Saturday extra

So we had an extra day this week.

The house battery bank box got the last bits coated in epoxy.

I finished the vertical posts that the corridor and cockpit sides will fasten to. These got coated in epoxy and fastened in with thickened epoxy. They will also support the horizontal beams that the house battery bank will sit on.

Finally, we put the first coat of paint behind the saloon cushions.

Very pleased with the progress this weekend.

Friday progress 24

I suppose the most significant progress is that we has a guest sleeping on board with us for the first time. Stephen, one of our sons, in our social bubble, joined us for the night. The saloon single berth got a good rating.

Today, I ended up working for the morning but Jane and Stephen took the house battery bank apart and then reassembled it with thickened epoxy as glue. They have then coated nearly all of it with epoxy and added some fillet joints to strengthen the joint between the sides and the base.

Then we spent some time going over the design and plans for the electrics.

Meanwhile, one of the lasts part of our drivetrain had arrived (the shaft from the reduction belt pulley to be connected to the propeller shaft via the Aquadrive) so we have been able to lay things out and make sure everything fits (it does – just).

Motor frame on temporary wood supports at approximately the right height showing the motor shaft in about the right position to connect to the propeller shaft.

I’ve had to redesign the way the electric motor rests on the engine mounts so that we can support this shaft at the propeller shaft end. So a few more bits of metal and one extra bearing are now on order.

This shows the base of the box for the motor batteries.

It is slightly oversized at present but there is just space for it and still be able to open/close the seacocks. Access to the Aquadrive (which will be partly under the battery box) will be by making the new bulkhead to the after cabin open-able (after all no carbon monoxide or diesel fumes to worry about).

The house battery bank goes above the motor and the motor battery bank.

The two inverters go on the bulkhead forward of the motor and just above it (grey bulkhead at the bottom of the previous two images).

Given how tight everything is I’m sure we are going to have to pay attention to air flows and ventilation to ensure that the motor, the motor controller and the batteries don’t overheat. However, I’m pretty confident that we are going to be able to make that work fine for most climates with passive ventilation. We will probably need to assist that with fans in the tropics (but if it is hot there should be plenty of solar power available to charge things.

The centre of gravity of the batteries has moved up a little from what I had hoped for. However, I don’t think it is very different to when the diesel tanks were full (and it doesn’t move around). Fortunately, we have saved a whole lot of weight in other places and when we switch to dyneema rigging we will save a whole load of very high up weight.

So not huge visible progress but a lot of thinking and planning will help next steps.

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.

Capacity

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.

Holiday progress day 7: miscellaneous

So today we picked up a few jobs, none of which got completely finished. However, we did succeed with selling our Diesel engine (and have got paid this time!).

First job was to create FR4 backing plates for the new seacocks (the TruDesign fittings need a minimum thickness which is greater than the hull at that point. Before that we had to grind off some of the hull around the hole in the port side (it had been thickened for the old raw water inlet seacock but wasn’t very smooth). Made a huge mess as with a 40 grit flap disk the grinder creates loads of dust and sends it flying off at high speed so having the vacuum trying to suck up the dust as we went didn’t help a lot. Hopefully the last grinding needed in the engine room.

Cutting the holes in the FR4 was the final straw for the cheap 60mm hole saw, so I had to finish using the jig saw. Seems to be a good fit though. Next task will be to bond these in place with thickened epoxy (we will put a fillet around the edges to so there are no sharp transitions or edges).

Then I had to empty everything out of the Van (using it as our storeroom) to get to the timber, plywood and saws. Here is the start of my temporary woodworking shop.

I’ve been working on two projects.

First a box for the new house battery bank. That is 4 x 120AH Lithium (LiFePo4) batteries to be wired in parallel.

We are trying to combine some gaps for air circulation with both holding the batteries so they can’t move and fully protecting them (from moisture and also from anything/anyone touching the terminals or busbars).

This is all test assembly at the moment. Sanding still needed and I’ll be glueing the joints and coating all the wood in epoxy. The box will be above the motor and motor batteries, hence the depth of timbers, as it will need to span a fair distance to allow access underneath it.

Here you can see the batteries in situ with the busbars resting in position, next to them. The busbars are very much oversized (60mm x 6mm) to maximise efficiency.

I will be notching the timber under each busbar bolt so that there is easy access to tighten them.

The battery box cover will keep any water off the batteries and busbar, it will include a retaining bar to hold the batteries in place even if we invert. It will also protect the busbar from anything touching it.

The batteries will be slid in one at a time from the right hand end of the box (in this picture).

This is the box in approximate position. It will be higher, fixed to horizontal beams between the uprights that are not there yet. I am going to cut away the extra length of side at the left of this picture so that the batteries can be slid in and the rightward in the box. I have left the box length beams over-long to give me options for exactly where it and the uprights go.

I also started preparing the timber for the new cockpit floor corners (where the new drains will be) no picture though.

Tomorrow, should be a combination of epoxying all this stuff and maybe some other woodwork tasks.

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.

Motor

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.

Drivetrain

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?

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.

Measurements confirm layout choices

So I recently wrote Cabin Refurbishment: Part 4 Layout, however, at that point we hadn’t been on Vida for over 3 months during which time our thinking has been evolving. So our ideas were based on memory and the drawings which are a little inaccurate for the internal layout.

So, yesterday, we took lots of measurements :=)

Galley: In order to fit the worktop extension flap we are only going to have reduce the height of the bulkhead by about 50mm. We will be able to hinge the flap so that when it is in the up position it will cover the top of the bulkhead and so there will be no visible hinge to trap food, that will make it easier to keep hygienic.

Chart Table: We do want to keep a chart table suitable for a standard folded chart. The existing chart table is much, much larger than that, but sadly not quite big enough for an unfolded chart. We have enough space for a forward facing chart table with a permanent, forward facing bench seat (with storage underneath it). We will be able to have a shelf under the chart table to fit the sewing machine, without reducing knee room. This should end up being a comfortable place to sit when you are on watch (between getting up every 15 minutes for a full look around the horizon).

Corridor to aft cabin: The space at the outer starboard side (where the fuel tank was) is long enough to store both our bikes (providing we remove the wheels first). That means we don’t have to spend money on folding Bromptons (at least initially – folding bikes are a lot easier to transport ashore and can be kept with you in shops for security). We will fit it out with shelves to maximise the storage space around the bike frames.

It means that long term we can have at least one full-size bike for use on the indoor trainer for exercise 🙂

The changes to the chart table and turning the engine compartment into the motor room mean that the corridor can be widened, enough to make it practical for a foldaway sea berth. We can also add an opening porthole to the side of the cockpit to provide natural light and ventilation to the corridor as well as easier communication from the chart table or sea berth to the cockpit.

Electric Motor Room: We need a cool name for this space that is going to be so awesome. Something that sounds like it comes from the Starship Enterprise 🙂 We have confirmed that the motor, it’s battery bank, the house battery bank, the two inverters, the MPPT Solar controllers will all fit while still having good access to the only 2 seacocks in the boat (2 x 50mm Trudesign composite seacocks) for the cockpit drains.

After further study and thinking we are probably also going to fit an electric desiccant dehumidifier in this space so that we can improve the lifespan of all the electrics by drying the air thus avoiding them sucking in salty, humid air causing them to fail. More on this in the future, a nice side effect is that the dehumidifier also warms the air (and yes we will make sure that warm air gets directed outside the boar when we are in hotter climates).

I’m working on designs for battery boxes that fully enclose the batteries and hold them in place even in the catastrophic event of the boat rolling over. With the motor bank of 4 batteries weighing a total of 152 kg the thought of these flying around is terrifying.

Critically, we are going to be able to have really short and simple electrical connections between a) the batteries and motor b) the house batteries and the inverters with all fuses and master switches very accessible. We have some really chunky tinned copper (60 x 6 mm) for the main busbars so are very confident that we can get a really efficient house battery bank (that is very critical for 12 volt batteries connected in parallel where the current is very high) with a key focus on that connection to the inverters and also to the windlass as these are, by orders of magnitude, the items needing most power.

The route to our main 12volt switch panels (everything apart from the inverters and the windlass) is also simple as the panels will be above the entrance to the corridor (above the chart table, on the starboard side of the companionway). All the busbar connections for the lights etc will be accessible behind the switch panels above the corridor (there is a narrow space inside the edge of the cockpit), we will make them so that they drop down for easy access.

Forward heads: We feel we also have a measured plan for this space. We are sacrificing some, rather inaccessible, storage space for what will be a much more generous toilet, shower, dressing space.

The composting toilet will be on the port side, sitting on a raised platform which allows it to move outwards a bit. Above and behind it will be storage space for a hand washing machine and an electric spin dryer. As we won’t have the sliding door to the saloon we will be able to fit big handholds, on both sides, for when you use the toilet in rough weather.

The two big, awkward cupboards/wardrobes opposite, on the starboard side, will be removed. On the forward side there will be a narrow hanging locker/wardrobe for guest hanging clothes. Next to that the basin with vanity storage outboard and holding tank below.

The central section will be used (with full standing headroom and plenty of space) as the shower. The toilet and basin will be protected by shower curtains (although if it is rough you can sit on the toilet to shower). The shower drains straight into a sealed section of bilge which will be pumped directly into the larger holding tank.

There will be a hinged door to the saloon (will block off the basin when it is opened).

The hinged door to the v-berth will open and expand to be able to hide the toilet. When the v-berth is used as a guest cabin you can use the shower area with wash basin and hanging locker for getting dressed (with the toilet out of view). At night, if you wish, the door to the v-berth can be closed to act as a headboard. We will add a step to the lower part of the hanging locker to make it much easier to climb up into the v-berth when it is configured as a double.

We think the small loss of storage (which is currently very difficult to access and going to be very damp if you have a shower) is a small price to pay for a comfortable shower and space to get dressed when using the v-berth as a double.

The whole of this space will also be much lighter (thanks to the larger windows as they no longer have frames) and better ventilated as both windows have opening portholes.