IanD

Better than sprayfoam?

Yeah, charging isn't a problem in reality. With the benefit of hindsight, having batteries in the bow locker would have saved some steel ballast... 😉

A bowthruster uses a negligible amount of energy because it's only on for a short time. IIRC mine's about 5kW flat out (it's variable speed and I rarely use full power), even running it for a minute uses less than 0.1kWh. When I looked at the costs it was cheaper to run 48V cables along the boat (only 25mm2 IIRC) than to add separate batteries for the 48V BT, and have to worry about keeping them charged and lifetime. Not really feasible with 24V though, you'd need 100mm2 cables, and definitely a no-no for 12V which would need 400mm2... 😉

I looked at using a heat pump (actually a marine AC unit) to heat my boat, and also cool it in summer -- specifically, this one (the biggest 16000BTU version): https://www.frigomar.com/en/products/self-contained-unit-inverter-bldc/ Excellent efficiency (almost 5kW maximum output for 1kW of power) and can be throttled down to 25% -- note that it's a blown air unit so you have to run 5" diameter ducting through the boat. The problem is that it uses fresh water from the sea/river/canal and that the minimum temperature for this is +5C to stop it freezing in the heat exchanger -- so fine for most boats at sea, but not the canals in the winter when you *need* the heating... 😞 In theory you could use a massive skin tank and fill the system with antifreeze, but the unit will still turn itself off below +5C intake temperature. Also I was told by somebody who tried this (skin tank) that it didn't really work and they had to go back to fresh water intake. Unless you're only ever going to do short cruises away from base (a big battery bank will last up to 2 days) or no more than a couple of hours per day in summer (recharging from solar, but you'll only get about 5kWh per day on a boat that size) you'll need an onboard generator, and cocooned diesel ones are expensive (around £15000 installed). It would be nice to run this on HVO but this isn't widely available on the canals, if at all. Finesse used to reckon that the cost of the electric drive including batteries, inverter, and generator was around £30000 but that was several years ago. Given the price rises I saw during construction of my boat (a couple of grand just for the generator!) I expect this would be closer to £40000 today. They've built a lot of electric (well, series hybrid...) boats and don't cut corners, I can certainly recommend them.

It makes no difference whether it's one use of a lock by one or more (or no) boats or many uses, the fact remains that the amount of water used -- meaning, transferred from the upper pound to the lower one -- by one lock cycle is exactly the same in all cases, regardless of how big or how many boats are in the lock. Assuming they stay afloat at all times... 😉 Widebeams in a wide lock use more water per boat movement than narrowbeams sharing a lock, but the same amount as one boat of any size -- even a canoe -- if sharing doesn't happen. Which is the vast majority of the time...

As I thought I'd made clear above, boaters who have no other realistic option than a stove shouldn't be made to feel guilty or blamed, the problem with woodburners -- which has lead to the rapid increase in PM2.5 pollution from them over the last decade or so -- is the large numbers that have been installed in otherwise centrally-heated houses as a "lifestyle choice". And this is the reason that a ban on woodburners is likely to be brought in, maybe with exceptions for those who *need* to use them (or live in rural areas) as opposed to *choosing* to do so -- though given that most stoves can burn smokeless fuel which is many times less harmful this probably won't happen. The likely consequence is that boaters will have to switch from (cheap/free) wood to (more expensive) smokeless fuel, which causes much lower levels of PM2.5 pollution. There's also the fact that the effects are even worse on the boater than people outside, but like any other activity that increases risk (e.g. drinking, eating vast amounts of bacon...) that's down to the boater -- but still, this is something that people should be aware of.

Correct, by the time this suggestion came up on CWDF the shell had already been built, otherwise I might well have done it. However the gap between the edge of the solar panels and the rail on mine looks narrower than the above photo, and I can imagine that the protruding handhold would make getting the panels in and vacuum bonding them down more difficult -- see photo.

Why don't you just take your troll postings over to Thunderboat and try and wind people up there instead? 😞 Meanwhile, Archimedes was still right... 😉

No it doesn't. When the boat is outside the lock, the water is at a given level. When it moves into the lock, the water level doesn't change, so this doesn't "use" any water -- meaning, water that has to be replaced. Nope. Really, just nope. The same amount of water is "used" (moved from above lock to below lock) regardless of how many boats of what size are in the lock when it empties or fills. Go and make a drawing showing the state of the (full) lock before the boat enters it, after the boat enters it, after the boat has gone down in the lock, and after the boat has left the lock. The amount of water moved from the upper pound to the lower one -- "used" -- is the same in all cases, it's the drop in water level (the fall of the lock) multiplied by the area of the lock. Archimedes understood this, but it seems that you don't... 😉

Sometimes, but this is usually for a specific case where the householders complain. What's coming is likely to be a blanket ban on woodburners in towns and cities because this is where the high PM2.5 pollution levels are and woodburners are now the biggest source here -- about 3x as big as road traffic. If the local rules still allow smokeless fuel then boaters can use this, but wood will be banned. If smokeless fuel is banned too (might be in some places?) then this option disappears, it means solid fuel stoves will be banned. Before anyone says "but this can't be enforced!" -- of course it can, it will be enforced on houses and there are far more of these than boats.

I seem to remember reading that it was symbolic rather than useful -- but the book saying this is on the boat so I can't check...

It's also what is likely to lead to a ban on woodburning stoves in urban/smoke control areas in the near future. Which is a good thing if it gets rid of the vanity ones in houses with CH which are causing the PM2.5 problem, but not such a good thing if it applies to boaters with no other source of heating... 😞 Let's hope that the councils allow exceptions for cases like this, but seeing how they often work I wouldn't hold out much hope for boaters being a "special case"... 😞

This whole idea that boat displacement has any effect on water usage in a lock is wrong, the above post which says it's just lock area x lock fall is correct. Imagine you're going down and the lock is full. When you go into the lock the water level doesn't change, regardless of the size of boat. Now empty the lock, the water level (drawn from below the boat) falls by the drop regardless of size of boat, so the water used is the same. Now open the bottom gates; moving the boat out of the lock doesn't change the water level. One lock turn -- in either direction -- uses the same amount of water whether the lock has one or two narrowboats or one wideboat in it, or indeed no boat at all.

A bow thruster and a Schilling rudder does just that, the boat turns around its centrepoint... 😉

It'll be interesting to see how well it works in practice, but also whether getting debris round the prop happens more and it's then much more difficult to remove -- which I think is what many people expect to happen... There are other ways of getting more effective steering from a prop that also work up to high rudder angles (about 75 degrees) and don't risk the fouling problem... 😉

Maybe you should get a sense of humour too instead of sniping? 😉 *Oh* yes we were... 😉 (Panto season is here, hurrah!)

I was being sarcastic, just like the posters I replied to 🙂