IanD
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Posts posted by IanD
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12 hours ago, PD1964 said:
Nope, they don’t bung out as much pollution or Nope, you will not save them the trouble of Googling?
Can’t believe @IanD has missed the opportunity of writing a “War & Peace” multi paragraph reply for a Post.
Both 🙂
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45 minutes ago, MtB said:
Indeed, so the ballasted weight of this plastic boat will be the same as a steel boat, for the same depth in the water.
Is the HDPE actually physically strong enough to cope with carrying 30 tonnes of ballast and coming to an instant halt hitting say, a lock sill at 2mph without rupturing somehow?
No, unless it's 50mm thick which would make it roughly as rigid and strong as a 4mm steel hull -- but 50% heavier, and probably more expensive, and very difficult to build with... 😞
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4 minutes ago, MtB said:
Swerving off at a tangent, do diesel stoves like this bung out more particulate pollution than wood burners?
Or less?
Just wondering if IanD will save me the trouble of googling.... 😄
Nope... 😉
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Me. Through the ice, on Xmas day in 1986, after a lunchtime pub session at Cosgrove. Didn't spill a drop, all they could see was an arm holding a tankard sticking up through the hole in the ice. Legendary... 😉
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3 minutes ago, Jon57 said:
Could be good for winding without the winding hole then 👍
You'd have to get it pretty hot though -- maybe douse one side in petrol and set it on fire... 😉
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1 minute ago, Jon57 said:
Crt will have to be informed about the additional length if it goes into the next license bracket.🤣🤣🤣
Even better, if you moor it for hours with one side in the hot sun and the other in the shade it'll bend sideways and not fit in locks any more... 😉
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2 minutes ago, doratheexplorer said:
And that root cause could be easily addressed with a direct wealth tax. Of course, any politician advocating such a thing would be thoroughly vilified in the press and many, many people would obediently genuflect to that vilification, all the while telling themselves that they've made up their own minds.
And that wealth tax would have to be also levied on properties other than your primary residence since these count as "wealth" -- they are, after all, simply an investment.
But BTL landlords would object vociferously to this, for obvious reasons... 😉
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9 minutes ago, doratheexplorer said:
If by "root cause" you mean the prioritisation of property building/ownership/tenancies for profit/investment as opposed to providing decent places to live, then I'm in complete agreement with you 🙂
It's a chicken and egg problem; did the attitude cause the housing shortage and inflated prices, or did these cause the attitude?
Either way the UK housing market is fundamentally broken, and this government shows not the slightest inclination to fix it -- perhaps because Tory MPs and their cronies benefit greatly from it as it stands... 😞
Of course the number of people who have invested in property also doesn't help, the last thing they want is to see house prices fall significantly, which would be an inevitable consequence of fixing the problem...
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13 minutes ago, system 4-50 said:
Decision 019. Not To Smooth. BAD, but not very.
When the hull was mostly finished, Colecraft asked me if I wanted the roof edge ground flat. This is where the vertical cabin side meets the roof. Normal welding never gives a "perfect" flush edge so normal practice is to grind it flat on top. This takes away metal so nominally reduces strength by a minute amount but guarantees the roof looks flat. I had made it clear to Colecraft that I wasn't interested in them doing any work for purely cosmetic reasons, they were already doing me quite a lot of extras for the price I was paying, so I looked at the roof and there was no sign of wavyness and it looked "right" as it was, so I said no. This was a mistake albeit a small one. I later found that rain, which can contain dirt, flowed nicely off the roof (having rails not angles) but dropped very fine particles just before it went over the edge. There must have been an invisible slight rise at the edge. This sometimes left a 1? cm dirty streak along the length of each side of the roof! Naturally, I washed and polished the roof every day (!) so that the occasional dirty rain was not much of a problem. I should make it clear that the mistake was mine not Colecraft's.
Decision 020. Engine Choice. VERY GOOD.
I was offered a Beta 43 or an Isuzu (I think) as standard options though I think they would have fitted anything subject to negotiation. I opted for the Beta because I like the reputation it had on this forum and it was fairly British. It was a excellent decision and I would do it again, though I would seriously consider adding the Travel Power option. (This discussion does not consider the inevitable migration to electric power that is coming shortly.) I had a small number of dealings with BetaMarine and they were excellent and went beyond what I could reasonably expect to help me when I thought I needed it. Like a number of other parties I met in my canal life, they would go out of their way to help, provided that:
1. You had done the sensible investigative work first.
2. You were clear about what you wanted.
3. You didn't keep changing your mind.
4. You were ready to pay the likely costs.
It came with a large Hospital silencer which was easily housed under the cruiser deck and made for quiet running. After hiring an air-cooled boat once I was determined to have a quiet engine and this was, despite not having the Beta sound insulation package.
As I believe is standard on Colecraft hulls it had substantial skin tanks on both sides connected at floor level on the bow side of the engine via a metal channel and to the engine by hoses at floor level. This worked well but I never tested it hard, the fastest I ever went was doing doughnuts on Tixall Wide. I never got on to a proper river. Doing it again I would ask for the hose to connect to a T and then the skin tank, with the other arm going to a drain cock and a hose connector so that a drain hose could be connected for changing the coolant/antifreeze. Draining it into the bilge is nasty - I aimed at and mostly succeeded in having a dry bilge.
Access to the engine was excellent. I believe I could actually get right round the engine though I'm not sure I ever did the circuit in a single pass.
The Beta had a built-in oil drain pump. It was ok but when I discovered the Pela, i always used that as I found it easier.
While we are in the hole:
The weed hatch was very good, sealed well, but was heavy which is good for its operation but got heavier (why does gravity do this?) as I got older. It never leaked and I used it very rarely. I even got round the BCN Challenge without opening it! Revisiting, I would design and fit some sort of lifting mechanism to take the weight and slide it to one side to allow easy access to the hole.
The stern gland was a standard greaser type. It stayed dry for most of my time but more on that later.
On the same side as the silencer was 4 x 110Ah lead-acid batteries. Being a square stern there was a lot of uxter(?) plate space.
There was also a propellor but I don't know much about that.
The roof edge problem is one reason many boats nowadays go for handrails as part of the roof. Because this then traps rainwater on the roof you need to consider how it gets off, you don't want it all flowing to the stern (especially in a downpour) and draining onto it (and possibly into the bilges). One solution is to have a cross-beam near the stern end of the roof with a gap in the rail and drain channels down the cabin side so most of the water goes this way, like here...
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15 minutes ago, doratheexplorer said:
I never said that the shortage of new houses being built was the *only* problem, in fact I mentioned many of the others -- but it's the underlying root cause which indirectly causes many of the others, and without fixing it the problem isn't going to go away.
All the other issues (housebuilders avoiding affordable homes, RTB, BTL, property as an investment not a place to live, taxation on housing, lack of infrastructure, many others....) are indeed big contributors to the problem, but not the root cause.
The simple fact is that what the UK really needs (a good supply of affordable new houses of decent quality, and lower house prices) is in direct opposition to the interests of the developers who build almost all UK housing and whose primary target is profit. Because as companies, that's their job, not doing what's right for the country -- that's the government's job, at least in theory if not in practice today... 😞
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9 minutes ago, shaun15124 said:
thank you for this
and your feedback has been helpful on so many ways, (now can you pop up to Leeds and help 🙂 )
You're welcome 🙂
I think you need to get somebody involved with the project who really understands these issues (like robustness and thermal stresses) and get some advice from them, because you're trying to do something pretty much new and there are always bear-traps lying in wait for you when you do this -- I should know. I've spent pretty much my entire professional life inventing better mousetraps and trying to spot unforeseen problems with them, thankfully mostly successfully... 😉
The further you depart from normal practice the higher the chance of problems like this cropping up, and it sometimes takes a fresh eye from outside to spot them, hopefully before they become a killer -- I've had this happen many times, it's *usually* possible to find a solution but it might need big changes to do it if the problems are big, which I think yours are... 😞
Unfortunately I can't really help apart from commenting on here -- and TBH some of the problems with an HDPE canal boat identified on this thread are pretty fundamental and not going to be easy to solve... 😞
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14 hours ago, ditchcrawler said:
We have also had two this week who have commissioned hulls and now cant fit in them what they want.
Of course even if you do a lot of careful planning, you can still find that with real life constraints things won't quite fit where you want and you have to change things... 😉
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10 minutes ago, MtB said:
Intuitively, my prediction is welds will split rather than the boat going banana-shaped. And if below the waterline this could be an utter disaster.
I suspect even proper stress analysis would unable to correctly predict (possibly imperfect) welds splitting.
The welds won't split because the roof is in compression when hot not tension, and thin panels (like the roof) buckle under compression at far lower stress than they (or welds) break under tension (like the cabin sides). The hull is much stronger and stiffer than the roof and is in tension; this is a battle that the roof is guaranteed to lose... 😉
Before you ask -- yes I studied all this as part of my engineering degree, and work with problems like this (but *much* smaller) on a daily basis. Nowadays engineers faced with problems like this tend not to do extensive hand calculations which are difficult, time-consuming and error prone, they use CAD programs designed for the job which are far more accurate and less prone to error for complex structures (and can include weld stresses) -- for example Solidworks, which IIRC costs about £4000 per user... 😞
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55 minutes ago, MtB said:
Expanding on this if you'll forgive the pun, it gets worse.
In the summer sun the roof will get up to 40c or much more, and try to get 4" longer. At the same time, the hull will be sitting in water at say 15c and not expanding anything like as much. Will the plastic and the welds especially have the structural strength to cope with the stresses generated by such large differential temperature changes as the seasons pass? Or even just the days and nights? As the top of the boat changes with air temperature and the hull is held at the same temp by the water it is in?
Funnily enough I'm currently working on a similar problem right now on a *much* smaller scale (a hot silicon chip in a cool package) and the biggest problem is warpage -- so here the hot roof will try and expand but the cold baseplate won't, and the difference in lengths works out at about 5mm per meter with a 25C difference (which is perfectly possible), which is 17x bigger than steel -- so the length change is similar to steel with the roof more than 400C hotter than the baseplate... 😞
Since the baseplate and cold hull bottom sides are far thicker and more rigid than the roof, what's most likely is that the roof will buckle when it heats up -- or possibly the boat will go slightly banana-shaped with the centre raising up, though I suspect the hull is too rigid for this. Or maybe a bit of both when the cabin sides join in too... 😉
What is needed is some proper thermal/physical stress analysis, which as noted above is what a naval/marine engineer would do. Of course this either needs an expensive 3D modelling program (like we use) or enough expertise to do extensive hand calculations, neither of which a boatbuilder is likely to have... 😞
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26 minutes ago, Tony Brooks said:
In series with what?
If you mean the rads then apart from a longer warm up I can't see why it would not work. I doubt it would be easy to get gravity circulation if you did that, but as you seem to have a pumped system it should work, but what you hope to achieve I don't know.
Mine will be in series -- calorifier first, rads second -- to give the fastest possible water warm-up time with shortest generator/boiler running time when the demand is for hot water only, when all the water goes through the calorifier.
For this to work without a bypass you need a big heat source as well as a big coil calorifier, otherwise it would take too long for the rads to heat up when you also want heating. My boat will have this, both diesel pressure-jet boiler and generator can push about 10kW of heat into the (pumped) system (with 5kW calorifier coils), but most boats don't so a bypass would be needed for when you want quick radiator heating, then some of the hot water goes straight to the rads and some through the calorifier.
This solution should work for me but most people will need something different, you need to design the system based on your particular requirements not "one-size-fits-all"... 😉
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1 hour ago, Tacet said:
What does the temperature difference need to be to achieve a 5kW transfer?
Not sure, I assume they're rated with a hot output from the boiler into a cold tank -- maybe 50C difference? (I expect there's a standard spec for this).
I do know the coil surface area is 0.6m2 per coil (including fins) which is a lot bigger than a standard one, also the coil pipes are bigger diameter (22mm?).
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Just now, nb Innisfree said:
The answer is: There is no answer.
But what is the question?
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40 minutes ago, nb Innisfree said:
2x smaller cals with auto or manual change over valve (assuming enough space & deep pockets)
Quick heat up for 1st one and 2nd one as extra heat sink if req.
The capacity of the calorifier to absorb heat (in kW) is set by coil size; a smaller calorifier with the same size coil heats up faster (less water) but doesn't absorb any more heat.
You could get twice the coil capacity by using both coils of a twin-coil one if there's only one heat source, or use two smaller calorifiers in series -- but this will probably cost more than one bigger calorifier with bigger coils... 😉
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22 minutes ago, Tony Brooks said:
For general discussion, not a direct reply to the quote
But one has to remember that as the calorifier heats up the transfer oh heat will drop, so whatever heating capacity the coil has it will gradually reduce. The question is, will you have enough and hot enough water before this reduction causes the boiler to start cycling up and down.
I'm aware of that, and there are things in the system design (e.g. thermal storage) to reduce the effect. The boiler is more akin to a domestic oil-fired boiler than a Webasto, it's designed to cycle on and off in exactly the same way.
It doesn't change the fact that if you want to heat the tank up faster and reduce boiler cycling, bigger coils are always better than smaller ones.
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10 minutes ago, doratheexplorer said:
God that was a depressing read. Not suprising though, coming from a banker. All he wants is 'more houses, more houses, more houses' and attributes the lack of house building to red tape and nimbyism, implying that simply building more houses is the answer to everything. Absolutely nothing mentioned about the infrastructure needed to support those new houses. A prime example of the bloodsuckers who spend their lives ruining the world.
They live off whatever their pension provides and the state picks up the difference.
I disagree. Every in-depth analysis shows that the underlying cause of the UK housing market fiasco is that we aren't building enough new houses, and haven't done for many years, which is exactly what he says.
NIMBYism is undoubtedly another of the contributors to the problem -- and this applies not just to houses but things like wind turbines and solar farms. And 5G masts, for those wearing tin hats... 😉
It's obvious that if you build more houses you need to services to support them -- not just infrastructure like roads and sewers but public transport and facilities and community centres and doctors and shops and pubs and... -- and not doing this is another problem with many developments. And these are skimped on or ignored because the housebuilders have no incentive to provide them, it just reduces their profits. Like them trying to wriggle out of their agreed percentage of social housing... 😞
But none of this pointing out the faults of housebuilders and the planning system changes the fact that we're not building enough houses, and especially not affordable or social housing because expensive executive homes make a lot more money for the housebuilders.
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2 minutes ago, magnetman said:
I know that.
I doubt the pictured boat is going to be a powered canal boat.
So why does it have a narrowboat hull shape, with a swim and uxter plate at the stern?
A houseboat can just be a rectangular box, cheaper to build and more space inside...
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14 minutes ago, Colin Brendan said:
Have you already bought a diesel heater? If not maybe you can spec it to the calorifier output (with maybe a bit extra for towel rail, and 3 small rads) - I'm not an expert though.
I feel like the problem with the 5.2kw webasto is that some people suggest surecal coils soak up about 1kw (not sure how correct this is) leaving it vastly overpowered/short cycling if you don't have significant rads on. Maybe IanD's suggestion of a bespoke one is the way to go if not - then you can spec the calorifier to suit the heater. I think he said £1000+ though....
I'd like to know if there are any off the shelf high output calorifiers out there - NautiQuick seem to say they are - but no stats to back this up
I'd also like to know if there are any high output rads out there - aluminium rads are supposed to have high output but feel like they may pose other dissimilar metal problems - copper boiler etc.We have immersion heater - and if I was on shorepower and electric wasn't absurdly expensive I'd use that all the time
The 1.1kW figure for a standard Surecal came from actual measurements Dave Jesse made on a 55l twin-coil one.
If I could have found any calorifiers offering high-output coils as standard off-the-shelf I'd probably have gone that way, but I couldn't, hence the custom one. But I also have different requirements to most boaters since the coils connect to either a generator or a pressure-jet diesel boiler, and I want the generator to heat up the tank in less than an hour (expected running time per day) and to reduce boiler cycling (peak output abut 10kW) when that's being used, so I want really hefty (~5kW) coils -- most people don't need this.
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5 minutes ago, magnetman said:
Static houseboats innit.
And maintenance-free HDPE would work well for them, because they don't bash into locks and other boats.
However the boat being discussed in this thread is clearly not a static houseboat...
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1 hour ago, Tony Brooks said:
I think that illustrates the difference between a boat builder and a proper engineer or naval architect. Both the latter would have done the calculations such as you have done.
The boatbuilder "rule-of-thumb/estimation" approach is absolutely fine when you're building things that you've built before and are familiar with and are known to work and be robust, like steel narrowboat hulls.
Where it all goes wrong is when you try and apply this experience to completely new materials (like HDPE) which are very different without understanding the different properties, and that's when proper analysis is needed... 😞
Single woman buys narrowboat to get on property ladder
in General Boating
Posted
This is what happens when interest rates go up rapidly thanks to the Kwarteng/Truss fiasco; people locked in on fixed-rate mortgages (owners and landlords) are fine, new buyers are clobbered -- so for a short time renting can be cheaper than a mortgage.
When the fixed-rate deals run out in a few years renting will become more expensive than a new mortgage again, just like they were before the interest rate rise.
If rates ever drop back the reverse will happen, renting from landlords locked into a higher-rate mortgage renting will become *way* more expensive than buying -- unless they exit early and remortgage, which usually carries a big financial penalty.
It's the way that renting vs. buying works -- at least if you buy you're in control, as opposed to paying whatever the landlord demands, which is why so many people want to do it -- but many can't afford the deposit... 😞