this stage the jig will have served its purpose and be disassembled so that the hull can be moved out of the building and using a pair of large cranes the hull will be very carefully and slowly “flipped” right way up and moved back into the bay.  While all this hull building has been going on the Pilot House structure will have been built in a bay off to the side and ready to be positioned on top of the deck and the complete hull can now be welded up.  Finishing all the welding or “hot works” marks the end of Stage 1 of our 4 stage process to build the fully finished boat.  We estimate this Stage 1 will take about 5 months so the current rough estimate is that we hope to have all the “hot works” done by the end of September and be ready for Stage 2 which is the fitting of the engine, CPP propulsion and most of the systems onboard for HVAC, water, electrical, etc.

But let’s get back to the current task at hand; building the jig for building the hull.

Hull jig frameworkTo help you make sense of what you see in the videos and photos here are some photos of the drawings the guys are using to build the jig.   This first one shows an isometric view of all the AL components of the completed jig.

Hull jig frame spacingThis is a plan/top view of the hull building jig and if you click to enlarge this you can see all the dimensions they use to bolt all the vertical supports to the concrete floor.

There are a total of 22 frames spaced one meter apart and sequentially numbered with Frame #1 located aft of the bow and frame #22 at about the end of the aft deck.  Add in the meter in front of Frame #1 for the bow and almost 2 meters aft of #22 for the last bit of the Workshop and then the outer swim step and boarding area and you have a 24 meter boat.

Hull jig support profileKeeping in mind the hull will be built upside down on this jig, and depending on your spatial thinking abilities, this profile view of the jig might help you make sense of what you’ll see in the videos and photos.  The top of the jig surface is at about deck level and as you move from left to right on this profile/side view, you first see the aft deck which will be overtop of the Workshop, the Engine room and then Christine’s office/Guest Cabin.  Next comes the spot on deck where you will step down to the floor level as you enter the Pilot House or what we are calling the SuperSalon.  Being upside down this means the jig needs to go up and then where the Super Salon ends the forward deck begins and extends to the bow on the far right of this drawing.  The first 4 meters or so of the bow are sloped down as you move forward toward the bow as this is the anchor deck overtop of the forepeak storage area and we want all the muck and water from washing down the anchor as it is raised to easily run off the deck at the bow.

IMG_20180326_123351This is the bay, approximately 30 meters long overall where the hull for Möbius will be built but as you can see the first order of business was to clear and clean it out and there was one rather large item to remove in particular.  This is the GreeNaval 47 or GN47 electric hybrid which has been been fully powered up and already run through some initial sea trials (video here).  Now she is waiting find her new owners so they can make the decisions on the interior build.  In the meantime we need this bay to build the hull for Möbius.


One of the many benefits of being located in the Free Zone is the ready access to any amount of support equipment and services and so after taking down the surrounding scaffolding and clearing out all the materials that were surrounding the boat one of several boat moving machines was called in to relocate the GN47 elsewhere in the Naval shipyard.

This blue mover is the smallest one but plenty big enough for the GN47 and the operator, using a wireless remote control box soon had it positioned under the hull as you see here.

IMG_20180326_160435If you look closely in the foreground of this shot you can see the tread marks on the concrete floor of how the GN47 was lifted up by the hydraulic rams running down both sides of the mover and then deftly moved forward and around this corner where she will live while we are building Möbius.

IMG_20180329_115855This next size up boat mover is available for moving larger boats and this one is about the same length as Möbius.  Here you see one of the boats in the neighboring shipyard being moved from the yard where all her hotworks (welding) were completed and over to the yard where she will be fitted out with engines, props and systems. 

IMG_20180326_160444And Voila!  an empty bay ready to be prepped for building the hull. 

The first thing that needs to be done is build the jig as explained above and the next series of pictures will walk you through that process.

IMG_20180404_180729Because the jig provides the base for building the hull it needs to be measured out very precisely as indicated in the paper drawings you saw above.  Using a laser line sight, tape measures, etc. the floor is marked out to match the drawings from the model and holes are drilled to bolt the square steel plates you see here.

IMG_20180403_125740Concrete expansion studs are inserted and the base plates bolted securely to the floor.


Steel L or angle iron lengths ae cut and welded to each plate to provide the vertical supports for the jig base itself which will be made from CNC cut AL plate.


Each leg has been drilled for bolts which will secure the AL jig plates.


And soon the outline of the boats begins to emerge.


The first shipment from the AL supplier/cutter up in Istanbul arrives with the jig parts in the foreground and the very first set of AL pieces of Möbius in the back.  After more than two years of dreaming and designing Möbius is becoming real as I get to hold an actual physical piece of her in my hand for the first time!  But more on that in future posts, let’s get back to building the jig first. 

IMG_20180412_163656The AL jig parts are laid out on the floor and cleaned up ready for mounting on the steel legs.

IMG_20180413_172022IMG_20180413_172125Using the laser line level for heights and a sight string running precisely down the center of the hull, the AL jig pieces are bolted to the steel legs.

IMG_20180413_085109Here we are standing behind the hull looking forward so this is the aft deck area.  Keep remembering this is all upside down so that curve will end up creating the convex camber of the deck to assist with shedding water well. 

This aft deck area is about 7.5m/24ft long and about 5m/16ft wide and will be home to the large AL tender on the Port/left side as well as our outdoor eating area with sink, BBQ, etc.

The observant amongst you will notice the vertical slots in all the jig pieces and these are where the longitudinal jig pieces will be fitted and welded in place next week.


I climbed up higher to better see the overall size and shape of the hull at deck level.

If you remember the paper drawing above showing the side profile of the jig the raised section in the middle of the jig is about where the floor level of the raised Pilot House or what we are calling the Super Salon.  You will step down into the SuperSalon which is our primary living space having the galley, eating and lounge areas as well a main helm station at the front.

And that raised area as the jig moves toward the bow?  That’s where the deck steps down and slopes forward to separate the anchor deck area and make it easy to wash all the anchor muck off the decks and out the big drain and snubber hole in the very forward end of the bow.  More on all that in future posts.

IMG_20180413_171844This photo looking aft from the Pilot House aft provides a sense of size and scale to the jig and the aft deck

And that brings us up to date for Friday April 13, a very lucky day and milestone for Team Möbius as the jig is up and the building of Möbius truly underway.

NOTE:  We will divide the boat’s aluminium structure into two halves, the hull itself from the keel up to the deck as one part and then the second part will be the Pilot House and what we are calling the SkyBridge which are the structures which sit above deck level. What you are seeing in these initial videos is the preparation for building the first part, the hull structure and the second part will be built in a similar fashion in the bay on the other side of the one you are seeing so far. Work on the 2nd Pilot House structure will get started a bit later but both parts will be worked on simultaneously and then when the hull portion is flipped right side up the Pilot House structure will be lifted into place and welded to create a single unified structure.  It should all become clear as the build goes forward and cover all this in future posts.

VIDEO:  As promised at the top, I’ve put together a very rough compilation of different videos I shot over the past 2 seeks of the jig being built.  Apologies in advance for my extreme amateur videography, all new to me and I hope to improve as I do more for this project.  Möbius is not the only thing that is a work in progress, I am too!  So please do send me any and all comments and suggestions you have to improve any aspects of these posts. I can’t guarantee I’ll be able to implement them all but rest assured I will read them and use them to keep making this blog more useful and interesting for you.

Hope you enjoy the video and this blog as we bring you into the ground floor of the building of the good ship Möbius. 

It means a lot to both Christine and I to have you joining us on this grand adventure and I look forward to bringing you more as the progress continues.  .