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Posts posted by IanD

  1. Flexible solar panels are more than 5x as expensive as rigid ones for the same output, which is why most boaters use rigid. They also have a reputation for having short lifetime unless carefully/professionally/expensively installed.


    Flexible ones can look a lot better but you really pay a lot of money for this.

  2. 12 minutes ago, Tony Brooks said:

    Don't rule out the Russian/Chinese version of those heaters. We seem to be getting fair reports about them.

    The same choice as for many other bits of kit such as inverters -- you can pay more for stuff supplied and supported (including spares) by companies like Evo/Webby, or buy something considerably cheaper from a less reliable supplier. The kit might or might not be as well designed and made -- it may be made in the same factories, or almost identical -- but is more likely to have issues with spares and support/maintenance in future.


    You might get a good one which is reliable, or one which turns out to be junk that breaks down and is essentially unfixable -- but you'll have saved a lot of money up front.


    Literally, you pays your money and you takes your choice... 😉


    (N.B. "I bought a cheap Chinese one and it was fine" is anecdote not evidence, just like "I didn't wear a mask and I didn't catch Covid" -- you need to get a lot of them out there to know if they really *are* good or bad...)

  3. 1 hour ago, Captain Pegg said:


    No plates were punctured in the sinking of the Titanic.


    And what it mostly explains anyway is why ships are built in steel grades with yield stresses typically twice that of those used in narrowboat construction.

    And there are lots of debates about whether the Titanic steel was brittle at cold water temperatures, whether the rivet material was bad and so on.


    But to answer the OPs question, the hull of a narrowboat made from 6mm plate is a *lot* stronger than that of a typical ship (or the Titanic), to be similar it would need about 2.5mm plate.


    Which is why narrowboats are robust, even when bashed into things harder than icebergs... 😉

  4. 52 minutes ago, Nightwatch said:

    My temporary next door neighbour has bought a refurbed (not new) Webasto diesel heater. He hasn’t fitted it yet. I need water heating and heating capability not just hot air blowing.


    This has got me thinking more. I’m looking at the Autoterm unit, but also considering the Webasto, the Eberspacher, and the Mikuni.


    So mayI ask others opinions of the four units. We all have our favourites. But ease of installation, reliability, and anything else I may have to consider.


  5. 1 hour ago, TheBiscuits said:


    The Haynes Manual (via Wikipedia) says:


    The 2,000 hull plates were single pieces of rolled steel plate, mostly up to 6 feet (1.8 m) wide and 30 feet (9.1 m) long and weighing between 2.5 and 3 tons. Their thickness varied from 1 inch (2.5 cm) to 1.5 inches (3.8 cm).




    Hutchings, David F.; de Kerbrech, Richard P. (2011). RMS Titanic 1909–12 (Olympic Class): Owners' Workshop Manual. Sparkford, Yeovil: Haynes. ISBN 978-1-84425-662-4.

    Oops, misread cm for inches and then did the conversion... 😞


    1" amidships seems to be the accepted figure, so that's equivalent to 2.5mm for a narrowboat. Explains a lot....

  6. 19 hours ago, blackrose said:

    I really enjoy watching this programme and also Aircrash Investigation. Not sure why? Maybe from morbid curiosity but I think it's more to do with the way the investigators systematically uncover the causes of the disasters, which often include a series or chain of events.


    Anyway, I'm just watching one where a 166m vessel capsized as a result of going into shallow water and hitting rocks and it just made me think about how strong steel canal boats are - at least in terms of plate thickness. I don't think I could puncture the 6mm plate on the sides of my 29 tonne widebeam even if I deliberately ran against rocks at full speed. 


    For example, at 114,000 tonnes, how thick would the plate on a vessel like the Concordia need to be to have bounced off those rocks rather than being sliced open? That's a rhetorical question, you don't need to do the calculation, but I dare say a few feet thick and completely impractical. I know some commercial hulls are double skinned instead.

    Stiffness/strength of a panel -- like a hull -- goes up as the square of thickness, but mass/hull forces in a collision go up with the cube of size. So if you scaled up a narrowboat 10x in all dimensions to a ship 700' long and 70' wide drawing 20' or water weighing about 20000 tons, the hull would need to be built from 60mm plate to be as strong as a narrowboat built from 6mm plate.


    Still wouldn't make it impossible to hole, but difficult. The hull of the Titanic (roughly the size above) was built with 48mm plate...

  7. 9 hours ago, David Mack said:

    That describes itself as a cooling unit. I would be looking for something specifically designed as a heat pump for heating, and not necessarily cooling.  And having a separate piped heat exchanger looks inefficient compared with something that uses the large surface area already in contact with the heat source (canal water). What it needs is the refrigerant pipes thermally bonded to a narrowboat bottom plate!

    It's a cooling and heating unit, the heat pump connections just get swapped over -- the heating is "free" with the aircon (or vice versa).


    All heat pumps units like this -- ground source home ones included -- use a secondary liquid cooling loop as well as the primary HFC one, the heat then has to be transferred from this to the environment somehow. The ground source ones use a network of brine-filled pipes, which you could then take to a skin tank. This unit is designed to use fresh water directly, hence the 5C intake limit.

  8. 3 hours ago, Alan de Enfield said:


    It is a 'standard' heating / AC method on bigger leisure vessels. We spoke with the suppier with a view to adding it but they actually suggested that it would not really work anywhere North of a line (roughly) Norfolk across to Wales as the Sea was too cold - particularly the Northern North Sea due to being fed with very cold waters from the likes of the baltic.


    They told us that once the water gets to ~5*C you need a secondary source of heating to boost the heat generated.


    Water temperature of the North Sea - real time map and monthly temperatures (seatemperatu.re)


    The seasonal average for the water temperature in the month of January is between 3.1°C and 8.5°C. The lowest sea temperature measured this month is -0.9°C and the highest is 9.9°C.


    The marine aircon/heating heat pumps don't work with inlet water temperatures below 5C, they shut down -- I looked at using this one for a narrowboat.




    So you need another source of heating for when the water is cooler than this, for example a diesel heater or stove.

  9. As was pointed out, loaded trad boats didn't have much freeboard when loaded, but also drew a lot of water (up to 3'6" or more). Tugs designed to pull them were heavily ballasted so they also sat quite deep in the water to allow them to use a large diameter propeller for best pulling power.


    Most modern boats draw much less than either because poorly dredged canals today mean a deep-draughted boat can have difficulties getting around some canals, but since the internal height still needs to be tall enough for people they sit less deeply in the water, usually not much more than 2' draught though some are deeper -- so a lot more of the hull sticks out of the water, they look more like a lightly-loaded trad boat.


    Modern tug-style boats which are high out of the water look wrong (because in the old days tugs didn't have much freeboard) so they're often more heavily ballasted than non-tug-style boats which means they draw more water. Look "sleeker" and lower -- a bit like a sports car -- but can be a bit less practical because of this (also like a sports car)...

    • Greenie 1
  10. 1 minute ago, ditchcrawler said:

    Its going to need to be a lot to create a positive pressure with half a dozen 4" diameter holes in the roof and a couple of big louver vents near the deck  its going to need to be big, and don't consider opening a door. How much air goes up a chimney with the fire going, it has to supply that as well

    All it needs to do is make sure that the net airflow everywhere except the fan is outwards, which needs very little pressure but it does need flow. 160cfm is -- as I said -- quite a lot, almost 3 cubic feet per second which is *way* bigger than what goes up a chimney.

  11. 2 hours ago, Quattrodave said:

    I wouldn't use a resistor to drop a fans speed, it will use the same amount of electricity, just turn the excess power into heat... a PWM (pulse width modulation) controller will turn on and off rapidly lowering the fan speed and also be adjustable! Will a computer fan be powerful enough?

    Depends which computer fan you use and how much noise you can put up with. This one moves 270m3/hr or 160cfm at full speed which is quite a lot...




    If the noise/airflow is too much, it can always be slower down by a PWM controller like this...



  12. 5 minutes ago, Tacet said:



     You say No - but seem to mean Yes.  You are saying that a fuse is both certain to blow at less than 55A and yet may not blow at all between 25A and 55A - all in the 10s timeframe.  Between 25A and 55A is definitely less than 55A, of that I am sure


    In the graph provided, it is only more than 55A at which the fuse is certain to blow within 10s.



    I think we're arguing about different interpretations of what was written, not disagreeing on the facts... 😉


    You said:


    "Should not the 13a fuse shown blow (at the 10 second scale) on more, not less, than 55A?"


    Yes it will definitely blow within 10s above 55A -- but it might also blow above 25A.


    It will definitely not blow within 10s below 25A -- but it might also not blow below 55A.


    25A to 55A is a region of uncertainly, where we don't know if it will blow within 10s or not.



  13. 2 hours ago, Tacet said:

    Should not the 13a fuse shown blow (at the 10 second scale) on more, not less, than 55a?

    No. The current at which the fuse blows after 10 seconds is between 25A and 55A, varying from one fuse to another. Below 25A, no fuse will blow within 10s. Above 55A, all fuses will blow within 10s. In between 25A and 55A the fuse might or might not blow within 10s.

  14. 1 hour ago, Stilllearning said:


    George -- Formby, not Hinchcliffe -- had a whole heap of ukuleles and banjoleles, all tuned to different keys for different songs because he only played in one key (one set of fingerings/chords)...

  15. 19 minutes ago, Laurie Booth said:

    Love them :)


    Glad to hear that, me too -- have seen them many times, since long before they because famous(-ish).


    I do remember a folk club gig they did (pre-Millenium?) where a bunch of uke players from one of the societies turned up, and were very dischuffed when not a single George Formby number was performed.


    George (Hinchcliffe) tried explaining that this wasn't what the Ukes did, but they still weren't happy -- I think "Fly me off the Handel" pushed them over the edge... 😉


    (me too -- I almost fell off my chair laughing when "Hotel California" came in. And I'd heard it before so I knew what was coming...)

    • Greenie 1
  16. 2 minutes ago, cuthound said:


    Worcester, who have gone out of business.


    I have seen a few other boats with flaking powder coating. It just doesn't seem to adhere as well to aluminium as well as it does to brass.


    If you just wipe the anodising with a damp cloth it lasts forever. If however you try to polish it with metal polish, as someone did on my first shareboat, then it is quickly polished through...

    Thanks for the info. I've asked Caldwells what their view is on the long-term durability of their powder coating, it'll be interesting to see what they say.

  17. 3 hours ago, cuthound said:


    The aluminium windows and aluminium mushroom vents on my boat were powder coated in gold paint from new. After about seven years it began to flake off in small patches. The same has happened to my aluminium garden furniture after a similar time span.


    It then becomes a maintence problem as the finish only comes off in certain areas, leaving a lumpy finish after painting and the still attached powder coat is almost impossible to remove without damaging the aluminium.


    I wish the original owner of the boat had specified anodising.

    Do you know who manufactured the windows? Asking because powder coating vs. anodising (double-glazed portholes from Caldwell) is a decision I need to make in the near future...


    (if you don't want to name names publicly, please PM me)

  18. 1 hour ago, Tracy D'arth said:

    The worst I had was a gecko in a swimming pool control panel. It took out the relay, cut-out and the most of tracks on the pcb.  Not in the UK of course, Montaleigne, S. France.

    We had a cat in the local substation (11kV? 33kV?), which proved that our UPSs worked but also not for long enough... 😞


    Leastways we think it was a cat, it's not easy to identify a pile of charcoal...

  19. 2 hours ago, Hudds Lad said:

    Having clipped a pipe bridge that was lower than i thought it was i’d disagree :) 


    Only time i’ve come close to going in was avoiding a puddle by skirting it on the cut side rather than the hedge side and my tyre slid off the path edge. Unfortunately my wife was with me on this occasion and will mention it at least twice if i head off to cycle the towpath to this day. The incident was at least 20 years ago :( 

    I now get "Don't fall in!" every time I go out for a ride...

    • Greenie 1
  20. 14 minutes ago, Hudds Lad said:

    @Kendorr that is great news, i learned to canoe in my youth with Scouts in Elland basin so have been in several times doing capsize drill and eskimo rolls. I now don’t have to submerge again as i’m already a proper boater 👍😁

    I think you have to fall in once from each mode of transport to be fully qualified.


    I've only fallen in off a boat once in forty years. Did it properly though -- on Xmas day, after a pub session, *through* the ice... 😞


    Never fallen into the cut from a car, train or plane though -- must try harder... 😉

  21. 11 minutes ago, David Schweizer said:


    You do an excellent line in sarcstic hypocracy.

    As you do, superba vehentem equitem 😉


    So how much towpath cycling *do* you do? If you've clocked up 50,000 miles without an incident then that is indeed admirable 🙂

  22. 23 hours ago, Tracy D'arth said:

    Found the remains of an insect on the back of the main processor pcb, may have shorted across some components as it fried. Nothing else obvious, still dead.

    I give up, where is the best place to get it fixed?

    Only an insect? You were lucky, you should see what mess a slug on the back of a dishwasher PCB can do... 😞

  23. 1 hour ago, David Schweizer said:

    Whilst I have the greatest sympathy for the gentleman and his family, I have never really understood how so many cyclists manage to fall into the canal, unless it is due to careless, reckless or unobservant riding. As already mentioned towpaths are often narrow with obstructions, so why do cyclists fail to take these factors into account when using the towpath. Of course there are the head down and pedal like hell merchants who are destined to cause themselves (or someone else!) serious injury, but I am not a particularly fast or adventurous cyclist, and always slow right down when any potential hazard presents itself (also have a bell and loud voice!) In more than fifty years of being associated with the canals, I have never managed to cycle into, or fall off a bike, into the canal.

    I'm so glad that your superior cycling skills mean that you have never fallen into the canal, mine are obviously inferior... 😞


    Slow down, bell, loud voice, do all that -- so how would you cope when a pedestrian steps sideways so you can pass (fairly slowly) on the hedge side, and there's a pointed cut-off branch stub hidden amongst the foliage right at eye level which you spot just before it takes your eye out. Do your superior skills/reaction time/brakes allow you to react and stop instantly, or do you have a diamond-coated eyeball so it wouldn't hurt you? Or is it possible that you too would swerve to avoid it and end up in the cut? Hindsight is wonderful but not very helpful at the time... 😉


    Incidentally, how many miles of canal towpath cycling (with consequent accident potential) do you do -- as a rough benchmark, more or less than a thousand per year?

    • Greenie 1
    • Haha 1
  24. 12 minutes ago, buccaneer66 said:

    Yes I've spotted a few oddities while mapping, this is near Welford on the old OS Maps.




    Maybe a waggish landowner decided to plant those trees to celebrate something, or the mapmaker put them in as a hidden-in-plain-sight map/copyright identifier...

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