Holiday progress day 15: the end

Just eating a black eyed bean curry from our multi cooker. Then heading home.

The cockpit floor is fitted, the main drain hoses are test fitted. We just need some hose adapters 32mm to 50mm and then we can connect the forward drains.

With very straight 50mm drains the cockpit should drain superfast, we are slightly concerned that small children might get sucked out with the torrent 😉 So we will add a small step halfway up back of the cockpit. That will also help our knees a lot.

We also had a big sort out of the forecabin which had become a messy dumping area for tools and bits. That allowed us to check our anchoring plans (and happy they will work). So we removed the very old, rusty, anchor windlass and a couple of other bits.

We also did some measuring for our aft cabin plans and again happy that they will be an improvement.

So, despite all the named storms, and the impact of COVID-19, we have had a good holiday and made a lot of progress towards being ready to launch next spring.

Holiday progress day 9: Electric Motor reliability

Well not much progress today because we nipped home last night as our old Diesel engine was being collected today. The forecast had also helped make the decision with another storm coming through.

So rain nearly all day for the time we were in Manchester, rain for the journey back to Beaumaris and rain most of the evening.

The key progress is emotional, with the sense of freedom from having an engine sitting in our trailer, waiting to be sold. As we were driving back we were remembering all the expensive work we would have had to do in order to get what was a good engine working.

  • The survey required the raw water seacock to be changed. That was bonded in so thoroughly it needed cutting out with a hole saw. Possible with the engine in (although the two cockpit drains would have been much more difficult).
  • the survey warned that the cutlass bearing was worn and that the stuffing box needed to be repacked. We found that the propeller side of the coupling to the gearbox needed to be cut off (and so would have needed a replacement). We also found that the propeller shaft is too long to slide out because of the skeg, so we would have had to lift the engine for the propeller shaft to come out under it, that would have meant cutting off the rusty original engine mounts and replacing them.
  • the survey warned of a leaking fuel filter, would we then have found that several of the valves in the various fuel lines were seized and would we have felt we needed to add inspection hatches to the fuel tanks, replaced all the fuel lines and thoroughly cleaned all the system and all the fuel? As we did that we might have noticed and been concerned about the very rusty fuel vent fittings and the condition of the fuel filler hoses.
  • In this process would we have noticed and dealt with the rusty paraffin fuel tank for the boat heater (that failed and spilt paraffin everywhere just as I arrived at the recycling centre).
  • When would we have taken out the hot water calorifier (heated by the engine or by a mains system condemned in the survey) that was buried behind the paraffin tank, under the rusty fridge compressor and under the unreliable water pump? Because when we did take it out, we found it rusty and leaking out of sight.

In short, because everything around the engine wasn’t replaced with the new engine, we would have had large costs to get afloat with this engine and far more over time to get it to a point where it would be reliable with the many problems with the setup diesel supply (particularly water in the fuel and no way to get it out, modern problems diesel bug growing due to the use of bio-diesel and no way to get it out, old sludge in the tanks causing blockages in the pipes before the filters).

We are more and more glad that we took the plunge and decided to go fossil fuel free from the beginning rather than first fixing what we had. So we have not spent any money on fixing the diesel but all on preparing for where we believe all yachts need to be going – fossil fuel free.

Again we have been watching more YouTube videos and seeing more people having problems with diesel fuel, the old idea that diesel engines are this magical safety device because they are always reliable just isn’t the case for lots of people. Also the amount of nasty, cramped, smelly maintenance and the impact that has on sea sickness and morale needs to be acknowledged more openly in the sailing community.

Obviously, at the moment we have very little to be sure of in terms of the reliability of our electric motor system, how dependable will it be. However, from all we have studied so far we are quite confident. We will have a good installation of a brushless motor, that will be in as dry a place as possible, with potential backup batteries and tools/spares for making cables.

We have come to realise that the Rival 38 centre cockpit has a number of really good features for a reliable electric motor installation.

  • the bilge is really deep and large. So even if we get a lot of water on board it is going to be a long way from the motor or the batteries, we have made this so it is visible for checking as well as making it possible to access the pumps and hoses (initially we are fitting both an automatic large capacity electric pump and updating the original manual pump)
  • the motor compartment is not accessible from the companionway steps (but instead from the corridor to the aft cabin). Very often these steps lift up for access but that also means there is potential for water to get into the motor compartment whether it be from spray or people climbing in with wet clothing etc
  • the motor compartment is large enough so that our batteries, motor and controller can be right next to each other, so short cables that we cann easily inspect that don’t go through bulkheads where they can get damaged or through bilges where they can get wet.

We are also implementing a few things they we hope are best practice to help with the reliability

  • The motor is brushless for no maintenance and high efficiency. It is air cooled to keep our moisture (we will need to monitor temperature and might need exhaust fans)
  • All our battery banks are going to be in boxes that are watertight from below with a top that means any drips from above will not make it in. Build from epoxy coated plywood with a strong timber frame that does not allow battery movement but does allow air circulation for cooling.
  • The motor frame will have a watertight undertray and a lid that directs any drips clear of the motor.
  • Our batteries that are connected in series will have automatic battery balancers to ensure they are evenly charged. Those in parallel will have huge busbars and identical cables for equal loading.
  • We are over specifying all our battery cables and have a full size professional crimping tool to make the best possible connections.
  • Most of the batteries (5 out out of 8) have a bluetooth BMS and I will be monitoring this automatically from our Raspberry Pi system
  • All our solar chargers, battery balancers, battery monitors are from Victron with bluetooth capability so we can monitor them from their app and from the Raspberry Pi system
  • The SignalK system on the RaspberryPi will allow us to add a number of sensors to monitor temperature, humidity etc of everything, so we should know if there is a problem in any battery, bearing, motor, motor controller etc
  • We are installing a dripless seal for the sterntube. This should minimise maintenance and the chance of any salt water coming into the engine compartment.
  • We are installing an Aquadrive. This absorbs all the thrust from the propeller which means the engine and the bearings are free from these loads. It also means that the alignment of the motor is not critical. Both these mean that the motor will be on very flexible mountings so there should be much less vibration in the motor frame as well as in the boat. That should help avoid things shaking loose.
  • We plan to install an automatic dehumidifier for the motor compartment so keep the air in and around the motor plus electronics as dry as possible.
  • The cockpit floor is removable for lifting diesel engines in and out. All our electric stuff is small and light (heaviest individual items under 40kg). Even the motor in it’s frame is under 70kg and we can put it in the frame in the corridor next to where it will go. So we will use a more secure sealant on the cockpit floor, it would be possible to get it up but not as easy as it has been.
  • We will have a much more sealed bulkhead between the motor compartment and cockpit locker. So when you put wet ropes, fenders, sails in there it will drain into the bilge directly and not splash through lots of holes.
  • We are re-routing the vent for the main water tank so it doesn’t go through the motor compartment (reduce chances of water ingress)
  • The boat does not have a working electrical earth at present, we will make sure it is implemented and tested to protect the systems from galvanic corrosion.
  • All new composite cockpit drains and seacocks should reduce condensation and with much higher quality hoses should be more watertight.
  • We are not in a rush and so we can take the time to build it up slowly, carefully and with clear layouts and documentation
  • As we are doing all the work ourselves we know how it is installed and how to maintain it

Despite all that there are still some risks:

  • The biggest is the motor controller, the wiring is complex (for us, fortunately we can bring in our son who is an electrician). Also they are programmable and we don’t have the tools to reprogram it (particularly for regen but potentially also for things like throttle response and max revs)
  • We don’t manage to generate enough electricity to charge the batteries enough (separate updated blog post on generation to come)
  • We do something stupid with one of the expensive components so we need to spend a lot of money replacing it (eg shorting a battery, wiring something wrong).
  • Something we have not thought of

Compared to our lack of understanding of diesel engines this feels like a comfortable place to be 🙂 We think that overall we should be more reliable than diesel, better to live with and because of these be both more convenient and safer than a diesel engine while obviously being incredibly better for the planet.

Going 100% electric: the “house”

I recently detailed where we are at with the Electric Motor, now for the domestic “House” side.

The House power supply

I have started building the battery box which will sit above the motor and motor batteries in the motor compartment.

We have 4 x 120AH Lithium (LiFePo4) batteries from KS Energy KS-LT120B. These have Bluetooth BMS’ which I have been able to connect to from a Raspberry Pi (so one day will be able to monitor and control from the integrated navigation system). Their high continuous current rating of 160 Amp and 30 seconds surge at 250 Amp means they are easily able to power our inverters. It also means that we could rewire them in series to replace the motor batteries if we needed to.

These batteries are going to be connected in parallel so they act as a 12 volt, 480AH bank. This is one decision we agonised over. An alternative would be to have a 48volt house battery bank (and even have a common battery bank for the motor and house – such as Sailing Uma have). The biggest advantage of a 48 volt system would have been for the inverters. However, there are also disadvantages, particularly if you want to add additional battery capacity (you need to add four 12 volt batteries at a time).

Powerful 12 volt inverters require a lot of current, they therefore need very thick cables and short cable runs. Ours are going to be very short and so on balance we have gone for the simplicity of running everything on the house side at 12 volts.

So our batteries are connected in parallel using a massive 60mm x 6mm tinned copper busbar. We will be using very short 95mm2 cables to connect the batteries to the busbar. All 8 cables will be the same length. This form of connection is one of recommended ways (simplest of them in our opinion) of making sure that the battery use is balanced equally across the batteries.

From the battery box +ve busbar we will have doubled 95mm2 cables to a fuse. Then doubled 95mm2 cables to a shunt (used so that the Victron battery monitor sees everything). Then again doubled 95mm2 cables to the main battery switch. Finally the doubled 95mm2 cables go to a +ve secondary busbar at the forward end of the battery box.

From the battery box -ve busbar we will have doubled 95mm2 cables direct to the -ve secondary busbar at the forward end of the battery box.

The reason for doubling the 95mm2 cables is twofold. First, our inverters could potentially draw more current than one 95mm2 cable can carry. Second, the inverters are very sensitive to any voltage drop over the cable (it can cause fluctuations which can damage the batteries). By doubling the cables and keeping the lengths very short we should avoid both problems.

We will have 4 connections from each secondary busbar. All of them will have circuit breakers or fuses on the positive and all of them will have 95mm2 cables to the circuit breakers/fuses.

  • Inverter 1: a Victron 12V inverter giving up to 2000 watts (95mm2 cable)
  • Inverter 2: a Victron 12V inverter giving up to 2000 watts (95mm2 cable)
  • Lofrans Tigres Horizontal Anchor Windlass windlass 12v connected via 70mm2 cables (thicker than the 50mm2 specified by the manufacturer)
  • Distribution busbar for Main 12volt switch panel (busbars situated above the corridor to the aft cabin, switch panels on the bulkhead above the entrance to the corridor)

The 230volt AC systems

The Victron inverters get connected together into a single mains supply. So we have a 230V 4000watt mains supply via a standard circuit breaker box. The main purpose of having so much 230 volt power is the galley. In the galley we have

  • 2 x single induction hobs (max 2000watts each)
  • Microwave/combination oven/grill (max approx 1000watts)
  • Multi-cooker (max 900watts)

And no doubt we will be adding coffee machine and a few other gadgets.

So we will be able to run any 2 of these devices at full power at the same time (and to be safe we won’t run both hobs on full power at the same time).

Beyond the galley we have

  • 230volt water heater to supply sinks and shower
  • Device like our current laptops which only have 230 volt power connectors.
  • Two wall infrared panel heaters.
  • Power tools (most of them are now cordless but the batteries are charged from 230volts)
  • One day in the future a 230volt watermaker

Our electric outboard motor for the dinghy has a 12volt charger as well as a 230volt one.

4000 watts should be plenty with some simple house rules

  • only one cooking device while using the windlass (why would anyone be cooking when you are either raising or lowering the anchor?)
  • if using two cooking devices then turn off most other mains devices (possibly via the circuit breaker?)

The 12volt DC systems

These are mostly very normal for boats with lights, instruments, electric autopilot (we mainly want to use a windvane anyway), fridge (not planning a freezer), windlass (a lot of current but not for very long).

However, we are also going to be building our navigation, entertainment and office systems around 12volt Raspberry Pi computers and 12 volt screens. This will include WiFi to our phones etc. We will be fitting a hi power/long range 3G/4G antenna that will make it’s connection available via WiFi to everything else.

The Raspberry Pi’s will be used for navigation (we have a touch screen for the cockpit) with OpenCPN as well as for general use (everything from NetFlix to general office to video editing) on a TV screen in the saloon.

We will be using a SignalK server to connect the Raspberry Pi systems to marine instruments (AIS, Radar, WindSpeed/Direction etc). Anyway that is a whole lot of other posts.


While it is perfectly ok for us to plan the system so that we can deliver 4000watts for cooking at full power on two hobs or run all these other devices the fact is that we still have a battery bank with limited capacity.

Here we admit there are a lot of unknowns and variables. However, we think that being able to monitor our battery use very accurately will allow us to modify our behaviour to suit the available battery charge (eg no hot showers or minimise cooking power use).

The next key part of the picture is how we recharge our batteries, both house and motor banks). That will have to be a separate blog post.

Preparing the motor compartment from the bottom up

So we have a clean and painted bilge below where the electric motor, batteries, motor controller, inverter, battery balancers etc are all going.

Our “only” problem, before fitting everything, is that the bilge is gradually filling with water. There are currently quite a few sources of this, none of them surprising.

First, we have disconnected the hoses from the two cockpit drains. So any water getting onto the cockpit floor drips straight in. The reason for disconnecting the hoses was that they have to be replaced (and the cockpit drains at the top plus the seacocks at the bottom). The hoses were very brittle and splitting where they were connected at the ends.

Second, the cockpit floor is not bolted down at the moment. We had to remove it to take it out to get the engine out, we haven’t permanently refitted it as a) it needs a new rubber seal b) it needs the last of the old sound insulation removing and then it can be painted (much easier when not in position). So water can get in around this and through the bolt holes.

Third, we have removed lots of bits from the sides of the cockpit (engine controls, autopilot control, pump etc) so there are quite a few holes (and they are not small).

However, none of these would matter if no water got into the cockpit in the first place. With the hardtop wheelhouse, which gets closed off at the back by the cover, when we are not there, in theory no water should be getting in. But for a long time since taking the engine out we have had a temporary bit of old ply covering the wheelhouse skylight (needed so you can see the mainsail when sailing). However, we fixed that other Friday and our new wheelhouse skylight doesn’t leak and you can see through it.

When we are on the boat we almost always have the cover off (at least partially) for easy access (it isn’t designed to be closed/opened from inside) so when we are onboard water goes get into the cockpit.

Now that all the old seacocks are filled, we can start the work to prepare for the motor, bit for access reasons it is important to start from the bottom. We are starting with the new seacocks, then the pumps. We want to do these now because they will gradually become less accessible as the propeller shaft, then motor frame and batteries go on top.

As soon as we have the new seacocks we can fit the new cockpit drains which are going to be a major upgrade. The old ones were connected with 1.25 inch hose to blakes seacocks and I think the inside of those was only about 1″. Our new TruDesign seacocks have a 2″ internal diameter. That means potentially 5.7 times more flow.

Also we are changing the drains within the cockpit. At the forward end of the cockpit we are fitting new 32mm drains. But we are adding to the aft end two 2″ drains. The design for fitting these has changed a few times. Now we plan to shorten the removable cockpit floor and add a new slightly lower floor at the aft end that the drains will be in with almost a straight run down to the seacock. We are also going to add a step going across the back of the cockpit, just above this new bit of floor, as we find the step down into the cockpit a bit too big to be comfortable.

The forward drains will come aft just gently sloping downwards and be connected to T’s on the main 2″ hoses. I still need to find a way to connect the 32mm hose to the 50mm T fitting.

We have also upgraded the hoses from the rather feeble PVC hoses that had lost all their flexibility to much heavier duty hoses that are fire resistant. We have all the jubilee clips to connect everything (2 clips at each connection as recommended).

The other task is the bilge pumps (one automatic electric one and one manual) we need to get the pipes in at least (because they go to the bilge under the motor). We hope to be able to reuse the old manual bilge pump (we think it just needs a new seal to waterproof it to the deck and new plastic ring that holds the seal in place). What we are not yet sure about is where we are going to have the pump hoses exit the boat. The old position was so inaccessible that the valve had never been closed. But wherever they exit is going to be higher than the motor and batteries so we can sort it later.

We want to get all this work done before fitting the motor stuff both to make sure we are not getting any water near the motor but also because it is going to be a lot easier access without the motor.

Oh and by the way, we have another cunning plan for our new fast draining cockpit. When we fit a watermaker we will not need to fit an extra seacock. Instead the raw water intake pipe will be able to drop right through one cockpit drain into the sea. The brine discharge will be able to drop into the other cockpit drain. Yes, it means we can’t have a fully automatic watermaker (although nothing stopping an automatic flush cycle as that doesn’t need a raw salt water input and can drain into the cockpit).

Going 100% electric: the Motor

A few people have been asking for product information about our electric plans. Bear in mind that this isn’t yet fully implemented and certainly not proven by us. Also that our choice is to be fossil fuel free and live with the impacts. If it means we can’t go as far or as fast, or if we have to do a lot of active management in order to be fossil fuel free then that is ok with us.

Note that we are not qualified to offer any advice, this is our own journey, learning as we go.

Finally, this isn’t a rush job. we are planning to get this sorted over a number of years. I have a minimum of 3 more years in my current appointment with extensions possible before we retire to live-aboard. Therefore we have time to get everything sorted, until then our sailing will be odd days and holidays.


We bought our motor and it’s controller in the UK from Falcon Electric. They work with electric car projects but we chose a motor that is sold in the US for yachts by Thunderstruck Motors. We couldn’t find a EU marine dealer for these motors.

What we bought is a package of motor, controller, wiring loom and meter. So the motor is a HPEVS AC-34 and the Controller to go with it is a Curtis 1236SE-5621 (48v, 600a, 40hp).

We looked at many other motors. Either they were out of our price range or they were not brushless. We also like this being air-cooled as we want as few holes and as little complexity as possible. We know this might mean needing forced air ventilation for the motor compartment in hot weather, however for us that is a lot cheaper and simpler than water cooling.

We have bought the Curtis throttle from Kit Elec Shop we are going to make our own handle for it. This was tricky to find, with expertise we could probably have bought a non-Curtis item.

We are not yet sure to what extent the controller will need programming for best performance, the devices to do this are quite expensive so not rushing to buy one. We also expect to need to add a larger cooling plate to the controller.


We are reusing the existing 3 bladed propeller (design max speed 1600 rpm). Our hope is that, rather than this being a big drag slowing us down while sailing, it will prove powerful driving the motor in regen mode. Upgrading to a folding prop that would have less drag while sailing a slow speeds while still being able to unfold for regen is a long term possibility (although expensive).

We are replacing the cutlass bearing due to normal wear and tear. The length of the propeller shaft and the position of the skeg require the propeller shaft to be taken out inwards. Having to remove the engine for this work was a motivation in switching from diesel now.

The original stuffing box had been leaking and needed a lot of work. We decided that as we want to minimise salt water near the electric motor we would replace it with a PSS Pro Dripless seal we chose this a) because it does not require a pressurised water feed (with an air cooled motor we don’t have one) b) it has a wide variety of sizes. We are re-using the flange that screws onto the stern tube that the stuffing box used to be attached to (have ground and sanded it smooth). The PSS Pro is therefore for a shaft of 1-1/4″ and a flange of 2-3/4″. We will be adding their Hy-Vent to provide water to the seal.

The propeller shaft will be connected to an Aquadrive system CVB10.10 (all the drivetrain components are being supplied by T.Norris Marine where Jonathan has been really helpful).

From the Aquadrive (via a coupling from T. Norris) we have a shaft that goes through our motor frame to an 80 tooth pulley for a 30mm wide timing belt (two bearings are fitted, one at each end of the frame). The motor frame is now at the forward end of the motor compartment so we are probably going to add an additional bearing for the shaft near to the Aquadrive (with the coupling etc there is quite a lot of weight on that end).

The motor sits above the shaft in a custom frame we have built and we have a 56 tooth timing belt on it. This reduction gear (56T to 80T) should allow the motor to run at peak torque with the propeller at design maximum speed. Given the motor is, at least in straight numbers, more powerful than the 29HP diesel with more torque available at low speeds we expect to not need to push the motor very hard. The motor can be moved up and down in the frame to tension the belt.

We bought the pulleys and timing belt from Bearing Boys, the stainless steel bearings from Simply Bearings, the Stainless steel for the frame from Metals4U and all the bolts from Accu. See various posts about the motor frame.

We have 4 engine mounts coming from T.Norris.

This means we should have few alignment issues for the motor and as the thrust is taken by the Aquadrive the motor should be free to float on it’s mounts which will reduce vibration and noise.

Motor Battery Bank

We are running the motor with a 48 volt battery bank (we decided we did not want to go for a higher voltage as then there are safety issues and also you need so many batteries in the bank).

We are building this bank from four KS Energy KS-LT300B 12V 300Ah LiFePo4 batteries. So 4 x 300Ah is 1200Ah. We chose them as being cheap, open about the technology and high density. It should be a lot simpler to wire just 4 batteries together rather than a larger number of smaller batteries (and was cheaper).

This battery bank will fit above the shaft just aft of the motor frame, forward of the aquadrive. It will be 2 layers of 2 batteries. as a 2×2 block. This keeps weight low and central with short wiring runs.

The batteries will be encased in an epoxy coated plywood box for protection.

We don’t have space to add additional batteries to this bank. However, in an (slow) emergency our house bank could be rewired as a replacement motor battery bank (by changing from parallel to series connection).

Our very rough estimate is about 1 hour at close to hull speed and about a day at slow speed (2 or 3 knots). Hopefully up to about 20 miles.

I’ll cover cabling in a later post. We are making our own cables and have the proper crimp tool. For efficiency and reliability we are using thicker cabling than is required. There will be a shunt (for measuring battery bank). There will be a shut off switch and a fuse. We will be fitting 3 Victron battery balancers (as they recommend for a bank of 4).

That is all I can think if for the moment. Have I missed out anything useful?

Convenient sizing helps

We can’t easily fit a whole sheet of plywood in our van. To fit it has to be lifted at the front to rest on top of our headrests and then slope down to the back. It doesn’t feel very safe and it doesn’t make it easy to carry much else.

However, this time one of the key purposes in taking plywood, when we go for our holiday is to build the house battery bank box.

It so happens that the bottom and top of the battery box need to be 440mm wide and the sides 2x220mm. By cutting 440mm off the sheets of plywood they fit in the bottom of the van.

So we have shortened 2 sheets 12mm ply (bottom and sides of battery box) , 1 sheet 9mm ply (top of battery box) and 1 sheet of 5mm ply (for headlining).

They all now fit. The 2.4m lengths of timber for framing all fit diagonally.

Then we needed table saw and mitre saw plus support.

By the time we have added the batteries, cable etc plus other tools, it is starting to look quite full.

Still we only need to add clothes and food for a couple of weeks 😊

Looks like the van will need to be our storage shed once we get there. No way do we want all this stuff filling the boat.

Electric Motor compartment changes

Our process for designing the electric motor compartment has had to be somewhat adaptable. We started from knowing nothing and so it has been a constant process of learning and then changing our plans.

The work over the last two weeks (Stuffing box flange is off, Yanmar Diesel 3JH5E for sale and Friday progress #21) has been a catalyst for some more changes. We now have a much clearer understanding of how all the parts between the motor and the propeller fit together. We also have a much better idea of what we need to fit (and many thanks to Tristan for his comments on our post Staycation Electric Motor Progress which got us rethinking our drivetrain).

So we are now close to deciding upon a PSS Pro Shaft Seal to keep the water from coming into the boat through the stern tube. We like this dripless seal as we shouldn’t need to provide a raw water supply to lubricate it. That is good because as our motor is air cooled we don’t have any raw (salt) water to divert into the seal. Some brands require 4 litres per minute which would mean installing both an extra seacock and a pump.

The challenge of providing water lubrication to the dripless seal isn’t just that we would need to provide it when the motor is running but that we would also need to provide it when sailing and using the spinning propeller to generate electricity using the regen feature.

So the PSS Pro shaft seal allows you to provide an air vented hose if your speed will be less than 12 knots (if we ever reach 12 knots it will be a short lived and no doubt terrifying moment!). However, if we find that water lubrication is required to reduce wear when running in regen mode for days at a time, then we can add a seacock salt water inlet and connect it directly to the seal without needing a pump.

The PSS Pro shaft seal is also available with a wider range of support for propeller shaft and stern tube flange sizes. We hope/plan to reuse the flange that used to hold the stuffing box, it is a larger diameter than would otherwise be the case and most dripless seals can’t cope with that.

So that is all good 🙂 The only downside is that the PSS Pro Shaft Seal is a bit longer than many of the solutions.

That brings us to then next piece of the puzzle which is where Tristan was so helpful. Our initial plans used thrust bearings within the motor frame to absorb the push and pull from the propeller. These have two grub screws that pass the thrust from the propeller shaft onto the motor frame and then that gets passed through the motor mounts to actually move the boat.

It turned out that as a very basic and cheap solution it was flawed. Two grub screws are not very much when it comes to transmitting the thrust generated by a 40hp motor spinning a propeller ar 1600 rpm to move 9 tons of boat. Also if the motor mounts need to transmit all the thrust to the boat they can’t be very flexible and so they won’t absorb much vibration.

So we are adding an Aquadrive to the drivetrain. This helps us in several ways. The propeller shaft ends at the Aquadrive which is fixed in perfect alignment with the cutlass bearing. So vibration and wear is minimised. The Aquadrive then passes all the thrust directly to the boat, so no thrust is acting on the motor which can therefore be mounted on much softer mounts so less vibration is passed onto the boat. Plus the connection from the Aquadrive allows for a lot of freedom in alignment for the motor requiring a less accurate installation.

Apart from the cost of the Aquadrive (nearly £1,000) this is all good. However, the impact on our layout is that the Aquadrive is over 250mm long.

With the PSS Pro Shaft Seal and the Aquadrive our motor needs to be moved forward so much that instead fitting the motor batteries (2 rows of 2) in front of the motor there is barely space for one.

So, we think we are switching things around. We will move the motor to the forward end of the motor compartment, a longer shaft will connect the motor frame to the Aquadrive. The motor batteries will then go aft of the motor above the shaft and Aquadrive (it raises them by about 200mm).

We will probably move the house bank batteries to above the motor to keep the weight distribution approximately the same fore and aft. The centre of gravity will be a bit higher although we think still lower than with the diesel and full tanks.

We have not tried to fully plan where all the electrical items will go (motor controller, and inverters are the biggest) yet.

The plan is to build from the bottom up. So

  • Remove the old bulkhead to the corridor to ease access to the motor space. Finish the cleaning, then sand the whole area.
  • Fill the old seacock holes from the cockpit drains and the diesel water cooling (these will end up somewhat hidden by the battery box).
  • Paint the whole of the motor compartment and the cockpit locker.
  • Fit new Cutlass bearing (need to sort out grub screws to hold it in place), then the propeller shaft with the dripless seal. Add the (still to be fully cleaned) propeller and an extra zinc for galvanic corrosion protection.
  • Next will be the Aquadrive, which includes building the frame that will transmit the thrust. We should be able to fix this to the moulded in engine bearers.
  • That will allow us to mount the motor and fit the new shaft connecting it to the Aquadrive.
  • Now we will be able to fit the new cockpit drain seacocks where we can get easy access and route the hoses efficiently.
  • Then the battery box for the 48 volt motor battery bank of 4 x 300AH can be built above the shaft/Aquadrive.
  • Then the battery box for the 12 volt house battery bank of 4 x 120AH (position a little uncertain at the moment)
  • This will allow us to build the full bulkheads separating the motor compartment from the cockpit locker and from the corridor (and also steal a bit more space into the aft cabin).
  • Then we can fit all the electrical items and wire everything up (big job).

Fortunately, while the list is long the uncertainty is getting less. The biggest unknown is now how well the default program settings of the motor controller will work. Will we need to hire or buy the tool to reprogram it? Within that the biggest questions are about the regen and we won’t be able to know much about that until we are actually sailing.

So quite happy with all this :-).

Friday progress #21

So we have come of age 😉 21 today. Not too bad, we are still a month away from owning Vida for a year and we were unable to visit for nearly 4 months due to the lockdown.

We arrived late last night (slightly delayed by a poorly signposted diversion). We had to sneak in quietly, as another couple from the NWVYC were asleep in their motorcaravan, in the carpark 🙂 So just the essentials to carry to and up onto the boat at 10:45pm.

This time that included one of our Natures Head Composting Toilets. We took it home last time as it was getting full and we decided to continue to avoid using any shared facilities, so took it home to empty. Again Composting Toilets prove to be by far the best toilet during a Pandemic. No capacity limit. No need to use anyone else’s facilities.

Anyway, after a good sleep we got stuck into our first task. Removing the Cutlass Bearing. Really the last key piece that needs to be removed (so it can be replaced with a new one) in order to progress with the electric motor installation. This is the part closest to the propeller, it is a bronze sleeve with rubber insert that slips inside the stern tube that is built into the boat.

So I had bought these bits.

A 1m long 24mm diameter threaded rod. To go on the inside end a lock nut then two washers, one with a 24mm hole to fit snugly and then one with the right outside diameter to fit inside the stern tube but not inside the cutlass bearing. So this gets pushed in from inside the boat until the threaded rod appears and the washer is snug against the inside end of the cutlass bearing.

On the outside I have a 63.5mm stainless steel tube that goes around the end of the stern tube to push against the keel. Then a huge 70mm diameter washer and another nut.

On site I used a hole saw so that I had a piece of wood to protect the keep from the stainless tube.

Here you can see the outside nearly ready to go.

It proved to be a really hard task, we tried tightening the outside nut (had to file flats onto the threaded rod so we could use a spanner to stop it moving). Got it really tight but no movement.

Tried using our short section of propeller shaft and a hammer from the inside to knock it out. No movement.

Tried to cut the cutlass bearing lengthways with the Dremmel. Managed to cut a lot out but still it didn’t move.

Then rather than hit the propeller shaft with a hammer I used the shaft itself as a sliding hammer down the stern tube. It worked!!! Took until about 2:30pm but finally we managed to get it out.

This is the sterntube without a cutlass bearing.

This is the Cutlass Bearing, you can see where I had cut it and trimmed it with the Dremmel to try to free it.

With that done we could get on with other jobs.

First up was more cleaning of the old cockpit locker and diesel engine bay. After several hours it is now mostly clean enough for sanding and painting.

After working on part of the cleaning together I moved onto the glass windows of the wheelhouse. We have noticed a few leaks and wanted to fix those and check their condition.

The corrosion wasn’t too bad. The seals were pretty rubbish though and several of the screws rather loose. I cleaned and refitted using a neoprene strip 6mm thick. We can plan something better for the future now we know what is there.

Last job of the day was to fit the first two uprights that will become the sides of the motor and battery compartment. We wanted to add some additional strength to support the cockpit, particularly on the port side where there is a footwell for when you are steering. Plus we need uprights to fasten the sides that separate the motor space from the cockpit locker on one side and the corridor on the other.

These will be epoxy coated and fixed in place, more will added when we are sure where the motor mounts will go.

The new space for the motor and batteries is going to be a lot narrower than the old. So we can extra space in the cockpit locker and in the corridor to the aft cabin.

I’ve set them both vertical which turns out to nearly perfectly line up from the engine bearers to the flange that the cockpit floor bolts to. Now these are in place I’ll be able to remove the old corridor side which is going to make access much easier.

It is now horrible outside, the wind has got up and it has been raining hard for 3 hours. Yet we have left the cockpit floor and cockpit locker lid off to continue to air them out (yet again a significant improvement in the smell). So good that we have a wheelhouse above). You can see how much cleaner they look. Once they are painted it will make such a difference!

Eventually the cockpit floor is going to be bolted down more permanently (because we don’t need to take it out to fit an electric motor) with two new, bigger, drains fitted in the rear corners. Until then it does provide lots of light and makes it easier to get the larger timber in.

As we move to boxing in the cockpit locker we will need to build a ladder, probably on the aft bulkhead in order to get in and out.

Next a good sleep, a lie in and then back home to work.

Thursday progress

In my earlier post Stuffing box flange is off! we achieved the job that has been worrying me most during lockdown. So with that done we spent the rest of this extra day off clearing more debris from the diesel engine and preparing for the electric motor.

This is the stern tube where it emerges from the back of the keel (after we removed all the paint). This is the same tube that, on the inside, we removed the stuffing box flange from. So it is a bronze tube about 1m long fibreglassed into the structure of the boat. The propeller shaft runs through it.
After help from the Rival Owners Association with think the 3 holes, in a line, are from something fitted in the past to cut ropes that would otherwise get caught around the propeller.

The single hole is matched with one on the other side and these should have grub screws in them to hold the cutlass bearing in place.

This is the cutlass bearing. It is a bronze tube about 20cm long that fits inside the stern tube. It contains a rubber bearing with grooves cut in it. This is what the propeller shaft turns in. The grooves allow water in as a lubricant and for cooling.

It needs replacing and we managed to get the rubber insert out but not it’s bronze tube. It seems that we will have to make a couple of lengthwise cuts in the cutlass bronze tube so that we can get it out. Then the new one should just slip in. H’mm, we will see how easy that is.

Then we made some more holes in the cockpit. Top, semi circular is where the holder for the old engine gear lever/throttle was. We will take it home and prep it for the new tiny electric throttle.

The rectangle below that is from the autopilot which we have removed for cleaning and to get easier access to all that wiring.

Below that a round hole and a square hole were from two vents, we think they were for the fridge compressor. We will be blocking them up.

The rough, round hole on the left is from the manual bilge pump. We are taking it home to service, we think it will be fine, it just needs a new plastic ring on the outside as the current one was broken. All the pipes for the bilge pump will be new and routes differently so that we have access to the skin fitting where they exit the boat (we will have it a bit higher too and it will have a proper valve on it).

To do these jobs we removed both the cockpit locker and the cockpit floor for light and access. Jane did some cleaning, to get rid of the diesel stains where we have removed the fuel tank from the cockpit locker. It is now so deep only her head pokes out from it. Steps are going to be needed, at the moment we climb across the empty engine room from the corridor on the left of this picture.

This is looking from the corridor across the engine bay to the area Jane was cleaning. It looks very different. Before the whole area was as dark as the darkest part in this picture. When we have finished cleaning it will be sanded and painted to look pristine. Then a new vertical bulkhead (“wall”) will separate this locker from the electric motor room.

Meanwhile I cut the big piece of wood and fibreglass out from the side of the corridor. It was the support for the fuel tank (and an edge to stop the tank slipping into the corridor. Yet more saving of weight and taking out smell (untreated wood soaking up diesel for 42 years, yuck!).

That big chunk came from the left of the floorboard in the next picture.

In the bottom left of the picture you can see a cut out in the bulkhead which was for the fuel tank tap. This is the bulkhead at the aft end of the chart table which you can see in the picture. We are having a smaller chart table so that you sit facing forward (back leaning against this bulkhead). So we are going to trim the width of the bulkhead to match that tap cutout. Another step towards making the corridor to our cabin wider and easier.

We have now measured and we should be able to store two bike frames (with wheels taken off) in this space to the side of the corridor. We will probably hang them from hooks.

The right side of the corridor as you look in this picture will also move as we don’t need as much space or sound insulation for the electric motor.

Finally, we have been able to make lots of progress around the boatyard. Here I’m partway through removing the storage box we built around it while storing it in the cockpit since we lifted it out in February (see Diesel engine is out. Zero fossil fuel cruising on the way). We hadn’t expected it to be stored there so long. Tomorrow, the yard are going to life it out and down to the ground. Then we can sell it 🙂

We were also able to sort a few things with the other people who work around here. Steve is going to clear away the stainless steel and old diesel and he has sold the rigid dinghy that came with Vida for us.

Trevor is preparing to fit the new toerail (it will look a bit like an escalator handrail), before lockdown Gary got the preparation done by cleaning and filling the joint that the toerail covers with special flexible epoxy resin. This will be a lovely job to have finished as it was in progress a year ago when we bought Vida.

Only after we removed the autopilot and came below did we realise that this has left a big gap to be filled between the galley and the cockpit locker. Planning the rewiring is quite a big job as our electrical system is going to be so different, plus the switch panel is moving to the other side of the boat. We are intending to fit plastic tubes as conduit for all the wiring so that it is possible to pull new wires through in the future. However, we have both 240volt AC and 12volt DC to do and they need to be kept separate.

Sustaining Electrics

We have had lots of comments that salt water and electrics are not compatible. We also see lots of YouTube channels who find that their electronics (laptops, hard disks, cameras etc) do not last well in salt water environments.

This shouldn’t come as a surprise. So what are we doing about it?

First, we need to recognise that Salt Water and Diesel are also not compatible. Also that diesel engines still need some electrics (very few modern diesel engines can be started by hand).

Second, there is a lot that can be done to help electrics survive better and to be more sustainable in our use of them. So here are a few things we are doing that particularly relate to the electric motor.

  1. Keep salt water out of the boat.
    1. Reduce the number of holes in the boat. We are down to 2 seacocks which are for the cockpit drains and so there is no opening from them into the interior of the boat.
    2. Change the traditional stuffing box to seal the propeller shaft with a modern dripless seal. The stuffing boxes always leak a little, right next to the motor which is clearly a bad thing.
  2. Actively dry the air, we will be fitting and electric dehumidifier into the motor compartment so that the air used to cool the motor will be dryer. The model we are looking at (Ecor Pro Dryboat 12) removes the moisture in an warm, damp exhaust to the outside (so we don’t need to have a water drain inside). A side effect is warm, dry air that can be used to warm the cabin, dry clothes etc.
  3. Box in the motor. While not fully sealing the motor (it is air cooled so needs air flow) we will make sure that it isn’t directly open to the bilge and that the air into the motor compartment comes from drier parts of the boat (such as the aft cabin which is far from the entrance and from wet clothes lockers). The compartment will be fully sealed from the cockpit locker where wet ropes, fenders etc will be stored. Also fully sealed from the galley where we create steam.
  4. Keep other water away from the motor compartment. So no plumbing at all. No water pump, no hot water tank etc.

We are also considering sustainability when it comes to other electronics such as used for navigation, general computing, entertainment etc.

Here our intention is to avoid integrated proprietary solutions in favour of low cost, open solutions. Also to use wireless communications where possible.

So our key platform will be Raspberry Pi single board computers. These do not require fans, can be installed in fully waterproof cases and run off 5Volt DC so are easy to power from our battery banks. They can be used for navigation (using OpenCPN), communication between sensors (such as wind speed, boat speed, AIS etc using SignalK as well as wired connections), entertainment (video etc), work (office software, video editing etc etc).

All the software is free and open source which is always far more sustainable than closed proprietary solutions that companies can stop supporting (or the companies can disappear). Even if you are not a programmer you still benefit from this.

Waterproof screens are now widely available and replacement screens can be bought anywhere (anything with an hdmi connection will work). That compares to replacement screen needing to be bought from B&G or Garmin or Apple.

As Raspberry Pi computers are cheap (the most powerful, more than we need is £74) and can be used for so many tasks, we can have several meaning we gain redundancy.

More and more sailors are switching from the very expensive dedicated units such as from B&G, Garmin, Raymarine and instead using the phone, iPad or tablet. However, these are generally not very waterproof and as they are all in one units they are expensive to replace.

Instead we can have a “dumb” but waterproof screen and keep the brains (the Raspberry Pi) separate, away from the elements. If there is a failure we haven’t lost the whole unit bit can easily replace just the broken part.

The open source element also allows a great deal of integration For example I can write code to access our Batteries Management systems over bluetooth from our Raspberry Pi (and make it available to the boat management system) without needing to wait for our unknown brand to be supported by the navigation system supplier. Others have connected sensors for temperature, humidity and much more.

There are a number of new sensors for sailing becoming available eg wind sensors from both OpenWind and Calypso that are solar powered and wireless. Both can be connected to Raspberry Pi systems. This should prove more reliable that systems requiring wires up the mast for power and data signals.

Whilst the (very expensive) integrated systems from B&G etc are very sophisticated they also tie you into an ecosystem that does not have sustainability at it’s core. To gain that you need to have more control yourself which is what the OpenSource approach gives.

Plus neither we nor the planet can afford to keep replacing Macbook laptop computers every year or two.