Speed vs Sustainability

One of the most visible conflicts when aiming for Sustainability in almost any area, is between it and Speed.

The obvious starting place is speed in terms of moving fast, where the sustainability cost is clear and huge. Speed never comes free. All forms of transport require significantly more energy per unit of distance at higher speeds. That is because air resistance increases much faster than the speed (typically by the speed squared). For boats the drag of the water is much greater as it is so much more dense than air.

However, it is even more complicated for boats. When not planing, a boat has a maximum hull speed (approx between 1.34 and 1.51 times the square root of the waterline length in feet – see WikiPedia). For Vida that gives an approximate maximum hull speed of about 7.5 knots.

In practice what that means for Sustainability is that however powerful an engine we put in we will not go any faster than 7.5 knots. As a boat moves through the water it creates a standing wave which is very visible if you look at a boat moving, just behind the front of the boat is a peak, at full hull speed there is just one wave with the trough at the back of the boat. Any extra speed makes that wave steeper and you can never climb up it and so you can’t go faster.

But the real issue is that the amount of energy needed to reach the maximum speed isn’t simply a proportional increase. We can only estimate at the moment because there are so many variables according to hull shape, loading, windage, sea state etc we won’t know exactly without a lot of real world testing. However, we would expect to need twice the energy to do 7.5 knots as say 5.5knots.

The impact on our electric motor will be all about range. At full speed we might expect roughly 7.5 knots for 1.5 hours ie 10.75 Nautical Miles. However, if we drop the speed to 4 knots we might be able to motor for 6 hours or 24 Nautical Miles. Of we drop again to 3 knots (or typical canal speed) then we will add considerably more range.

Even when not directly burning fossil fuels, speed is costly in Sustainability when sailing. To go faster you need a longer and lighter boat (typically built using more “exotic”, less sustainable materials and methods). You will need higher tech sails that perform better but use more exotic materials and typically need replacing more often.

To go really fast you need to get past the hull speed restrictions. You can achieve that either by having a boat than can plane (flat bottom, lots of power and very low weight – typically not going to be affordable or suitable for live aboard cruising with a small crew) or a multi-hull (trimaran or catamaran) where the hulls are so narrow that the hull speed formula no longer applies).

Length is the “easiest” way to get extra hull speed which is one reason why sailing cruisers keep getting bigger but this is also going in the opposite direction to sustainability as then they use more resources at build time and throughout their life (and they increase much faster than the length does).

On the other hand speed increases do have a multiplying effect. Faster boats can more dynamically route to get huge benefits by being in the right place for far more advantageous weather systems. That can make a far bigger difference to ocean crossing times than the simple speed difference. This video shows this at it’s most dramatic (but is pretty much as far from sustainability as you can get in a sailing boat)

However, I want to move beyond thinking speed in terms of movement and extend it to speed of progress.

In every area, progress is not proportional to the resources used. We know this from every area of life. As you add more and more people to a job it doesn’t keep getting done faster at a proportional rate. If you want to have your driveway paved it will not get done 100x faster by 100 people compared to 1 person (most of us can’t fit a 100 people on our driveway, even if we could they would be getting in each others way, getting the materials to them fast enough for them all to work at full speed would be difficult, you would need people set aside to co-ordinate them etc).

So as we seek to be more sustainable I suggest that we will also need to slow down, in our expectations, in our plans, in our work rates and in our spending.

The benefits multiply across all our areas of sustainability (Environmentally; Financially; Mentally; Physically) if we slow down. We can have time to plan better, to find better options/bargains, reduce mental and physical stress, to avoid mistakes.

This is why we decided to start the process of getting to a live aboard cruising retirement life years before we will be living aboard. By doing so we can be more sustainable, achieve more for less.

What works for us in this example scales up in all kinds of ways across society. Faster isn’t better, slower is usually more sustainable. All we need to do is reprogram our expectations (all we need to do!!!! Hollow laugh). Fortunately, once people of tried slowing down they tend to prefer it and become advocates, which is a good reason for hope. It has left us thinking that one of the things we should be looking to offer when Vida is afloat is the chance to experience cruising on a zero fossil fuel yacht in sustainable ways.

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.

Another not Friday progress

We won’t be making direct progress on Vida this Friday as I’m working. Still we have been making some progress at home.

Jane has ordered more foam for the saloon (dinette backrests and the outboard portion of the sea berth).

I’ve been collecting a few more parts for the remaining jobs. Now that we have discovered the bilge, I’ve got a water level sensor and an electric bilge pump that it will control. That will mean that should there be a leak we can focus on finding and solving the cause while the pump keeps the water at bay as much as possible. Also if water comes in while we are off the boat then at least it will get pumped out for a while (given that the only holes below the waterline will be for the cockpit drains we have massively reduced the chances of this, unless sea lions attack us). However, there are some problems.

Firstly, at the moment we don’t have good enough access.

Secondly, it looks disgusting. We can’t allow water to get contaminated with all this yuck get pumped out into the sea.

So I’ve got some heavy duty bilge cleaner to try to get it clean enough to not contaminate any water that sits in it. Plus we want to get it clean enough for epoxy resin to stick to it, so that we have options for reducing it’s size and adding some strength (more bio-epoxy arriving soon).

Another area of progress has been towards more visible progress. We’ve ordered everything to fully refurbish our two hatches (one over thee aft cabin and the other over the saloon). Currently, the acrylic is so crazed that you can’t see through it, we had thought we would leave this until later but there are leaks between then acrylic and the frame, leaks in the seal in the frame and leaks between the frame and the deck. At the same time we have ordered a new acrylic panel for the roof of the wheelhouse, you couldn’t see through it and it was also leaking. All of that from Hadlow Marine for less than half the cost of one new hatch.

Finally, a spot of good news is that while the extra batteries are delayed due to the Coronavirus our electric motor has been shipped and we should have it in a couple of weeks (I’m by no means minimising the terrible effects of the virus and fully recognise that a bit of inconvenience for us counts as nothing).

I’ve also corrected the part of the drivetrain that I’d got wrong (maybe I’m on the way to becoming a tapered bush bearing expert) and we should have that soon. There are still some decisions to make and parts to order before we will be ready to connect the motor to the propeller but no rush as I don’t want to make mistakes.

Thursday triumphs

A couple of very good moments today amidst clearing up, measuring and preparing to come home.

First, despite strong winds and a fairly cold, very wet night we woke to find the temperature in the aft cabin at 12.7°C. The thermostat was set to 11°C so clearly the combination of the insulation and the heat Jane radiates at night kept me nice and warm.

Secondly, we investigated the bilge which is below the oil catch tray from the diesel engine. Yuck!

We pumped 5.5 builders buckets of water out of of this bilge and found it is 750mm deep below the oil tray.

Temporary access hole

We are having some discussions with other Rival owners to decide whether to do anything about this. Some people have expressed concerns that this open area of the keel is a bit of a weak spot. So there are suggestions to fill it in, at least partially, with epoxy resin and lead shot. We feel that it is a bit too deep for easy access so think that maybe 400mm deep would be enough for a sump. That would make it easier to fit a float switch, an electric pump as well as a hose for the manual pump. But we will have to see if we can clean it enough for epoxy to stick to it.

Been having some good conversations with people in the boatyard about electric motors, a lot of interest in how it will turn out 😊 More understanding than I expected as it turns out that everyone has a story to tell of a diesel engine stopping at an awkward time due to filters or fuel pipes clogging up.

Snug in a gale and planning to be even more so

So tonight is another wet and windy night. Currently forecast says gusts of upto 45mph which is almost the top of a Beaufort force 8 gale. A bit warmer than a few nights ago with a minimum of 5°C.

We are snug inside with our wallpaper panel heaters on, at the moment it is 18°C in the saloon although overnight it generally drops to about 11°C in the saloon. The aft cabin is warmer with us sleeping there and so we typically set the thermostat to 11°C. The heater isn’t on much of the time then.

When we are away from the boat we have both heaters set to 5°C which is one reason why we are consistently making progress at drying the boat out.

Apart from the places where we want access to bolts (under side decks, around the hatch, the mast foot and some deck hardware around the mast) our aft cabin is now fully insulated with 10mm of closed cell foam. So we will see how much difference that makes tonight. Although we have always felt pretty snug sleeping there.

When in the boatyard it makes such a difference to have composting toilets. We don’t have to go out in the rain and wind to use the clubhouse toilets. Generally we empty the urine bottle every 48 hours or so. The solids about every 3 months (averaging about 24 hours on board a week).

We couldn’t have used the original direct discharge toilets at all. If we had a holding tank it would probably be full by now with no means of emptying it. Plus there would be no water to flush the toilet with.

Talking of water the boatyard does have a tap but you have to pay with a token for each 15 minutes. Not sure how much we would want to use it for drinking anyway. So we are filling 2 litre water bottles from a normal indoor kitchen tap and using them. Waste goes in a bucket which take off the boat and pour down a drain.

So despite it being a horrible evening we are snug and don’t have to venture out.

When we do go out we have our wheelhouse as a porch. Especially with the prevailing winds coming at us head on (as they normally will at anchor) the wheelhouse is great. We have a dry, wind free entrance into the boat and when we put the back cover on the wheelhouse it keeps the heat from rushing out too fast.

While the protection and convenience of the wheelhouse is great, this winter has demonstrated that we are going to have to do some upgrades.

First, we are replacing the rooflight. It was very crazed (defeating it’s purpose of allowing you to look up when steering and see the mainsail) and leaked a bit. So when we took it off to build the engine removal gantry we decided to get new acrylic for it.

Just visible is the temporary plywood cover for the rooflight

Our hatch top and hatch boards also need some TLC, fortunately as they are so protected we can manage for the moment.

More of an issue is the bright blue rear cover. It is really only designed to be closed up from outside when you leave the boat. So closing it with us inside is a pain (but essential when the wind and rain come from behind). It also flaps, bangs and rattles a bit in the wind. Some of snaps used to secure it have broken. We will need to modify it or create a replacement. That would also give us a chance to remove the last of the wood trim for renovation.

Once we get started on the electrical system we have 4 x 40 wattage solar panels to go on it’s roof along with renovated handrails.

One day the glass windscreen will get some care, the middle section might be better if it was opening for hotter climates.

I remember a few days as a teenager when our family of 5 was stuck on our Eygthene 24 foot boat on a mooring during the 1979 Fastnet Storm. The lack of a protected space outside and what was an almost completely open plan interior meant very close quarters living. The combination of our very separate, self contained ensuite aft sleeping cabin, the centre cockpit with a wheelhouse that can be setup with varying amounts of openness, a comfortable saloon as well as main heads and forecabin makes Vida a really good place to wait out bad weather. We have space to relax together, get on with jobs, have meals, do jobs, move stuff out of the way etc.

So despite the weather we are happy and enjoying both the dreams for the future and the process of getting there.

Besides, during a wet and stormy half term this is about as nice a place to be as any.

Afternoon progress on aft cabin insulation

Jane is still busy insulating the aft cabin. Cutting the last piece now.

The underside of the side decks (which have various bolts coming through) are very wet where there isn’t a wood soffit. We are leaving these for now as we are not sure if it is leaks or condensation.

We will remove, clean and refit all these and improve the backing plates at some point. That is why we wanted to improve access. Then we will have insulation panels held on by velcro to cover them.

The insulation will be painted white (a special paint for closed cell foam which surprisingly B&Q sell). Before that we are thinking of taping all the joins. Obviously something that sticks well to closed cell foam but also the paint needs to stick to it.

We will make a nice surround for the hatch which will have a magnetic strip to hold up an insult square to cut down on condensation from the aluminium framed hatch.

Before thats we have new acrylic and seals for the hatch. So on a dry day it will come off to be thoroughly refurbished and refitted so no more leaks (the identical hatch over the saloon has been dropping noticeably now that the water doesn’t run into the headlining, so that is getting the same treatment).

Meanwhile, I’ve prepared dinner which is now on in tthe multi-cooker. Required my first full washing up in the new sinks (the clubhouse kitchen, where we have mostly been washing up, is being replaced at the moment).

Currently there seems to be an unforecasted break in the rain but it is blowing hard. Plenty of standing water in the boatyard.

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.

Diesel engine is out. Zero fossil fuel cruising on the way

Today we successfully removed our diesel engine. It is now in our cockpit, under the wheelhouse.

All went pretty much as planned. Three of the 4 engine mounts had to be cut off. But the lift went smoothly. Always a bit tense when lifting nearly 200kg over 1.7m.

We used two 6:1 block and tackles. One of these is a Jimmy Green Marie Handy Billy designed for hauling someone back on board as part of recovery from them going over box. The other is the mainsheet from our Sprint 15 catamaran.

We used ratchet webbing straps as a backup and as additional strops around the engine. So the weight was always taken by two means when any one of them was able to hold the whole weight. It did mean that we needed to pause to reset the webbing ratchets several times (and the mainsheet had to be reset at least 3 times due to the limited line length). Once we had the engine above the cockpit floor we were able to shackle the handy billy directly to the engine lifting point and hook the mainsheet to the other lifting point. That tidied things up.

As soon as it was level with the cockpit seats we were able to use timber to setup supports for the engine mounts. Then we used levers to gently move it to the side where we wanted it. At that point to get better control we had 4 webbing straps, one per engine mount, plus a line going aft to pull the whole engine aft using the genoa winch.

Hail and darkness then stopped play. Tomorrow we will build a custom wood box around it to protect it until a crane can get access to lift it off. Although it is already protected from the weather by the wheelhouse as long as the rear cover is on.

The amount of space it has left behind is incredible! Going to be able to make much better use of this 😊

This engine can now be considered as for sale. But delivery or collection won’t be possible for a couple of months 😉

Now we can really start the preparation jobs for the new electric motor. Yippee.

Tuesday diesel engine removal update

The bit I expected to be tricky has been.

The rusty bolts on the coupling between gearbox and propeller shaft wouldn’t undo. Angle grinder to the rescue.

So far only managed to undo 1 of 4 engine mount bolts as again very rusty. Currently soaking in wd40 but might need to cut them.

The gantry to lift is finished (going to attach lifting lines before cutting engine mount bolts).