NB Willawaw

www.aquafax.co.uk www.alde.co.uk (smev cookers) Best Regards Mark

I happened to collect my copy of a well-known canal mag today and noticed a very interesting problem reported by a reader. I'd thought I'd share the problem with you all for suggestions as to possible causes: The symptom was a number of rusty spots at and just below the waterline. The boat was docked and pressure washed. The spots became bright silver in colour and about 15mm in diameter. The yard who docked her thought it might be due to some problem on the negative supply to some lights onboard. The wiring was checked but seemed ok. The boat in question doesn't have a shoreline, but does use an inverter, although that and the batteries driving it are isolated when the boat is not in use and left on the moorings. The nearest other boat using a landline at the mooring is 7 boats down. Any ideas ??

We have a fixed double, longitudinally, because we didn't want the hassle of fiddling with it each day (folding the end up). We do have the problem of clambering over each other, but strangely have mystically and unintentionally found it has synchronised our nocturnal visits to galley and toilet, etc. However, the main reason, is we like our heads to be at the bow end of the bedroom, so if our water tank is a bit light, we don't end up with head lower than toes, etc. Best Regards Mark NB Willawaw Lechlade, Thames

It sounds like the power supply in the TV's acting imperfectly don't like the modified sine wave. As you have already deduced, the only solution is to buy a more expensive pure sine wave inverter which will probably run all the TV's (at a cost) or to try different TV's until you find one that can live with the output from your inverter. Best Regards Mark NB Willawaw Lechlade, River Thames

opinionated unduly attached to one's own opinions: stubborn Chambers 20th Century Dictionary You can have the last word if you want.

Modified Sine Waves can be quite noisy in themselves and are not suitable for all appliances. It might be that your TV would need a pure sine wave inverter which is a lot more expensive, so 12V might be a more economical route. Mark

In this case, I agree with John. 1. Ensure the inverter is isolated i.e. only driving one appliance, the TV If no change: 2. If its a combi or you have a DVD/VCR on board, trying playing a tape or disc without the aerial connected, to see if the noise disappears. 3. Ensure that the TV isn't too close to the site of the inverter - inverters often have thyristors inside which generate a lot of electrical noise. 4. Try borrowing another TV from another boat, etc and see if the noise manifests itself on that set. Mark

From the manufacturers website: QUOTE The Schilling VecTwin rudder system offers significant manoeuvring enhancement for single-screw vessels. Twin asymmetric Schilling rudders operate independently behind a single propeller, allowing full 360° vectoring of the propeller thrust. System outline Twin asymmetric special Schilling spade rudders operating on a single propeller. Full 360 degree vectoring of propeller thrust. All manoeuvring commands made without reversing either the propeller rotation direction or pitch setting, thus minimising main engine, gearbox and propeller wear. Superior manoeuvring performance and yaw-checking. For normal sea voyages the rudders operate in parallel, controlled by conventional wheel or autopilot. For slow-speed and harbour manoeuvring the control joystick position automatically sets rudder angle combinations. Emergency crash stop mode automatically puts the rudders into ‘clamshell’ position. This mode can reduce ahead reach by as much as 50%. At all times manual intervention is possible to control trajectory. In combination with suitable bow thrusters the system allows precise harbour positioning of the vessel. UNQUOTE They must have fitted at least one ship; the photo is not a mock-up. Oh well, you can't be an expert on everything.

The picture that shows two rudders is usually a system where they can be locked together hydraulically for normal wheel steering. The advantage of a double rudder is twice the surface area. For manoeuvring, the rudders are unlocked and can be set independently by small console mounted tiller levers. A linked double rudder on a narrowboat wouldn't make any difference to handling. Mark

Probably both, but its largely academic as the dual rudders need to be capable of independent movement and thats not possible on a traditional tiller system. If you are talking about the single fishtail rudder mentioned earlier in the thread, which is almost a different subject fro the dual rudder idea, then it would probably be the same size, but with a fishtail cross-section, which is really what might make the difference in steering performance. Its all largely theoretical, unless someone is brave enough to fabricate one up and experiment. Ideally, the prototype would need to be adjustable in terms of size/balance, to see what works best. If somebody out there is a wiz with hydrodynamics, it could probably all be worked out on paper or a PC programme. Any naval architects tuning in ? Mark

Its kind of true. The boat has to be moving forward though I think on a single rudder. I have a conventional rudder and If I motor ahead at slow speed, I can make my boat "draw" sideways by using a certain amount of rudder and bow thruster. The Schilling just accentuates this. If you have a double Schilling rudder, you can block the water flow off completely astern and then by opening just one rudder a little, create an imbalance and therefore side force, but now we are getting beyond the scope of a narrowboat fitting - interesting though !

I prefer cratchless actually. I think the extra ventilation is much better for your health and when I get holes in my knickers, nobody notices so I don't have to throw them out. Oh you mean those wooden things to hold the tunnel lamp up ?

I'd be interested to know the thoughts of the community on narrowboat paint. I've got Masons on the topsides and Jotun blacking, which I insisted on at the time of build for no more reason that I'm familiar with the maker on commercial ships. I haven't had the occasion to re-paint yet, so am a paint virgin. I thought it might be interesting to hear other peoples preferences, experiences, likes, dislikes, etc on paint ????? Best Regards Mark NB Willawaw Oxford :ph34r:

With all the various talk about tillers and rudders on another thread, its got me thinking whether a Schilling rudder would improve the steering on inland waterways craft. The basic feature of a Schilling rudder is that it is fishtail shaped in cross section, when looking at it from above (if I knew how to upload JPEG illustrations to this thread, I would show you a diagram). The idea is that the flow of water across the rudder surface speeds up like airflow over a aircraft wing, due to the shape of the rudder. The benefit of this is that it gives improved rudder response at low speeds and is supposed to be ideal to maintain steering control at low speed. I notice that a Dutch barge maker in the Isle of Wight is already using these, presumerably for this very reason. They involve a bit more steel work than the conventional narrowboat fin plate, but there are no moving parts to them. I appreciate that barges tend to have hydraulic steering gear, but presumerably, the Schilling could have an extra bit of plating added ahead of the rudder stock to balance the thrust and avoid rudder-judder and undue tiller back pressure. Gary, what do you think ? Best Regards Mark NB Willawaw Oxford

Lend out the boat ? N-Nooooooooooooooooo ! Mark

Thanks Gary. Understood. Mark