Canopus and Sculptor

[ditchcrawler]

The Norfolk Wherries where built in yards with no drawings at all, The man in charge just built them by eye.

[FadeToScarlet]

Fair comment, I'm far from being an historical expert. I thus doubt it will surprise you as it did me, but naval architects were writing papers about canal narrowboat boat design and associated hydrodynamics back in 1837, and that's some 179 years ago...

 

http://www.ma.hw.ac.uk/solitons/HISTORY_OF_EXPRESS_CANAL_BOATS.pdf

 

It mentions that narrowboat hull designs from the scientific community were circulated to builders back in 1833.

It's a bit of a hodge-podge throughout history, with builders compromising between hydrodynamics and load carrying capacity.

 

On the one hand, you had 18th century fly or packet boats, often narrower than 7' (5' in some cases), round chines, and very long swims, to allow them to travel at a very high speed.

 

At the other end of the spectrum, there's boats like mine (a "tree" Severner) designed in 1935 to carry the maximum possible tonnage- 33 tons on a single motor, nearly as much as a Josher pair.... At the price of hydrodynamics and comfort for the boatman. Very "chunky" and short at each end, relatively short, slab sided swims, welded construction, back cabin and engine room position swapped for a shorter back end. Designed by naval architects, but not a thing of beauty! Similarly the "Admiral" class boats can carry 20 or so tons on a draft of less than three feet!

[Derek R.]

It is also interesting to note that the speed at which the craft in which William Houston traveled, was discovered not by any naval architect, but through accident and observation of the effects of the bolted horse. Only after was any analysis of how it happened undertaken. - Horse before the Naval architect Cart!

 

It takes a long thin, finely shaped hull to achieve the speeds required to ride waves relative to the cross sectional area of the particular canal.

 

I had a similar fluid dynamic experience when being flushed out of a lock on the Napton flight. Going downhill we were stuck quite fast with spread hull sides, but the lockie, an old boy wearing flat cap and bicycle clips, knew his pound. Lifting and closing the top paddles for a certain time, he created a wave that went down the cut - bounced off the next lock down and back. Having done this more than three times, the ever increasing return wave lifted us a good foot or more, loosing us and carrying us with such effortlessness that by the time our stern was clearing the bottom gates we must have been doing six mph or more. Had our lockie done work with graphs and mathematics? I very much doubt it. He'd learned from the experiences of past lockies and lengthsmen who doubtless had passed on the information and which he himself had cause from time to time to practice.

 

Not to say that fluid dynamics are a waste of time studying, they are essential to a great many things from dams, groynes, harbour walls and entrances, as well as craft shape for efficiency of movement against fuel consumed. But the cut (as Dpaws is discovering) is a shallow ditch along which much silting, and lack of dredging has made into a comparatively narrow channel the depth and width of which is created by the deepest draughted vessels. And if everyone had boats of 2' draught - all would suffer heavy steering as 2' alone would be the depth overall, and the fastest vessels the canoe and motor powered punt.

 

Not so much boating - as ploughing. And as ploughs also have their optimum shapes - there's science there too, but don't tell that to the man who invented the iron tip'd wooden plough (as if you could!) - you'd probably get clobbered by something harder than a keyboard!

[Guest]

Thanks Derek, I take your points of course

 

- and what a charming story about the lockie. I'd love to have seen the canals in their heyday, I find their world fascinating, tough men.

[Ray T]

Thanks Derek, I take your points of course

 

- and what a charming story about the lockie. I'd love to have seen the canals in their heyday, I find their world fascinating, tough men.

 

Every week I visit a retired Barlow's / BW narrowboat captain. It wasn't just the men it was tough for. The boating women had an even tougher life. They were expected to do all the work the men would plus bring up a family. The women would often be back at work the day following a birth.

 

From here: http://www.waterwaysongs.co.uk/hard_life.htm

 

It's a hard life for a girl on the cut

Doing the work of a full grown man

Pushing a barrow and shov'lin' the coal

Plenty of work on her hands

 

It's a hard life for a wife on the cut

Spending her days with a bargee man

Sharing his work through the good times and bad

Coping as well as she can

 

It's a hard life for a mum on the cut

Rearing her family the decent way

Mending and cooking and keeping them clean

Nothing but work all the day

 

I've shown this picture before from Canal Recollections by Julian Holland:

 

 

Jeannie Humphris was 14 when this photo was taken.

Edited December 28, 2016 by Ray T

[JohnO]

SNIP...

An obvious example and a pet hate of mine - the installation of bow thrusters. The instructions for their correct positioning, tunnel profiling and grill profiling are widely available in the public domain and yet incompetence is commonplace and highly visible at Crick.

 

 

I think a good way to approach your research would be to question why certain practices via away from the expected norm, especially when carried out by professionals. A bowthruster fitted with the "Vetus grill profiling" on a inland waterway vessel would have you in dry dock fishing out carrier bags and dealing with the resulting damage to thruster. Makes you wonder how they work at all with mesh over the opening. There is usually a reason.

edit: dropped an e

Edited December 28, 2016 by JohnO

[Dalslandia]

I think in the future all canal boats need a radically new design, to improve things, and make it more modern.

[Guest]

 

 

I think a good way to approach your research would be to question why certain practices via away from the expected norm, specially when carried out by professionals. A bowthruster fitted with the "Vetus grill profiling" on a inland waterway vessel would have you in dry dock fishing out carrier bags and dealing with the resulting damage to thruster. Makes you wonder how they work at all with mesh over the opening. There is usually a reason.

 

 

There's rarely a good enough reason to justify their positioning. Look at the photo I posted before, see how close the thruster is to the keel plate? How much power loss would you estimate from this "compromise"? It's huge! Nine times out of ten you'll find nothing obstructing a more optimal tube position - at best their position is a complete guess. Just ask Vetus UK...

I think in the future all canal boats need a radically new design, to improve things, and make it more modern.

 

You mean without toxic sediments but with soft under-Arco lighting? Self-driving and self-locking... hmmmm

 

But then my Luana wouldn't have any hunky volunteer lockies to lust after... and I may have to talk to her instead! It's losing it's appeal rapidly Jan...

Edited December 28, 2016 by dpaws

[Guest]

 

Every week I visit a retired Barlow's / BW narrowboat captain. It wasn't just the men it was tough for. The boating women had an even tougher life. They were expected to do all the work the men would plus bring up a family. The women would often be back at work the day following a birth.

 

I've shown this picture before from Canal Recollections by Julian Holland:

 

Rose Skinner & Jean Humphries.jpg

 

Jeannie Humphris was 14 when this photo was taken.

 

Amazing isn't it! How times have changed so quickly - it's no wonder that the world's full of delicate snowflakes these days...

Edited December 28, 2016 by dpaws

[JohnO]

I think the whole fitting of bowthrusters to narrow boats is one great compromise. I believe the generally low positioning of thrusters on canal craft is to reduce the risk of floating/semi submersed objects eg. leaves, being drawn to the tube. Narrow boat bows generally are not that deep in the water. It's a hard life in a muddy ditch.

 

edit: missed a space

Edited December 28, 2016 by JohnO

[matty40s]

Canopus has one hell of a bowthruster.....sad really on a boat with an engine that doesn't really need it and trying to copy a kind of boat built before they were invented.

[ditchcrawler]

I think it was Matt who posted a picture of a wide beam with an eyebrow over the bow thruster tube so that it didn't suck air. Some Narrowboats are not very deep at the bows.

[Guest]

Canopus has one hell of a bowthruster.....sad really on a boat with an engine that doesn't really need it and trying to copy a kind of boat built before they were invented.

 

Yes, it's a very good 24V Sidepower 10hp model, very controllable - I can understand why it was fitted to Canopus.

 

No narrowboat "needs" one, but they're ruddy brilliant for picking up, dropping off and for counteracting storm force gusts of wind and rounding marina islands in such weather apparently - wouldn't ever want to be without one on a day to day basis.

 

I could see the appeal of a boat without contraptions to preserve the skills of a traditional boatman, but I prefer the safer option myself.

[GUMPY]

Nothing safer about a bowvthruster if you know how to handle a boat properly there is no advantage to having a bowthruster.

Edited December 28, 2016 by Loddon

[cuthound]

Nothing safer about a bowvthruster if you know how to handle a boat properly there is no advantage to having a bowthruster.

Having boated for 41 years before getting a boat with a bow thruster, I cannot agree.

 

I find the bowthruster extremely useful when reversing, especially in a wind which I previously found impossible single handed.

Edited December 28, 2016 by cuthound

[Dalslandia]

Having boated for 41 years before getting a boat with a bow thruster, I cannot agree.

 

I find the bowthruster extremely useful when reversing, especially in a wind which I previously found impossible single handed.

I agree fully

[Guest]

Whist you're drifting across a pound 'cos the next gate isn't quite ready I can hold her online in even inclement conditions, even traverse against the wind. Priceless.

[JohnO]

I like Sidepower over Vetus. Consideration needs to taken in positioning the thruster tunnel tube eg. in relationship to a well deck for clearance. If the builder constructs a boat then the customer asks for a bow thruster, thats one way to end up with what you see. I think it is safe to say if you have a 200kg thruster on a narrow boat it will not be delivering that.

[GUMPY]

Well I must live in a parrallel universe as I can quite happily hold station and reverse as far as I want without a bow thruster.

ETA I'm only a newbie when it comes to boats excluding my canoeing and dinghy sailing I started in 1970

Edited December 28, 2016 by Loddon

[Dalslandia]

Some boats need a bowtruster, some boats do not need a bowthruster, the rest of all boats come in between the two some.

 

With a bow thruster it is possible to use the boat in ways that isn't possible without one.

[bargemast]

Well I must live in a parrallel universe as I can quite happily hold station and reverse as far as I want without a bow thruster.

ETA I'm only a newbie when it comes to boats excluding my canoeing and dinghy sailing I started in 1970

 

I've had quite a few commercial barges of which most were round bilged Dutch barges of different types, and a couple of Freycinet barges too, the round bilged barges weren't easy to keep station in strong side winds, evenmore so in the flat Netherlands, at the time we used the anchors a lot to avoid accidents, the straight sides Freycinet barges kept track a bit easier, but when empty in strong side winds it required a lot of hard work, I never had a bow-thruster in any of them.

 

Nowadays, I occasionally help friends on their barges that are much better equipped than mine ever have been, and most of them do have bow-thrusters, and now I realise how useful these can be, if I would still be operating my barges, I would have bow-thrusters fitted in them too, as they can make the life of a working bargee so much easier.

 

Peter.

[Guest]

I think it is safe to say if you have a 200kg thruster on a narrow boat it will not be delivering that.

 

I've been desperately searching for the article by Vetus that estimates the losses if only the protecting grill bar profile isn't optimised. I recall it being 20%, but tragically can't find my source to back that up - it was so much higher than I'd anticipated and that's why the number stuck in my head.

 

I can verify that my Sidepower gives Canopus a firm shove, but with minimal practice the blips of power on the lever are hugely controllable and very satisfying.

 

The only feature that drives me nuts it that it switches off into "safety" standby mode after 3 minutes I think, meaning two touch pads have to be pressed to activate it again. One of my first jobs will be to remove that "safety" feature, leaving only a local master on/off under the forward hatch.

[ditchcrawler]

 

I've been desperately searching for the article by Vetus that estimates the losses if only the protecting grill bar profile isn't optimised. I recall it being 20%, but tragically can't find my source to back that up - it was so much higher than I'd anticipated and that's why the number stuck in my head.

 

I can verify that my Sidepower gives Canopus a firm shove, but with minimal practice the blips of power on the lever are hugely controllable and very satisfying.

 

The only feature that drives me nuts it that it switches off into "safety" standby mode after 3 minutes I think, meaning two touch pads have to be pressed to activate it again. One of my first jobs will be to remove that "safety" feature, leaving only a local master on/off under the forward hatch.

And then you will come to use it in a hurry and it wont work at all. That timed cutout is there for a reason

[matty40s]

I moved a 60x12 ft widebeam last week with a big bowthruster.

Didn't use it once.

Just as well as the batteries are fooked after sitting on a mooring for 14 years.

[Guest]

You don't have to use them if they're fitted, but it's a very nice feature to have up your sleeve