IanD
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Posts posted by IanD
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55 minutes ago, MtB said:
Thinking laterally one could swerve all these problems by putting the motive force on the bank, and pulling the boat along with a line.
I'm surprised no-one has thought of this before. That nice Mr De Bono would have been delighted with this solution
Horses don't make much noise or vibration either, and their emissions are both more useful and less harmful than those from diesel engines... 😉
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27 minutes ago, johnmck said:
Sorry to resurrect a very old post, but it does give context.
The set up fitted in 2016 has served us very well, even enabling due to a change in circumstances, Ali to work off the boat over the last few summers.
At the moment, the boat roof is being repainted and removal of the Fullband dome antenna is required, so it seems a good time to upgrade our system a little. The Huawei mifi is still working, but becoming some what old technology now.
As previously stated, I am a technophobe.
I propose to replace the existing dome antenna with a Fullband FB4X4MINIDOME and the mifi with a TP-Link MR600 (V3) router. In fact I have these ready to fit once the roof is ready. Already linked the existing antenna to the new router on our trip to the painters and it worked fine. But...
The new antenna has four leads. The router has two sma antenna ports. Do I try using just two of the leads, or could I try using a Tuolink sma splitter cable (sma male to dual sma female), or would this compromise signal quality?
Appreciate your thoughts.
Don't use splitter (or in this case, combiner) cables, they'll make things a lot worse not better -- just use two of the antenna cables, it'll work fine. If two are marked as "primary" use these, otherwise pick any two -- you could try different pairs and run speedtests to see if one combination is better than the others.
If you want to make better use of the antenna you need a 4x4 MIMO router, and it would make sense to get one which supports 5G. Lots of people (including me) have had success buying secondhand Zyxel NR5103E (ex-Three) routers, these are about £150 on eBay.
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17 minutes ago, Rob-M said:
When we used to hire we often hired a boat that had no hire company details on it so looked like a private boat and I found we got a different reception at locks to when we hired something that had a company name on it. With the unmarked boat people would be happy to slate hire boaters, but I then liked to point out we were hiring.
And that's the problem with judging by appearances -- I've come across (plenty of) friendly helpful scruffy boaters and nasty arrogant shiny boaters, skilled/knowledgeable hirers and incompetent/ignorant owners/liveaboards. And the opposite in all those cases... 😉
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21 minutes ago, dmr said:
Yes, the 1E (rotational frequency) component is actually a pitch. Many off the shelf 3 cylinder engines will have an out of balance flywheel and front pulley to turn half of this into a yaw as a best compromise.
A proper (automotive) design would establish the sensitivity of the vehicle structure to the various force inputs and design the mounts and pitch/yaw split correctly. This is also sometimes done on big plastic boats but I don't know if it has been tried on a narrowboat, it would be an interesting project.
Balance shafts use/waste a bit of power and would have limited gain on a three due to the various frequencies, they work a treat on the I4 (standard inline four cylinder engine) as this has one major harmonic (but do have to run at twice engine speed).
Traddy boats have a rigidly mounted big heavy engine, I don't know how well a lighter modern regidly mounted engine would work but suspect boaters who choose not to have a "proper" engine aspire to near xero noise and vibration so mounts are the way to go.
Putting the engine right at the back of the boat is probably good for noise but maybe not optimum for vibration.
If you really want to cut down engine vibration induced in the hull, the best solution is probably the one that generators use in critical applications like hospitals which is an inertia base -- the existing flexible engine mounting feet are used but onto a heavy frame (usually a steel one filled with concrete) which is in turn mounted on soft vibration-absorbing feet to the hull/building.
This is what I did with my generator and it made a big difference, there's a lot less vibration and noise inside (and outside) the boat when it's running than the normal mounting method.
But to work properly (and avoid introducing new resonance problems) it has to be heavy (at least as heavy as the engine/gearbox), and mounted on relatively soft feet -- on mine the frame plus steel plate infill under the generator (almost 2" thick!) weighs about 200kg so was not exactly cheap to build along with the Aquadrive feet... 😞
To do this with a diesel engine you'd need to modify the engine beds, both to lower them and to get enough space to fit the frame in, and I guess most people wouldn't think the extra cost and complexity was worth it (but I was going to do it when I was considering a diesel or series hybrid boat) -- you'd also definitely need a good flexible drive coupling (Aquadrive?) to cope with any increased engine movement.
It also adds several hundred kg of weight right at the stern, which can make things interesting when it comes to ballasting the boat... 😉
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56 minutes ago, MrsM said:
I think it could best be summed up as 'patronising'. I guess when our boat looked well used they assumed we knew what we were doing, but when our boat looked shiny and unscathed they assumed that we hardly ever left the marina (which couldn't have been further from the truth). Quite logical I suppose.
Aah, the "BMW" problem... 😉
Mind you a lot of people -- boaters included -- have a similar attitude to hire boats, regardless of the fact that some hirers have spent far longer actually cruising on the canals over the years than most liveaboards... 😞
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33 minutes ago, dmr said:
In a modern car one or more mounts are often quite high up to give a "neutral axis" installation where the mounts are on the axis about which the engine wants to rotate. In boats the mounts are low down and not "designed" so more engine movement is likely. The three cylinder engine is quite difficult as it produces two harmonic series, one at the firing frequency (1.5 times rotation) and one at rotation frequency, so its difficult to steer clear of all the resonances.
There's also a big low-frequency (rotation frequency) rocking couple which is hard to suppress, it's why modern cars with 3-cyl engines use complex and carefully placed engine mounts, often soft and with added damping, and sometimes added masses, as well as sophisticated computer analysis of all the vibration modes -- it's all this which has made them usable (and popular) in modern cars.
In boats which don't bother with any of this (modern technology, uurgh...) the vibration can be a problem with 3-cyls, the rocking couple wants to make the prop shaft wiggle up and down (and side to side) which is not good for flexible couplings and/or stern tube, especially if there's an engine mount resonance within the rev range -- which there probably will be unless the mounting feet are very soft (e.g. Yanmar), which they often aren't... 😞
Technically speaking, the proper solution is either to use an internal balancer shaft (e.g. Bukh) or have a slower speed engine bolted to the bedplates instead of flexible mounted, which is what trad engines do, but at the cost of vibration throughout the boat -- which can be really bad if this then hits a hull resonance, like the Bolinder-powered boat (yes, a single-cylinder...) I saw on the Trent where the entire stern was bouncing up and down by several inches. Most marinisers seem to just use flexible feet and hope there won't be a problem, and they usually get away with this -- but not always, as cheesegas has found... 😞
5 minutes ago, cheesegas said:I'd rather have one, if only because it's under a cruiser stern and lifting the boards above the engine always results in a bit of grit etc falling into the engine bay. The intake end of the manifold is also perfectly positioned to suck in belt dust from the alternator
It's a full cast iron block and head so yeah, probably quite top heavy. I haven't tried adding weight to a point lower than the mounts but I'm not sure how feasible it is to get weights down there because clearance is quite tight.
The problem is that to affect resonances like this you need a *lot* of weight, especially with a heavy cast iron engine like yours -- a few tens of kg is unlikely to fix the problem.
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1 minute ago, cheesegas said:
To be honest the replacement is so small, made completely of rubber and mounts directly onto the intake I can't see it resonating at all. Should be delivered today so I'll fit it and see how it goes.
The existing filter assembly has a thick steel bracket that bolts to the manifold into blind threaded holes, then the canister is bolted to that with a short flexible hose to join it to the intake. One of the bolts sheared flush with the manifold and my stud extractor can't get it out so I think it's easier to scrap the whole assembly!
Should be fine then, a rubber assembly will have plenty of damping unlike a steel one.
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Just now, MrsM said:
I have no idea why, but it was quite noticeable that some lockies treated us quite differently after the boat looked all fresh and shiny.
Better or worse? 😉
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On 07/04/2024 at 09:33, cheesegas said:
It does seem to be a high frequency, low displacement vibration so this might work, but as you say, there's no suitable strong mounting points nearby without welding something on!
The chap at R&D actually suggested a weight above the mount that's most lightly loaded - I've tried this with both my own 80kg mass and varying cast iron ballast weights on top of the gearbox but movement is in the wrong axes. Appears to be the reaction force spinning the block in the other direction to the crank each time a cylinder fires, so the weight would need to be high up to have an effect... It's got a fairly hefty cast alu camshaft cover but I don't think its bolts would hold up to a weight on top!
If the problem now is just the air filter resonance at 1000rpm, adding some mass to it (bolt on a lump of steel?) could help -- an extra 20% (of the air filter mass) will bring the resonance down to 910rpm which could still be a problem, adding 40% will bring it down to 850rpm which should be fine. Your suggestion of a lighter air filter assembly will move the resonance up the rev range which might be an even bigger problem when you're cruising...
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On 06/04/2024 at 17:39, agg221 said:
I've met a few people from the forum who have introduced themselves, usually when passing through locks. The problem is that the noise level on the boat is much higher than on the towpath, even immediately adjacent to it, so people assume I can hear them but unfortunately I can't!
Alec
Maybe you need a quieter boat?... 😉
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13 hours ago, dmr said:
I like a boat with an engine room, Jims boat doesn't even have an engine 'ole, its just got a big white thing stuck on the back 😀.
Have helped a friend up the C&H in a 55 footer, I really would not fancy doing those locks in a 60 footer.
Got a bit restless with the home moorer stuff so having a few days out, left the mooring at 9:30 yesterday morning and sitting in the Golden Lon with a pint in hand before 3, I reckon we could almost keep up with the hire boats.
We had no problems taking a 60' boat up the C&H last year. OTOH the boat was deliberately designed with features to make this easier such as a watertight bow (and stern, but we were going up) and short stern button/rudder, we had no problems with protruding bottom gate walkways and didn't even have to lift a fender.
But I certainly wouldn't have wanted to be taking a boat that length with an open well deck through, given the amount of top gate leakage in some locks... 😞
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10 minutes ago, dmr said:
HVO and FAME are two totally different fuels. They might be made from the same feedstock but the process of manufacture is different. FAME is pretty rubbish stuff but the government insists on diluting our diesel with it. HVO is good stuff and even better than "dinodiesel". HVO is not hygroscopic and is also long term stable.
If only you could actually get HVO on the canals... 😞
(though I've been told this situation may improve...)
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1 minute ago, Sea Dog said:
I would always wish a tiller to not extend beyond the side of the boat when the rudder is hard over. This is particularly to avoid the hazard of it fouling a lock wall when hard over. Any tiller longer that that should have a hinge to prevent said hazard - not a rarity on the cut.
I did look at whether the tiller could be made telescopic with a twist-to-lock like you get on other extending handles (e.g. telescopic boathooks) but we couldn't figure out an easy way to do it in the time we had available...
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1 hour ago, Jon57 said:
So all electric like I said then.
Not if I go out cruising, then the generator is needed -- unless you cruise only a bit, only in summer, or *very* slowly... 😉
(also heating is diesel)
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If this had a sleeve so it could slip on over the existing handle/tiller bar I'd buy one 🙂
My tiller bar at the moment (semi-trad stern) is about right for steering standing up just inside the doors, too long for steering from the stern, and too short for sitting down in front of the control pillar... 😞
(yes I know about steering from the stern, dangerous, getting knocked off etc -- which is why I only do it when going ahead...)
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15 minutes ago, Ken X said:
Second vote for the Corn Mill in Llangollen. As Ian says they don't give it away but we find the foods always good.
The Aquaduct Inn at Froncysylite is another we use. Last time we moored at Trefor basin and walked over the Ponty to it. The walk back in the dark was interesting 🙂 Particularly as it was January.
We often pop into the short Whitchurch arm overnight to shop and eat if timings are right for us.
Aqueduct Inn had excellent beer and a fantastic view from the terrace (see below), can't vouch for the food since we didn't eat there. Trefor Inn (next to the basin) is OK at best.
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27 minutes ago, Jon57 said:
Looks like the boat doesn't go far. Perfect. 😁👍
I haven't run my generator since going out cruising in October. Mind you, the boat's been plugged into shoreline all winter... 😉
(and hasn't used any shore power for the last couple of weeks, solar has been enough -- no domestic use though...)
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3 hours ago, Sir Nibble said:
The trick is to not get the paddles wrong.
Which is exactly what I said... 😉
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2 hours ago, Stroudwater1 said:
The Chainbridge hotel where Ian’s picture is taken is where you can sit and watch folk come down the river Dee in rubber rings that I mentioned .
https://www.beardedmenadventures.com/activities/river-tubing-langollen-north-wales/
From there you may also be able to watch a steam locomotive pass by above you. You won’t see them for too much time though, as it’s a tiny length of the railway that’s visible from there. It’s mostly luck. We weren’t there for long and saw both.
Ditto, IIRC the train stops opposite the chain bridge for passengers to get on off.
Recommendation for the Willeymoor Lock Tavern seconded, friendly family-run pub with excellent beer and decent pub grub (but note pub/kitchen opening times) and reasonable prices. We moored below the lock fifty yards or so from the pub both times, the towpath above the lock can be a complete swamp.
Would also recommend the Bridge Inn at Chirk Bank (good beer and *very* good value food), and the Corn Mill in Llangollen (pricey but good).
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7 minutes ago, Jon57 said:
6 Go all electric...
...with no generator. Good luck with that... 😉
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33 minutes ago, Sir Nibble said:
Going up. Bowline on the centre rope over a bollard towards the back of the lock, forward gear, tickover.
Agreed -- but that still doesn't stop the boat being pushed across the lock if you get the paddles wrong, or the lock hates you... 😉
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59 minutes ago, Hudds Lad said:
The Motor Museum in Llangollen is worth a look, but it may not be open when you're there as a quick look at the website says they now only open 1st-7th of the month since Covid
A trip on the steam train from Llangollen is also good, or a walk from the basin up to Horseshoe Falls where the canal begins is a good appetite enhancer before the evening meal (don't expect something like Niagara
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And you can call in at the chain bridge for a pint on the way back...
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1 hour ago, MtB said:
So
as a newbie then,you hardly know anythingyet.FTFY... 😉
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58 minutes ago, Tracy D'arth said:
Big Lock in Middlewich is a classic for anything can happen. The hire boats first day out have a high old time at this lock.
That's one I remember being tricky too, nothing you do seems to work -- and I'll be going through it next week...
51 minutes ago, Mike Tee said:Its no good - I'm going to have to buy a widebeam for when I'm on wide canals..............
Why not just hang some enormous 3' diameter fenders down both sides? 😉
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3 cylinder diesel resonances, what's the best solution?
in Boat Building & Maintenance
Posted · Edited by IanD
I suspect it's not just the space though, Aquadrives and similar (and their super-flexible feet...) cost a lot more than simple flexible couplings...
Nothing wrong with that if properly designed (large shaft diameter is really only needed to prevent torsional whipping on long shafts), and it means they can be fitted in a lot more boats. Still too expensive for a lot of boaters though...