Awful incident a Autherley Junction today.

[IanD]

6 hours ago, GUMPY said:

But some would say it's not possible and you need a special rudder 😱🤔

Nobody would say that. But a special rudder is *better* at doing it... 😉

[BoatinglifeupNorth]

23 hours ago, IanD said:

It's also not true with a Schilling rudder which can be effective up to about 75 degrees... 😉

 

(at which point they can provide sideways thrust only, just like a stern thruster)

 

But obviously there's no point doing this because a flat plate rudder was good enough in the old days... 😉

and flat plate blade rudders are perfectly good enough for today’s modern electric boats, that’s why they’re still being fitted by every Narrowboat builder.

Edited June 6, 2023 by BoatinglifeupNorth

[magnetman]

5p does not seem excessive for a specially made rudder. 

[Captain Pegg]

45 minutes ago, IanD said:

Nobody would say that. But a special rudder is *better* at doing it... 😉

 

Does anybody need to, don't the laws of physics tell us it's not possible to literally turn a narrowboat within it's own length?

 

I don't think I've ever knowingly put my rudder to 90 degrees. It sounds like a learnt behaviour from driving a car i.e. if you want to turn more tightly put some more lock on. I've certainly done that instinctively and then corrected myself (as I see it). Boats don't steer like cars.

 

45 degrees in alternate directions while using forward and reverse is how I was taught and with a quick burst of power to start the motion off and then throttle back to avoid excess forward drift. Also don't move the tiller until the power is off when going between forward and reverse otherwise you kill the rotation that you're aiming to preserve by use of the rudder. Until I was taught to steer (or perhaps more accurately "trim") the boat in reverse I didn't think it was really possible. 

 

But I'm up for a bit of experimentation so it's a pity that I'm not still at Tixall wide. I'll try and spin the boat with the rudder held at 90 degrees when I next get a chance and compare it to the method I was taught.

 

17 minutes ago, BoatinglifeupNorth said:

And perfectly good enough for today’s modern electric boats, that’s why they’re still being fitted by every Narrowboat builder.

 

I think the key will be whether all the things that render narrowboats the closest thing to a floating brick on the water will simply over-ride most of the benefit of a technically superior rudder shape. I think that's pretty much the issue with all theoretical hydrodynamically beneficial design improvements on canal boats but folk can do what they like with their own money. There's always a chance the rest of us might one day benefit but we don't have anything to lose. Of course the old stuff works but what does not working actually look like, a bit of mild contact between two lumps of steel and mild bruising to the ego?

 

On that note whatever did happen to Canopus, is it steaming down the GU at 5mph while burning 0.5 litre/hr of fuel yet?

 

Edited June 6, 2023 by Captain Pegg

[BoatinglifeupNorth]

I suppose if you wanted to be different while still being traditional with the blade rudder you could fit a stern thruster to go with the bow thruster.

 

Edited June 6, 2023 by BoatinglifeupNorth

[Captain Pegg]

5 minutes ago, BoatinglifeupNorth said:

I suppose if you wanted to be different while still being traditional with the blade rudder you could fit a stern thruster to go with the bow thruster.

 

 

Option heavy boat that one.

 

That stern fender and the towing hook are an interesting combination.

[BoatinglifeupNorth]

4 minutes ago, Captain Pegg said:

 

Option heavy boat that one.

 

That stern fender and the towing hook are an interesting combination.

It’s a lovely looking boat, I would say the nicest I’ve seen from that builder.

[ditchcrawler]

20 minutes ago, BoatinglifeupNorth said:

I suppose if you wanted to be different while still being traditional with the blade rudder you could fit a stern thruster to go with the bow thruster.

 

Someone has ground the rivet heads off below the waterline 

[MtB]

14 minutes ago, Captain Pegg said:

That stern fender and the towing hook are an interesting combination.

 

Weirdest-looking stern fender I've seen in a quite while. Any lower and it'll be wicking up canal water.

 

 

 

 

[Captain Pegg]

21 minutes ago, BoatinglifeupNorth said:

It’s a lovely looking boat, I would say the nicest I’ve seen from that builder.

 

One person's lovely is another person's bling.

 

The thing about old canal traditions is that all had a purpose or a reason for being like the way they were. Inset panels and scribed lines on a shell made of steel plate? Fake rivets? The hook?

 

Are they for any purpose, other than to look like something they aren't?

 

There's no logic in thinking they are good features while deriding Ian for ignoring that sort of thing (which I think he has) in favour of something that is intended to have a purpose.

 

8 minutes ago, MtB said:

 

Weirdest-looking stern fender I've seen in a quite while. Any lower and it'll be wicking up canal water.

 

 

 

 

 

My nice new tipcats are so low - due to lack of freeboard - that when underway they get constantly wetted underneath. Which is a shame.

 

But they don't droop, the man from Tradline wouldn't let that happen.

Edited June 6, 2023 by Captain Pegg

[Ken X]

Apologies if I have pinched somebodies picture but we always liked this tipcat.

 

[IanD]

8 hours ago, BoatinglifeupNorth said:

I suppose if you wanted to be different while still being traditional with the blade rudder you could fit a stern thruster to go with the bow thruster.

 

Sure, you could spend 3x as much on something which did the same job but was more likely to get fouled if you wanted to, but a different shaped bit of metal is a simpler, more robust solution. Nobody's forcing anyone who thinks this is pointless to have one... 😉

 

It seems strange to me that people who think every slope and profile of their boat swim matters -- in an attempt to give something which is basically a brick in a drain some of the hydrodynamics of a ship -- don't also ask themselves why every modern ship out there has a high-lift rudder not a flat plate -- and some where low- speed manouevring is more important than drag even dare to use a fishtail/Schilling one.

 

But I guess the reason is that if the ODGs on the canals didn't do it, it can't possibly be worth doing, especially such a new-fangled gizmo... 🙂

Edited June 7, 2023 by IanD

[magnetman]

It is an interesting idea. 

 

Are any of these ships with high lift rudders steered by a manually controlled tiller? 

 

I've got a feeling the answer will be no. 

 

Hopefully it works alright and no unexpected problems turn up. This rudder type may only usually be installed with powered or hydraulic steering systems. 

 

 

 

 

[Tacet]

10 hours ago, ditchcrawler said:

Someone has ground the rivet heads off below the waterline 

Improves performance.  Same as flush rivets on a Spitfire

11 hours ago, Captain Pegg said:

 

Does anybody need to, don't the laws of physics tell us it's not possible to literally turn a narrowboat within it's own length?

 

 

That is my initial reaction when someone claims their boat can turn in its own length, using only propeller and rudder.

 

But IanD has previously posted some graphs and data suggesting that a Schilling rudder can give reverse thrust when the engine is ahead.  If so, a boat turning in its own length will be more feasible.

 

I am genuinely interested to see how it works out on his new boat.  Bollard pull (push?) might be a key indicator

[booke23]

10 minutes ago, Tacet said:

Improves performance.  Same as flush rivets on a Spitfire

 

Indeed. That boat is now capable of cruising at 3.8 mph as apposed to 3.79 before the rivets were ground off!

[IanD]

2 hours ago, Tacet said:

Improves performance.  Same as flush rivets on a Spitfire

That is my initial reaction when someone claims their boat can turn in its own length, using only propeller and rudder.

 

But IanD has previously posted some graphs and data suggesting that a Schilling rudder can give reverse thrust when the engine is ahead.  If so, a boat turning in its own length will be more feasible.

 

I am genuinely interested to see how it works out on his new boat.  Bollard pull (push?) might be a key indicator

A Schilling rudder should certainly be able to give pure lateral thrust, I'll try and get pull measurements to show this -- whether it will go all the way to a small reverse thrust remains to be seen, but this isn't needed.

 

IiRC the few people who have actually tried them on canal boats have reported very good results. With tiller steering you need less balance (about 25%) than the powered ones on ships, which use up to 40% but this would mean a tiller slamming hard over.

[BoatinglifeupNorth]

12 hours ago, IanD said:

 

It seems strange to me that people who think every slope and profile of their boat swim matters -- in an attempt to give something which is basically a brick in a drain some of the hydrodynamics of a ship -- don't also ask themselves why every modern ship out there has a high-lift rudder not a flat plate -- and some where low- speed manouevring is more important than drag even dare to use a fishtail/Schilling one.

 I don’t think there is anything different to that swim profile compared to yours as both from the same builder, all they have done is fit a stern thruster, you have fitted a Schilling rudder to what you say is a brick on a drain be it a shallow muddy one. Obviously a stern thruster/rudder working with a bow thruster will give better steerage/turning ability than a rudder and bow thruster, no matter what design of rudder it is. 
 If I was having a bespoke boat built and was concerned that my moorings/waterways had tight turns and manoeuvrability issues, I would fit a stern thruster rather than a fishtail/Schilling or Kitchen rudder to make life easier.

 Or to hell with it, just fit a Schilling rudder a Stern Thruster and Bow Thruster and swivel on a sixpence.

Edited June 7, 2023 by BoatinglifeupNorth

[Francis Herne]

20 hours ago, Captain Pegg said:

Does anybody need to, don't the laws of physics tell us it's not possible to literally turn a narrowboat within it's own length?

 

I don't think I've ever knowingly put my rudder to 90 degrees. It sounds like a learnt behaviour from driving a car i.e. if you want to turn more tightly put some more lock on. I've certainly done that instinctively and then corrected myself (as I see it). Boats don't steer like cars.

 

With the rudder over to 90°, from roughly stopped, Lark will turn very nearly on the spot - I need roughly 40ft of clear width to turn 31ft of boat in continuous forward gear. Dropping out of gear once the boat is spinning (and getting perpendicular to the channel), then back in as the bow starts swinging away from the bank again, works a little better, maybe 36ft.

 

Reversing is better still, and with enough shuffling I can turn in my own length plus a few inches without hitting the sides. It's a lot easier to just nose up to one bank and drive the stern around though!

 

On this boat at least, 90° rudder angle is very clearly better than 45° - the latter has an obvious forward component to the motion and I end up T-boning the bank. Left is slightly better than right because of the prop walk.

 

I thought I'd better re-try 45° based on your recommendation, so my neighbours have just spent the last 10 minutes wondering what the heck all that spinning was about.

Edited June 7, 2023 by Francis Herne

[GUMPY]

22 hours ago, BoatinglifeupNorth said:

I suppose if you wanted to be different while still being traditional with the blade rudder you could fit a stern thruster to go with the bow thruster.

 

I will not comment on the above the swim nonsense but the swim is typical of a modern boat. It only curves in one plane, decent swims curve in two planes, if you have only ever steered a modern boat you don't know what you have missed.  

Loddon although it doesn't have proper double curves at least slopes in towards the base plate allowing a better flow of water to the prop.

 

Edited June 7, 2023 by GUMPY

[Peugeot 106]

36 minutes ago, Francis Herne said:

 

With the rudder over to 90°, from roughly stopped, Lark will turn very nearly on the spot - I need roughly 40ft of clear width to turn 31ft of boat in continuous forward gear. Dropping out of gear once the boat is spinning (and getting perpendicular to the channel), then back in as the bow starts swinging away from the bank again, works a little better, maybe 36ft.

 

Reversing is better still, and with enough shuffling I can turn in my own length plus a few inches without hitting the sides. It's a lot easier to just nose up to one bank and drive the stern around though!

 

On this boat at least, 90° rudder angle is very clearly better than 45° - the latter has an obvious forward component to the motion and I end up T-boning the bank. Left is slightly better than right because of the prop walk.

 

I thought I'd better re-try 45° based on your recommendation, so my neighbours have just spent the last 10 minutes wondering what the heck all that spinning was about.

I’m exactly the same with 25ft Narrowboat. Do it all the time very little forward movement. I’ve tried 45deg rudder it just doesn’t work.

 

I’ve been told clockwise turn forwards is better with RH prop but out doesn’t seem to make much difference. 

it’s my party trick and always raises a smile! Where are you we could do synchronised spinning?

[ditchcrawler]

24 minutes ago, GUMPY said:

I will not comment on the above swim nonsense but the swim is typical of a modern boat. It only curves in one plane, decent swims curve in two planes, if you have only ever steered a modern boat you don't know what you have missed.  

Loddon although it doesn't have proper double curves at least slopes in towards the base plate allowing a better flow of water to the prop.

 

Is that your stern thruster just ahead of the anode  ?😁

[BoatinglifeupNorth]

1 hour ago, GUMPY said:

I will not comment on the above swim nonsense but the swim is typical of a modern boat. It only curves in one plane, decent swims curve in two planes, if you have only ever steered a modern boat you don't know what you have missed.  

 

 As you say a modern swim on a modern boat, exactly the same as IanD’s swim, he has a Schilling rudder that one has a stern thruster. I doubt any of those will be standard industry fitment this time next year, just as Axiom Props aren’t fitted to every Narrowboat despite the claims and tests of the manufacturer.

  You pay your money and you can have whatever you want, Rudders, Thrusters, Rivets, Hatches, Recessed Panels, whatever floats your boat or brick.

Edited June 7, 2023 by BoatinglifeupNorth

[blackrose]

Black Rose 57 x 12ft widebeam without a Schilling rudder and without using the bow thruster. It doesn't turn within its own length but it's not bad.

 

 

I'll have to get someone to video me from the bank one day.

[GUMPY]

1 hour ago, ditchcrawler said:

Is that your stern thruster just ahead of the anode  ?😁

You know full well what that is 🤔

[dave moore]

Going back to the starn end modern photo, I thought that the fender fitment rather awful. My long term understanding is that the rear fenders were fitted to overhang the rudder by a few inches, offering protection in the case of impact. Traditionally, two tip cats and a button were sufficient, all seated high around the counter and with a lift from first to last. One of the old school, Roger Hatchard, used to put a real lift to his rear fenders, they became known as “ Hatchard’s Cannons” because of their rakish uplift.

The dreary chains and low siting of a short fender on the photo would do little to achieve the original purpose, to my eyes.