Timleech
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Posts posted by Timleech
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But nonetheless pretty strong circumstantial evidence of us being barking up completely the wrong tree ... ah well, at least it's still in the tradition of painting your engine any colour you like; and it is still green, so hopefully should go OK ... and ... it does look smashing!
The important thing is that you're happy with it. It's not a museum exhibit, after all!
Tim
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How much room is there around the gas cylinder? Is it a really tight fit?
Do you have enough room for a sleeve?
Say, a steel sleeve that slides inside your current gas locker with a nice new water proof lid?
Rusty gas lockers can be a bit of a nightmare. Luckily it sounds as though yours is well above the waterline.
A sleeve can be a good answer, but remember it'll need a drain plumbing in to the outside world, and your rusty steel will continue to fester around it (OK, you can take steps to arrest that to some degree)
Fibreglassing might work for a couple of years, then whoever gets the job of fixing it properly will curse the bloke who did the fibreglassing.
It sounds as though your job needs looking at soon, as judging by your description any leaking gas will be going into your bilges.
If you're passing (not on a bank holiday
) and can manage to get out of the tunnel, by all means give me a shout & I'll offer an opinion.Tim
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As I said, I didn't ask about alternative access so people can leave the lock open, it was just a general question as it can't be the most easiest way of getting working gear to the dry dock.. I'm thinking along the lines of engine replacements and heavy machinery.
It isn't, but I've lived with it for more than 20 years. Heavy stuff has to come in by boat or, very occasionally, across the farmer's fields.
Anyway, getting back on topic... you say you've had problems with cruising clubs? I'm a member of one of the cruising clubs on the Bridgewater. Maybe you could let me know which ones are causing a problem via PM, so I can have a quiet word with the people associated to them, if you want to, of course.Thanks for the offer, it's not really 'problems with cruising clubs' so much as problems created by the sheer numbers of boats when the CCs come through, on top of already heavy bank holiday traffic. 40 or 50 boats trying to come through tunnel & lock as close together as they can is bound to stretch things a bit. It's not as bad as it was with the old tunnel times, when it wasn't unknown for the whole lot to come through on one 'tunnel', things did tend to get seriously manic then!
Tim
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Not because people want to leave the gates open of course, but why don't you look into other ways of access to the dry dock?
Why should I (and do you really think I haven't thought about it ?
)?There is access provided by BW as part of my agreement, if the lock is operated properly there's no problem.
Of course I would love to have road access, but it would be prohibitively expensive bearing in mind the other limitations of the site. Also it would be the more than a mile by 'road' from my workshop, which is on the other side of the lock, 100 metres on foot.
The only other way would be a swing bridge or high level bridge, the swing bridge wouldn't be any better than the lock gates in the Bank Holiday situation.
It's only really a problem at Bank Holidays when the Cruising Clubs are out en masse. BW's answer when I raised the matter some years ago and suggested manning the lock was that the CCs should work within the rules (and BW wrote to tell them so), there was no reason why BW should incur extra costs to accomodate them just because they wanted to go on mass cruises.
Tim
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The ideal solution, for me, would be to leave the stop lock as it is at Preston Brook, but on busy weekends, just swing both gates open to get the boats through, making you close them after you.
If only life were that simple !
Several snags with that idea:-
one, the people opening the gates may have the best of intentions of getting them closed afterwards; I can tell you from observation that it doesn't work (usually). Somebody somewhere down the line will lose interest/lose the plot/not give a stuff, and the gates will get left open.
two, it isn't always safe to do it - sometimes the difference in levels is too great, but you can bet your life some idiots will still try. Who decides when it's safe, and takes the rap if it isn't & there's harm done?
three, there's a right of way across the lock. For me & my customers. It's the only access to my business premises, customers moorings etc. In years gone by, I've often been slaving away on Easter & may bank holiday weekends to get boats ready. It used to be Hotel boats for the start of the season. If I (and others) are doing our best to get the job done it can be intensely aggravating when there's a line of boats (illegaly) going through the lock & every one of the boaters thinks it more important for them to get through than for you to get your work done. Some of the Cruising clubs seem to have rules which require them to keep in a continuous line behind the admiral or commodore or whatever he is, and can get really agitated if the line is broken.
Even worse if we're stuck the wrong side of the lock with the gates left open (abandoned). That can be a ridiculous time waster
In recent years I've tried to avoid working on Bank Holiday weekends simply because it's bad for my blood pressure, but it's not always possible.
I have suggested in the past to BW that they man the lock on Bank Holiday weekends, their men could decide when it's safe to force the gates, and make sure that access is maintained. I honestly think that would be the best answer but they don't want to know because it would involve paying overtime.
If boaters stick strictly to the times, and keep a safe distance behind the boat in front, there should be no more than about 10 boats passing each way per hour and not much of a problem with queues. Unfortunately they don't.
Rant over
Tim
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I have no data, just seems (to me) that over the years reading of CO incidents many seem to be caused by fridges. It would be good to see real data.
Ian
I think you'll probably find the main 'cause' (most accidents are the result of more than one cause coinciding) is often blocked/inadequate ventilation.
Tim
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Yeah, but its all about the sahpe of the torque curves as well as gearing.
- Which is why deisal cars drive diffrently to petrol cars, even though they use a diffrent gearbox to "correct" it as best they can.
Or somthing
Daniel
Not really, that was my point about the prop torque going up with the square of the rpm.
A diesel engine torque/rpm curve will be flattish, the square law prop curve will always be steep enough that it's only full load/speed engine torque which matters & available torque below that speed will always AFAIAA be loads more than is needed to turn the prop.
Or something.
Until you get that mattress on the prop
Tim
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One of the reasons for using large low revving diesels for narrowboats is the low rev torque which allows you to use large propellers which get a good grip on the water straight away. It's good for acceleration and collision avoidance, I believe. High torque at zero revs makes this as good as it can get!
Nick
Weelll....
You can run whatever size prop you like with any engine, it's all a question of gearing.
Working motor Narrow Boats *in general* used props in the 24" to 28" dia range, turning at around 400 to 600 rpm max with around 15 to 25 bhp. If you take the specific example of the National/RN used in the GU fleet, they had 18hp engines turning a 27" (ish) prop at 500 rpm max.
You could get exactly the same performance by driving that same prop with a modern sewing machine type engine by gearing it down to that same 500 rpm, and apart from a little extra for gearing losses it would need the same 18 hp. THe torque to turn the prop is the same, with the modern engine it comes from gearing the engine down more than the 2:1 used on the original National.
Torque needed to turn a prop goes up with approximately the square of the rpm, so torque needed at zero speed is only that needed to overcome inertia of prop & shaft, and high torque is only needed when prop speed gets close to maximum.
YMMV, as they say
Tim
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Also electric motors have maximum torque at zero speed so they are particularly good for narrowboat manoeuvring.
N
I'm not sure why that makes them particularly suitable, except that it means they don't need a clutch?
Tim
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Of course, when there is a lot of traffic coming through Preston Brook Tunnel, it is usually possible for a couple of hefty blokes to open Dutton Stop lock at both ends simultaneously, and get all the boats through at the same time.
IIRC, BW do occasionaly do it deliberately when there is a lot of traffic expected.
They did it once or twice when the lock was manned for boats attending the IWA national, at that time levels were fairly equal.
Generally, they strongly discourage the practice and have in the past written to the local Cruising Clubs to ask them to desist from doing it. If it's done when there's a substantial difference, there's risk of injury through gates flying shut, damage to gates or the structure, the wave sent along the canal can cause disruption to boats in the tunnel and to moored boats, etc etc.
Tim
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Interesting stuff, but I somehow dont think the wind could manage to lower levels by as much as six inches on the canals? A westerly gale perhaps? On the sea it is different because there is a much larger catchment area of water plus the tides and wind working together can achieve some considerable effect - such as those conditions which led to the disastrous floods of 1953.
I've lived on or by the canal at Dutton/Preston Brook for 40 years, off and on, & I can assure you that I haven't made it up
The width of waterway is more or less irrelevant, it's the length along which the wind is blowing which matters. It's not an instant effect, it is most marked after a couple of days of sustained wind.
Tim
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Hi Ian,
The reserve power needed for manouvering is where the battery bank comes into play.
For instance, lets say your diesel powered boat needs 20hp to start and stop effectively, but only 3hp to cruise. That 20 hp is only produced at near max rpm so you fit a 30hp engine to give you the extra torque and power to accelerate the engine and prop to full revs.
Rick
Rick
I agree with the rest of what you say, but not that bit.
You might need to allow a few extra HP for running alternators etc., but not to accelerate the engine.
Tim
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I've owned at least seven Nationals, 2- and 4- cylinder, over the last 40 years, most of them *not* ex-Narrow Boat engines, all were the 'usual green' except for one Brunton's gearbox which was more a sort of pale diarrhoea colour. That gearbox could equally have come from an RN.
I also remember seeing one National, 40 years ago, very convincingly painted grey.
Proves nothing, of course.
Tim
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All very interesting stuff, about how little power (ie shaft horsepower or whatever) is needed to move a NB through the water. However, what happens when you want to stop? In my (diesel-powered) experience, it's one thing needing 1050rev/min to cruise at 3.5mph, and quite another to stop 15 tonnes of boat in a hurry: you need the power at 2500 or 3000 rev/min when some eejit appears at 6mph through a blind bridge 'ole.
Surely the hybrid/diesel electric approach doesn't produce enough power to control all that momentum, especially with a propeller going backwards (and thus inefficient)?
Have I missed something here?
Ian
Two things -
First, you boat within your limitations (or should do
), so you get to know how quickly your boat will stop, and proceed accordingly. If you're approaching a blind bridgehole with poor brakes, you don't approach it at full (cruising) speed. There's a generation of boaters now which expects to be able to stop on a sixpence, it hasn't always been thus.Second, stopping (and starting) effectiveness has a lot to do with propellor size. 10hp through a 24" prop will have far more effect than through a 12" prop, even if the rpm etc is properly matched to the prop. Therefore if you're designing an installation from scratch where you know the bhp is limited, it will pay to design it around a decent sized propellor.
Tim
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I've just come across this old thread, & would like to make a couple of points about Dutton stop lock.
First, the levels were more equal some years ago, as for some years the Bridgewater was maintained at a higher level to facilitate the Kellogs grain traffic through Trafford Park. At that time, I'm told that British Waterways did decide to remove the gates altogether (circa 1960, I believe). They quickly found that it was a bad mistake, as there was too much variation in levels at Middlewich.
With the lock in place, the Bridgewater level at Dutton/Preston Brook can drop by 5 or 6 inches if there's a strong W or SW wind for a couple of days. This is caused by the action of the wind on the water surface, blowing the water away to Manchester and Wigan. If you extend the pound right through to Middlewich, that effect will be increased, and that was indeed found to be the case. Also 6 inches drop on the T&M is much more significant than 6 inches on the deeper Bridgewater. Because the difference in levels at the lock was usually very small, a single top gate was fitted with a very long beam and extremely large paddle. This enabled the lock to be used as, in effect, a Flash lock.
The end of the Kellogs traffic more or less coincided with the very bad breach at Bollington (1971?), after which MSC became cautious about their water levels and maintained the Bridgewater on average several inches lower than the T&M. The lock then became difficult/unsafe to use with the single gate, so new bottom gates were made (by MSC Co!) and fitted.
Those who advocate removing the lock should think back to a much more recent time, when a failed paddle in Manchester led to the Bridgewater dropping by a couple of feet. The stop lock protected the T&M entirely, without it every boat between Dutton and Middlewich would have been on the bottom.
Tim
) and can manage to get out of the tunnel, by all means give me a shout & I'll offer an opinion.
New Tiller
in Boat Building & Maintenance
Posted
I'm not entirely sure what it is you're looking for - a reshaped wooden tiller, or a more conventional steel arrangement?
In either case unless it's a mass-produced boat they will be one-off items, any decent 'skilled' boatyard should be able to sort you out.
If it's the wooden one you're after you do really need to find out whether they have the right skills & know what you're talking about.
What part of the country are you in?
Tim