Arnot

GOTTIT! I will just sprag one cylinder on tickover and Hey Presto! a puff of white smoke... I could even rent it out to the Vatican from time to time. Ha! Arnot

Bugger! Arnot

The lure of the vintage engine is obviously mainly in the lovely sound of them. After that comes the size, beauty of the machinery etc etc. But what about the visual aspects? Playing around with my Ruston VRO just now (before stripping it for some renovation) I realised that one of the aspects that appealed to me was the regualr smoke rings it blew and how far it blew them. I even experimented with blipping the pump to see if I could get one ring to pass through the centre of the last one (with limited success) The question is; has any one played around with exhaust pipe design to optimise the smoke ring blowing ability? Sad but intrigueing... Regards Arnot

If you are anywhere near Stone in Staffordshire, I have all the relevant bits and would happily make them up for you. Regards Arnot

He didn't seem to have packed it in while I working with him last night... I will be seeing him again in half an hour or so and will let him know ;-) In fact we were discussing workload until March next year when the new season starts to come to life (after starting a magnificent old Dorman up for the first time in a while and getting very black spotted by the exhaust) Regards Arnot

It is usually the intercell connectors failing. A typical van Battery consists of six cells connected in series to give a 12v battery (of cells). Internally the cells are connected together with lead straps that are spot welded together to make contact. After a while the effects of vibration, temperature change, corrosion etc etc weaken this weld and at an inopportune moment it will fail and the battery becomes virtually open circuit. When tested by itself the voltage is usually OK, its just when any load is connected it drops like a stone. The good news is that sometimes when this happens, it ignites the gasses in the battery and just blows the top off. This effect often happens when doing a heavy discharge test and quite ruins your day... Regards Arnot

My take is that if they are already installed and seem to work leave them be. As others have posted, most (if not all) will work fine on 12VDC even if they are not rated for it. My concern is that they are not intended to be reliable when subjected to the levels of vibration, change of temperature and change humidity that electrical equipment on boats usually needs to contend with. My suspicion is that they would work fine when new but could not be relied on in the longer term. Of course this is why most vehicles tend to use old fashioned fuses... They tend to be reliable longer and if they do fail, they fail safe rather than jamming. When an electrical sytem is tested, the MCB's are almost never tested except in installations where their operation is absolutley critical. The reason for this is that they are very difficult to test effectively and any testing routine would also strain other parts of the installation thus compromising future reliability. In most cases on boats, the amount of power available from a generator, inverter or average shore line would not be able to cause overheating of the wiring by over current given it has been wired with the appropriate cable and it is the RCD that provides the majority of the protection for mains systems. Also it is unusual to find loads that draw higher continuous currents such as heaters, immersion heaters and electric cooking devices. On the 12VDC systems this is not the case, there are a lot of devices that draw continuous higher currents (not least of which are inverters and power supplies for laptops and monitors) and the potential short circuit current of a battery is probably higher than anything that could be delivered by the mains. For these reasons as well, I would propose that fuses were a better option... Regards Arnot

Marine craft are an exclusion from the wiring regs but still give guidance to best practice so no need to worry.. Also, even when applicable, wiring regs are not cast iron legislation, just a code of practice that can be varied if the circmstances dictate. The present system of relying on an RCD (or RCBO) as the primary safety device for protection against electric shock works as well as the variety of power sources used in boats will reasonably allow. The only thing that worries me a bit (as a professional electrical installation tester) is that there is no part of the BSS that actually tests the operation of any mains electrical system installed in a boat. I have tested many systems and although most worked adequately, there were some death traps that had obviously been unchanged since the last BSS safety cert. From the boaters point of veiw, it is a bit of a problem. Where would you go to get a mains system properly tested or for detailed instructions on how such a system should be installed? The BSS manual doesn't go anywhere near far enough. Regards Arnot

My boat "Orianne" is an ex horse drawn barge that was motorised by the installation of a large diesel and a large prop with fish plates for the reduction of cavitation. All the work was done below the water line (more or less) and so the original look of the hull is retained. Whilst it has been replaced, the rudder is as the original would have been and the tiller is the appropriate long curved bar. As you observe, "It is wonderfully sensitive, slightly dangerous but steerable (well reasonably so) in reverse and when,(as often happenes) the temperamental diesel engine dies it will keep steering long enough to make a sensible choice of temporary mooring AND allow one to avoid passing or moored cruisers". In fact it will steer even to a standstill with a bit of work on the tiller which is useful when dawdling up to locks, it saves all that messing about with ropes and jumping around and the time can be constructively spent in rolling a fag! In fact on calm water in good weather, it is a delight and can be taken through bridge holes with less than an inch to spare with absolute certainty. There are a couple of down sides though, one is that if you forget and apply a few revs when the rudder is more than 10 ish degrees from straight, the tiller tries to eject you from the back of the boat and possibly into orbit. If you don't have a tight hold, you will get very bruised. The other down side is that when ploughing shallow ditches you have to continuously wrestle with the tiller to keep the thing in a more or less forward direction and after a few hours it can get damned tiring and the margin of control can get remarkably thin... You have to roll your fags in advance under these conditions. Another phoenomenon is that as with most boats of this nature, Orianne is about as big as narrow boats get and very heavy. The consequence of this along with the large rudder is that when you make a correction, there is a significant delay before any effect is aparrent and when it does start to happen, it doesn't stop quickly. This isn't really a problem but it does require a good level of anticipation. This effect has an added frisson when under power when the wash effect of the large prop throws the back out when turning one way and the front out when turning the other, and of course this effect varies with speed, power and other variables. Since I work with boats for a living and often steer all sorts, despite the fact that I love Orianne to bits and love cruising her, I have to accept that it isn't the easiest job in the world. The more conventional motor counter with a balanced rudder and "Z" tiller is easier by far. The reason for the curve in the tiller bar is, as stated, to reverse it when moored. The importance of this is firmly impressed in your cranium when you forget and get out of the low back cabin to answer the call of nature in the middle of the night. The effect will bring stars to even the cloudiest of nights. I suspect that motor boats have the layout they do is so as not to knacker the crew. I have to say that if I had to use Orianne as a full time working boat, I would sacrifice the looks for comfort and practicality PDQ. As it is, when it gets tiring I just stop a while or go dead slow when it is far easier. Hope this helps in your design considerations, Regards Arnot

Just a long shot but have you checked the fanbelt is tight enough? Regards Arnot

My boat was built in 1884 and the engine in 1939 and they both show little signs of wearing out. It seems, strangely, that the more modern a boat is, the more quickly it deteriorates, certainly up to the late 80's anyway. It seems to me (based on my customers experiences) that between 1970 and 1990, the condition of boats is very much related to how they have been cared for. If you purchase an older boat then do allow for increased maintenance costs and also for upgrading some systems to current standards (or expectations). Hope this helps, Regards Arnot.

They are Lucas A127's and most of these will do 75A, some a little more, some a little less. The best I have ever had from one is 90A but it got a bit on the warm side after a while... They will run in either direction with the appropriate fan. Knowing what they are and knowing the weakness of the rectifiers in these, I am more sure that you have a rectifier problem if the light is staying on dimly but do check that there is not just a problem with the connection between the alternator output and the battery, this will give the same red light symptoms almost. A regular problem on these is if the large lucar blades are used for the output rather than the stud, the blades are only rated to 35A and when pushed they warm up, arc on the contact faces and burn black grooves in the blades on the alternator. In this case (providing the rest of the alternator is still OK) just use the stud instead.... Hope this helps, Regards Arnot

Without wishing to criticise the Victron equipment in any way, have you looked at the Mastervolt equivalent? My experience is that the mains/inverter changeover is better on the Victron and the temporary overload is better on the Mastervolt. Thus if you do anticipate spikes of power requirement above the rated output, Mastervolt may be a better bet. On test, when I was comparing them on a load bank, the Victron quickly detected an overload and shut down at about 25% over and the mastervolt went on to deliver more than 75% overload albeit with a reduction in quality and voltage. Just a thought.... Regards Arnot

The dim light may indicate a problem in the rectifier of the alternator, especially when accompanied by a reduced charging voltage. Does the alternator seem to be making a bit more noise than usual or gettting rather warmer than usual? These are also symptoms of rectifier failure. What sort of alternators are they? This may allow me to provide more infromation... Regards Arnot

Generally they will go to about 12000RPM but it's better to find out from the manufacturer of the alternator if it will go higher. You can sometimes get away with just wiring them both to the same battery bank but occassionally they will conflict and the regualtors will pulse against each other under certain conditions. It could be worth fitting a dual sensing voltage sensitive relay between the batteries an see what happens, the danger signs are mechanical noise from the alternators, rapid fluctuation of the voltage under steady state conditions and one alternator obviously doing the lions share of the work and thus getting much warmer. This varies with the type of alternator but in general, it is not the speed that dictates the efficiency, more the output. You will notice that as the output increases, they get warmer - this is the wasted energy. To compound matters, the hotter they get, the more heat they generate so keeping them cool helps. Obviously the faster they run, the more cooling the fan provides so, once again as a generalisation, the faster you run them (not exceeding the maximum speed) the better. From the figures you supply I would suggest that you could increase the size of the engine pully to about 10:1 to give optimum charging. This will shorten the bearing life but since this is usually almost infinite in practice, I don't think it would ever be a real problem, the brushes and slip rings would almost certainly go before the bearings and these tend to last longer at speed. Hope this helps... Regards Arnot

Wow! thanks... I didn't know about this one, what a wonderful site. Now bookmarked. Regards Arnot I got some boat plans from Lawrence Hogg which have helped a bit with the hull detail and intend to call in at Stoke Bruerne when passing in Orianne as soon as I can get her to stay moving under her own power for more than a few hours... (another few stories of towpath engineering). It all helps fill the picture, thanks! Regards Arnot

Many thanks, I think that this is probably more or less what Orianne looked like originally, I believe that it was even an actual GWR day boat and was originally named "Superb" but aparrently the records of that time were lost in a fire some years ago. However, despite this my present thoughts are to restore (if that's the right word) it to something more like Saturn but with an engine. The engine I have for it is a Ruston and Hornsby 3VRO which is at present being restored. I am slightly torn between restoration to the original build spec and keeping to what it might have been to make it more usable. My current intentions (and they are not set in iron yet) are to build a slightly higher cabin extended to include a low boatmans cabin and an engine room. Then fore of that build a small section to house a toilet and a shower with all the rest of the hold planked out in elm and with a series of detachable panels over which a tarpaulin can be stretched to give the original look in winter but with the option of removing it all in the summer. To go back to the original question, I want to find out more about the construction of contemporary boatmans cabins to see how viable this would be given my skills and facilities. Possible some old photos of similar boats or boatyards would help here but I have not been able to find anything yet... Regards Arnot

I have just bought a boat (Orianne) and want to do a refit to take her back to the sort of thing she might have been ( but wasn't ) by constructing a boatmens cabin with an engine room possibly hidden under tarps. Orianne is a Mk1 Bantock horse boat now motorised, originally of composite construction and now with a steel shoe. When the shoe was fitted, they took the opportunity to raise it by about 6-12" so headroom may be an issue. I suspect that the original cabins would have been built out of wood, probably with an ash frame and pine panelling but feel free to correct me if I'm wrong. The question of the post is does anyone have any suggestions of original boats to look at to get a better feel for what would have been? Regards Arnot

Many thanks for saving me the effort. Is the source public domain, I couldn't seem to find it? Regards Arnot

do you know, thats a jolly good question and I cannot find the accurate answer readily. I will however attempt to find out and get back to you (all). However, in general terms, the maximum working speed of that average alternator is about 12,000 rpm. Regards Arnot

My take for what its worth... 1) The faster you can spin the alternator the better (up to it's maximum speed rating). To achieve this find the maximum speed for the engine, divide the max engine speed by the max alternator speed and multiply the result by the engine pulley diameter, this will give you the optimum alternator pulley diameter to achieve the maximum overall speed. 2) The smaller the pulley (with a given section) the less power it can transmit so when using the above if the result is below about 3" don't go any smaller. 3) One way round the problem described in "2" is to convert the engine to a ribbed or polyvee drive system, as they have a far better contact area and can withstand much higher tensions without premature failure you can probably get down to about 1.5". I have to say that from my experience you got it about right first time given the characteristics of Bosch alternators and BMC 1.5's. If you gear the alternator up too much you may find that at low engine revs the power demand of the alternator is higher than the output of the engine and when the batteries are flattish it could become an accidental rev limiter... Hope this helps, Regards Arnot

Thanks for that Chris, from your calculations it seems that a 1.5:1 is most suitable but is that reducing the engine speed to the prop or increasing it! I am presuming that it is 1.5 (engine) to 1 (prop) but I might be wrong... Do you know of any information that I can download that will help me understand the whole basis of the prop size/speed relationship? I am guessing that a given prop has a maximum speed beyond which it cavitates in fresh water and that the maximum speed of the engine should be aligned with this as near as it can be. Or am I missing something... Regards Arnot

I am just in the process of concluding the purchase of a boat that has a 23x20 prop, which is driven by a Petter 4PJ engine with a proprietary gearbox at the moment. The boat is a 71’ x 7’ ex horse drawn riveted steel hull. It is my intention in the fullness of time to replace this engine with my Ruston 3VRO. The Ruston seems to tick over from about 120 rpm, is quoted as having 33hp at 1000 rpm and has a maximum of 40hp at 1200 rpm. It has a flywheel that will suffice for a fair bit of ballast. I am wondering what to do about a gearbox? Aside from the question of mechanical/hydraulic drive could anyone give some advice on the subject of ratios? Not that I know a lot about this but my feeling is that the rev range of the Ruston is probably fairly well matched to the prop and thus somewhere near 1:1 should be OK. Any suggestions? Regards Arnot

Here Here! Well said that man, I agree entirely! I was beginning to wonder when there would be someone prepared to tackle this thorny subject. How long will it be before the sometimes extensive and high power mains systems often installed on boats are subject to any form of testing? Similar systems installed in vehicles that are used as places of work have been tested annually (or at least should have been by law) for many years, I know because thats what I do... Regular testing of the RCD with the button provided gives some assurance but for a reasonable assurance of protection, the whole installation should be tested thoroughly. Regards Arnot