Farey

I've got a Vetus bow thruster (12 years old now). One problem I've had is the brushes sticking causing a poor contact with the commutator. You can take the brushes out and clean them up, whcih solves the problem. Or the brushes could be worn and need replacing, but even after 12 years mine don't show much sign of wear. To check the battery you could check whether the voltage drops under load.

We moored up overnight by the Manor Arms pub at Daw End a couple of years ago. The moorings were very secluded, and it was a very nice pub.

I had a boat safety check 18 months ago. I'd fitted a bubble test when I fitted the boat out 11 years ago. When we tried the bubble tester, all it did was cut off the gas supply. After some investigation I discovered that the problem was the liquid had congealed into a thick goo, in which bubbles could not form. Cleaning it out and putting in new fluid fixed it.

Don't do what I did earlier this year. I turned of the stop cock and this disconnected the pipe without first opening a tap to drop the pressure. I got a faceful of water!

Coming up Stockton Flight yesterday I spotted a (sadly dead) eel floating in one of the locks halfway up the flight. It was about 4 feet long, with a body about 2 inches in diameter. Googling I found that a similar one had been found recently in West Bromwich: http://www.itv.com/news/central/2016-09-06/rare-eel-from-bermuda-discovered-in-west-bromwich-canal/ I wonder if its just coincidence, or if they're getting more common? It's amazing to think they could travel all the way up (or down) so many miles of the Grand Union canal.

I'll be setting out in a couple of hours, planning to arrive around midday Thursday. If its like previous years it will be busy; hopefully we'll be able to breast up against someone...

Our first trip was in March 1974, on Greylag from Willow Wren in Rugby. I believe the hull was an old working boat, with a cabin built on top. The next year we went from Middlewich on Sycamore - there's some photos here: https://goo.gl/photos/CDuY11wZb4zkHBmQ6 Sadly I don't have any old brochures.

So, I went to the boat yesterday. The purple wire was not live, so I fitted a Voltage Sensing Relay, with the main alternator fed going to the domestic batteries and the relay feeding the starter battery (as it was with the previous relay). I started the engine, and was surprised to get a voltage reading of over 15 volts from the voltmeter connected to the domestic bank, but a more sensible reading of around 14 volts across the starter battery, which makes no sense to me, unless there was a significant drop across the VSR. So now I'm even more puzzled? I also checked electrics come more, and found that before I connected the new relay, I still had 12.4 volts on the (disconnected) starter battery terminal. I traced it back, and found it was coming from the Victron Multiplus charger/inverter, which has a trickle charge connection for charging the starter battery. It appears that this is live even when the charger is disconnected from shore power, so that the domestic batteries are potentially charging the starter battery. I contacted Victron, and was told this was correct, and that a dud starter battery could potentially flatten the domestic batteries (but not vice versa). I think I'll add a switch, so that I can turn off the trickle charge when the boat is not on shore power.

I asked about mooring in the marina for the festival a couple of years ago, and was told that all the available spaces go very early on. If you're prepared to walk a mile or so, there are usually mooring by Varney's lock - I've moored there several times, ariving on the Thursday at the start of the festival. Also, you may be able to find boats moored closer who are prepared to let you breast up against them.

I found this one for £44: http://www.12voltplanet.co.uk/voltage-sensitive-relay-12v-140a.html or this more expensive one with flashing lights: http://sterling-power.com/products/pro-con-vsr-voltage-sensitive-relay-12-24-auto-select-plus-fine-adjust-1?variant=884583603 But I'll check the feed to the existing one first. Thanks for all your help.

Unfortunately I'm not on the boat, and its a 2 hour drive away, but I got someone at the marina to take a look. I appears that the purple wire goes to the engine control panel, so I presume that means its controlled by the ignition switch. It does look like a Lucas relay, as suggested by Sir Nibble, so that would make sense. If I was to change to a VSR, is there a manufacturer/model you'd recommend?

The ignition switch was definitely turned off. If the relay closes when the ignition switch is turned on, wouldn't that mean that the starter was drawing power from the domestic batteries?

Is there a relay you'd recommend?

Thanks for the responses. Here's a photo of the relay: I'm not on the boat now, but I'm pretty sure the alternator output went direct to the starter battery, not the domestic batteries.

I've got an 11 year old boat, owned from new, fitted with a Vetus m4.17 engine which charges a domestic bank of 4 batteries, the starter battery and a bow thruster battery. A while ago my wife accidentally ran down the domestic batteries while we were moored up, but when I came to start the boat the starter battery was also flat. This made me suspicious that they may in fact be connected together, so I checked the wiring, and found that they did do indeed appear to be connected. With the engine stopped I disconnected the terminal from the starter battery, and found the disconnected terminal had the same charge as the domestic batteries rather than zero. By disconnecting various things I was able to isolate the connection to the split charging system. I searched the internet for more information, and found http://www.12voltplanet.co.uk/split-charging.html where the wiring setup appears to match the third example shown, a voltage sensitive/sensing relay (VSR). Is this likely to be caused by a failed relay, or is there possibly another fault? If so, what can I do to diagnose the problem? And is a VSR the best solution for my set-up? Any help or advice would be appreciated.

We arrived at 6.30 yesterday evening, and the gate had been lifted out of its mount an hour before. CRT arrived just as it was getting dark, and said they'd be back with jacks at 8am this morning. They had the gate back in position by 8.30am - I was impressed!

Meth lab? ... maybe I've been watching too much Breaking Bad

I've just got back from an 11 day trip, Calcutt to GU Leicester / Soar, all pretty quiet, Trent and then Fossdyke to Lincoln and back, still pretty quiet, T & M to Fradley, still pretty quiet, Saturday on the Coventry to Sutton Stop, getting quite busy, then Sunday on the North Oxford back to Calcutt we seemed to pass a boat every 5 minutes. Maybe people are sticking to canals without many locks?

I've got a Mezzo, my wife's got a Brompton, both of which are good and fold quite small. Having a bike can speed up locks quite a bit, especially if there's just 2 of you, But the big problem with road bike tyres on a towpath is frequent punctures from all the brambles. A 16" wheel bike can also be very hard going if the towpath is uneven and/or muddy.

My wife was cycling to work this week, and a low flying duck hit her on the head. I guess it was saying "duck".

We did the trip in August. We joined the Thames at Dukes Cut, not far from Eynsham at about 3pm and spent the first night at Abingdon, arriving about 7.30pm. Next day set out around 9am, arriving at Henley at around 8.30 pm with an hour and a half break for lunch at Wallingford. The next day we set out sometime after 9am, had a 90 minute lunch in Windsor and reached Hampton Court at around 8.30 that evening. The next day we set out at 5.30am (to catch the tide), went through Teddington at 6am and arrived at Brentford just before 7.30. Most locks were lock-keep operated, but we did a few ourselves.

Its a long time since I studied fluid dynamics, but surely there's more to it than that? Things are never 100% efficient - is propellor efficiency a factor? And a big issue with fluid frow is turbulence; I would expect a propellor which produced less turbulence to be more efficient and to produce better handling. I (possibly naively) thought that was where the Axiom got its benefit. As for non-technical explanations - the problem is that to really understand anything in physics you need to understand the underlying mathematics and physical principles. While you can try to produce non-technical explanations, they always lose something in translation. As an extreme example, consider something like quantum mechanics. So, while Axiom failing to produce a non-technical explantion may be a concern, I'd be much more interested in the opinion of someone who has a good understanding of propellor science. MtB says he is technical and that Axioms technical literature is 'psycho-babble'; if we think Axiom's claims are incorrect, I think a technical refutation would be very valuable.

The aviation thread drift seems to be continuing so ... I think you're wrong stating that most light aircraft have Fowler flaps. All the definitions I've seen state that a Fowler flap is one which moves both backwards and down, whereas most light aricraft have simple hinged flaps - but the manufacturer's pilot operating handbooks still quote lower stalling speeds with flaps extended. However, I accept that the reduction in stalling speed may be higher with a Fowler flap than a simple flap.

I did the trip last week. We got on the Thames from Duke's cut on Monday afternoon, and left at Brentford early Thursday morning. It was a great trip, with lots of nice scenery, and we managed to avoid any mooring fees. The Thames locks are all meant to be lock-keeper operated during the day, but some weren't due to staff shortages. When there's no lock keeper there's a self service sign up, and you press a sequence of buttons (described in another thread). We got caught out at one lock. The self service sign was up, so we started pushing buttons, only to have an irate lock keeper appear asking what we were doing. We pointed out the sign and he looked a little embarrassed. If you call Teddington Lock they will advise you on tide times and when Brentford lock is open, or you can pre-book a passage at a specified time. We were advised to be at Teddington 6am Thursday morning. We set out from Hampton Court at 5.30, and arrived at about 6.20. Teddington lock was open as it was high tide, so we went straight through, as was Richmond. The lock keeper advised us to take it slowly, as Brentford was not open until 8am (and would close at 8.15). Even on an idle power setting we arrived at Brentford 7.30, so we sent downstream for another 5 minutes then turned round. It took us over 15 minutes to get back to Brentford against the tide, so that was probably a bad idea. The southern edge of the GU, though Southall and Hayes is not particularly inspiring. We stopped at a canalside pub in Hayes called the Woolpack, only to discover it doubled as a strip club. The ladies in our party insisted we sit outside. I've done the trip once before, all the way to Limehouse, which is great if you've got the time. However, by the time we got to Limehouse the tide was flowing very strongly.

Apologies for digressing into aerodynamics, but you don't need Fowler flaps to get reduced stall speed when flaps are deployed. There's a very good description of the aerodynamic principles here. Section 5.5 deals with the effect of flaps. Does anyone know of a similar article descriping the principles of a boat propellor? I'm happy to accept a slight loss of top speed for improved performance in reverse.