Avoiding engineering calculation paralysis

Two recent examples have in equal measures frustrated and amused me.

In their plans for Ruby Rose 2 Nick and Terysa have oodles of calculations but they appear to be aimed at justifying fitting large diesel engines because an all electric boat isn’t possible. They seem to have totally missed what was shown to be possible in their interview with Dan and Kika from Sailing Uma.

Then there is the subscription website “Attainable Adventure Cruising, The Offshore Voyaging Reference Site” with an article in the last week “Induction Cooking For Boatsβ€”Part 1, Is It Practical?” where I joined a discussion coming from our very different approach.

Both these present a numbers based “engineering” approach to decision making about the “practicalities” of moving away from fossil fuels. Sadly due to the initial assumptions the approach almost always leads to the conclusion that renewable energy sources cannot provide enough power for either propulsion or cooking.

The approach rejects working examples because they don’t present numbers in an “acceptable” way.

Our problem with this approach is that it is simply too easy to make assumptions about what is needed and the conclusion depends far more on the assumptions than on the calculations. In both these cases the assumptions are based on the expectations and lifestyle of a couple.

Ruby Rose have assumptions about never compromising on a luxury lifestyle with every modern convenience.

John and Phyllis have decades of experience cruising in high latitudes and strong views on what is safe and seaworthy. They have a stated goal of not considering anything that has not got a 10 year history of reliability.

Both these approaches are flawed if the goal is sustainability (or if budget constraints are tight). So if your assumptions are that you need to motor for an hour at full speed, and 500 miles at cruising speed, cook for a couple of hours every day, run a water maker, washing machine, multiple fridges and freezers, electric auto pilot, video editing laptops every day then you are going to conclude that renewable energy sources can’t cope.

Cynically if you control the list of things that you want to run all the time or anytime regardless of the conditions then you can guarantee that you will never be able to manage with renewable resources (at least until the last oil well has run dry and the Netherlands has disappeared under the sea).

Yet there is another way. One that we find most often from people with limited resources.

Embrace the limitations

Or start at the other end. Start with the resources that are possible.

  • What battery bank capacity can I afford?
  • What size battery bank can I fit (size and weight)
  • How many solar panels can I fit (and afford)?
  • Is wind generation going to fit my boat, my budget, my geography?
  • Is water power generation either from regen on an electric motor or something like Watt and Sea going to work (how much time sailing at suitable speeds)

These provide the constraints. Then sustainability becomes how you live within the constraints. There are plenty of options.

  • A vegetarian or vegan diet (as recommended as a key way of reducing our carbon footprint) can reduce the cooking energy significantly (no a roast chicken cooked for several hours is not required every week, if you want it then save your energy up first, or use a solar oven)
  • Set your passage plans according to the energy you have, probably slower (but then the whole point of sailing is surely to sail)
  • Set your cruising ground according to the season and energy available and required (so you probably can’t sail sustainably into an Arctic winter which is just a constraint, like the ones the majority of people live with all the time)
  • Have food available that doesn’t need to be cooked if you are short of energy (Huel and the like)
  • Plan to use appliances when you have the energy, keep the ones that have to be on to a minimum (eg freezers, fridges, autopilots).
  • Embrace the constraints. Do you really have to be able to do the washing, make water and cook for 2 hours on the same cloudy day – if yes then why?
  • To be honest the list is endless, we have gone in just a few years from it being normal to only use an engine in harbours to expecting to motor constantly for days at a time. From no refrigeration and basic hobs to dishwashers and ovens and drinks coolers in the cockpit.

The argument that it isn’t possible to live within the constraints of renewable energy is disproved by history. It is disproved by the examples already documenting their experiences eg Sailing Uma; and Beau and Brandy.

The challenge is to our assumptions, our privilege, our expectations of luxury. The opportunity is to open ourselves to the impact our lives have on others and to stop seeing ourselves as deserving something that our actions deny for others both now and in the future.

Opportunity for reflection leading to decisions

So we have a holiday, it being half-term, however, as Manchester is in a tier 3 Lockdown and Wales in a Firebreak, we are at home. It does mean we can take time not just to do jobs and study (including propeller shaft and RYA Yachtmaster course) but also time to reflect on where we have got to and what next.

As we have been talking through where we have go to we realise we have reached the point where we can make some changes:

Our Van.

We have realised that we have now reached the point where we can avoid big/heavy loads to and from the boat. All the major clearing out is done. The largest/heaviest stuff has already been taken.

I’ll create a Van page with details that will be updated as we prepare it for sale, it is a Citroen Dispatch panel van (65 plate), we had the back professionally fitted out with windows, floor, carpet lining, LED lighting and 3 reclining seats with 3 point seatbelts – it has been completely reliable and awesomely useful and flexible.

We had bought the VAN as we were overloading our previous Citroen Berlingo because we had our Sprint 15 Caravan on the roof, bikes inside and caravan behind for holidays. The Van was absolutely brilliant for this.

It proved brilliant when we were refurbishing a house for our sons and for carrying all the rubbish, tools, cushions, timber, electric motor etc for the boat. Several trips with the van full, often towing a very full trailer too.

But now we think we can change down. For the first time, we think we can manage without needing to tow anything. That means we can switch to a 100% electric vehicle (none of them can tow anything). It will take careful planning in what we take when and we will mostly need to cut timber to size at home.

The biggest challenge will be our RIB dinghy after we launch Vida. There is nowhere to store it securely where we need to launch it for our mooring. So we need to keep it at home and take it each time. At the moment it can either go inside the van (if we deflate it) or we could put it on the luggage trailer.

Our Sprint 15

Our Sprint 15 is what really helped us rediscover our love of sailing. We had a long gap due in part to our sons not enjoying sailing and in part my work taking us a long way from the sea. Then a short few sails on my brothers Laser 13 reminded us that we were missing out big time. We tried the Laser Pico that the boys had ignored for years and discovered to nobodies surprise that the two of us didn’t really fit in it. Plus it was really heavy to lift onto the Berlingo roof (and so much wind noise it was horrible).

Almost by chance we found the Sprint 15 and had a half day test sail/training with Windsport International. It was brilliant and unique. We couldn’t find any other dinghy that could sail with 2 adults and that we could manage to lift onto a roof rack (needed because we were going to be towing a caravan). So we bought one, and have had some fantastic times with it (see our video playlist). They are brilliant boats to sail and also have a really friendly class association. Highly recommended πŸ™‚

Anyway, we can’t carry the Sprint 15 on Vida and can’t tow it behind an electric car so it is also going up for sale.

Luggage Trailer

Yup, the Daxara 147 trailer is going to be up for sale too. A really useful size that has been brilliant for taking stuff to the recycling centre, and for both house and boat building projects.

The Next Car

So we have been looking and within our price range/needs there is only one option so far as we can see. It is just under 100 miles to the boat and also to our sons. We need to be able to carry 4 adults and we need to be able to put our RIB dinghy on the roof.

That means a Nissan Leaf. If we get a 30kWh model from around 2017, even allowing for battery degradation (not too much if under 50,000 miles) it should have a range of about 100 miles. We recognise that, at least in winter or with the dinghy on top, we will need to stop between home and the boat for a 20 to 30 minute recharge.

By default the roof rack load limit is not quite enough. However, a towbar can be fitted (not for towing but for bike carriers and the like). With a T-bar on this, where the top is level with the roof bars, the combined weight capacity is nearly 100kg (for a 59kg dinghy). That might be unusual and will probably attract a fair bit of attention but at least it will be within the limits πŸ™‚ It also means we can carry our bikes at other times though πŸ™‚

Looking at the alternatives, the Renault Zoe isn’t approved for roof racks, plus most have leased battery packs costing about Β£50 a month (for a vehicle that is roughly the same price as a Leaf that is Β£600 a year more expensive). Only one or two examples of anything else in our price range (so far I’ve seen one Kia Soul but ugh!)

Progress

So as soon as we can sell our van we will be going electric for the car. Obviously that fits much better with our sustainable living goals. By doing it now, as soon as we can, we will not only be cutting our carbon footprint and contribution to air pollution significantly but we will also save ourselves a lot of money each year (for the cost of about 30 to 45 minutes longer journey times to/from Vida – currently about 1h45m).

So watch for some more For Sale pages and posts. Get in touch if you are interested in the Van, Sprint 15 or Luggage trailer πŸ™‚

Into 2nd wave lockdowns

So a quick update on where we are at. The situation for Manchester is still chaos without agreement between the national and local governments regarding the level of lockdown we should be in. However, we are expecting to be more restricted soon (bearing in mind that Manchester has had it’d own lockdown for months anyway). As for travelling to Wales it is hard to find clear guidance as to whether the Welsh government have now made it illegal to travel from either tier 2 (High) or 3 (Very High). We took the view that it would have been wrong to go on Thursday when a ban was expected from 6pm on Friday (still unclear if that has happened). There now seems to be an expectation that a Welsh “Circuit Break” ban for a few weeks will be announced in the morning. We are working on the assumption that we might not be able to get to the boat again this year.

Fortunately we left her in good shape, the most watertight yet. So we are not worried about any problems on board.

We have some jobs we can do at home, while many of these are not urgent as far as launching is concerned they will at least allow us to feel we are making some progress while we can’t get to the boat.

Propeller Shaft: I wrote about the pitting issues in my last post. As none of the pitting is where bearings or seals go we decided to try to tackle it. Where there is pitting which is probably caused by electrical currents – either through poor earthing (electrolytic) or by currents between dissimilar metals (galvanic) – we are going to remove it. Pitting encourages more corrosion. The best way to avoid corrosion in stainless steel is a bright mirror polish and to have not used any other metals (eg saws or files) to achieve it.

So I have started removing the pitting using the angle grinder with a flap sanding disk. None of it is deeper than about 1mm. So far I’ve done about half of it (starting with the worst bits).

Once I have used the 80grit flap sanding disk to remove the pitting the shaft is no longer perfectly round and is definitely not smooth or polished. So I have 50m of a 25mm wide strip of 80 grit Emery Cloth. Using a strip of this wrapped around the shaft it should be possible to get it pretty smooth and round. I then have finer grades to remove the scratches before using a paste with a cloth to polish it as smooth as possible.

That should keep me busy for hours. A new propeller shaft would be a simpler solution but this should be perfectly serviceable for a few more years and saves waste.

Motor Mount brackets: I have the 4 angle brackets that will be bolted to the original engine bearers and which the flexible mounts will be bolted to. Just got another 10 or more holes to drill in them (10mm). That will leave only the 4 holes in the motor frame for the flexible mounts (not quite sure what size they are and the position isn’t finalised yet).

Domestic Battery Box: I’ve got to make some cut-outs in the timber for the nuts where the leads bolt to the busbar so that the busbars can be fitted. I can also make a lid (and adjust the design for a new expectation that the batteries will be lowered into it via opening the cockpit floor).

Motor Throttle Our motor throttle has a 6mm square shaft and I need to make or find a control lever for it. Trying to find something that doesn’t cost much, is reliable and doesn’t look clunky.

Motor Controller Heatsink: I want to get a really big and effective (and cheap) heatsink for the controller (because apparently they get really hot). My idea is so mount this through the (to be built) bulkhead between the motor compartment and the cockpit locker. This way the heat gets put into the cockpit locker while the controller is away from it in the motor compartment.

Dinghy: Jane has nearly finished the cover for the dinghy. I need to get and fit removable launching wheels to get it over the mixture of rocks and shingle where we will launch it.

Solar Panel mounts: I should be able to make everything I need to mount the solar panels to to the boat both on the wheelhouse roof and at the guardrails.

Propeller: We have the propeller at home and it still needs a lot of cleaning. One day money permitting we will replace it with a Bruntons Autoprop Ecostar, until then cleaning it is.

Emergency Steering: The two part emergency tiller (if the wheel steering breaks) has probably been in storage under the after cabin bunk for the whole life of the boat. There has been a little corrosion which means the parts no longer fit together. So we will fix this.

Consumer Unit mount: We now have a consumer unit for the mains power. We have a place for it which will allow us to access the trip switches. It is quite large as we have one switch for each of the 13 sockets we will have around the boat, we are running a separate wire to each rather than a ring main. However, it will need to be lowered for full access so I’m making a wooden frame for it to slide up and down in.

Navigation and control systems: I have plenty of fun planned getting Raspberry Pi computers sorted to run the chart plotter and other navigation software. I want them to interface with all our instruments, with the battery management systems, the solar charge controllers etc. We will have an indoor and an outdoor Pi so we can see everything when steering or when below. The indoor one will also be our entertainment centre and office computer.

Propeller shaft pitting

So I’ve started the cleaning up of our propeller shaft. It had some brown gunk (like a dried muddy residue from corrosion) but no rust of itself.

However, in a number of places it has uncovered pitting. This seems to be concentrated on the bits that were just outside the various bearings etc. So the taper for the propeller itself is clean. The section where the cutlass bearing goes is clean although it looks as if the pitting at the inboard might have been made worse by a worn cutlass bearing causing some damage. There is also pitting around where the stuffing box was, fortunately the dripless seal will be in one of the cleanest sections.

So far I’ve used a strip of 150 grit emery cloth. I’ve got 3 other grades upto 400 grit, so we will go over it with all of them. In all cases we are sanding round the shaft not up and down the length which is apparently important for the seal.

Just wondering whether we need to do anything about the pitting. Chemicals? More sanding? Or what?

Also what caused it. Was it the poor grounding causing galvanic/electrolytic corrosion? Is it something to do with the bearing?

Anyway here is a gallery of pictures of the pitting. What do you think?

Friday progress 28

Today, thanks to help from one of our sons, we got the motor in its frame onto the boat and into the motor compartment.

That means we have been able to measure all the holes for the motor mounts and the holes to fit them to the brackets and the holes in the brackets to fasten them into the boat.

We managed to drill 6 1/2 holes of 20 before the drill bits gave up. We can now finish the rest at home.

Then we took out the bulkhead between the aft cabin and the motor compartment (to make the cabin larger and improve access to the drive train). The new bulkhead will be lined up with the support for the Aquadrive.

We also removed the door to the aft cabin. That removes an awkward trip hazard and will allow us to fit a wider door, easier for my shoulders and also to get the toilet through.

Motor ready for installation

At last the electric motor is in it’s frame with reduction gear and extra bearing to support the coupling and Aquadrive connection.

Just got to fit the motor mounts into the boat and drill the holes in the frame for them.

That does mean 20 more holes in 6mm stainless steel. Best not to think about that too much.

Also got to lift this beast onto the boat. Best not to worry too much about that either.

Friday progress 27

We haven’t gone to Vida this week. Jane is busy on an essay and has first aid training.

So I got some work on done on the extension to the motor frame. This is to support the 400mm length of shaft that connects to the aquadrive. That has several kg of couplings and CV joint hanging on the end of it.

Made reasonable progress but I’ve run out of 10mm drill bits. The 6mm stainless steel is tough to drill. I’ve done nearly 10 holes which is less than 1/3 of this job. Not just hard on the drill bits but also very tiring. Still I can see how it is going to work, but you will have to wait πŸ™‚