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IanD

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Posts posted by IanD

  1. 17 minutes ago, Mike Todd said:

    I have no direct facts but it may be that the lower prices of supermarkets were achieved through long term contracts - great when prices are rising but very hard when they fall as they may well have to wait until the expiry of the contract before they get a reduction.

    Supermarkets sell fuel at low margins because this brings shoppers in who hopefully spend a load in the shop too -- they don't even need to make a profit on fuel then, so they can undercut standalone petrol stations.

  2. 13 hours ago, libali said:

    Thanks to everyone for your really helpful replies, it's all feeling much more possible now. Yes, we were aware of the need to book the Frankton Locks - I'm pretty sure it's an online booking but need to check.

     

     

    No, we start on Tuesday and we'll probably only set off at about 4pm (boat pick up is 2-4pm and we can't get there until about 3-3.30). Slightly nervous about not being able to book in advance, but good to know for sure.

     

     

    Glad to hear that it's worth it 👍🏼

     

    I confess that we were hoping to get to Grindley primarily because of liking locks... but the Monty might scratch that itch enough!

     

    Lots of good info in everyone's replies, thanks so much. 

     

    If you're staring on a Tuesday I'd definitely suggest going away from Llangollen first, Tuesday/Wednesday nights are the busiest especially at this time of year.

     

    I'd go the other way first, over the aqueduct and stop at Chirk Bank the first night (walk down to the Bridge Inn), then carry on east. Wherever you then go, maybe aim to get back to Llangollen on Sunday afternoon when it's quiet. That will then give you Monday in Llangollen to do things (walk up to Horseshoe Falls? Railway? Museum?), then moor at Trevor Basin (under the bridge past the hire base) on Monday night and walk over the aqueduct and up to the Aqueduct Inn for the last evening.

  3. 26 minutes ago, Sea Dog said:

    Supermarket prices, and hence those of others, were influence hugely by competition with Asda who usually led the way on low fuel prices. It seems that the new owners of Asda akready owned the largest fleet of petrol stations in the country. The potential conflict of interest was raised by motoring bodies, but was dismissed. So now we see the likes of Texaco, not noticeably keen to be highly competitive on price in the past, being amongst the first in the slow bicycle race to reduce fuel prices. 

     

    The cheapest petrol round here is an Asda (standalone, not part of a supermarket complex) and has been since they took it over several years ago, it's usually 10p or so cheaper than the BP up the road.

     

    The only problem is that it's just off the sliproad onto the A40, and it was so popular when prices were at their peak a few weeks back that the queues backed up onto the Target roundabout and gridlocked it... 😞

  4. 4 minutes ago, peterboat said:

    Here is a nice electric boat that shouldn't have a y problem pushing the tide....

    Screenshot_20220812-123830_Facebook.jpg

    Absolutely true -- has 3500kW of electric motors with 2800kWh of batteries and 2000kW of onboard genny though, so on a slightly different scale... 😉

     

    (incidentally that comes out as 1 ton of pull per 50kW, a bit better than the 1 ton per 100hp "rule-of-thumb" for propellors -- but it does have cowled thruster props which add maybe 25%, so pretty close)

  5. 46 minutes ago, Leemc said:

    Made it Llangollen yesterday. No queues  for any of the tunnels or aqueducts. Slowest part of day was in those two narrow sections, battling(slight exaggeration 😉) against the current!

    if it’s the same on Friday should get up to 10mph💪

     

    It depends exactly when you go through, it's very noticeable that the water speed can vary -- at least it was when we went up, there was a big visible surge in flow (at the wrong time for us!) which later died away after we moored online. I assume some extra water had been let in at the top end...

  6. 4 minutes ago, billh said:

    Just come up from Brum, through Manchester to Ashton. Very few boats actually on the move anywhere. However, many boats were moored not moving particularly at Nantwich, seemed like miles of boats, many with people aboard .Perhaps " we can't go anywhere cos of water shortage" so staying put. Normal water levels on all canals except part of Rochdale 9  and summit of Ashton (about 6ins down). Slight delays at Audlem with slow boats.

     

    Nantwich was absolutely rammed when we went through in early June before peak season and the water shortages.

  7. 2 hours ago, MtB said:

     

     

    Jeez, you'll be asking us the difference between a buffalo and a bison next.... 🤣

     

    (I remember my dad coming home from work with bothe these jokes when I was about seven!)

     

     

    But regarding props, I agree with IanD, the boat propeller cannot tell what power source is turning the shaft at any given RPM so the engine can't possibly matter for a given shaft speed

     

    Where blade diameter makes a bigger difference than Ian suggests is in the brakes. i"ve owned a succession on NBs with ever larger blade diameters and my own experience is the smaller the blade, the less effectively it bites the water in astern. This is why stopping with an Axiom blade was supposedly so good - they designed them to be less efficient in ahead to get higher efficiency in astern, which in turn plays well with people who just shelled out £2k on one! 

     

    But broadly my second NB with the 15" blade and Beta Greenline used to need me to rev the nuts off it to get it to slow down and stop - most embarrassing. My Kelvin K2 with 26" blade bites the water beautifully and stops the boat in astern at only little above tickover - far more elegant. 

     

    I suspect your findings are more to do with hull and propeller design and sizing (and how much you rev the engine!) than how fast it turns, because "stopping power" is pretty much equivalent to "bollard pull" except the water is flowing the other way.

     

    A K2 with a 26" prop will just plain do *everything* better at low revs (44hp, 750rpm max, 160rpm idle, 26" x 20" prop? -- and probably a very nice hull shape) than a Beta (30hp at 3600rpm,15" x 9" prop? -- and probably a much less nice hull shape) -- to get the same bollard pull (about 150lb) as the K2 running at 400rpm you'd need to run the Beta at maybe 2200rpm, even more if the hull and prop were less efficient which is likely. The other problem is that a Beta with a 2:1 gearbox is spinning the prop at 1800rpm at maximum power, well above the 1000rpm normally recommended for best prop design, which will make the stopping performance even worse.

     

    Which as you say means revving the nuts off the Beta when you want to stop, as opposed to having the K2 running far slower... 🙂

  8. 27 minutes ago, Leemc said:

    I just did what Ian told me to do. Brilliant afternoon in Bridge Inn. 3 pints of Salopian Shropshire Gold and may go back for evening meal later. Great beer and very nice prices

    cheers

     

    Glad to help 🙂

     

    They had Shropshire Gold when we were there, but we drank them out of it by the time we left -- admittedly this took us some time, but we're nothing if not persistent. And we had to wash the food down somehow -- good simple pub food cooked while you wait (may take a bit, oh dear, let's have another beer...) at excellent prices. Still a proper pub, not a thinly-disguised restaurant... 😉

     

    BTW if you want to eat in Llangollen the Corn Mill is an excellent (if rather more pricey) gastropub with very good beer, but busy so you might need to book.

     

    Also have a lovely walk up to the Horseshoe Falls and stop for a refreshing pint or two at the Chainbridge Hotel, see photo. Are you starting to see a certain pattern here? 😉

     

     

    chainbridge.png

  9. 18 minutes ago, dmr said:

     

    When the court passes judgement on CRT for criminal lack of maintanance then CRT will plead poverty (and a very bad parent) and offer to pay off the £20,000,000 maintainance backlog at 20p per week.

     

    Except responsibility will then pass to the parent (the government) for failing to provide enough money (from all sources) to allow CART (their child) to meet their obligations -- the government set up the laws/duties, the government set up CART and its funding and is legally responsible for it, in the end it's their responsibility to find a way that CART can discharge this duty.

     

    Putting a layer of spurious charity-based isolation in between doesn't mean the government can evade its responsibility, thought I've no doubt that they'll try -- otherwise every company in the land contractually responsible for delivering *anything* would do exactly the same, set up a shell company to take the flak and then claim "it wasn't me, guv..." 😞

  10. 12 minutes ago, Alan de Enfield said:

     

    The fall back is that should C&RT fail to achieve its plans and/or KPI's the Government will appoint a new Charity (or an existing Charity with 'silmilar aims') to replace them.

     

    It is all written up in the transition documents when the Governement handed control to the private sector.

     

    But if the government replace CART with another charity or body responsible for running and maintaining the canals, they legally become "The Waterways Board" as mentioned in the Transport Act (just like CART were), with the same legal obligation to keep Cruising Waterways open for use, as set down in an Act of Parliament.

     

    No amount of renaming or replacing CART will remove this duty, unless it is changed by another Act of Parliament -- which would very likely spark off protests (which the government might try and ignore) and resistance in the House of Lords (which they can't ignore).

  11. 1 hour ago, Leemc said:

    Bit busier today between Whittington and Chirk. Stopped to help two holiday boats through The New Marton locks, they had no clue what to do, hirers handover virtually non-existent with regards to locks.

    Now moored up in Chirk- great spot 👍👍

    Depending where you are (Chirk? Chirk Bank?) a walk down to the Bridge Inn is recommended, proper friendly locals pub with good cheap beer and food 🙂

     

    You could also do worse than strolling up to The Aqueduct Inn for a beer before going over it...

  12. 2 hours ago, Loddon said:

    But that is like comparing apples with pears both engines were chosen for their max HP at whatever revs so saying a Beta 43 can do it is not comparing like for like so is complete bollauex

     

    <sigh> A 60' narrowboat which might have had a 20hp traditional engine fitted might typically have a 40hp-50hp modern diesel fitted, for the practical reasons I gave -- nobody would recommend fitting a Beta 20, for example. HP into the prop is all that matters, a gearbox can give you whatever prop size/rpm you want (e.g. use a 3:1 instead of a 2:1 to get a bigger slower prop). James Watt told us that it doesn't matter whether the power comes from a horse, or a diesel, or a treadmill powered by lots of hamsters -- all that matters is the (horse) power.

     

    If the boat *needs* 20hp at the prop to push it up the Thames/Trent/Ribble link for several hours, either solution (20hp trad or 40+hp modern) is perfectly valid and in common use today. It's why people say "a 20hp trad engine is much better than a modern engine of the same power" -- yes it is, you need a modern engine of about double the power to be as "bombproof". Which is why that's exactly what is usually fitted...

     

    Of course the trad engine will still cost twice as much and occupy twice as much space as the "double power" modern engine, which many people would say is not in its favour even if it does sound nicer... 😉

     

     

  13. 22 minutes ago, Tony Brooks said:

     

    Whilst I have observed a 70ft coal boat charging up the Thames with apparent little effort I think it has more to do with prop size than engine torque or HPBHP (or HP as the marketeers have it) uses both torque and RPM in the calculation and the fact remains that despite a diesel's relatively flat torque curve the torque and thus the prop spinning ability is falling long before maximum BHP is achieved. If you look at the curves derived from a full dynamometer test across a number of modern engines you find that typically the maximum torque occurs at a bit over half maximum revs. This seems to accord with Ian's figures. Trying to decide how much power (HP) a boat needs to do a specific speed really needs a new HP calculation to be done at that speed, you can't just take the maximum stated HP as the be all and end all for comparisons.

     

    It all depends how the prop size is chosen, because prop torque rises *way* faster with rpm than engine torque drops, see attached Beta 43 plot (which shows power). At WOT (Wide Open Throttle) the prop rpm will increase until the two curves intersect, which should be at maximum engine rpm/power. If the boat is overpropped the blue curve moves to the left and the engine won't reach maximum rpm/power. If the boat is underpropped the blue curve moves to the right and the engine reaches maximum rpm at lower than full power i.e. the throttle has to be closed a bit to prevent over-revving. At all lower rpm the engine is capable of generating more power than the prop can absorb, so you run at lower throttle openings (yes I know a diesel doesn't have a throttle...).

     

    All the stuff about diesels (or electric motors) being great for boats because they have a lot of torque at low rpm is misunderstanding how propellers and engines work together -- at low rpm the torque needed to turn a prop is tiny...

     

    In theory there's nothing stopping you running a modern engine at full power/rpm for hours but it isn't really advisable, both from a wear/lifetime point of view, possibly overheating if the skin tank is too small, and definitely from the noise/vibration point of view -- from these curves the Beta 43 will run at about 2150rpm while generating 20hp, and should be able to do this all day.

     

    And if it had a gearbox chosen to give the same prop speed as a JP2 and the same size prop, the boat won't be able to tell the difference charging up the Thames -- until there's an emergency when you can slam the Beta 43 throttle wide open and double the power, the JP2 is already running flat out...

    diesel_efficiency.png

    24 minutes ago, Ronaldo47 said:

    I think a more likely  scenario would be that the law would be changed to remove the obligation. 

     

    As I said, that depends on whether changing the law against strong protests (and probably resistance in the House of Lords) -- and finding time to do it in a packed Parliamentary schedule -- is more or less painful than coughing up what is effectively pocket change to the Government... 😉

  14. 6 minutes ago, Alan de Enfield said:

    I was under the impression that the bollard pull is to simulate pulling a ship from dead in the water, and is simulated by hooking the tug to a bollard via a load cell and the reading taken.

    Correct, but that's nothing directly to do with the size of the ship it's trying to pull.

     

    If you want 100t of pull you need a 10000hp tug. If you want 500t of pull you need a 50000hp tug.

    3 minutes ago, dmr said:

    Does "can't get blood out of a stone" not trump anything the law can do?.  There have been a few newbies on this forum threatening to buy a new 70 x 14 widebeam and when warned against this say the published dimension say it will fit and they have legal experience and so will sue CRT to make it fit.

     

    Another analogy might be the folk who employ a cheap incompetent builder who does a bad job and then use legal action to force the builder to come back and do a better job (that is beyond their abilities).

     

    The law doesn't care whether you can *afford* to do something you're legally obliged to do. And in this case "the stone" is the government which set up CART in the first place, together with the legal obligations on it.

     

    In the end, it'll be the governments problem -- and of course they have *very* deep pockets... 😉

     

    (actually almost infinitely deep, they can just print more money)

  15. 10 minutes ago, Ronaldo47 said:

    All very well in theory, but I recall a  report of a local authority being taken to court for failure to do something which it had a statutory obligation to do (it was more than a decade ago, and may have been road repairs). The court acknowledged the legal obligation, but took into account the fact that the government did not provide sufficient funding for the local authority to do all the things that parliament had obliged it to do, conceded that precedence had to be given to the most essential work,  and refused to compel the council to do the work that the statute obliged it to do.

     

    That's an issue for the courts to decide; since the government wrote the laws that say CART have to keep those canals open, and the government set up CART (and partly fund them), it's in the end going to be the government's problem if the court finds that CART has illegally breached its duty.

  16. 16 minutes ago, dmr said:

     

    These discussions about closure are all a bit academic, the "law" can't force CRT to keep a canal open if it doesn't also provide the funding to keep it open, a bit like listed buildings just fading away. However, even without a formal closure, just letting a canal decay to the state where nobody wants to use it is a "not closure closure".

     

    The Rochdale is always quoted as top of the list (probably by boaters who have never visited it and just see the "North" as some far off land) but the Rochdale is owned by the Rochdale Canal Company and only leased to CRT, and the councils who funded the restoration specified that it must be kept open for some period of time (I think). I do confess to having a vested interest in the Rochdale staying open as its my favourite canal.

     

    The law says that CART have a legal duty to keep the cruising canals open and usable; if they breach this duty they can be brought to court and an order enforced on them to do this. If CART and/or the government don't then come up with the money to do this, what happens -- do CART go bust? And if so, does the government have to take responsibility for the canals, under the same laws?

     

    8 minutes ago, Alan de Enfield said:

     

    Are you sure that is correct (and not reversed ?) that would suggest that for a 200,000 tonne ship it would require a tug with 20,000,000 hp.

     

    I was always taught the 'quick guideline' is 100 tones per hp.

     

    You're confusing propulsion power and ship deadweight with bollard pull.

     

    If you want to propel a ship through the water, 100 tons per hp is *very* small -- the big container ships are about 200,000 tons and have about 100,000hp, which is 2 tons per hp.

     

    If you want a tug to pull such a ship around it might have to provide a pulling force ("bollard pull") of 100 tons, which would need a 10000hp engine.

  17. 4 minutes ago, Loddon said:

    Ok You tell me what would happen to a 70ft loaded working NB with a Beta 20 and a matched prop compared to a 70ft loaded working NB with a JP2 and a matched prop both working upstream against the flow.

     

     

    The Beta 20 would possibly overheat and probably have a short lifetime, running flat out at 3600rpm.

     

    But a Beta 43 running at around 2000rpm and putting out 20hp would be just as capable as a JP2, assuming both have matched props and gearboxes.

     

    In fact you could choose the gearbox ratio so they both ended up with identical props at identical rpm and the performance would be *exactly* the same, because the prop has no idea what's at the other side of the gearbox 🙂

  18. 31 minutes ago, Loddon said:

    Except it's Torque at low revs swinging a big 24"+ prop that gets a boat with a JP2 through.

    20Hp from a JP2 is not the same as 20Hp from a Beta 3

     

    Perhaps you'd like to explain to all the *real* marine engineers why they're wrong then -- you know, the ones who actually design and analyse ships and propulsion?

     

    Because they all say that things like boat performance/speed and bollard pull are almost entirely dependent on power absorbed by the prop, unless you go to ridiculously small high-speed egg-beaters.

     

    Prop size and speed does have a small effect because if affects efficiency, but the differences are usually small (maybe up to 10%) unless the design is *really* awful. There are even some "rules-of-thumb" on the lines of "bollard pull is typically one ton per 100hp". Any of the online tools like Vicprop will also show the same trend, boat speed is pretty much only dependent on engine power with a properly matched prop -- yes a big slow prop is a little bit better, but the difference is small. *Engine* speed matters not a jot, it's propeller rpm (gearbox output) that matters.

     

    https://www.marineinsight.com/naval-architecture/bollard-pull-everything-you-wanted-to-know/

    https://thenavalarch.com/bollard-pull-calculations-introduction/

     

    There are other marine engineering "rules-of-thumb" -- again, based on actual measurements -- for slow boats like on canals, which says that the optimum prop tip speed is about 25m/s, and the optimum pitch/diameter ratio is around 0.6-0.8. A prop which is *too* large and slow actually loses some efficiency because it needs too big a pitch/diameter ratio, so more power is lost into swirling the water around and less into propelling the boat.

     

    From memory, for 20hp the optimum is something like an 18" x 12" prop running at 1000rpm, but I wouldn't put money on that without going back and checking...

  19. 44 minutes ago, Up-Side-Down said:

    I think that's a pretty realistic analysis Ian and I suspect that is the sort of default position CRT keep in the back of their minds in their current negotiations with DEFRA to set the next round of funding for the waterways, beginning 2027. I believe their are currently 3 scenarios based on possible funding outcomes that CRT have tentatively outlined, and a couple of them are not terribly palatable from the boaters point of view.

     

    I'm not surprised, it's often been pointed out that the license fee is pretty cheap for what you (ought to) get for it...

     

    My view is that it will increase by quite a lot, and that to avoid forcing poorer boaters off the canals (and extracting more money from richer ones) it will have to be much more heavily graduated than it is now, very likely by boat size (especially wideboats) and/or boat value/age and/or location. It should be possible to come up with a scheme that increases the average license fee by at least 50% -- possibly as much as 100% -- without hitting the poorest at all, but the corollary will be that those with big new expensive wideboats in prime areas will pay a *lot* more than today, maybe 5x as much or even more when everything is taken into account.

     

    I'm sure this will lead to screams of protest, but it's no different to any other market like housing where different people pay vastly different prices depending on what they can afford, what they live in, and where it is... 😉

  20. 11 minutes ago, peterboat said:

    No money no repairs, put up license people sell up and leave so even less revenue!

    Now don't get me wrong I love my boating life, but if I thought the writing was on the wall I would sell immediately, we have a bungalow and a camper which I would change for a Morris JE Asap to convert to a campervan. At my age I wouldn't fight a battle that I have little prospect of winning 

     

    The fact remains that CART are effectively prevented from closing most of the canals (all those classed as Commercial or Cruising), with the possible exception of the Rochdale and HNC (TBD).

     

    Since they have a legally binding duty as follows:

     

    (1)With a view to securing the general availability of the commercial and cruising waterways for public use, it shall be the duty of the Waterways Board, subject to the provisions of this section—

    (a)to maintain the commercial waterways in a suitable condition for use by commercial freight-carrying vessels; and

    (b)to maintain the cruising waterways in a suitable condition for use by cruising craft, that is to say, vessels constructed or adapted for the carriage of passengers and driven by mechanical power.

     

    if they don't do this they'll find themselves open to legal action, possibly from an organisation of canal users -- I'm sure nowadays that funding to bring such an action could easily be raised by crowdfunding, and legally speaking CART wouldn't have a leg to stand on.

     

    This isn't a case of CART being able to do what they want, they have a legal duty to keep these canals open and usable. If they protest "we can't afford to do this" then this doesn't resolve them of this duty, so the only options are for changes to the law to remove this duty (needs an Act of Parliament) or find a way to provide the money to enable them to do their duty.

     

    Given the relatively modest sum involved and the terrible publicity that would result from canal closures (destroying our national heritage!), I suspect the government (and CART) will find that raising more money is a much less unpleasant option... 😉

  21. 10 minutes ago, Up-Side-Down said:

    I remember that there was great rejoicing when the two Scottish Lowland Canals were reclassified as Cruising canals about 10 years ago, following their restoration in 2002. 

     

    Whilst this greatly increases the likelihood that they will be maintained, it certainly doesn't guarantee it, nor for that matter does a Commercial designation guarantee that a waterway will be maintained for commercial use, dredged to its original depth. There is a wee clause in the wording of the Act that says something to the effect that the relevant minister (currently George Eustace) can over ride this requirement. I suspect the same is true when it comes to maintaining a navigation as a Cruiseway. 

     

    The Minister can reclassify canals but needs the approval of Parliament to do so -- this is how the K&A and the Scottish canals got upgraded. I imagine any attempt to downgrade canals from Cruising to Remainder would meet with strong opposition...

     

    For Cruising waterways CART are legally bound to "maintain the cruising waterways in a suitable condition for use by cruising craft", i.e. keep them open for use by craft of "appropriate dimensions".

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