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.

Staycation Progress 1

So on holiday this week but still at home. Very much trying not to take risks or push boundaries of the rules.

So today Jane has finished another Saloon backrest:

We have also been making more motor progress. Working on 2 frame back plates, I finished drilling the end stop holes for the 4 slots that are used to attach it to the motor with it’s height adjustment.

The one end plate at a time we started using the Dremel to connect the holes into slots.

We managed to finish all 4 slots in one of the plates and do a test fit. Perfect first time 🙂 On this plate we now need to notch the edge (marked in read) to clear the control wires that come out the back of the motor.

Then repeat the slots in the 2nd back plate.

Once we have the front and back plates all done we can start adding the lengths of angle stainless steel to the edges, plus more to connect the front and back plates at the four corners. Then one flat stainless steel bar per side as a diagonal cross member.

At that point we should be able to add the bearings for the shaft that will connect to the propeller shaft, then the shaft, the belt drive pulleys and the belt drive itself.

The motor throttle is due later this month and the 4th battery (so we will have 4 x 12 volt 300AH batteries connected in series to give 1200AH in total, delivered at 48 volts.

Hopefully it won’t be too long before we are able to get to the boat, at least for a day trip, so that we can collect all the battery cables and crimp connectors. Then we can get it all wired up and tested at home.

Started other 3 motor frame end panels

I’m really pleased with where we have reached today.

I took the plunge and started the other panels for the motor frame. Both the front and back panels are made up of 2x 3mm panels as I couldn’t find 6mm sheet stainless steel. Turns out that was probably a good thing as I don’t think my tools would have coped with 6mm sheets.

So the most critical task was to get bolt holes through all 4 sheets so that I could ensure that the bearings for the shaft are perfectly aligned along the full length of the frame. These were tricky as the 16mm Bosch drill bit I just bought really couldn’t cope with stainless steel. These 4 are the only 16mm holes on the whole frame so I used a 13mm and then widened it.

I’ve also drilled the two holes for the top bar that is used to lift the motor for belt tensioning. Again straight through all 4 sheets so that everything can now be held perfectly aligned.

Here you can see the result.

This photo is a slight cheat as the bearings are temporarily positioned on the wrong side of the plates. What you can see here is the outside face of the front and rear panels. The bearings go on the side face.

The remaining really critical task is marking and cutting the motor bolt slots on the back panel. Not only are the 45 degrees rotated ie NE, SE, SW, NW instead of N, E, S, W but the bolts are 1/2″ instead of the 3/8″ that are used on the motor front face (life would be a lot easier without those differences, but I assume that it is probably for situations where the motor is only bolted to a frame at one end).

Cutting the slots in the 2nd front sheet is straightforward as we just draw round the ones in the first sheet.

Once all the slots are cut we can make the holes for the rest of the angle framing which goes all the way around the back panels. The front panel framing is a bit trickier as it has to avoid the motor and pulleys.

Once the panel edge framing is done we add 4 lengths of angle to connect the front and rear panels at the corners.

Then one diagonal brace per side.

At that point the frame itself is complete. We can then take it to the boat (without the motor in so it is easier to lift) to sort out where the big angled steel lengths need to go (across the frame and sticking out the sides) so that they can rest on the engine mounts with the lower frame shaft perfectly aligned with the propeller shaft.

We still need to source the engine mounts and the coupling to the propeller shaft.

Before we can fit the motor into the boat we need to properly sort everything for the propeller shaft and propeller.

So when we can get on the boat again the biggest part of this still to be sorted is removing the old, stuck, bronze mount for the stuffing box. We think we will need to get a replacement custom milled piece of bronze that will have a flange bolted to the boat and a suitable smooth tube that a modern dripless seal can be fitted to the outside of with the propeller shaft coming through the middle.

As I look at the photo, I’m wondering if we might be able to reuse this. If we can get the last bolt out then maybe I can grind off the flange with the 2 bolt holes that the stuffing box was attached to. That would give a smooth tube to attach the dripless seal to (albeit maybe a rather large diameter difference between it and the propeller shaft). If we can do this it will be fantastic, saving a lot of time and money.

The propeller shaft exits the boat though a cutlass bearing. Ours is worn but there was a new spare on board that we will use. Hopefully as reasonably straightforward job to swap that while everything else is out of the boat.

I think we need to add an internal bearing for the propeller shaft between the dripless seal and the coupling to the motor. The old stuffing box would have supported the propeller shaft in a way the dripless seal won’t. If aligned perfectly, and fixed very rigidly to the hull, it should reduce the wear on the cutlass bearing.

Before the fitting of the motor frame we still have the 2 new composite seacocks to fit for the cockpit drains and the old engine cooling water intake to fill.

Beyond all these mechanical/physical elements to the motor install we have all the electronics and controls to sort out. We have got nearly everything for this area of the work (last battery due in a couple of months, throttle assembly due in a month). So plenty of work still to do.

Reduction gears for yacht Electric Motor

So we have the main components for the reduction gears for our electric motor. Note that in the picture the items are laid out on their side, in reality the electric motor will be above the reduction box shaft.

On the left is a sheet of paper representing the electric motor (An HPEVS AC-34 ) out of the top comes it’s 1.1/8″ drive shaft.

Connected to the motor drive shaft is a 2012-1.1/8 Taper Bush (Dunlop) which is used to attach a 56-8M-30 Taperlock Timing Pulley The Taper bush has key (a length of square section metal that connects slots in the motor drive shaft and in the taper bush to keep them locked together when the motor spins).

This 56 tooth pulley is connected to a 80 tooth pulley by a 30mm wide timing belt with 8mm pitch teeth.

The ratio from the 56 tooth to the 80 tooth pulleys is chosen so that the motor can be set to spin the propeller at it’s designed maximum of 1400 rpm.

The 80-8M-30 Taperlock Timing Pulley is connected to a 1.1/4″ stainless sheet reduction box shaft via a 2517-1.1/4 Taper Bush (Dunlop) which again will be prevented from rotating with a key connected a slot (to be cut) in the shaft to the slot in the Taper Bush.

On the reduction box shaft there are two stainless steel thrust bearings. One of these will be bolted to each end of the motor frame. They will be facing in opposite directions to absorb the thrust from the propeller in both forward and reverse directions.

The ends of the motor frame are each made of 2 sheets of 3mm stainless steel sheet. These sheet frame ends will be bolted directly to the two ends of the motor and to these bearings. We have lengths of stainless steel right angle and flat bar to hold this frame together rigidly and attach it to the engine mounts (one we buy them). The motor will be bolted to slots in the frame so that the belt tension can be adjusted by raising or lowering the motor in the frame.

At the bottom of the picture we will connect the reduction box shaft to the existing 1.1/4″ propeller shaft. A Clamp on Coupling on the reduction box shaft will be bolted to flexible coupling on the propeller shaft. This means we don’t need to achieve perfect alignment of the reduction gear shaft and the propeller shaft. It also helps reduce vibration as the motor can be attached to more flexible mountings.

To keep the electric motor in as dry and salt free environment as possible the original stuffing box (that creates a waterproof seal around the propeller shaft as it exits the boat) will be replaced by a modern dripless model. While very reliable the original stuff box isn’t maintenance free and always drips a little salt water into the boat. We are looking at the Manecraft Deep Sea Seal at the moment (we are trying to avoid products that require a pressured water supply to the seal as we won’t have engine cooling water to connect to it). These dripless seals also cope better with vibration and movement in the shaft without causing wear in the bearings.

As the propeller shaft goes out of the boat in runs in a cutlass bearing. These wear out and ours needs replacing. Until we can get the existing one out I’m not sure of the dimensions we need.

The propeller needs a clean but otherwise is in good condition so we won’t be replacing it. The three bladed design creates more drag when sailing than either two bladed or folding designs. However, it is more efficient when using the motor and should also be better at regen (charging the batteries by turning when sailing and using the electric motor as a generator).

Once the motor arrives with it’s controller we can get the details of the frame sorted and start on all the connections to power and control the motor.

So much space gained by switching to an electric motor

Now that our engine compartment is empty we have been able to more accurately work out where everything will go.

We can fit the motor batteries (each 300AH) at the side of the motor. By stacking two batteries each side we can have the entire motor and it’s “fuel” in about 600mm length from the end of the existing propeller shaft. Plus we could add a 3rd layer of batteries if we needed to double the motor battery capacity (while that would be higher than fully desirable the tops would be about level with the top of the existing fuel tanks so not much impact on stability). .

Forward of the motor and batteries we can fit up to 7 x 120AH house batteries within the existing engine compartment (we are starting with 4). These will be nice and low in the boat (considerably lower centre of gravity than the existing engine and tanks). Our busbars will also be mounted here.

Above the house batteries there is plenty of space for our two Victron inverters. Aft of the motor, where the fuel filters are we will be able to fit all our Solar MPPT controllers so they have short cable runs to the batteries.

All this means that we won’t need to use the original wet locker for the inverters and MPPT controllers, so we get that back.

When the fuel tanks are removed we will gain a huge amount of space in the cockpit locker (which used to lose space to 4 batteries, fuel tank, hot water tank, water pump, fridge compressor). We will also gain in the corridor to the aft cabin which we will be able to make a bit wider and have a huge storage area with shelves for boxes of clothes (maybe one day a redesign of this and the chart table will create space for our bikes).

So not only did the diesel engine fill this large space (and leak fumes out all into spaces in every direction), it also took lots of extra space for fuel, starter battery etc.

The electric motor doesn’t just bring all it’s systems into the one space it also allows a whole load of other things to fit into the same space, thus creating yet more space elsewhere.

In all this we will be able to see and reach every battery’s cable connection and LCD battery monitoring display. We will be able to remove every battery (although we will have to remove several to get to the furthest ones). We will be able to see and reach the last two remaining seacocks (for cockpit drains). We will have access to the propeller shaft and whatever shaft seal we end up with. We will also have better access to the deepest part of the bilge for the manual and electric bilge pumps that we plan to fit.

For a boat that we intend to live on when we retire all this extra space and accessibility are two reasons that alone would make going for an electric motor a great improvement. But we still have all the other benefits too.

Friday #15 Saloon headlining

Today hasn’t been quite what we expected. But then when you start taking very old bits of boat apart exposing areas that have been hidden since 1977 you never know quite what to expect.

The main cabin roof area turned out to have a mesh backed foam behind the vinyl.

However, we found this wouldn’t pull off the plywood lining. Then we discovered that the plywood was wet and damaged in a few areas, particularly around the hatch, the dorade vents and the transition to the higher roof under the wheelhouse.

Turns out it was much easier to remove the plywood than the foam from the plywood.

Now we can see that the dorade vents are the worst problem. The wood deck core is pretty wet and the water was running along the roof above the plywood.

The only holes in the cabin roof at the mast foot bolts and cable runs (now all sealed), two backing plates for strong points on deck with a total of 4 bolts (clearly need refitting but not leaking much) and the dorade vents. So, although disappointing that the dorade vents have been leaking so much for years, at least there are not lots of holes to deal with.

Jane removing a magic box for the very old wind instruments.

We now have clear access to all the backs of the instruments, easy access for the wiring.

Next you can see that there was a pause in the rain so we quickly took off the dorade boxes. The wood was soaking wet and in poor condition. So temporarily we have fitted closed cell foam pads over the holes and sealed them.

We won’t be refitting a plywood lining. Instead we will glue 10mm closed cell foam to the cabin roof with cut outs for all the bolts, vents etc.

Much the same around the wheelhouse area but might need some framing to bridge the gaps.

First we need to fit the conduit for all the electrical cabling, and we will want to review all the holes in the side decks which come through into the main cabin.

So this was a very messy job but very pleased we bit the bullet and did it. Now we can continue to move forward.

Making Electric Motor plans

So, if we do decide to fit an electric motor what are we looking at?

We follow five sailing channels on Youtube who have fitted electric motors:

Our plans are different, in part because we are in the UK and so pricing and availability is different. In the UK there are a small number of suppliers who will fit complete systems but they are outside our price range (about the same cost as the boat). Unfortunately we have not found UK suppliers of sailing boat specific kits.

So we are looking at buying parts and installing it ourselves. However, we are also not wanting to be too adventurous, so we are looking at components that have been used for marine applications by others.

This is where we are at so far:

How powerful should the electric motor be?

Calculating what size of engine to get is quite complex. The nature of a boat moving through water is that the power required to move faster rapidly increases with speed, until the point where adding more power does not give more speed (probably around 7 knots/13kph for Vida). So there is no point in buying a really powerful motor.

On the other hand, when you are motoring into a strong headwind more power is needed for the same speed. While we intend to be cautious and avoid dangerous situations where we can, however, we recognise that the time when a motor increases your safety most, is when you have to motor away from a shore in a strong headwind (and if that is somewhere with a restricted channel or an adverse tide then sailing will be most difficult). At these times more power is needed for the same speed.

In the end a sensible rule of thumb seems to be to replace a 39hp diesel with about the same hp in an electric motor (although the two hp figures are not directly comparable for reasons I still don’t understand).

Fortunately, at slower speeds (using less power – so that the batteries last longer), a 40hp engine at 25% power isn’t very different in efficiency than a 20hp engine at 50% power (and will be less likely to overheat).

So we are looking at a 40hp motor, unfortunately that restricts the options in the UK as the most widely available motors are less powerful than this (or are designed for speedboats rather than heavy cruising boats).

Voltage

Most 40hp DC electric motors run at 72 or 96 volts. A few run a 48 volts. Higher voltages mean that at the same power the wires can be thinner as the current is reduced. Electric motors draw a lot of power and so with lower voltages the current can be very high.

However, there are two disadvantages of higher voltages. Firstly, they get more dangerous. Secondly, they need more batteries. You get high voltages by connecting batteries in series. So four 12volt batteries in series gives 48colts. You need 6 batteries for 72volts and 8 for 96volts. That gets expensive! If you decide you want to increase your range you can add extra batteries in parallel to your battery bank, but if your bank is 96volts you need to buy 8 batteries at a time.

So we have decided to look for 48 volt motors and start with a relatively small bank of batteries that we can add to in the future.

Brushless

Unlike Kikka and Dan on Sailing UMA we have decided to go for a brushless motor. More expensive, hard to find secondhand but safer as they don’t have the same risk of sparks (some authorities and insurance companies won’t insure boats with motors with brushes, especially if they have gas on board due to the risk of explosions).

Cooling

Some electric motors are water cooled (typically using fresh water with a sealed system and a radiator). Others are air cooled, some with integrated fans.

Our preference is for air cooled for simplicity, we will have to make sure we provide an adequate supply of dry air to the engine room.

Motor of choice

So we are looking for a 40hp, 48volt, air cooled, brushless motor.

The US supplier used by Beau and Brandy is Thunderstruck-ev and they have a HPEVS AC35 motor kit. I’ve have found a UK supplier of these HPEVS AC motors. So yesterday I was able to pop in and visit Falcon Electric who are focused on electric cars. That takes us a few steps forward.

So we are looking at an HPEVS AC51 motor package from Falcon Electric which gives 40hp at 48volts. It comes with a lot of the stuff we need (Controller, Wiring harness and display).

Other stuff

Of course we don’t just need the motor, there are lots of other bits too.

Drivetrain

We hope to be able to reuse the propeller and the propshaft (after the existing coupling has been cut-off).

We will need to replace the cutlass bearing (this is the bearing through which the propeller shaft enters the boat, it is typically water cooled by the sea). Once the existing engine is out this should be straightforward.

We are looking at replacing the original stuffing box (this is what stops water from entering the boat through the propeller shaft opening). There are much more modern, drip free, reduced maintenance options now available.

We will need a thrust bearing as electric motors are not designed to resist the push of the propeller.

We will need a way of connecting the motor drive shaft to the propeller shaft. This will probably need to be a belt with pulleys as the motor has a maximum speed of 10,000 rpm and the propeller is much less (probably in the region of 3,000). This is something we need to calculate as the propeller speed needs to be matched with the propeller itself and the boat hull shape/speed. In the US Thunderstruck-ev sell these, I’ve not found anything but suppliers of parts here.

The engine will need a mounting (at one end part of the gear reduction). Fortunately, there is a stainless steel fabricator at Beaumaris we should be able to use. With the gear reduction we should be able to position the motor reasonably high so we can be confident it won’t get flooded even if the boat took on a lot of water. We will sort out some form of cover to direct cooling air and make sure that air is as dry as possible (and it might be nice if we can choose to divert the warmed air outside in warm climates and inside in cooler places).

Power

The dimensions of the electric motor are far smaller than the current diesel so we will be able to fit the battery bank in the same space (giving us loads of extra space where the fuel tanks are at the moment). We will start with a small battery bank, probably four 12V 100AH Lithium-ion Phosphate. When we see how that works for range we can decide how much more to add.

We need to plan exactly how we will handle charging. Probably the simplest (but not most efficient) will be to install a DC to Dc charger so we can keep all our renewable energy charging our house battery bank and then charge the engine bank from that. Otherwise the voltage switching and balancing gets a bit complicated.

Controls and monitoring

We want to end up with a simple, single lever control that controls both direction and speed (eg push forward to go forward with speed controlled by how far you push, pull backwards for reverse). We will need to sort out displays of battery and range that we can see outside. Obviously, these are slightly different for boats than cars (speed is an order of magnitude different for a start).

Timing

This is going to need more thought. There are lots of dependencies to work out. For example, we are going to need the yard to lift the old engine off the boat at least (we probably need to get it out from under the cockpit floor which is under the wheelhouse roof ourselves). However, as the yard is very full that will need to wait until some other boats have been launched in the spring. At least this will allow us to workout all the details before rushing into it.

Other advantages

  • We don’t have to learn how to maintain diesel engines 🙂
  • We should be able to sell the existing engine for more now than in a few years time.
  • We gain lots of space in the cockpit locker
  • We gain storage space in the corridor to our aft cabin.
  • We don’t have to replace the water coolant seacock, we can get rid of it.
  • Access to the cockpit drain seacocks and bilge will be much easier
  • The boat will be lighter
  • We should reduce the amount of maintenance we need to do in the future
  • Fossil fuel free 🙂
  • Much quieter when motoring
  • No Diesel smell (brilliant for helping reduce seasickness)
  • Zero fuel cost and much more independence from harbours when cruising

Disadvantages

  • Cost (rough budget about £12,000)
  • Reduced range (depends on the size of the battery bank but certainly only a few minutes at full power initially)
  • Renewable generation limits. How fast can we charge everything? We are going to need to cover the boat with solar and move them around to maximise power generation.
  • Restricted cruising grounds by availability of enough sun to charge everything – we might need to go south for the winter 😉
  • With electric cooking, electric dinghy motor and this electric motor we will need to carry petrol generator in case we can’t keep up through renewable generation.

The problems of interconnected systems

I’m not writing about IT or programming here (although there can be similar problems).

By this I’m thinking of Single Point of Failures (SPOF) and taking that a bit further. By SPOF I mean the danger of one item failing and causing a cascade of failures. For example suppose your hot water comes from the engine, your emergency bilge pump is powered by the engine shaft, your battery charging comes from the engine alternator, your hydraulic system for bow thruster, windlass and winches is powered by the engine. Then there would be lots of simple small failures that would cause everything on the boat to fail eg some dirty diesel blocks the fuel filter, the sea water cooling fails in any one of 10 different ways.

One of the shocking things when you look for SPOFs is how critical to your safety some very small items are. So far too much of Vida’s systems relied on the engine working (battery charging and hot water being obvious examples). Although the engines themselves tend to be very reliable there are far too many individual things that can stop a diesel engine from working (on boats the most vulnerable things are fuel supply and water cooling).

Generally though on boats as old as Vida (42 years) things were not very integrated. Modern boats will have far more integration of electrics (eg electric toilets, so any electrical failure and you can’t go to the loo) and also electronics (where all the instruments talk to each other but if the main data cable fails due to corrosion nothing works).

However, the area that is proving most challenging in terms of interconnected systems on Vida isn’t about direct connections, it is about space.

Back in the 1970’s boat hull shapes were very different to modern boats. They were much narrower overall and the stern particularly was much narrower (in fact modern 38 foot boats will have a stern that is about the same width as Vida is at her widest). Typically the sides are much more vertical with a hard(ish) transition from the side to the bottom, Vida is more of a wine glass shape. The modern boats have a lot more height above the water (less depth below the water but not by as much).

All this means that there is far less interior volume to fit everything in. Our centre cockpit exacerbates this problem (but is still a design feature that we love and a key reason for choosing Vida).

So getting to the point, the over all boat shape combined with the centre cockpit and through access to the aft cabin means that they suffered from a real lack of space for “machinery” (engine, batteries, water systems, bilge pumps, autopilot, fridge compressor). I suspect that if the production run had been longer than about 6 boats they would have made changes (indeed one of the drawings shows making the galley larger so it is a U shape rather than an L shape – that would have helped this problem a lot).

What the lack of space for all the “machinery” did was create a whole host of problems caused by the various systems getting interconnected by being squashed into a very limited and inaccessible space.

They wanted to have a cockpit locker on the port side as the passageway to the aft cabin means there is no space for one on the starboard side. Storage for gas bottles, sails, fenders, rope etc etc is very limited so they made the locker as big as possible. However, that meant squashing all the “machinery” either under the cockpit locker floor (diesel tank and batteries) or forward of it (underneath where you stand when steering).

What we have found that this meant was that we couldn’t inspect, maintain or replace lots of machinery directly because you couldn’t get access until you had removed other items.

For example to remove the hot water tank (calorifier), which the electrics for heating were condemned in the survey, we had to do the following:

  • Empty the contents of the cockpit locker
  • Remove two levels of floor in the cockpit locker (and all the stuff hidden under the first floor)
  • Disconnect and remove four 12 volt batteries,
  • Disconnect and remove one (very rusty and leaky) paraffin fuel tank for the heating system.
  • Disconnect and remove the pump for the domestic water system
  • Remove the wooden shelf for the water pump
  • Cut out a wooden post supporting the cockpit floor where the person steering stands
  • cut away the top of the wood cradle for the hot water tank
  • disconnect the wiring
  • disconnect the domestic cold water in and hot water out
  • disconnect the two hoses from the engine (which used the hot water from the cooling system to indirectly heat the domestic water)

Having removed all this we now have access to be able to replace the bilge pump hose, also to replace the hose for the cockpit drain (perished where it clamps to the drain and also clearly partially blocked), also to get to the vent hose for the main water tank.

My point is that, because all these systems were packed into such a tight space, with inadequate access, they all became interconnected. If anyone of these failed while at sea a repair would be very difficult. Potentially dangerous so many potential failures could disable the boat completely (at least if a repair was attempted).

There would be no point in carrying a service/repair kit for the water pump if installing it would mean taking all the batteries out of the cockpit locker and the heater fuel tank in order to be able reach it. To do all that while at sea would be very dangerous (eg no engine or instruments while the batteries are disconnected; let alone the danger of lifting heavy lead acid batteries out of a locker onto the deck in any kind of rough weather).

This is why our new plumbing system is not using the engine for hot water (and also because eventually we won’t have a diesel engine anyway) and is all being located under a seat in the saloon. We lose a very useful food storage space but suddenly all the plumbing is accessible.

Obviously we are potentially creating a new set of SPOFs by relying on electricity for everything (cooking, navigation, heating, water heating etc). However, we are trying to minimise this by the way we do things. For example:

  • Using busbars to connect 3 batteries in parallel means any one battery can be easily disconnected without affecting the wiring of any of the others, without affecting the voltage (just the capacity).
  • Using multiple solar panels and multiple MPPT controllers
  • Using two 2,000 watt inverters instead of one 4,000 watt
  • Using two individual 2,000 watt hobs instead of a double hob

We are also very focused on making sure we have easy access to everything. That is helped by getting rid of stuff which took a lot of space and needed to be accessible (hot air heating ducts, seacocks for toilets, basins, sinks, gas bottles, hoses and cut off taps).

Living aboard a boat and sailing it around is often likened to “doing boat maintenance in exotic places”. It is amazing how much YouTube video time is taken by shots of people stuck in lockers or around the engine trying to fix things. Also the jokes when experienced people look at potential boats and joke about how much time they will spend in the “engine room” and how comfortable or not that will be.

So I’d much rather have far less integration of space (and systems) so that when maintenance is needed it is simpler and less potentially dangerous. Against this the cost of losing some storage space to make things more accessible is a small price.

Fortunately, it seems that the more sustainable choices have a nice side effect of reducing this integration and dependence Composting toilets are a great example. They have no integration with or dependence on anything else (eg no plumbing connections at all). So lots of nasty (as in particularly smelly) points of failure are eliminated. Plus no need for any access to or maintenance of hoses, joints, pumps and seacocks.

As is often the case sustainable choices have all kinds of side benefits 🙂

Building the battery box

So I’ve started building the new battery box at home. So far just a dry assembly. All the timber will be sanded and epoxy coated before using epoxy to glue as well as screws.

Apart from the plywood base (left over from settee bases) the rest of the wood comes from old Ikea bed slats.

Among the complications is the access. I’ve built as much as I can that will actually (hopefully) fit through the cockpit locker opening. This will be fixed into the extended original battery box and so will hold the batteries from moving forwards, backwards or side to side. Once all in place I’ll fix slats to stop them falling out if we ever get knocked right over.

Here you can see all that can be pre-assembled. The cockpit locker opening is about half the length.
First battery will be lowered in and slide forwards
Battery 2 goes straight down through the hatch.
Slats added to hold battery 1 down and provide a platform for battery 3
Battery 3 in position (fills the remaining space above battery 1). It does go a bit further forward as it isn’t blocked by the diesel fuel line.
Looking from above you can see all the battery terminals and the little Battery Management System displays.

The smaller battery for engine starting (which is still Lead Acid because it doesn’t need all the fancy features of Lithium) will be on the aft end (left in the pictures) on the top of battery 2. It will be in a sealed plastic box as unlike the Lithium batteries can leak.

Once all these batteries are all in place I’ll fix the busbars (copper bar that the battery terminals connect to) above forward end of battery 2 (right next to the lead acid battery box so they don’t cover battery 2’s terminals). 6 identical cables (3 red and 3 black) connect the batteries to the busbars (this way we can ensure the batteries are evenly charged and discharged).

From the busbars for our supply we run 2 big cables for +ve and 2 for -ve to the main switch , due to the high current demands. The -ve cables will have a shunt in them (used to measure battery condition and use). From the main switch we go onward to the inverters, windlass and 12 volt system.

Also from the busbars we will run a slightly smaller pair of cables to a common connection point for all the solar and wind controllers (that keeps the cable runs to the batteries much shorter).

Once the cabling is in then I’ll add a waterproof top and seal it off from the cockpit locker and engine compartment (with sound insulation to the engine side).

Quite pleased with this. The main struggle at the moment is to find a supplier for tinned copper bar (50mm x 6mm should be about right) to make the busbars from.

Gentle start to Friday #9

A quiet and gentle start today after a busy week.

First job has been to fit our 2nd Radiant wall panel heater. This is 320 Watts and is in the main cabin (no printed image at the moment). Again using a radio thermostat and timer that controls the 13 amp socket that the heater is plugged into.

Of course when not posing for pictures the thermostat isn’t tight next to the the heater.

We won’t know for quite a while whether we can generate enough electricity to use this when afloat. However, even if we are only able to use it when in the boatyard it is still a cost effective way to heat the boat.

Of course the real benefit is when the electricity comes from renewable energy. We have no control over the boatyard electricity supplier, which is why running it from our own system would be preferred.

I’m working on long term plans to automate the maximum use of our renewable energy when the boat is unoccupied. Even in winter our full solar panels (when installed) will be far more than is needed to keep the batteries fully charged. So normally a lot of the solar power will be thrown away.

Our Victron solar panel controllers (MPPT) have an open interface and tools so that a computer can talk to them. So does our Victron battery monitor.

How can we use that? Well I’ve started playing with Raspberry Pi zero w computers. I’ve used bigger Raspberry Pi’s before, but these are tiny. I can connect temperature (and humidity) sensors. I can control mains sockets and I can get information from the Victron systems.

So eventually I should be able to have a Raspberry Pi in each cabin measuring the temperature and knowing roughly how much energy can be generated each day. It can then control the heaters to use exactly that much energy so that the boat is as warm as possible while still fully recharging the batteries each day.

I’m also going to be able to use Raspberry Pi’s to run our navigation systems (using something called OpenPlotter), act as a media player, general purpose computer for Internet browsing, wordprocessing etc. All with a far lower power need than a PC or laptop and no moving parts. Plus very much cheaper and more reliable.

[UPDATE] The heater is keeping the main cabin at 19 degrees C, even with the hatch open (the cover for the wheelhouse is nearly fully closed). And we can see snow on the mountains 😍