The Perfect River Raid Boat (PRRB)

[Chris Waite]

Yes,

It's a longer, lower, leaner 'Polly Wee'

Just like I told you

CW

[Port-Na-Storm]

Trying to sail on rivers can be problematic, but it is good to take advantage of the breeze when it does go your way.


I'm beginning to think that the PRRB depends more on your idea of a Perfect River, than the Perfect Boat to float on it.
My Perfect River has perfect little corners for camping ashore where nobody minds.

I think I need to emigrate (again).

[Port-Na-Storm]

Or, you could adopt an alternative power source, but its best to ensure there are enough refuelling stops along the way.


Thanks to Chris P for the photo, and the muscle power.



 

[Randonneur]

Port-Na-Storm wrote

My Perfect River has perfect little corners for camping ashore where nobody minds.

That's a fine looking vessel Graham :-)

There're plenty of nice secluded corners if you look hard enough!





http://www.flickr.com/photos/27533969@N05/sets/72157635475193796/

[Port-Na-Storm]

That's the place!

But why do you need a Kettle the size of a Milk Churn?

Reminds me of Father Ted. "No Dougal this one is Small that one is Far Away"

[John P]

Lots of activity here all of a sudden - with all these new boats being planned perhaps we could do with some suggestions for outings next year!

CWs new boat is clearly shows a family likeness!  Look forward to following this development.

Here are some pictures of my recent 'virtual cardboard models'.  Only plain cardboard, no pretty renderings and fancy seascape backgrounds. Not finished yet, not even the 'cardboard' models, let alone a wooden version.

I was surprised how far forward I had to move the forward person in order to balance the boat in the water with two aboard, this results in a long space aft of the rear seat and I am not sure about the aesthetics of that. At least it allows for a 'boot' to carry the trolley (which separates into three bits). If we use the trolley to take the boat down to the beach (about ten minutes walk going down, at least 15 going back up, so I think we need some wheels) we cant really leave the trolley on the beach, so it will need to go in the boat. Notice how much the stem sinks with two aboard, compared with one aboard, more than I would like really.

I will believe Chris P when he says we don't need a sliding seat, he is the expert. However, the layout of the boat makes it so easy to incorporate a sliding seat it seams a pity not to at least make a 'cardboard' one. For the real boat I probably make a simple fixed seat, at least to begin with. The 'rails' that carry the sliding seat can also support a simpler fixed seat and I think they could also be used for a 'sliding rowlock' like the one Gerald T. had at Cobnor.

The rudder is a first attempt, I think it looks ugly, have an idea for something neater but needless to say more complicated. I do like Timmo's tiller stick with built in rudder lifting control!

Outriggers for the rowlocks seem to be pretty well essential for such a narrow rowing boat, either fixed or sliding seat.  I need to run my stress analysis program to see if these ones will be strong enough. After removing a pin in the end of each stay, the outriggers can turn 90 degrees to allow for berthing alongside a quay or another vessel.

John














 

[Paul H (admin)]

Chris,

She looks like a stretched Premise.....

[eric17]

You did it, John !!!
a five panel hull with rounded forefoot, it's exactly what I called a "JP x CW mongrel".
EXcellent !

PS : can't you put the wheels in the space behind the rear seat ?

[John P]

Well, with this special 'cardboard' I can have any shape I fancy!   Our grey dinghy is actually a six sided hull forward, blending into a five sided one further aft, i.e. the flat bottom panel is folded into a Vee shape forward.  I drew the new boat the same to begin with, then decided that it looked at least as good five sided all the length.  I have just about managed to avoid 'hollow waterlines' - I don't like those!

Peter Glover's rowing boat (picture earlier in this series) is also a five sided boat but with more flare to the topsides, possibly because it doesn't have outriggers for the rowlocks.  Re rowlocks, my sketches show a rough representation of  'Gaco' rowlocks from Australia. I don't know much about rowlocks (other than that the cheap plastic ones are hopeless), but these look neat to me although it seems a pity that you need a screwdriver to open them, I would have thought they could have made them click open somehow. Mind you, I could use any other type of rowlock, we have cast galvanised ones on our dinghy but I have covered the 'horns' with plastic tube which seems to work well.

Comparing CWs latest cardboard boat with his Octavia, dare I say it, I think Octavia actually looks nicer - more curvy and less boxy in the middle, but that might be because we are looking at an early cardboard model, perhaps the wooden one will better justify the name.  Is Chris building a whole new boat simply to get a version of Octavia with a wider transom to fit the peduloh system?  If so, perhaps he could keep the forward section of Octavia and just make an alternative back section?

Eric - yes the idea was to stow the wheels, and the picnic, in the space behind the rear seat - see below.

[Paul H (admin)]

SolidWorks is a very professional CAD modeller - so Graham don't even ask about the price because it will give a Scotsman a heart attack, even if you've gone easy on the Mars bars (mmmm I'll take 2).


John, can it calculate C of G and all the hydrostatic gobbledegook ? Also you may be able to export it to the free version of Delftship (http://www.delftship.net/) which can calculate those parameters and "balance" the boat.


There is of course Chris P's tried and tested formula - "move some of that junk you didn't need to bring to the other end" - sorted.

-Paul

[BrianP]

Perhaps I should have said "my" rather than "the" most perfect RRB.

Just a few reasons why she caught my eye so strongly.

Gilles Montaubin has been designing boats for 30 years, and he keeps designing ones that perform very well in Raids. Different model, different Raids, yet his designs constantly perform well. I have to respect that. His simple looking boxy shapes have real knowledge of what is happening as the hull moves under oar and sail.

I never said anything about using the sail rig on the Thames Raid. To quote ChrisW "I cannot afford to build such a boat merely to use it from Lechlade to Beale once a year" Nor can I and as much as I can see a punt being perfect for the Thames, my local western Solent conditions dictate a more seaworthy craft as "my" PRRB.

A word about the sail rig. The rolling around the mast reefing works very well indeed. Loved it on my sailing canoe. Easy to have the right amount of sail and rolls away to nothing. No flapping about when launching or landing which is nice, but best of no bulking rig when dropped. My lug rigs are bulky when dropped, and I found a rolled away rig much better and has to be far better when living aboard.

The mylar high angled batten sail is similar to a Hobie but with the added feature of a boom to hold out the sail off the wind. I have watched my friend using the Hobie at Keyhaven and it works great, rolled away in an instant which is a great feature for a river boat if anyone does want to sail on stretches where the conditions permit.

Swallow Boats showed a similar rig on their sailing canoes featured in Watercraft. All using a very lightweight carbon tube mast.

So Brol has a rig which I currently consider perfect for me on any narrow hulled craft I may use.

So, a perfect rig for me, how about the hull.

I love sailing "sailing canoes". All the pleasure of sailing and added responsiveness of the long narrow hull. Brol is in the same beam length but not simply a canoe used for sailing, but the very best effort of a successful designer to make the best hull shape possible.  That's why I was excited to see Brol. A top designer's best attempt to solve this most difficult of design conundrums. Sail power with least rowing drag.

Look at the rowing picture, bearing in mind it might look boxy and simple but his boats keep winning Raids.



The main chine is clear of the water along it's whole length when rowing but will very quickly immerse when healed for sailing or living aboard.

The bottom is V shaped and looking under the transom there is very little immersed hull being dragged along. Her immersed shape looks to be a very fine double ender.

So, yes I should have said MY, but she does excite me. I have been wrong before, Raid41 failed with evil handling, perhaps Giles has the skills needed to make "my ideal" work. I do hope so, even though it cannot be me who proves it either way.

John, Neaves Rowing Services supply the proper gates for rowing. We have found them very helpful and efficient. I think your design looks terrific.



http://www.neaves-rowing.com/sculling-gates.htm

Brian

[Chris Partridge]

Brian! Now you bring those goalposts and put them back where you found them!
Of course, everything you say is true but we were talking about the perfect river raid boat. The need to use any boat for lots of different purposes is the exact reason why so most of the boats on the Thames/Kennet raid had drawbacks of one kind or another. The boat I brought, for example, was impossible to camp in. Tim O'Connor's Zelva was closest to being perfect - fast, easy to propel, facing forward, lots of room to camp. Gets my vote.
But in the Western Solent, Brol might well be the ideal boat as you rightly point out.

[Chris Partridge]

What a lovely hull.
Actually, she is so long and thin you might as well go the whole hog and install a sliding seat. It is a system - sliding seats work with slender hulls and outriggers by giving the length of stroke to match the long oars. I had rather assumed that you would be going for traditional beamier hull in the interests of seaworthiness in the waters round Plymouth, in which case a sliding seat would not offer much extra speed and would get in the way. What does Josephine think?
Have you seen the Westport Jolly Boat, made by the Westport Group in Crownhill Fort? It has a pair of neat folding outriggers that might serve your purposes if you can persuade him to sell you a pair separately.
Love the wheel storage arrangement.....

[Timmo]

Like the whole computer generated image, know I couldn't make a computer do that for me, regardless of the software! Respect.

Having observed CP leaping nimbly across the gap created by the outrigger between Snarleymow and the bank I can see real advantages to an outrigger that is easily folded when mooring or even when descending a lock.

Tim.

On 28 Oct 2013, at 15:22, Chris Partridge [via UK HBBR Forum] wrote:

Have you seen the Westport Jolly Boat, made by the Westport Group in Crownhill Fort? It has a pair of neat folding outriggers that might serve your purposes if you can persuade him to sell you a pair separately.

[BrianP]

Here's a question.

John's lovely hull has a narrow bottom plywood keel plank. (at least I think it has)

Perfect for a mirage drive installation, to meet the forward facing needs of elder travellers.

Is there a way of having drive housings for single pedaling and then dual pedaling? Or same thing weight wise with one pedaling and one preparing the drinks.

Sounds like a false floor with three housing along the centre.

I saw a chap with one of the inflatable Hobies in the summer. It was made for two people and on his own he pedalled from the rear position and the bows ended up high in the air.

Brian

Spelling corrected, see post below.

[Timmo]

Is it Pedalling or Peddling? Just checked the dictionary and find it's actually Pedaling, though the double L is becoming common usage. Not wishing to be common (always something my Mother warned against!) I will henceforth use pedaling.

Remember you can pedal a mirage drive from front or back and there is an argument for having the two pedalers facing each other (more sociable.)

So one possibility is that the forward drive slot is used by a solo pedaler. That same slot is used by the forward pedaler when two up, only they're facing toward the stern and the stern most pedaller drops back to use a slot further aft and balance the weight of the extra person toward the bows. Just two slots required if it can work.

When two up the middle zone becomes the place for the picnic basket, wine cooler and other necessaries.

I have a vague idea that it's more sociable still to pedal side by side when two up. Sorts out trim fore and aft, but not sure how to balance port/starboard when one up (or when there's a noticeable difference in mass between the two people.) Either means quite a wide flat bottom plank or the need to mount drives through garboard or even next strake up the hull, not impossible but more fiddly and will prevent the outer fins coming flat against the hull. They will have to be far enough apart not to hit each other. It's something that could be done in a wider hull that would also be a good for sailing. Two drives would push a GP14 or even Wayfarer type hull along quite well. Trick would be to incorporate the drive boxes into a thwart or under the foredeck so they aren't intruding into useable space while keeping trim right. May not be worth the hassle but picture pedaling off hand in hand, sun on the water and wine chilling in the cooler between you. Worth thinking about at least!

Tim.

On 28 Oct 2013, at 16:56, BrianP [via UK HBBR Forum] wrote:

Is there a way of having drive housings for single peddling and then dual peddling? Or same thing weight wise with one peddling and one preparing the drinks.

Sounds like a false floor with three housing along the centre.

[BrianP]

Chris, i have such a aversion to flat bottom hulls after Raid41 when I saw this picture

 

my reaction was,

such a nice shaped bottom curve on the transom. lots of curves from transom to the main mould, and lots of shape back from the bows to the main mould.

what would happen if the main mould had a slight curve on its bottom edge?

Would it stop everything working, or would it perhaps allow the curves a slightly softer transition from forward to rear?

hope it's ok to ask.

Brian

[eric17]

Not possible, Brian, watch the "curvature diagramm" I posted on the (hijacked) thread "Jotun Penguard HB and Hardtop HB advice, please", page 3, Jul 16, 2012.
It has to be a straight line there, that's THE reason why I went to 5 sided hulls...



PS : By the way, I never got the picture of the forefoot of your (upsidedown) Trouper .....

[Port-Na-Storm]

The Ply Torturer General (or is it Admiral) may beg to differ, as he manages to get all sorts of shapes out of a sheet of ply, but if you have a look below.........



Just behind where the Vee bottom stops you can see that the bottom becomes flat athwartships. If you tried to induce a curve the rocker towards the stern would flatten out. You can't have both. Well you could manage to force a little curve into the bottom but what have you gained? You'd be forever spilling your drink as it rolled around on the mud.

While I am on, I am equally in awe of the two design methods on display here. CW's origami and John's CAD. Truly amazing in both cases. I am currently in a fight to the death with an old version of TurboCAD in an attempt to get it to do anything elegant.  My money is on TuboCAD.
Now where did I leave my Mars Bar?  

[Chris Partridge]

On the subject of rudders, rowing boat rudders don't need to be nearly as big as sailing boat rudders because you don't need to yank the boat round to go about. And the oarsman can steer the boat with the oars if the rudder isn't man enough for the job.
The only rowing boat with a pivoting rudder I have ever coxed, the bloody thing would cant over somehow and insist on steering hard to port. So I suggest all you need is a small non-pivoting rudder with a yoke and lines. Simple and effective.