Schilling rudder project on narrowboat

[Guest]

Just now, ditchcrawler said:

Have you actually made it, ready to fit?

Not as yet, I've other financial priorities at the moment, it's on the to-do list... I won't be doing the fabrication itself, but the design has been accepted already.

[PD1964]

7 hours ago, IanD said:

 

Bolt-on plates do indeed give you a lot more opportunity to play, just watch that you don't have possible corrosion issues with the steel plate underneath if water gets in behind them.

 

If you can I also suggest trying to get the prop rather further away from the deadwood (tip of swim) than is often done in narrowboats, this helps smooth the water entry into the prop and reduce prop walk -- and putting it closer to the rudder improves rudder response too. Can be difficult to do after the hull has been built though, you really need to extend the stern tube/bearing backwards -- or do what I'm doing and move the whole thing back a couple of inches so it sticks out less inside the hull and more outside.

 

8 hours ago, dpaws said:

My own Shilling design and stern re-work for one day when the hull's out of the water... https://skfb.ly/6TqHH

 

Of course, the science holds up, but you'll never change the opinions of the bretheren because it highlights ignorance, and no one likes to be told that they're wrong 😂

Can I ask what actual real life experience you have on the canals ? As all I’m seeing is CAD dream world. Your rudder might be the dogs bollox in deep open water but have you done anything on canals?  Looked at your link and all it is, is CAD?? also what is your link with XRD, anything?

Edited December 1, 2022 by PD1964

[PD1964]

6 hours ago, dpaws said:

Not as yet, I've other financial priorities at the moment, it's on the to-do list... I won't be doing the fabrication itself, but the design has been accepted already.

You seam to talk a lot of bollox, let us know your real world experience, you haven’t had your boat out of the water to try your design? I thought that would be priority to promote it, you seam all CAD, at least I’ve seen  @IanD design in the flesh on his boat, at the minute your coming across as all talk.

[Guest]

4 minutes ago, PD1964 said:

You seam to talk a lot of bollox, let us know your real world experience, you haven’t had your boat out of the water to try your design? I thought that would be priority to promote it, you seam all CAD, at least I’ve seen  @IanD design in the flesh on his boat, at the minute your coming across as all talk.

Whilst I really care not for your opinion, we've been boating on UK canals for about 8 years and I've been an owner for 6. Although it's none of your business my priorities at this moment are the financial needs of my family. There's simply no need to prove Shilling rudders, they have been in use for many years and are well regarded in my industry; I'm a Marine Superintendent. 

 

In simple terms CAD is a tool that translates mathematics into physical objects. It's been around for some years now, there's no need to be afraid. It actually saves time because you get it right first time.

 

If the above is seen by yourself as being bollox then I can only suggest that you try education, although I appreciate that the maths maybe a little too complicated, given your rustic vocabulary. 

 

Or maybe just move on and get over yourself.

[blackrose]

On 08/10/2022 at 22:37, Andy Br said:

 

 

This diagram is just simply the turning circles of a ship in relation to the ships length. (L)

 

I realise your question relates to narrowboats, but a big element of a vessel's turning circle is the vessel's length:width ratio which relates to its directional stability. Think about a circular coracle with no directional stability which will spin on the spot.

 

So rudder design is very much a secondary factor compared to hull length width ratio. I can turn my widebeam in much tighter circles than most narrowboats and this is with a simple flat plate rudder at about 1000rpm (no BT).

 

 

 

Edited December 1, 2022 by blackrose

[Guest]

Yes, circles aren't the issue. To turn better you can simply remove ballast for the bow. The correct relationship between swim and prop and rudder is important, but inefficiency can be overcome with excessive power. I wish to traverse, and that's more complicated. 

 

"So rudder design is very much a secondary factor compared to hull length width ratio. " Very much so; the VLCCs are a bitch to keep track compared with a Suexmax tanker. And obviously, that's why tugs are the shaped as they are.

Edited December 1, 2022 by dpaws

[Alan de Enfield]

1 minute ago, dpaws said:

I wish to traverse, and that's more complicated. 

 

 

Do you mean "ferry glide" ?

If so it is a quite normal mooring manoeuver, but having a tad of current / flow or wind does help.

[Guest]

Yes, sort of. My wife had a bad bike injury years ago and it's coming back to haunt her by limiting her mobility.

 

I've faced handling issues across exposed lock pounds in strong winds due to the cabin's high windage area.

 

Usually the crew can shaft back onto track, but I don't have that luxury. With a large thruster in the bow (again, to solve mobility issues by holding the bow against the shore for disembarkation) and a Shilling I'm confident that I'd be able to traverse the hull. It will solve a problem that maybe unique to me. 

 

For the stern swim's redesign that's to correct the hull's poor handling characteristics.

[IanM]

1 hour ago, dpaws said:

I'm a Marine Superintendent. 

That sounds very impressive but on a canal that means nothing at all. 

 

1 hour ago, dpaws said:

n simple terms CAD is a tool that translates mathematics into physical objects. It's been around for some years now, there's no need to be afraid. It actually saves time because you get it right first time.

As a person who works with CAD for a living I can tell you that your statement is incorrect. If very much depends on what you’re doing. If you’re making a precise piece of equipment manufactured by someone who knows what they’re doing then you get it right first time. However, your fancy rudder has no such guarantee as it’s all based on principles and whilst it may work on paper and the fabricator will make it to the CAD model doesn’t mean it will work with your boat in real world conditions. 
 

Over engineering and over thinking things based on knowledge from a similar but ever so slightly different field can be quite a bitch sometimes.  I’ll simplify that by saying over thinking anything on the canals leads to more stress than is ever needed. 
 

 

[Guest]

24 minutes ago, IanM said:

That sounds very impressive but on a canal that means nothing at all. 

 

As a person who works with CAD for a living I can tell you that your statement is incorrect. If very much depends on what you’re doing. If you’re making a precise piece of equipment manufactured by someone who knows what they’re doing then you get it right first time. However, your fancy rudder has no such guarantee as it’s all based on principles and whilst it may work on paper and the fabricator will make it to the CAD model doesn’t mean it will work with your boat in real world conditions. 
 

Over engineering and over thinking things based on knowledge from a similar but ever so slightly different field can be quite a bitch sometimes.  I’ll simplify that by saying over thinking anything on the canals leads to more stress than is ever needed. 
 

 

 

CFD analysis is a bitch to achieve on a paper model. Canals are canals, ship handling in confined channels, whether it be the Coventry or the Suez or the Panama; the principals and the hull interactions are the same.

Edited December 2, 2022 by dpaws

[PD1964]

8 hours ago, dpaws said:

Whilst I really care not for your opinion, we've been boating on UK canals for about 8 years and I've been an owner for 6. Although it's none of your business my priorities at this moment are the financial needs of my family. There's simply no need to prove Shilling rudders, they have been in use for many years and are well regarded in my industry; I'm a Marine Superintendent. 

 

In simple terms CAD is a tool that translates mathematics into physical objects. It's been around for some years now, there's no need to be afraid. It actually saves time because you get it right first time.

 

If the above is seen by yourself as being bollox then I can only suggest that you try education, although I appreciate that the maths maybe a little too complicated, given your rustic vocabulary. 

 

Or maybe just move on and get over yourself.

Sorry Superintendent, I’ve only just owned my boat for the last 13 years and lived full time on the canals boating which I believe you call it the last 13 years full time. Sorry I’m not as educated as you I’m also not as you a Pompous twit.  luckily though I was privileged to be financially secure for life at the ripe old age of 45 years so retired with my children financially secure. 

Edited December 2, 2022 by Athy
Removal of offensive language.

[PD1964]

56 minutes ago, dpaws said:

Yes, sort of. My wife had a bad bike injury years ago and it's coming back to haunt her by limiting her mobility.

 

I've faced handling issues across exposed lock pounds in strong winds due to the cabin's high windage area.

 

Usually the crew can shaft back onto track, but I don't have that luxury. With a large thruster in the bow (again, to solve mobility issues by holding the bow against the shore for disembarkation) and a Shilling I'm confident that I'd be able to traverse the hull. It will solve a problem that maybe unique to me. 

 

For the stern swim's redesign that's to correct the hull's poor handling characteristics.

What? Your coming across as a bit of a joke, sorry Superintendent. Sounds like you don’t really know how to handle a boat on the canal and looking back on the Threads you’ve started a bit real world clueless old boy. Come on please enlighten us all. What is a Marine Superintendent? 🤦‍♂️ 

Edited December 2, 2022 by PD1964

[Jon57]

6 hours ago, PD1964 said:

What? Your coming across as a bit of a joke, sorry Superintendent. Sounds like you don’t really know how to handle a boat on the canal and looking back on the Threads you’ve started a bit real world clueless old boy. Come on please enlighten us all. What is a Marine Superintendent? 🤦‍♂️ 

Sounds like someone who ruddy knows nothing about the real reality of the muddy ditches. 🤔

[GUMPY]

From a quick Google of

"Marine Superintendent"

The Marine Technical Superintendent (MTS) is a shore-based, technical role responsible for the safe and economic operation of one or more vessels.

 

https://www.instituteforapprenticeships.org/apprenticeship-standards/marine-technical-superintendent-degree-v1-1#:~:text=The Marine Technical Superintendent (MTS,of one or more vessels.

 

https://www.practicaladultinsights.com/what-does-a-marine-superintendent-do.htm

 

Edited December 2, 2022 by Loddon

[Jon57]

5 minutes ago, Loddon said:

From a quick Google of

"Marine Superintendent"

The Marine Technical Superintendent (MTS) is a shore-based, technical role responsible for the safe and economic operation of one or more vessels.

 

https://www.instituteforapprenticeships.org/apprenticeship-standards/marine-technical-superintendent-degree-v1-1#:~:text=The Marine Technical Superintendent (MTS,of one or more vessels.

 

https://www.practicaladultinsights.com/what-does-a-marine-superintendent-do.htm

 

Sea going vessels 👍

[Tony Brooks]

1 hour ago, Jon57 said:

Sea going vessels 👍

 

I suppose it could include someone in charge of the likes of City Cruises in London, but I doubt they would use that particular title. Could it be extended to include the head of engineering on a large hire fleet? I doubt the hire fleet bod would need a detailed knowledge of Colregs etc, but may well need to know far more about the interaction of unskilled users and fairly complex electrical and mechanical systems.

[howardang]

5 minutes ago, Tony Brooks said:

 

I suppose it could include someone in charge of the likes of City Cruises in London, but I doubt they would use that particular title. Could it be extended to include the head of engineering on a large hire fleet? I doubt the hire fleet bod would need a detailed knowledge of Colregs etc, but may well need to know far more about the interaction of unskilled users and fairly complex electrical and mechanical systems.

This brief definition from the Marine Society may help.

 

"The term ‘marine superintendent’ generally refers to either a ‘nautical superintendent’ or ‘technical superintendent’. In smaller companies, the marine superintendent may be called upon to do the job of both superintendents whilst on board the company’s vessels. Nautical superintendents tend to be ex-master mariners whilst technical superintendents are former chief engineers."

 

Although predominantly a term used referring in the management of  sea going vessels there have been many instances over the years where master mariners have been involved in the management of canal vessels;  Captain Leslie Morton of Willow Wren springs to mind and there have been a number of others over the years.  Indeed I am also aware of a number of current or past marine superintendents who are  members of this forum, but who also own boats on the canal network or who have done so in previous years (me included).

 

Howard 

 

 

 

 

 

[Martin Nicholas]

Consider the following:

How do these advanced rudder designs affect efficiency in a straight line? Most narrowboats spend most of their time going in a straight line or very near it. Cd of a flat plate: 0.001-0.005. Cd of a streamlined body: 0.04 (Source: The Internet).

 

What is the effect on steering in reverse? Probably it would improve. A bowthruster would be better if that's what you are after.

 

How will this affect the forearm/tiller bar/rudder system? An increase in gain in this system isn't necessarily a good thing. It could lead to an unsteerable boat if the rudder is too effective. It could also result in vibration due to insufficient forearm damping.

 

What if the design is wrong? You'll need to make and fit a new one as modifications look to be difficult. Compare with a flat rudder where it can be trimmed or extended with relative ease. Too large a rudder can result in vibration. Too small, makes steering difficult for a given speed.

 

An improved rudder just increases cornering speed, no slowing down for a given corner, assuming the steerer has the skills and can push hard enough. How useful would this be?

 

This thing is not new. R&D's used to offer an advanced rudder to anyone who would pay for it. They didn't prove popular.

[ditchcrawler]

Dan has one on his steam boat

[IanD]

1 hour ago, ditchcrawler said:

Dan has one on his steam boat

And Dalslandia -- a voice of reason on the forum, sadly no more -- also had one. And a couple of others have tried them as well.

 

AFAIK every one who has tried one has been very pleased with the result, as have all the other users of them on low-speed non-canal boats where any extra drag is utterly insignificant, almost certainly much less than that from anodes... 😉

 

R&D would undoubtedly have found them unpopular because few people are willing to spend the extra money to have one made -- not far short of a grand today, for anyone interested. There's also the famous resistance of the canal world to anything new, on the principle that the ODGs knew best and nothing can possibly improve on the old ways of doing things... 😞

 

None of which changes the fact that all the analysis and trials have shown them to give better steering than a flat plate rudder, especially at large angles. Not saying that a boat can't steer well with a flat plate, but that it'd steer even better with a Schilling or similar rudder... 🙂

Edited December 4, 2022 by IanD

[ditchcrawler]

1 hour ago, IanD said:

And Dalslandia -- a voice of reason on the forum, sadly no more -- also had one. And a couple of others have tried them as well.

 

No the site owner

 

 

Edited December 4, 2022 by ditchcrawler

[IanD]

1 hour ago, ditchcrawler said:

No the site owner

I know Dan's got one on Emilyanne, AFAIK the owner of Dalslandia (someone else with a Schilling who knew a lot about them) died about 3 years ago... 😞

Edited December 4, 2022 by IanD

[GUMPY]

Dalslandia was quite a different boat from the average NB

https://www.dalslandskanaltrafik.se/boats/m-s-dalslandia/?lang=en

[IanD]

1 minute ago, Loddon said:

Dalslandia was quite a different boat from the average NB

https://www.dalslandskanaltrafik.se/boats/m-s-dalslandia/?lang=en

I know, but its owner actually knew his stuff about rudders...

[Martin Nicholas]

An update on the Drag coeffieicnts of Schilling rudder profiles, taken from
this reasearch. In a straight line, Cd ranges between 0.015-0.055 depending on the type of fish. A NACA 0024 foil shape was measured at 0.01 in this paper.

The introduction is a good read.