Bargebuilder

Just taken from the website of a 'Pilot' gas detector retailer, 'Pilot' being a very widely used marine unit, the current draw for the dual sensor unit is as follows: "Draws 172 milliamps on standby, 484 milliamps with the valve open." (Assuming you run at 12v) Your gas cut-off solenoid valve will of course be left open if the gas alarm is left powered up, so the drain on your battery will be a constant 1/2 amp, so 12 amp hours every day. Your battery bank shouldn't be run down to below 50% of its fully charged capacity to preserve it's life, so assuming your battery is used for nothing else, if you leave your boat for 14 days without some form of charging system, the minimum size of battery bank that you will need is 336 amp hours (three bigish batteries), and after the two weeks there will be nothing left for powering anything else on the boat, not even to start up the Propex. You will either need a sizeable battery bank, shore power or solar panels. This might be part of the reason that such detectors are less than popular with 'off grid' boaters, together with the reliability of the sensor heads and the cost of the unit and the inevitable spare parts.

It hadn't occurred to me that you might be running a tumble drier; wow! I didn't have one of those when I lived in a house. You certainly couldn't use a big inverter for that long without a big battery bank and simultaneously running the engine. You are already set up and satisfied and that's great. I notice that the Beta 30 outputs 10hp at just 800rpm, so at 1100-1400rpm, plenty enough for 4mph in many narrowboats, with plenty in reserve for emergencies Your concerns about 'spinning' your Travelpower might be unfounded. I have a Kubota OC60 based generator which is rated at just 6hp. For efficiency it is set at just 3/4 throttle and it powers a 200 amp alternator which at this setting and appropriate pulleys delivers 120amps from cold at 13 volts which equates to 1560 watts. This tiny engine does 'wind up' slowly from cold, but it doesn't stall. Compared to my tiny 6hp Kubota, your 43hp Beta will be producing impressive torque, even at low revs. If someone wanted a smaller engine to match the cruising demands of their craft, but found that their Travelpower was overwhelming their engine at low revs, couldn't they just change the pulley ratio so that the engine can spin faster? That is what I did with my little Kubota 12v generator.

Forgive me, but as a user of a composting toilet myself, it doesn't sound as if you are, for the following reasons: I have never had a fly infestation: If a fly got past the outer vent grill, it would then have to negotiate a long duct and a considerable head wind! Any odour cannot be detected at all in the bathroom, but a slight smell can be detected if you sniff the vent outlet, outside the boat; why would you though? Mixing the 'poo' with sawdust or similar has no effect on smell levels, it simply helps with the drying, aeration and composting process. In my experience, urine does not smell when poured onto the soil, but is absorbed and neutralised almost instantly. A compressed bale of pet bedding sawdust is very cheap to buy, is about 6"x4"x14" and lasts for about 3 months. It lives inside the outer toilet box with the bucket, so occupies zero boat space. The in-use bucket stays in place for 2 months and then it's contents are composted in a shallow, lidded but ventilated container, on the roof outside for a further 4 months. With the occasional addition of sawdust, peat, leaves etc and a stir now and then, what remains is completely odour free and crumbly.

Why do you need to have shat in one, to understand the temptation to prematurely and inappropriately dispose of the shit? Of course there is a percentage of people who break the rules and indulge in antisocial practices. People like this who use composting loos will dump their dessicated toilet waste into the c&rt bins, and those who use cassette toilets, will empty their toilet cassette into the rivers and canals. Given that there are infinitely more cassette toilet users than 'composters', which, overall, has the greatest detrimental effect on the environment?

Not exactly! Sewage systems and treatment works were introduced because people stopped composting their poo. Pollution, public health concerns and the most vile and intolerable stench was as a result of the replacement of poo pits with flushing toilets. In the days before flushing toilets, one had a 'pit' that one filled. A bit like a huge composting toilet in as much as the matter sat there, drying a bit and every few weeks the 'poo' man came round with his wheelbarrow and removed it for a small fee, before selling it on to local farms. Distasteful to us but a welcomed form of income for the 'poo man'. The problems with pollution only became extreme and the stench unbearable once flushing toilets became popular and the sewage was flushed, untreated, most notably into the Thames. Sewage treatment etc followed, to mitigate the problems associated with the increasing use of water closets.

It is cool, and I hope you tell us how you get on. If you can, have a single copper gas pipe to your Propex, with a joint at the heater and all other connections, bubble detectors, test points etc within the gas locker. Treat all other gas appliances the same way. As others have said, test all joints carefully, and periodically operate the bubble detector. There are small risks in everything, but if you are meticulous in your work and test everything regularly then go for it!

It doesn't even tell you why it is sounding it's alarm! Mine regularly goes off and shows how many parts per million of CO is present when there is no CO present at all, just because the solar panels are causing the batteries to gas and hydrogen is being released.

Hi Nick, I'm not missing the point at all, I haven't mentioned Travelpower and I wasn't talking about them or boats that use them. Since you clearly want 3Kw of 230v AC on board (not something I need), you could easily have it without the need to have too big an engine for every other aspect of cruising. Just have a battery bank and a 3Kw inverter. Charge the battery with your engine alternator/alternators when cruising, and with solar or a small generator when you are not and take your 3Kw from the battery for the limited time that you need it. Save money on a smaller boat engine that is better looked after by being operated as the manufacturer recommends and more money by not buying a Travelpower. Spend some of that money on a decent inverter and perhaps some solar panels or a compact generator.

You should try it, it does. Just look at the performance curves of a correctly sized engine, and what we are talking about here, one that has been specified too generously. The correctly specified engine will be at its most efficient when it is pushing ones boat along at its usual speed, leaving the inefficient top part of the curve for when you push the unit hard, when stopping or going upstream. Why pay more for a bigger engine that is running too slowly with insufficient load to reach its peak efficiency, whilst possibly damaging it through bore glazing? We are talking about people who buy a diesel which develops it's peak output at around 2800rpm and cruise at 1100rpm. Even when they push it hard they rarely exceed 2000rpm. They might have a 45hp engine which develops 8hp at 1100rpm, cruising speed and 25hp at 2000rpm for upstream work. This is not desirable for the engine or efficient with fuel. Obviously the above figures are illustrative and not meant to represent a specific engine, but purely to demonstrate the principle. Speaking personally, I did specify an engine that in hindsight was bigger than was needed. I have never used it at full revs, so I could have saved money on a smaller engine, run it at its optimum level and more efficiently. Perhaps others have done the same.

Its sounds like you have an impressive set-up. Not impressive at all. I got the 4 panels second hand from Bimble Solar and they operate through 2 Chinese (I think) mppt controllers. I do lift one edge to 23 degrees above the horizontal for summer use and raise them still further in the Winter, but I don't attempt to rotate them to follow the Sun at all. If you are unable to tilt your panels, then just add more to compensate if you have room. Nothing must be allowed to cast a shadow over any part of any of the panels to avoid a drastic reduction in output. That's it, no secret.

Both of these recommendations are because glazing is a concern to the manufacturers. I don't think that too much sleep should be lost worrying, but it is certainly 'best practice' to specify an engine correctly without adding a bit of extra power for 'good measure' and to avoid, if at all possible, running the engine simply to top up the batteries. What was concerning me about the direction of the thread, was that charging the batteries by using the main engine (whilst moored) was being discussed, when in fact such practice is not to be recommended. Not disastrous, but simply not best practice. Try to specify your engine so that is 'working' when cruising, but with a bit of 'grunt' in hand for going upstream and emergency stopping. Such an engine will last longer, be cheaper to buy and of course cheaper to run. Also, a smaller engine will be damaged less by being run just for battery charging when this is essential.

That is what I would do too, but if Wayne fancies automating his boat then why not?

It is a bit more than theoretical, I'm afraid. If you are happy that your engine is not at any danger from glazing, then that is great, but if others are reading this and deciding how to approach power generation on board, then they need to be aware of the following: Running the main engine without it being under load, for example for just charging the batteries can be very damaging. Even running a 40 plus horse power engine with maximum revs between 2500 and 3000 at 1500rpm at canal cruising speeds isn't a whole lot better. Periodic engine running of near maximum revs for at least 10-15 minutes will help to burn off the damaging residue, but pottering around at less than 2000rpm won't, as the engine will simply never attain its full temperature. Using less refined engine oil instead of the latest 'all singing, all dancing' oils will help to prevent glazing if your engine manufacturer sanctions their use. Investing in solar panels or a small generator to charge your battery might be cheaper in the long run than damaging your engine.

Piston rings are split and sit in a groove so they don't rely on expansion due to high temperature to work.

I wouldn't bee too confident: Glazing is insidious, building up at different rates depending on the degree of abuse. It is recognised by all manufacturers that the prolonged running of diesel engines when not under sufficient load results in glazing. The microscopic oil channels in the cylinder bore gradually get clogged, reducing lubrication to the piston rings, producing excessive heat, 'blow by' and rapid wear. All of which are best avoided. Running ones main engine to simple generate electricity is bad practice for this reason.

At last, someone who understands that modern diesel engines need to be 'worked' hard. Petrol engines don't care, not that you would want one in a boat, but the ideal for a modern diesel is for it to be operated at about 3/4 of its rated output. I know many of you will argue, but properly 'worked' diesel engines run hot and don't 'glaze' their cylinder bores. I have worked on many such engines and it is a real problem, particularly when the engine is left to run out of gear, simply to spin the alternators. In my opinion, new build fabricators are also guilty of over-selling engines, knowing that many people think that bigger must be better. I have a 85hp engine in my barge, and in hindsight I should have specified a 60hp, but I know of several people with similar barges who have opted for 110hp lumps! My barge only needs 15hp to push it along at 6 knots, the rest of the power is just for stopping it quickly. Your narrow boat will need less than 10hp, probably a lot less, to drive it at canal cruising speeds. A bit more power is handy for going upstream, but no amount of power will drive it at more than its hull speed, so above the optimum horse power, any engine is simply making an ever bigger bow wave up which the boat can't climb. Narrow boats carrying 20 tonnes were once drawn by a horse. Susequently these were replaced by wonderful engines of less than 10hp that swung a big prop for 'grip' on the water, now, people must have engines of 40hp plus, in boats that carry kitchen units and a couple of crew! There are many reasons of convenience for using ones main engine for generating electricity, but it isn't very good for it. A small generator, preferably diesel for safety, is much cheaper to run and your ships engine will thank you.

You are achieving poor results! My 4 X 235w solar panels regularly output over 70 amps at the charging voltage of 13 volts meaning I expect in Summer when the Sun is shining to get no less than 910 watts out of the rated 940 watts, and on perfect sunny days at noon, almost the full rated output. My calorifier contains a 1000w immersion heater which if operated for an hour when the Sun is shining will heat my water without making any noticeable demands on our battery bank; but only for about 4 Summer months. We use a Morco F11e the rest of the time.

Renewable energy from the lid and recycled manure/compost from the box; genius! Allan, I like your thinking.

Hi John, I did as you are doing some 8 years ago, building a liveaboard from a sail-away. My wife and I live 1/4 mile from the nearest mains electricity and so are completely off grid. We have all (well most) of the usual domestic appliances, apart from a washing machine, because we prefer to do clothes washing 'ashore'. Our only means of generating electricity are 940w of solar panels and a small wind turbine that is slightly better than useless. We do have a diesel generator that produces up to 120 amps at 12 volts, but last Winter we only needed to run this for about 4 hours on three separate occasions. We do not cruise in the Winter and I would never run the main engine just to charge the batteries: It really isn't good for a diesel engine to be run unless it is under load, and two 100 amp alternators isn't enough to load my engine. Prolonged such use will, of course, glaze the cylinder bores. To say that solar is of no use in the Winter is rubbish. It quite obviously produces much less power during the 'dark' months, but if your boat's systems are well designed and you choose your appliances carefully, it is very easy to cope without shore power; we do. During the Summer, with solar generated power I can heat the water in my calorifier and use an electric kettle, during the Winter I use a gas water heater and kettle. Heating is mainly from our mulifuel stove with two diesel space heaters as backups and we are always 'toastie'. We have a gas hob and oven and don't use a microwave. All lighting is 12v led of course and our refrigerator is a low energy one. We even use a heated underblanket when the nights are chilly. All this with solar panels with mppt controllers and a Rolls battery bank of about 1100Ahr C20. Off course what you are hoping to achieve is possible. Good luck and have fun with it!

Probably because your figures are just about right. Since faeces are 85 to 90% water, the drying out process alone reduces the weight and volume dramatically and that is without the microbial decomposition. 20Kg of finished compost could be derived from up to 1/5 tonne of raw product: 2 people contributing 260cc per person per day (including sawdust) for 6 months. I would point out though, that although achieving true, odour free, friable compost is very possible on a boat, the stored containers of maturing compost do need to be mixed occasionally and there is no possibility of using an airtight lid, because you don't want anaerobic decomposition. This means ventilation holes and so usually outside storage. What is needed is a relatively shallow box with a lid, but also with some rain-proof ventilation that can be stored on ones narrow boat roof. Given how much 'stuff' is stored on nb roofs, including flowers in tubs and troughs, a well designed poo/compost storage box need not look out of place at all. Remembering that there need only ever be two of them for a three bucket rotation, and a box containing 20Kg of maturing compost need only measure 50cm X 40cm X 15cm high.

It is surprising what is actually legal and acceptable to the river authorities. The journalist Steve Haywood from the publication Canal Boat and Tillergraph did some research directly with the Environment Agency and this is an extract from his article: "Finally, I got confirmation that boats could empty their sea toilets on not just the Great Ouse, and the Medway, but on the tributaries of the Great Ouse and the river Nene as well. The answer to my suggestion of emptying my cassette over the side was circumspect. ‘The regulations don’t specify what sort of toilet is permissible, However, if a boater is discharging materials/chemicals that could potentially cause pollution and kill fish it would be an offence against the Salmon and Freshwater Fisheries Act 1975, Section 4(1)." It would appear that tipping Elsan Blue into these rivers is illegal, but emptying your untreated toilet cassette is quite acceptable to the very authorities that look after them!

Why not turn the gas on remotely by sms, just before turning on the heater by sms? That way there would be no possibility of a gas accumulation within the boat when the heater springs into life and so no possibility of a gas explosion. It would be very easy to also fit a gas alarm that sends you an sms from the boat should there be a gas escape. The same alarm could also cut off the gas supply by operating a solenoid within the gas locker. All the equipment is readily and cheaply available from eBay if you do a bit of research.

Mine consumes just 15Ah at 12v per day as described earlier in this thread, considerably better than my Shoreline 12v fridge.

Like France, where there are 5000 miles of navigable waterways and at the last count (2015) there were just 40 pump-out stations. It is frowned upon to 'flush' into marinas and harbours, but a blind eye is turned in most other places. Most inland vessels do indeed still 'flush' directly into the canal.

It is surprising what is actually legal and acceptable to the river authorities. The journalist Steve Haywood from the publication Canal Boat and Tillergraph did some research directly with the Environment Agency and this is an extract from his article: "Finally, I got confirmation that boats could empty their sea toilets on not just the Great Ouse, and the Medway, but on the tributaries of the Great Ouse and the river Nene as well. The answer to my suggestion of emptying my cassette over the side was circumspect. ‘The regulations don’t specify what sort of toilet is permissible, However, if a boater is discharging materials/chemicals that could potentially cause pollution and kill fish it would be an offence against the Salmon and Freshwater Fisheries Act 1975, Section 4(1)." It would appear that tipping Elsan Blue into these rivers is illegal, but providing you don't use it, well...........