In Floor Heating Revisited Weekly Update 16 Jan 2022 XPM78-01 Möbius

In last week’s “Toasty Tootsies” post I went over the way our In Floor Heating system works and concluded my explanation with what I thought was a rhetorical question;

“Brilliantly simple don’t you think??!!

Well, based on the number of comments and Emails I received, while our In Floor Heating system might indeed be “Brilliantly Simple” my explanation was NOT!  Therefore, let me try and mend this by revisiting our In Floor Heating and do my best to improve my explanation of how this Open Direct type of system works.  If I’m successful I think that most of you will come to agree with my assessment that this Open Direct system is indeed “Brilliantly Simple”! 

But you will be the judge of that and so Please do add your comments as to how well this second attempt helps you to understand how our In Floor and Domestic Hot Water systems work and don’t hesitate to add your additional questions and things that still don’t make sense to you.

OK, here is my second attempt to show how this all works;

Deeper Dive into our Open Direct System;

One of the Emails I received, (thanks Benjamin), asked the following set of questions that included many of the points of confusion others sent me so I thought I’d use this to frame this expanded explanation of the Open Direct system I used to design our In Floor Heating or IFH and Domestic Hot Water or DHW System.

Benjamin wrote:

If I understood your installation diagram correctly, you run the drinking water through the same pipes as the water for the underfloor heating. Drinking water and “heating water” are identical, or not installed separately. First of all, this is economical because you one water circuit less. But I have a question about summer operation: drinking water and heating are usually installed separately, because in summer mode

  1. you want to avoid hot water flowing through the heating system, and
  2. the water should not stand still in parts of the circuit for a longer period of time to prevent the formation of legionella.

You can probably avoid point a. with valves that separate the entire heating circuit from the drinking water circuit in summer. But if the heating circuit is not flushed for several months during summer operation, legionella can form and then be flushed into the drinking water circuit when the heating system is put into operation. How do you avoid this? Is the underfloor heating completely drained during summer operation modus?

Thank you very much for further information!

First, let me try to resolve some common sources of misunderstanding that Benjamin and many of you mentioned;

I should have emphasized more how the various parts of our overall water systems are separated from each other.  In last week’s post I mostly left out the Cold or “drinking” water system so it needs to be understood that this has its own set of plumbing and ALL the water we drink and cook with comes directly from the water tanks to the cold water taps/showers onboard.  All the water in our water tanks comes directly from the onboard watermaker so it is as clean and close to pure H2O as is possible.

One of the things that seems to confuse many people at first is to understand that there are only TWO conditions that causes water to FLOW in a plumbing system:

  1. The regular water pressure in the system causes water to flow IF and ONLY IF water is being REMOVED from the system.
  2. There is a continuous circulation loop with its own PUMP that causes water to flow round and round through the CIRCULATION loop.

When neither 1 or 2 is true, there is NO FLOW of water through the plumbing. 

The Hot/Warm systems are the ones based on the Open/Direct system on Möbius and this has TWO different but interconnected systems:

  1. The In Floor Heating Mode which provides WARM water to heat floors when wanted.
  2. The DHW Domestic Hot Water Mode which provides HOT water to all the sinks and showers at all times.

I have modified the following illustrations from last week’s post to show a clearer picture of how these two systems work.


Open Direct HEATING Mode illustrationWhen no Hot water tap is open there is NO Cold water entering the system.  However, when one of  the In Floor thermostats turns on a Zone Circulation Pump, warm water then flows out of the Calorifier, through the in floor PEX tubing and back into the Calorifier.  This is a continuous loop so warm water is flowing through the floor tubing anytime the circulation pump is running.

Open Direct DHW Mode illustrationThe DHW system always takes priority so whenever a Hot water tap is opened, the system works like this in DHW Mode.  When any HOT water outlet at a sink or shower is opened, the regular pressure in the Cold water system which runs about 60 PSI, causes Cold water to enter and flow through the PEX tubing in the floors to refill the hot water that has been removed from the Calorifier.
Open Direct with DHW Circulation Loop schematicWhen the Hot water tap is closed the system automatically reverts back to In Floor Heating Mode and the Circulation Pump causes Warm water to circulate though the floor and keep it toasty warm.
To answer another question I received and as should now make sense, we do not actually “drink” water going through the DHW or In Floor Heating, though there would be no problems if we did.

It can initially be a bit confusing because when Hot water is consumed (taken out of the Calorifier by turning on the hot water at a sink or shower) and the system is in DHW mode as per above, it is necessary to replace the water that has been removed from the Calorifier so Cold “drinking water” does enter the DHW system.  This is exactly the same as in ANY home or other setup with a Water Heater or Calorifier; when Hot water is taken out, it must be replaced with water from the Cold water supply.

In operation this works extremely well and does so automatically by design.  Anytime Hot water is wanted, the Open Direct system ensures that this takes priority and Hot water flows from the Calorifier to the tap or shower as long as it is open.  As soon as you close that tap and are no longer needing Hot water, the system reverts to In Floor Heating Mode.

Summer vs Winter:

The difference between Summer and Winter is that in Summer/hot weather when the In Floor Heating is turned off, the IFH Circulation pumps never turn on so no water is flowing through the floor UNTIL a Hot Water tap is opened.  Said another way, the ONLY time water is flowing through the floor PEX is when the system is in DHW Mode because a Hot water tap has been turned on.  The rest of the time, there is NO water flowing through the floor tubes. 

This turns out to be part of the “brilliance” of this type of system in my opinion because the design ensures that the In Floor Heating automatically adapts to whatever the weather is.  HOT water ONLY flows through the floors when it is needed and the circulation pumps turn on in colder weather.  NO hot water flows through the floors in warmer weather because the circulation pumps never turn on.

This sets up the ideal system as it ensures that the water in the PEX tubing is always being refreshed and is never standing still for any length of time.

Better yet, in hot weather, when you are using DHW and there is water flowing through the floor tubes, it is absorbing some of the heat in the room or from sun shining on the floors and so that by the time the water gets to the Calorifier, it is now a bit warmer so you save energy in the Calorifier because the replacement water has already been warmed up and does not take as much energy to heat up to whatever temperature you have sent the Calorifier to maintain.

Once this all makes sense I think you too will see just how “brilliantly simple” this Open Direct system is.  It is completely automatic, no valves or switches to change, no need to drain the system or do anything else other than keep using everything on the boat/house as you always have.

Trust me, it does take a while to figure this type of system out.  It is one of those things where it is very simple but ONLY after you understand it!  To begin with, it can be VERY confusing!  My suggestion, and what I used to do a lot of, is to draw out a schematic for yourself and trace the flow of water in the different scenarios from summer to winter and from In Floor Heat Mode to DHW mode and I think you will quickly see how it works. 

Hope this helps and if it still doesn’t make sense just send me additional questions in the “Join the Discussion” box below to let me know what’s confusing or not making sense and I will do my best to answer them all as quickly as possible or in next week’s post.

Thanks for your patience with this not always so clear ex teacher!

-Wayne

Toasty Tootsies! XPM78-01 Möbius Update 10 Jan 2022

Welcome to this first Möbius Update post of 2022!  I hope you have 2022 off to a great start already as we work to do the same here aboard the Good Ship Möbius.  I am slowly warming up to getting back to weekly blog posts here so thanks very much for your patience in waiting for this first one of the new year.  I’ve been warming up particularly well now that I have the in floor heating all working which I think may well be Captain Christine’s favorite feature so far. 

PXL_20220109_142643818And apparently she’s not the only one as Ruby & Barney have discovered how well the in floor heating heats up their little doggie beds.

With the weather getting colder since our return at the beginning of December from our 2 months back in Canada and the USA, I’ve been mostly working on getting all the Domestic Hot Water or DHW systems fully operational and all the various bugs worked out.  I’ve received a number of questions about how our DHW system works and what components we have installed and a lot of interest in the in-floor heating system we’ve installed and that’s what Ill do my best to cover here in this week’s update.

Domestic Hot Water System

Our DHW system is pretty straight forward so let me cover that first.

There are just three basic components of the DHW System:
Kabola KB45 front view photoKabola KB45 Ecoline Combi diesel fired water heater/boiler

IsoTemp Basic 75L photoIsoTemp 75L Calorifier

with 3 internal heat exchangers
Jabsco 24V circulation pump

Hot Water circulation Loop that runs around the circumference of the boat


PXL_20220110_133823995The Kabola is the primary heating source for the whole DHW system as it is eXtremely efficient, quiet and very trouble free.

Ours is the “Combi” model which means that it has two separate heating loops inside.  The primary loop heats up the water in the IsoTherm Calorifier which holds all the DHW for the boat and the other loop heats up the fluid going to the four air handlers which can heat the air in each cabin if needed.
Kabola Combi back view outlets labelledThis view of the back of the Kabola shows the primary boiler loop Supply/Return connections at #1 & #2 and then the secondary loop flows in/out of #5 & 6.  The Primary loop has a built in circulation pump that constantly circulates the antifreeze/water fluid and a thermostat turns the burner on/off to keep the fluid at whatever temperature you set.

The secondary “Combi” loop has an external circulation pump that is part of the Webasto AirCon/Heating system.


PXL_20210313_130820596I’ve removed the front of the burner to show you how the internal heat exchangers work.  The large black tank you see on the Left contains all the antifreeze/water fluid and the diesel burner is inside the Grey tube on the Right. 

The larger diameter tubes/holes on the top are the secondary loop and the larger number on the bottom are the primary heating loop.
IMG_20210422_150228The Kabola is super simple to operate, just turn it on, set the thermostat to be whatever degrees you want the internal fluid inside the boiler to maintain and then pretty much forget it.  When the fluid temp goes down the burner automatically fires up, heats the water a bit past the set temp and then shuts off.  Could not be simpler or more efficient.
Now let’s follow where the heated fluid as it leaves the Kabola and flows over to the heat exchanger loop inside the Calorifier.


 IsoTemp Basic cut awayThis cutaway view shows how our IsoTherm Calorifier is similarly multi purposed with three different sources of heat to keep our DHW nice and hot.  There are two loops of SS pipes on the bottom here, one which has the fluid from the Kabola flowing in/out of it and the other loop a similar antifreeze/water fluid flowing through from the Gardner engine’s “cooling” system.  The top most loop is a 240V electric heating element that we can use if needed.


All SS construction and the outside never even gets warm so the heavy insulation has been working very well and the Kabola does not need to fire up very often to keep the water nice and hot all the time. 


IsoTemp In-Out connections labelledTurning the Calorifier above around and looking at the outside this sketch shows the three pairs of In/Out connections; one for the hot fluid from the Kabola, one for the hot fluid from the Gardner (when it is running) and then the Cold Fresh Water In and DHW Out.
PXL_20211217_103835692The end of the Calorifier in the illustration above is under my hand and if you look closely (click to enlarge any photo) you can see a Yellow ring labelled “Engine Water” on the far Right and a White ring on the Left labelled “Kabola White”  On the top Right the Red Label marks where the Hot Water comes out through the black wrapped insulated pipes which are split into one line going to the DHW loop and the other with the bottom Left Mixing Valve going to the In Floor Heating loops.
PXL_20210523_111132337Closer view of the adjustable Mixing Valve which controls the temperature of the water going out to the In Floor Heating system which wants warm not Hot water, usually about 55C/131F whereas the DHW runs about 65C/150F.
Open Direct with DHW Circulation Loop schematicTo make sure there is always hot water ready to come out of each sink and shower, the DHW flows around the whole boat in a continuous loop of insulated pipe.  In this schematic the DHW loop is on the Right hand side and the In/Out to the In Floor Heating is on the Left.

I will get back to the In Floor Heating a bit later below but the key point to keep in mind is that the In Floor Heating is all part of the same DHW system.
PXL_20211214_123715122

To keep the DHW flowing through the hot water loop feeding each tap and shower, this magnetically coupled impeller pump is very small, about the size of your fist and is highly efficiency with very low power consumption and absolutely silent.

We now have very hot water readily available at every tap and shower onboard and we are both eXtremely pleased with how well the whole DHW system has been working.



In-Floor Heating or IFH

Winters here in southern Turkey are rather mild compared to many locations with lows down to 8C/46F a few nights and day time highs as much as 20C/68F but winter is also when we get rainy days and so  can get chilly and so the real star of our DHW system the past while has been having nice warm floors throughout the boat to keep us toasty warm.

It has taken me some time to get it all adjusted and working properly but it is now running flawlessly and silently so let me walk you through how this system works.

As with the DHW system above, the In Floor Heating or IFH is a very simple system with the following main components:

Azel i-Link In Floor Heating control system sp83packageD508FAn Azel I-Link controller with three thermostats for each IFH zone on the boat, one in each cabin and one in the SuperSalon.
PEX Manifold Radiant Floor Heating Set 3 Loop System Stainless SteelA pair of SS manifolds, top Red one where the Warm water (about 50C/122F coming in at the top and then the Returning slightly cooler water exiting out the bottom Blue manifold.
Taco 3 speed circulation pump photoEach of the I-Link thermostats controls one of these Taco 3 speed 1/25HP circulation pumps which circulates the fresh DHW water from the Calorifier through the PEX tubing that runs in loops underneath all our floors as needed to keep our tootsies nice and warm.
Master Cabin In-Floor Heating PEX layout B&WWe worked out these serpentine patterns of PEX tubing in each of the three Zones to provide an even distribution of heat wherever there were bare floors and not under the built in furniture.  This is in the Master Cabin; Head/shower lower Left, bed center Right.
IMG_20200131_121507This is how the PEX tubing was laid down before the 10mm marine plywood floors were installed.  Serpentine grooves were cut into the foam with a router.
IMG_20200131_164746Foil tape was set into the groove in the foam and then the 15mm PEX tubing was press fit into the groove.
IMG_20200723_175142Here is how it looked in the forward end of the SuperSalon.

Let’s take a minute to walk through a brief explanation of how the In Floor Heating system works.


Open Direct with DHW Circulation Loop schematicFor our IFH system I decided to use what is called the “Open Direct” style as it is incredibly simple and efficient.  OPEN in this case refers to the fact that the IFH system is “open” to the same DHW that we use onboard for sinks and showers.  A “closed” system would be like the loops of antifreeze/water that the Kabola uses to heat up the water in the Calorifier.

DIRECT refers to the fact that the fresh warm water flowing through the PEX tubing is heating the floors directly, not through a heat exchanger like those in the Calorifier.
Open Direct schematicThis simple schematic adds the details of how the IFH portion of our DHW system works.  Warm water coming out of the Calorifier via the mixing valve is pumped on demand through the PEX tubing in the floors by the Taco circulation pumps. 
Part of the simple brilliance of an Open Direct system is that the DHW always takes precedence so anytime you turn on a hot water tap or the shower, hot water is diverted to them until shut of when the warm water returns to circulate through the floors as needed.  Huh?  How does THAT work you ask?  The following two illustrations should help make sense of this very simple but initially a bit confusing system works.


Open Direct HEATING Mode illustrationThis is In Floor Heating Mode that happens whenever the thermostat for this IFH Zone turns the circulation pump ON and warm DHW is pumped through the under floor PEX tubing in that zone and then returned back to the Calorifier (Water Heater).  Keep in mind that even though the whole DHW system is pressurized to about 4 Bar/60 PSI in this mode the ONLY way water flows is IF the circulation pump is running.
Even though it is available, Cold water cannot enter the system when the pump comes on unless someone is taking hot water out of the system by taking a shower, doing dishes, etc..


Open Direct DHW Mode illustrationWhen a Hot water tap is opened then the pressure drops and the system reverts to this DHW Mode and Hot water flows out of the Calorifier (Water Heater) to the HW tap and Cold water flows into the system to replace it.

The cold water goes through heating tubes within the floor on its way to the water heater. This flow pattern provides limited free cooling and other benefits. Stagnation is prevented and
priority is given to the domestic hot water use over the space heating use. A small amount of free cooling is realized in the summer.


Note that NO additional equipment, parts or power is needed to make these two modes work automatically. 

Brilliantly simple don’t you think??!!

PEX Manifold Radiant Floor Heating Set 3 Loop System Stainless SteelI found these beautiful SS manifolds on Amazon for a great price and they made the whole plumbing of the system very straightforward to install and control.  Red handled ball valve top Left is where the warm water from the Calorifier flows INTO the system and is made available to each of the three Red Flow Control Meters/Valves and into the PEX fittings on the bottom. 

Cooler water from each continuous PEX loop flows into the bottom three fittings, each with the White capped control valve and then OUT the Blue ball valve and back to the Calorifier.
PEX manifold Red Flow metersEach continuous loop of PEX in a zone has one of these Red Flow Meters that you adjust to get the correct flow rate, which is about 1-1.5 L/min for our zones.
PEX manifold temp gauges HOTEach ball valve has a temp gauge so you can check the differential of the water temp coming IN and how much it drops going OUT.  Ideal is about 50C/122F coming in and 40C/104 going OUT and you adjust this via the Mixing Valve on the Calorifier.
In Floor heating manifolds   pumps installedHere is what the whole IFH manifold looks like when assembled and installed with the three Taco circulation pumps. 

These Taco pumps are pretty much bullet proof and are miserly power consumers as they are very small 1/25HP AC motors.
Taco pumps 3 speed switchThe Taco pumps are absolutely silent and can be run at one of three speed settings to get you the flow you want.  They are also dead quiet and you can only tell they are running by watching the flow meters.
Azel i-Link In Floor Heating control system sp83packageD508FThis Azel I-Link controller is the brains of the IFH system and takes its orders from one of the three thermostats conveniently located in each Zone.
Azel thermostat photo with labelsEach thermostat is very easy to adjust and provides a full set of information of room temp, floor temp, when the “heating mode” or pumps are on, etc..
PXL_20220110_133752081Here is what one looks like in operation today.  Room temp is 22.3C/72F, Set Point is 24C, floor temp is 49C.
IMG_20200129_182654Each Zone has one of these little temperature sensors installed which connects to the thermostat of that Zone so it and the controller knows when to turn the circulation pump Off/On.
IMG_20200505_104911The main control box of the I-Link system is carefully tucked away into a small alcove in the Ship’s Office where it is well protected but easily viewed by opening the cupboard door.  Red lights on the far Right indicate when one of the 3 zones is working (pump on).

And that is it!  Just like the Kabola boiler, this is a “set it and forget it” system and has been working flawlessly and very easy to adjust as we learned what temps we liked in each zone.


You have to experience it to understand just how fabulous Toasty Tootsies are when the weather turns colder outside!

And that’s a wrap for this week, the first blog and Möbius Update of 2022 is done and dusted! 

Hope you enjoyed it and please be sure to tell me if you did or didn’t and add any other questions in the “Join the Discussion” box below.

I’ll do my best to be back again next weekend with another Möbius Update for you and thanks again for your patience in waiting for this one to go live.

-Wayne



Tender Loving Bits & Bobs XPM78-01 Möbius Sept 27-Oct 2, 2021

A rather scattered feeling week as Christine and I scurry about trying to get everything done before we fly back to the US and Canada for two months of long overdue and much needed Gramma & Grampa time with our kids, grandkids and many others.  It will be almost two years since I’ve been back there so I am REALLY looking forward to this chance to spend time with the loved ones we so gratefully get to count as our family and friends.  Our challenge is that this long list of friends and family are spread out all across North America so there is no one or even several common areas we can fly into where groups of them live. 

IMG_20170306_072525However this is nothing new for us and so our favorite method is to rent an SUV, do a quick DIY mini camper conversion by building a platform bed in the back, picking up a cooler and some basic culinary tools and hit the road.  We’ve been referring to these as the “Nauti Grandparents World Tour” and I think this will be our fourth or so NA Road trip 

Here is one example of how I setup this Ford Edge SUV for our two month trek back in 2018.  This is one of our favorite spots on the Florida everglades just a few miles away from where Christine’s son Tim lives where we have crocs to entertain us for our morning breakfast.  And NO that did not include them having Barney or Ruby FOR breakfast!
IMG_20171003_184802This was how I converted the 1998 Galloper that we were gifted by our dear friend John for our trek from Portugal to Turkey back in 2017.  Simple but effective and we have a treasure trove of great memories from these trips so it is a pattern we hare very happy to repeat.

I like living on The No Plan Plan so we don’t have a route or schedule worked out but our current thinking is that after we land in Miami this coming Thursday Oct. 7th I will get busy with the camper conversion of the SUV and  spend the weekend with friends and family in the southern Florida area before we start making our way North.  We will likely do a somewhat diagonal trek to see friends in northern Florida, Alabama, Chicago and South Dakota and probably cross into Canada around the Alberta/Saskatchewan border.  From there I’m looking forward to introducing Christine to some of Canada’s finest jewels by going through the Rockies to see spots such as Banff, Jasper and Lake Louise.  Lots more family and friends to see in BC as we eventually make our way over to Vancouver and then Vancouver Island before we need to head south along the Pacific coast down to the SF Bay area and LA where we’ll turn left and start making our way East back to Florida where we fly back to Turkey on the first of December.  It will be interesting to see what the odometer reads when we turn it in but likely more than 10K miles in total I’m guessing. 

I will keep you posted from time to time here on the blog and those who wish can also follow along on FB and Instagram but this will likely be a bit of a hiatus for my blog articles till we return to Möbius at the beginning of December. 

But enough of the future and let’s get back to the past week and what’s been going on.  As per the title, I’m just going to catch you up on the bits and bobs of jobs that we got done this past week.

Watermaker Update

PXL_20210922_124720511In last week’s post which you can read HERE I covered the installation of the big Blue Media or “sand” filter that I installed to more thoroughly filter the sea water as it gets pumped through the watermaker and converted into clear clean and almost pure H2O.  This extends the life of the other two sea water filters from weeks to about one year so well worth the time and trouble.
I received quite a few questions and Emails about this and you can read some of that in my answers to the comments on that posting but I thought some of this was worth posting here on its own with a few more details added. 

One part of the discussion was about how Watermakers work and I noted that I’ve never been sure that Watermakers use “Reverse Osmosis” as this is a purely mechanical process of forcing salt water under very high pressures to pass through a semi-permeable membrane that won’t allow the larger sized salt and other molecules pass through so you get close to pure H2O as a result. I think the confusion in terminology comes in due to the fact that these membranes are very universal in use for lots of different applications and one of those is for actual reverse osmosis treatment of water such as ones in homes that use the chemical process of reverse osmosis to “pull” the raw water through the membrane and filter out unwanted minerals and other molecules to create clean water on the other side of the membrane.


Chart of molecules filtered out by WatermakerMy understanding is that high quality membranes such as those from DOW and Parker, only allow particles smaller than 0.0001 microns to pass through so very little other than the H2O molecules themselves can make it through.

This graphic from SeaTask does a nice job of putting this into perspective and as it notes, not much more than the H2O molecules can make it through that membrane.

Several people asked if we were doing any additional treatments to the watermaker water before drinking it.  The short answer is no, we don’t do any additional treatment and drink the product water as it is called as it comes out of the watermaker.  The slightly longer answer is that while some others do add additional treatments ranging from the use of second actual RO filter to UV (Ultra Violet) radiation, we feel that these are superfluous. Both Christine and I have been drinking watermaker water for decades with no known side or ill effects so we are very comfortable with this.

However, we do also have a 210L/55USG polyethylene tank that we also keep filled with watermaker water at all times. We did this as a redundant backup type of system and a bit of a “belt & suspenders” approach for that critical to life commodity of potable water. This tank is completely independent with its own pump with a dedicated faucet in the galley sink and as with all our aluminium built in tanks, it too is ONLY ever filled with water from our watermaker. No shore water allowed onboard.  Therefore even if we were to somehow loose the entire 7300L/1900USG supply of potable water in the six aluminium tanks welded into the hull or their pumps or plumbing failed, we would always have about 200L to tide us over until we could fix the watermaker or whatever the problem was with our potable water system. We use this plastic water tank every day as literal drinking water supply from the faucet in the galley sink, but we do this just to keep this tank, pump, lines, etc. in good working condition, not because of any concern for the quality of the water itself and we regularly drink the water from all the other faucets as well.

I have read mixed reports of concerns that watermaker water is “too pure” in that the “good” parts such as some minerals and vitamins but we have always had a daily regime of multi vitamins, vitamin D & E, Omega 3, etc. as a “just in case” we might be short on any of those with our regular eating so these would more than make up for any lack of minerals and vitamins in our onboard potable water.

If anything, the only slight downside of drinking watermaker water is that it is pretty much tasteless and we do notice that when we are travelling or eating at other people’s homes that there is more “taste” the water, which of course can sometimes be very good and other times not so much so!

More XPM Family News

A few weeks ago in my post “The Artnautica Family Continues to Grow” I shared a few details of the next two XPM boats being built at Naval Yachts, the XPM78-02 Vanguard and the first of the larger XPM85 mode.  This week I received two new introduction videos that Naval has posted on YouTube and I thought you might enjoy seeing these so here are the links below.

XPM78-02 Vanguard Intro video

XPM85 intro video from Naval

I will do my best to keep you updated as these two new builds progress so do stay tuned for more XPM goodness in the coming months.

Some TLC for our Tender “Mobli”

I was finally able to carve out some time to work on getting our Tender which we have called “Mobli” as a slight play on Kipling’s character Mowgli. 

Tender skelton viewBasic specs are:

LOA 5.0m / 16.4ft

Beam  2.0m / 6.5ft

Draft  288mm / 13.8 inch

Weight:  1088 Kg / 2390 Lbs

Engine:  110HP Yanmar 4JH4-HTE

Propulsion:  Castoldi 224 Direct Drive Jet


Our design intent was not for a typical RIB dinghy to just ferry us ashore in an anchorage and much more so a full on Tender that we designed using the same four SCEM principles we used for Möbius; Safety, Comfort, Efficiency and Maintainability.  This will be our mini eXplorer boat to take us to places we can’t or don’t want to take Möbius to such as up small inlets and rivers, into super shallow bays and enable us to take multi day eXcursions in safety and comfortably dry in most any weather.  Should also make for a fun boat when we have grandkids and others that might want to go water skiing or wakeboarding.

Mobli will also be our backup plan if we should ever run into catastrophic problems with Möbius being either unable to move or worst yet, sinking or on fire.  As such Mobli will be both our lifeboat should we ever need to abandon ship and also be our emergency “get home” solution by being a little mini tugboat capable of pushing or pulling Möbius at a reasonable speed in reasonable sea conditions.  Hence the 110HP inboard, which also met our single fuel boat design criteria by eliminating gasoline for an outboard engine.  After seeing so many jet drives being used the pilot boats being built for Coast Guards, military and police use, we went with a jet drive for added safety, shallow water ability and high mobility in any direction.  Having industrial quality rubber fenders or rub rails wrapped around all sides gave us all the better abilities to be a mini tugboat and be that much safer and cleaner when we make contact with docks or other boats.


Granny bars on Tender bowFor ease of boarding we designed the bow on Mobli such that we can butt the squared off bow fender up against a dock or the end of the Swim Platform on Möbius and then use these two very solid handrails for maximum safety for those getting on/off.


PXL_20210508_142134749Prior to leaving the Antalya Free Zone back in May, Christine and had installed the Castoldi 224DD Jet Drive into the hull so she is watertight but I ran out of time during the launch and so I just set the 110HP Yanmar 4JH4-HTE engine in place on the engine beds and covered her up until this week.

So for the past months since launch, Mobli has been patiently waiting in her chocks on the Aft Deck for some time and attention to get her sea worthy too.
PXL_20210508_142020234You can see how Mobil has been designed for a Goldilocks close fit on the Aft Deck and by putting her at an angle the weight is kept very close to the centerline of Möbius and does not cause much heel when onboard.  What little listing there is we can easily compensate for by moving a bit of our potable water to tanks in the other side using the built in water transfer pump system.
PXL_20210928_113040002We designed the engine bay lid to hinge up and out of the way to provide maximum access all around when open and then fully sound proofed when closed.  Once I get the engine fully installed I have the sound insulation foam to install on all sides and the underside of the lid to keep Tender nice and quiet when underway, just like her sibling Möbius.
Castoldi Yanmar dim dwg screen grapOur decision on the whole jet drive propulsion system became very easy when we discovered that the Castoldi 224DD and Yanmar 4JH4-HTE were available as a total propulsion package that came with everything needed including all the wiring harnesses, hydraulic steering, dashboard instrumentation and switches, CentaFlex coupling and Transmec Cardon shaft, wet muffler, etc.  I’ve been most impressed with the completeness of this single package and will help to make the installation much more trouble free.
PXL_20210930_124236628If you look at the drawings above you can see how the CentaFlex flexible coupling on the left, bolts to the Yanmar’s flywheel and then the Transmec Cardon shaft on the right, bolts to that at the front and then the Castoldi input flange aft.  Here are all those parts in real life and one of my tasks this week was to work out the correct length and alignment of this drive train so I could then do the second job of bolting the 4 motor mounts on the Yanmar to the 20mm thick AL engine beds you can see them resting on here.
PXL_20210930_124250648A slightly different and closer view for you.  The CentaFlex coupling helps to eliminate any vibrations and provide a smoother coupling of the Yanmar’s power to the jet drive. 
PXL_20210930_124509824You may recall seeing a much larger version of this same kind of CentaFlex coupling that connects Mr. Gee to the Nogva CPP gearbox. so nice to keep it all in the same family.
PXL_20210930_135415263Once I had the fore/aft position of the Yanmar worked out, the next very important task was to align the output flange of the Yanmar flywheel to be precisely the same as the input flange on the Castoldi.  It is a bit tricky and time consuming as you need to align the centerline of the Yanmar’s crankshaft to the input shaft of the Castoldi.  As such, you need to measure and adjust the Yanmar in all six degrees. 

I clamped the aluminium flat bar to the face of the Castoldi flange and uses this as my horizontal and then rotated 90 degrees to be the vertical reference points from which I could measure to the machined surfaces of the flywheel and bellhousing. 
PXL_20210930_135427577Additionally, I needed to get the two centerlines to meet up and so I came up with this magnetic pointer that I could attach to the center shaft on the Castoldi and extend that to the centered hole in the end of the Yanmar’s crankshaft.  A ways out as you can see here so then I adjusted the rear two motor mounts down a bit and the front two up a bit to tilt the engine downwards until the pointer was dead centered.  Of course this now puts the vertical alignment out of whack a bit so you have to go back and reset those and around you go till you get them all just right.
PXL_20210930_143131534Once I had everything aligned I could centerpunch the locations for the two bolts that fasten each motor mount to the engine beds and drill them out for the 10mm hardened steel bolts.

Of course Mr. Murphey was on the job with me as always and to be able to get the drill into three of these bolt locations I had to lift and shift the engine out of the way which meant that I then had to go back and redo all the alignments! 
PXL_20210930_143136606Finally all done with mounting the engine and time to prep the CentaFlex Coupling and the Cardon shaft to be installed next.
PXL_20211003_141014242As the weekend slipped away, all I had time for was cleaning up and painting the drive components and getting them all safely stowed away for the next two months while we are away.  When we get back in December I will finish installing them and the drive system will be all good to go.  Then it will take me some time to install all the steering, control panels, hydraulic lines, starter batteries, throttle cable, wet exhaust system, etc. 

Looking forward to getting to all those jobs when I return and then being able to launch and test Mogli to see how she performs.  Launching will also require me to rig up the Davit Arch in order to launch Mobli so be sure to stay tuned for those updates as they start to roll out when we get back to Turkey in December.
That is about it for actual work on Möbius this week as I will be busy for the next few days before we fly out on Wednesday, getting Möbius tidied up and ready for the arrival of the wetter rainy months of winter here in Antalya.  I will do my best to post a brief update just before or after we fly out. 

Thanks so much for joining us on this grand adventure and don’t forget to add your comments and questions in the “Join the Discussion” box below.

Thanks!

-Wayne







 360 degree glass of Pilot House