Filleted chines on wide beam?

[Danny1234]

Hello

 

Assuming it's a fairly big wide beam (55' - 60' x 12') are sloping/filleted chines actually going to be of any use (on canals and the occasional trip along the Thames)?

From what I can see, these are generally not used on canal boats, only really on Dutch Barges (CAT C).

I figure I could 'fit in' maybe 100mm (horizontal, in line with the base plate) x 200mm vertical (up the sides of the hull) without it really affecting the internal space.

Is this frankly just a waste of time (and money!)?

One assumes that it would make the fabrication of the frame/shell a little bit more complicated. Though it shouldn't be something that a reputable builder couldn't accommodate. I suppose it would use slightly less steel, but I think that would be negligible. Am I going to get charged a lot of extra money for this (something that might not actually make any difference to the handling of the boat)

 

Regards

Danny

Edited May 10, 2012 by Danny1234

[bizzard]

Hello

 

Assuming it's a fairly big wide beam (55' - 60' x 12') are sloping/filleted chines actually going to be of any use (on canals and the occasional trip along the Thames)?

From what I can see, these are generally not used on canal boats, only really on Dutch Barges (CAT C).

I figure I could 'fit in' maybe 100mm (horizontal, in line with the base plate) x 200mm vertical (up the sides of the hull) without it really affecting the internal space.

Is this frankly just a waste of time (and money!)?

One assumes that it would make the fabrication of the frame/shell a little bit more complicated. Though it shouldn't be something that a reputable builder couldn't accommodate. I suppose it would use slightly less steel, but I think that would be negligible. Am I going to get charged a lot of extra money for this (something that might not actually make any difference to the handling of the boat)

 

Regards

Danny

I'm not a boat builder but here is my opinion.A multi-chine boat will have more draught for a given weight than a slab sided boat,but would generally handle much better,be much more comfortable in rough water, and be more economical on fuel especially with a nice fine bow entry,but will almost certainly be a lot more expensive to build.

[Biggles]

I went for a chined hull.

 

Better direction stability, sits well in the water and weighs in a lot less to do it, better MPG, get closer to shallow banks makes very little wake.

 

It uses more side steel but less base plate so overall less metal cost, but more labour, slight loss of space inside, more difficult to fit out.

 

IMO much better option.

 

Have a look through the blog. Plenty of inside and outside photos.

 

Edited May 10, 2012 by Biggles

[alan_fincher]

A multi-chine boat will have more draught for a given weight than a slab sided boat

When you put it in the water with no ballast in, yes, but surely you can choose what draught you want it to have, by how much you ballast it, and can end up with either a shaped hull, or a slab sided one, with exactly the same draught ?

[The Bagdad Boatman (waits)]

the canal bottom is not square but dish shaped so you use less force ( fuel) to move along and spend less time rubbing on the bottom plus you can get nearer the bank.

[bizzard]

When you put it in the water with no ballast in, yes, but surely you can choose what draught you want it to have, by how much you ballast it, and can end up with either a shaped hull, or a slab sided one, with exactly the same draught ?

Quite, that's why i said for a given weight. The same weights whether or not they're ballasted.

[tony collins]

If you use a square base to hull side join on a wide beam boat surely you will need to fit fillet plates for re-inforcement. An angled chine would give this support to degree already. I advocate a chined hull even on a narrow boat. see picture. This gave us a smooth and free flowing movement through the water and didn't really impinge on the cabin space inside as the floor level was at the point of the junction between sides and chine.

Edited May 10, 2012 by tony collins

[Robbo]

If you use a square base to hull side join on a wide beam boat surely you will need to fit fillet plates for re-inforcement. An angled chine would give this support to degree already. I advocate a chined hull even on a narrow boat.

 

Gary (forget second name) from a boat builders in Mirfield posted a reason on here a while ago, and I think he commented you should only really build a flat bottom boat to around 10ft base plate.

[Barry]

Gary (forget second name) from a boat builders in Mirfield posted a reason on here a while ago, and I think he commented you should only really build a flat bottom boat to around 10ft base plate.

 

Gary Peacock from Ledgard Boats?

[Grace and Favour]

Gary Peacock from Ledgard Boats?

 

That's the man!

[Robbo]

Gary Peacock from Ledgard Boats?

 

That's him, I can't find the post I was referring to thou only this...

 

http://www.canalworld.net/forums/index.php?showtopic=948&st=0&p=11406entry11406

 

The following link maybe useful for the OP...

 

http://www.canalworld.net/forums/index.php?showtopic=25781&view=findpost&p=432053

[Danny1234]

Hello there

Hhmmm, ... thanks, it would seem then that is generally desirable, particularly for boats over 10' wide.

Would these generally be formed by bending/folding the side plates, rather than welding a separate piece of steel between the base plate and the sides?

 

The linked topic (very useful) does make a good point about the most cost effective sizes for the base plate (related to the available sizes of the steel plates and the amount of cutting/welding/waste). I'll take note of this and query the various would be builders and see how they respond.

 

Most of the photos (and boats out of the water) I've seen, seem to have the 'fillet, mainly in the vertical. As in the rise up the plate is quite a bit more than the length going 'in' on the base plate. That would imply that it is the horizontal distance that is more important

Is this really the case?

How about a 45 deg angle?

 

Regards

Danny

[Biggles]

I guess mine is about 45°. And my base plate is 10' and my beam is 12'.

[Danny1234]

Hello

Thanks for the photos and comments

Indeed, .... the initial reply I got from one company (one I'm sure the likes of yourselves are familiar with, Colecraft)

'We incorporate a chine in the vessel to the base plate in order to use the most economical base plate size and to improve the handling of the boat. The majority of the chine goes into the floor.'

Seems the main driver there is then the size of the base plates. Not sure how 'scientific' their calculations then are for the effectiveness of the slope/angle, or it just 'seems about right' and works well with the size of the steel plates they use.

Don't know what the preferred size of their base plates is at this point. I'd guess then it may vary from builder to builder, depending on where the get their steel from.

For now then, I'll start of with a roughly 300 x 300 and see how that pans out

Cheers

Danny

[blackrose]

Hello there

Hhmmm, ... thanks, it would seem then that is generally desirable, particularly for boats over 10' wide.

 

It seems a bit odd to me that whenever this question comes up (either directly or as a result of threads going off-topic), the consensus is generally in favour of multi-chined hulls on widebeams, but few people ever advocate multi-chined hulls on narrowboats. Why is that exactly?

 

In my opinion if slab-sided is considered inferior, then it's the same for narrowboats too. But how many people on this forum have multi-chined narrowboats? The logical conclusion would seem to be that Springers are the best narrowboats!

 

My own widebeam is slab-sided with a draught of just over 2ft (less than many narrowboats). There are pros and cons to each design. If one of the advantages of a multi-chined hull is being able to get into shallower moorings, the disadvantage would be that the maximum draught of the multi-chined boat will be greater than the double-chined boat (all other things being equal). As has been said, you may be able to adjust a boats ballasting. However, if you want the counter or a bow thruster tunnel to be at the right height relative to the waterline then your ballast adjustment options may be limited. A boat needs a certain amount of ballast so it's not simply a case of have however much you want.

 

Slab-sided boats will be much more prone to currents which hit the boat beam on, so turning on a fast flowing river will be an experience, but the "hard" chines of a slab sided boat tend to grip the water, rather like the long bilge keels that you sometimes see on some Dutch barges. This means that a slab-sided boat will be less affected by sidewinds than a boat with a multi-chined hull.

 

Overall, I do agree that a multi-chined hull looks better and hydro-dynamically will respond better, but then most things that cost a lot more money are better.

 

Edit: The other thing is, how far are you prepared to go in improving the hull design? Some owners of traditonal Dutch barges with completely curved underwater profiles and no straight lines, think that the multi-chined hulls of more modern barges aren't very hydrodynamic. It's all relative.

Edited May 13, 2012 by blackrose

[Robbo]

It seems a bit odd to me that whenever this question comes up (either directly or as a result of threads going off-topic), the consensus is generally in favour of chined hulls on widebeams, but few people ever advocate chined hulls on narrowboats. Why is that exactly?

 

If you take the handling out of the question, I think I read in previous thread's when Gary was around that the same construction methods (which I presume are cheaper) couldn't be used as a narrowboat on a wide beam boat as it wouldn't really be strong enough?

[blackrose]

If you take the handling out of the question, I think I read in previous thread's when Gary was around that the same construction methods (which I presume are cheaper) couldn't be used as a narrowboat on a wide beam boat as it wouldn't really be strong enough?

 

I haven't read the thread again, but from memory, Gary was basically saying that you can't just widen a narrowboat beyond a certain point without the hull losing strength, hence the requirement for extra strenthening. That can be achieved with extra steel scantings and framing. I think some people have misunderstood what Gary said - he wasn't saying that you have to add more chines to anything over 10ft wide.

 

Have a look at this double-chined Piper 12ft widebeam hull being built. Piper are a very reputable builder.

 

Edited May 13, 2012 by blackrose

[Robbo]

he wasn't saying that you have to add chines to anything over 10ft wide.

 

I thought it was the next cheapest option (labour and material wise), and the handling been a benefit?

[blackrose]

I thought it was the next cheapest option (labour and material wise), and the handling been a benefit?

 

I wouldn't know about that, but I suspect adding extra scantlings is cheaper than adding more chines.

 

It adding more chines was cheaper then why do so many builders not do so when they build widebeams? I'm sure Liverpool Boats would have jumped straight onto the cheapest option!

Edited May 13, 2012 by blackrose

[Robbo]

I wouldn't know about that, but I suspect adding extra scantlings is cheaper than adding chines.

 

With the chines been usually not as thick as the base, and less welding? I'm not so sure.

[blackrose]

With the chines been usually not as thick as the base, and less welding? I'm not so sure.

 

Adding chines seem like more work to me - why less welding? I don't know enough about the subject to know for sure, but my gut feeling is that building multi-chined hulls is more expensive.

 

Anyway, perhaps the OP can get some quotes for multi-chined and double-chined hulls and let us know.

Edited May 13, 2012 by blackrose

[Robbo]

Chines seem like more work to me - why less welding? I don't know enough about the subject to know for sure, but my gut feeling is that building chined hulls is more expensive.

 

Less welding mainly due to less base plate welding. Remember the plate will need more 'weld' the thicker it is.

 

I've no knowledge on the subject either, and both 'arguments' make sense so I wonder if it's negligible and chines just make a better boat.

[blackrose]

I've no knowledge on the subject either, and both 'arguments' make sense so I wonder if it's negligible and chines just make a better boat.

 

I dare say they do, depending on what one intends to do with the boat. If it's just for canals and rivers then I doubt it makes all that much difference. My boat seems perfectly happy on canals, rivers & tideways.

 

My main point was that if multi-chined hulls make a better boat, then that includes narrowboats too.

Edited May 13, 2012 by blackrose

[David Mack]

In my opinion if slab-sided is considered inferior, then it's the same for narrowboats too. But how many people on this forum have chined narrowboats? The logical conclusion would seem to be that Springers are the best narrowboats!

 

Any significant degree of chine will intrude into the interior space compared with a slab sided boat. This might be acceptable on a widebeam, bit could seriously constrain the interior layout on a narrow boat.

[blackrose]

Any significant degree of chine will intrude into the interior space compared with a slab sided boat. This might be acceptable on a widebeam, bit could seriously constrain the interior layout on a narrow boat.

 

Not necessarily. I used to own a Springer and the shallow V bottom didn't intrude into the living space at all. That's assuming a V bottom is considered as multi-chined? Don't some Dutch barge style NBs have multi-chines?

 

Anyway, the point is that a slab-sided NB-style widebeam is no worse hydrodynamically than a slab-sided narrowboat. Since most people seem to be able to accept the idea of a slab-sided narrowboat, then there's no reason not to have the same (but strengthened) hull design in a wider boat.

Edited May 13, 2012 by blackrose