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Everything posted by nicknorman
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Depends on what you mean by “properly ballasted!” Having a lightly ballasted bow has its advantages eg when winding at a silted up winding hole (aren’t they all silted up?) and other times you want to poke the bow into somewhere shallow. Also means that the front of the boat can get into the side even if the stern can’t, so one can easily get on and off the boat. Steve Hudson built well deck boats like ours that were shallow at the front, whereas his tug deck boats were the same hull shape but ballasted down much more at the front. You can take your pick…
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If you have a bow thruster it’s easy. If you don’t it can be hard, but different narrowboats have different handling characteristics so it’s mostly about getting to understand your boat. But I think as a general point, one factor that makes narrowboats hard to reverse is the absence of any sort of keel and the very shallow draft at the bow vs deeper draft at the stern. Annoyingly, when reversing the bow is quite happy to skitter sideways across the water due to it only being a few inches in the water, whereas the much deeper stern prefers to go straight through the water. This means that any slight tendency to turn gradually increases as the bow tries to overtake the stern! Another thing I would mention, in contradiction to the first video, is that when changing from astern to ahead to kick the stern round, start out with the tiller straight and then after a couple of seconds once the water flow is established, move the tiller over, and not too far. Putting it into ahead when the tiller is already hard over causes the rudder to stall in the water flow - you will see water flow coming out both sides of the rudder, not just on the desired side and thus it is less effective. I always look at the water flow out the back when doing this sort of thing Finally there can be disruption caused by water circulating in the gap between the boat and the bank, made worse if it’s shallow. So if things are going really badly, stop and wait for the currents to subside (which takes a surprisingly long time) and then have another go.
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Yes but depends on the voltage setting of the solar controller vs the alternator's regulated voltage. If the solar is set below the engine regulated voltage then it will tend to contribute less and go to float early, so the contribution to charging will be much less. And even if they are much the same, you effectively have 2 things feeding one thing that has the same appetite, so each thing will only be feeding about half.
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Yes. 1300 is what we cruise at on most canals which is why I mentioned it, but no doubt 1200 would be fine.
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No I would say there definitely is a difference between light and heavy loads. But it’s not something we or a manufacturer could realistically quantify precisely. But if you are charging lead acid and the current has fallen off considerably, I’d be happy to charge at idle. If you are running a couple of hundred watts from the Travelpower, ditto. But once you go over about 500w for a significant length of time I would definitely be increasing the rpm. By 2kw I’d want to be at 1300rpm.
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I dont have any of that fancy stuff but I think we can say that the only fault is the mis-reading of the ac current on the Multiplus? If the MP doesn't know how much current is flowing through it, obviously it can't limit the current or know to invoke the power assist. Probably the Mutiplus uses a current transformer to measure the current, failing that some hall effect thing. Probably it is this that has failed within the Mutiplus. But that is mostly a guess!
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Yes, it’s a shame you derailed the thread. But it is to some extent about me because I do actually have an affected engine and a Travelpower, whereas you have neither.
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No but it is rather suspicious considering the ship he hit.
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There is a phrase about assumption being the mother of something. Anyway don’t be so touchy, I was not having a dig I was merely clarifying your misinterpretable writing to avoid other people being misled. It’s not all about you.
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I’d say the bulging most likely resulted from sulphation. I’m not sure what your charging regime was but Trojans like to be finish charged at 14.8v in summer, rising to perhaps 15.3v in winter when the batteries are cold. But that is history! Using battery power to heat water puts current out and then in to the battery, and it is simply this throughput of current that consumes battery life. It’s simply the case that using batteries shortens their life! Ordinary leisure batteries don’t have much life in the first place so it would not be a good idea. Trojans are more suited to this sort of use. But of course Li has such an enormous cycle life that even if it is shortened a bit, it is still enormous and likely to outlive the boat or boater!
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I’m only aware of what you write, not what you meant to write.
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Well a couple of things there firstly nothing wrong with running the Beta Greenline below 1200 rpm under heavy load, PROVIDED the load is not via the offset pulley at the front of the engine. And secondly modern cars have “fly by wire” throttles and the ECU mapping doesn’t allow damaging amounts of actual throttle (as opposed to accelerator pedal position) at low rpm.
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Well I think the answer to that is that Beta did not realise that the engine was not up to it, until bits started falling off a few years later! Same with the propeller I mentioned, when it first came out (1960s) after a few years, bits of propeller started falling off and eventually they worked out why, and issued an instruction to avoid the resonant rpm. Being American, they never bother to address the underlying issue so here we are 60 or so years later and it is still the same engine and the same propeller with the same issues! And Trump wonders why people tend not to import American stuff if they can avoid it!
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Not sure what was discussed earlier, I don't think the owner frequents this forum. Anyway I rather disagree. Something that is a consumer product like a leisure boat engine, should be fairly foolproof. For example, we wouldn't be too impressed if we bought a car and then read in the manual "please avoid driving between 45 and 48mph as otherwise a torsional resonance in the transmission might cause the wheels to fall off".
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I am aware of another Hudson boat built around the time of ours, with the same engine and new style crank and TP, that suffered the crank / pulley destruction thing a few years ago. So the problem is certainly not eliminated. But it is not a binary thing and so I try to minimise, but not eliminate, exposure to the triggering conditions. On the subject of torsional resonances, our glider tug has a hollow crankshaft end, and with the current wooden propeller there is no problem. But in the interests of improving takeoff performance we are shortly to change to an aluminium propeller, and this introduces an “avoid continuous operation between 2150 and 2350rpm” restriction. Failure to adhere to this limitation can result in the propeller blade tips breaking off, which is not a good look for an aeroplane. All about the torsional resonance of the crank and the heavier metal prop. A couple of years ago, we hired a Supercub with the same engine and prop combination, and you could strongly feel the vibration in that rpm “avoid band”.
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Well it’s not ideal, but there doesn’t seem to be an alternative unless we simply don’t use the tumble drier whilst cruising and have to run it and the engine whilst moored for a hour or so. My feeling is that sharing the load between the 2 alternators which are on opposite sides of the crank, and roughly halving the load on each belt and having the torque pulses from the alternators out of phase with each other, hopefully reduces the problem. The low rpm is only whilst passing moored boats and we wouldn’t for example run the tumble drier when doing locks. So hopefully it can tolerate 30 secs or so at 850 rpm from time to time, and we do have the later crank which was supposed to eliminate the problem (but actually only reduces it) and the Iskra pulley sticks less far out than the TP one
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Its a 6pk polyvee belt, not a toothed belt. The life depends a lot on how it is used and if it is aligned correctly. Obviously lots of high power usage at low rpm with the belt a bit slack will shorten the life, but time spent "idling" ie not producing any power, won't wear it much. I replaced our first one when it had done about 2000 hrs, there were signs of deterioration ie a few bits of the peaks were missing. I then replaced it again after another 1500 hrs but it was not noticably worn. They are not expensive. You missed where I said "for a given power". Unlike an alternator, which tends to supply as much power as it is able according to rpm (especially for Li batteries), a travelpower electrical output depends on the 230v loads connected. So for example if you connect a 1kW load, the TP outputs 1kW wether it be at idle or 2000 engine rpm. The 1kw derives from torque (or belt load) times rpm so the torque will decrease as rpm increases, although of course there is some influence from the fan too so it's not quite that simple. With a TP you cannot eg connect a 3.5kw load and then accept just 2kw coming out of it at idle - if the rpm is too low for the load, the TP will sag the voltage a bit but then trip off before the voltage gets too low. It will not act like and alternator and provide whatever it can provide for the rpm. Your graphs show what I am talking about to an extent although for the TP it is not practical because you need to run the engine at an appropriate rpm for the load connected. You can see that the torque decreases at higher rpm. It only doesn't show this behaviour at lower rpms on the graph, because when the graph data was generated, the TP load was adjusted to suit the rpm. Our 2011 boat came with freewheel pulleys on both the TP and the domestic 175A iskra alternator. Managing all this with practical boating (having to slow down to idle regularly to pass moored boats) was a bit tricky when we had the tumble drier on (2kw load) until I limited the TP current to about 5A (just over 1kw) in the Combi, and had the Combi mains support the rest via the inverter part, the Iskra running at 1/2 field current (via the alternator controller) which gives about 75A at idle, and the rest coming from the Li batteries. With the TP and the Iskra being on opposite sides of the engine hopefully the side forces are not too bad even at idle. It does pull the engine rpm down though, normal idle with no electrical load is approaching 900, and it goes below 800 with the 2kw load on. I just don't quite take it to idle under those conditions, keeping it to 850 which is the minimum recommended idle speed.
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It’s not really related to whether the TP is switched on or not - after all, the TP alternator is spinning with the engine regardless of whether it’s switched on or not - it is to do with the load. At light loads, rpm down to idle is fine. If you want to run something more than a few 100 watts then above idle is advised, even though the TP on a Beta 43 can provide 2kw or more at idle. 1300 rpm or more if you are going to use the full 3.5kW. It’s worth bearing in mind that the mechanical power input to the TP alternator is the product of rpm and belt force. for a given power, the less the rpm, the more the belt force and vice versa. So at high power, low rpm you get a lot of force on the belt and that of course becomes side force on the pulley and crankshaft. At higher rpm the force is much less for the same power. Also the torque pulses from the engine (each firing stroke etc) and the torque resistance from the alternator (rotor magnet passing field windings) is at a higher frequency at higher rpm and therefore more easily absorbed eg by belt flexing.
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Large Cargo Vessel Aground off Skye
nicknorman replied to Naughty Cal's topic in Waterways News & Press
Yes in fact they are now saying it was a bit foggy in the morning. -
No I don’t think you can reasonably or legally require him to take the parts off. What you can do is ask for an itemised bill listing the parts fitted and their cost, to check that his charges are reasonable. If they are reasonable then I think you are obliged to pay, or forfeit the engine. I’m not clear whether it is just the engine (presumably an outboard) that they have, or the entire boat. If it is an outboard then I think there is a fairly clear differentiation between the boat (which is yours) and the outboard (which is only yours if you pay for the work you asked them to do). Presumably this is not a canal boat?
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No you were right, the remote panel is optional.
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An alternator can just be connected to the batteries, it doesn’t really have anything to do with the Combi. We have a Beta 43 with 3 alternators - starter, domestic and travelpower. The travelpower via the Combi, and the domestic alternator, play quite happily together to charge the domestic batteries. Ah OK, the more recent Mastervolt Combis may be different and there are a couple of models. Exactly which model is it? With the power sharing thing, it is up to you to specify the maximum current taken from the travelpower (using the masterview) beyond which the inverter will kick in to supplement. The Combi can’t know what the maximum travelpower output is because it doesn’t know the engine rpm.
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Yes it can, however there is an internal dip switch to enable that function. It is off by default and Steve didn’t change that setting when he installed it. It’s something I enabled after we got the boat.
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Large Cargo Vessel Aground off Skye
nicknorman replied to Naughty Cal's topic in Waterways News & Press
Radiation fog and advection fog have different causes.