Paul C

Members
  • Content count

    9,627
  • Joined

  • Last visited

7 Followers

About Paul C

  • Rank
    Long Standing Member
  • Birthday

Profile Information

  • Gender
    Male
  1. Do you know what its quarter mile time is? 0-60 is a bit artificial (I know 1/4 mile is too, in a way) but some cars need a 2nd-3rd gearchange just before 60 so it distorts the figures etc.
  2. Hypothetically, its not such a good idea from the regulatory/safety point of view because "they" deem over 50 volts to be different than under 50 volts, in terms of electric shock hazard etc. With a %age over when charging, a 48 volt system would probably actually be 52-56V during charging. There was talk a while ago of moving over to 42 volt for car electrical systems, but its yet to occur and I suspect it won't anytime soon. Historically, they did of course changeover from 6 volt to 12 volt though. And there's plenty of crossover with certain commercial vehicles being available with both 12V and 24V for different variants/models. Airplanes use 28V DC (amongst others....there is a similarly unique AC voltage too, I think). So in theory, there is no technical reason not to but in practice the barrier of regulations and the non-availability of components will not make it occur. I personally don't think the technical advantages (of smaller wiring and/or lower voltage drop etc) are enough to justify the changeover. What might be more likely is a changeover to more widespread 230V AC use, ie more or most items powered by 230V AC, since (for example) a fridge might be that voltage and thus there's already a large inverter which is on most of the time. Indeed some boats are already like this.
  3. On the same grounds they denied the real owner's application - not satisfied blah blah blah.
  4. Licensing it "connects" them to the boat, in that they're responsible for the licence application.
  5. There are still plenty of boats with existing mortgages, even if you can't now obtain one. I don't know the figures on a number of boats, but there are definitely some out there.
  6. Plenty of boats are mortgaged, the finance company definitely isn't paying for the licence!!!
  7. The maths of the situation aren't massively complicated. When a boat is free floating, there is a bouyancy force acting upwards throuh the LCF (which is very similar to the LCB, for an unloaded boat) equivalent to the weight of the boat - its static, not a dynamic situation. When a boat gets hung up at the front centre, some of the weight is taken by the point it hangs up, and some is supported by buoyancy. So, the amount by buoyancy reduces. Furthermore, since the boat is tilting more and more (the front is out the water, the back's in it more) the LCF also moves (because the LCF is a function of the underwater shape of the hull) backwards. Both the amount of weight supported by buoyancy, and the place it exerts this, change (for the better - ie to lessen loss of freeboard at the back (low) end). Imagine an extreme example, a crane picks up a boat at the front and suspends it 89.9deg vertical and its back end just touches the waterline. Just as it starts floating, a small force is applied at the back, but almost all the weight of the boat is still supported by the crane at the front. Regarding the fact it was hung up at the side, its a similar bunch of calculations but for the side-to-side geometry. It may indeed be that the CRT man applied some kind of (erroneous) rule of thumb, that a 10" lift at the front results in a 1" loss of freeboard at the rear. Basic science tells us it can't be a 10" loss of freeboard at the rear, when the front is jammed and the water level under it drops a mere 1". Also remember that as the boat tilts more and more, eventually there's a point where the friction forces which are supporting the jammed end/side are overcome, partially because its angle is changing, and partly because more and more weight is being applied. It might be that on a particularly hard obstacle such as a large, strong bolt, or metal cill buffer or other metalwork, the weight does not deform the supporting area and the angle increases to allow it to slip off. But on a softer obstcle such as a wooden structure or certain types of masonry or a foreign object such as a tree branch etc, this deforms as more weight is applied, it might slip off due to the amount of deformation or deform in such a way as to 'lock' or 'stick' the boat on it more and more - becoming wedged in a certain position. And of course, the contact points of the boat are going to have some bearing (excuse the pun) on how this occurs and resolves itself.
  8. Its a shame even the most complicated boat heating system is as agricultural as relying on the user to send a text message. My heating at home uses geosensing so it knows how far away I am and when I'm on the way home, and automatically turns the heating on when I get close to home. Also it links with weather forecasts so it knows to turn it on a bit sooner if its really nippy. All automatic without intervention. Its Tado, in theory it could be adapted to a boat but in practice the interface uses a wired ethernet connector (so you'd need some kind of mifi device with an ethernet port, or a network bridge; also I use the expansion box and it uses mains relays (the thermostat on its own, is battery powered and may be adaptable to a boat CH system - my home CH needs the expansion box).
  9. Drilling cast iron is a non-issue, its softer than other kinds of steel and I think effectively self-lubicating too. Just use a metal drill bit and drill it.
  10. That's how silly your argument is.
  11. In the same manner, someone who doesn't drive and doesn't hold a driving licence, in your eyes, would be "guilty of not having a licence", or "the DSA consider the person guilty of incompetent driving". Its not so - all it means is they have not satisfied the DSA they're competent to drive, hence they do not have a licence. For millions of people in the UK this is a non-issue, because they don't want/need to drive anyway, or use public transport, etc etc However for a minority they think they're above the law and get a car anyway and drive it around, in doing so they have broken the law, one of them being driving without a licence. In a similar way, plenty of people don't own a boat on the canal network (they might even want to) and have no desire or need for a licence. Others do want a boat on the canals, so they get a licence and have no issues "satisfying the board" to obtain it. A minority want to have their boat on the canals but don't have the licence because they are unable to satisfy the board. Its a bit like people driving around illegally saying "the driving examiner was wrong to fail me on my driving test, I'll drive anyway, I reckon I'm a good driver and can do it without knocking over pedestrians, scaring other motorists or mounting the kerb too often, innocent until proven guilty right?".
  12. Plenty of other areas of legislation put the onus onto the person to satisfy some criteria.........for example driving licences, there is a requirement to satisfy the DSA that you have the required skills to drive, before they issue a driving licence. Not really a case of "innocent before proven guilty". There's tons of others too numerous to mention.
  13. It does, but also some of the weight of the boat is taken by the front pivot point, so the effect of the centre of buoyancy moving backwards as the boat is tilted is effectively cancelled out. At the point of hanging up, it goes from a 1 point to a 2 point model of static forces. Narrowboats get launched and retrieved from slipways without sinking, although the back end does dip lower.
  14. Imagine a boat with its front fender caught in the gate as the lock drains. The front pivot point is indeed fixed, but there's 2 points where the boat is supported. The pivot at the front is fixed, but as the water drains the other pivot point is the buoyancy of the water, around the middle of the boat, where the level of the water doesn't really vary. Because the height of each pivot is changing, when the water drains 1 foot, the front is 1 foot higher than the water level and the front of the boat is in the air. The back is 1 foot deeper in the water (2 foot overall....but the water level isn't the same as before).
  15. Well its sin 2deg, although they are very similar at low values. BUT the boat will pivot in the middle, so the front would be 1 foot higher and the back would be 1 foot lower. And if you refine the place it pivots, you'd probably say its more to the rear of the boat than the front (boat is heavier at rear with the engine), thus making it less than 1 foot lower at the back.