Wing riggers
Wallinford
Is it purely just the extra height that enables a drier day in rough water?
Also, carbon multistays are now being marketed, how much better are these than
aluminium ones?
Tony Curran
added clearance from waves, the sax board has to be cut lower to accommodate the
rigger so those same waves are spilling in over the side. They weigh more, they
flex more and in most cases you need backstays, but the newer ones claim not to
require these, tho Xeno Muller doesn't but how many WMs do you see around?
Hudson is just introducing a new rigger, again, with new claims of stiffer, more
aero hence faster - but what does that say about the boats he's been producing
since '91, or so?
See it on www.hudsonboatworks.com then go to www.carldouglas.com
Carl Douglas had a good post about back in July of last year, I'll e-mail it to
you if you are interested.
Carbon riggers have been around for a few years. Dreher in NE USA has been making
for the likes of Aylings in UK and Filippi in IT for quite a while - and probably
other as well. If I recall, Bakker (.sp) of Germany raced to a bronze at Sydney
Olys with these on his Empacher 1x.
Tony
Ottawa RC
sue thomas
also serves as your splash guard, and stops those waves coming into the boat
from bow side. I've been in some good chop and stayed dry. And with the
bow mounted rigger the aerodynamics are more similar to an aeroplane's, and
perhaps this results in less splash and effect from the wind. Check out the
pics at http://www.rowfluidesign.com/picture_gallery.htm
And even though the wings are "longer" (due to the bow mounting) I haven't
had any problem with flexing. And certainly weight isn't an issue ... my
boat weighs less than 31 pounds. An additional advantage of the
Fluidesign's rigger is that there is NO way you can put your oars into the
gates the wrong way on those sleepy mornings ... although you could still
mess up your port/starboard oar I guess .... ;-)
................
sue
Tony Curran wrote in message <3AD1B4CC...@nortelnetworks.com>...
chris harrison
> Personally, I don't see any advantage at all. Although the rigger may give you
> added clearance from waves, the sax board has to be cut lower to accommodate the
> rigger so those same waves are spilling in over the side. They weigh more, they
> flex more and in most cases you need backstays, but the newer ones claim not to
> require these, tho Xeno Muller doesn't but how many WMs do you see around?
I can't vouch for the veracity, but I was chatting to someone at the
weekend who rows a new Ray Sims "Evolution" single with wing riggers and
one advantage he cited was a lack of explicit shoulders, which meant that
the slides could be set further apart, which means that his calves don't
get quite so badly cut up as they have done in other boats.
Whether the setup is stiffer, whether the wider seat is more
comfortable, whether the boat will suffer in the long term and whether
it's all faster is unclear, but he's appreciating the lack of
blood dripping down his lower leg after outings.
--
chris harrison
webmaster, vesta rowing club
http://www.vesta.rowing.org.uk/
Tony Curran
I have a CD-X with 6.5inch width tracks and don't have any problem with calf bites. I
have my shoes set such the ball of the foot is level with the seat - as advised by a
member of the GB squad back in '80. I'm 6'4" size 11(UK) shoe.
Tony
Ottawa RC
Dr. Paul Thomas
> I can't vouch for the veracity, but I was chatting to someone at the
> weekend who rows a new Ray Sims "Evolution" single with wing riggers and
> one advantage he cited was a lack of explicit shoulders, which meant that
> the slides could be set further apart, which means that his calves don't
> get quite so badly cut up as they have done in other boats.
I think this is a common (and welcome) trait with the wing rigged
sculls.
I've looked at the Stampfli, the Filippi and the Hudson, and another
trait they all share is that the saxboard seems considerably cut down
relative to the height of the deck. Perhaps this combined with the lack
of a central shoulder means that the aerodynamic drag of the shell is
reduced. Certainly it ought to be less hassle in a crosswind.
On the subject of aerodynamic drag, those manufacturers like Stampfli,
Filippi and what used to be Glyn Locke who use a composite wing rather
than metal tubing might also enjoy a lower drag than from riggers.
Cylinders tend to give quite a lot of drag for their size even at low
speeds.
I also find that the wing boats are better in the rough as they don't
splash water into the boat. With conventional riggers, you have to
tape them up in the choppy water or the fixing plates and stays near the
shell at the central shoulder tend to splash water into the footwell.
> Whether the setup is stiffer, whether the wider seat is more
I think the difference in stiffness between a wing boat and a top-class
conventionally-rigged boat is small, but there are a lot of poorly
designed and built boats out there which do not cut the mustard as far
as rig stiffness goes. If you can bounce the blades in the gate by
striking down rapidly, you are losing effort which will cost you in a
race.
Paul.
Tony Curran
sue thomas wrote:
> And even though the wings are "longer" (due to the bow mounting) I haven't
> had any problem with flexing.
> ................
> sue
>
Sue,
Would you know if your riggers are flexing or not? Its not as if they are going
to be flapping in the wind. There is going to be a slight bend at the gate when
you take a catch a maybe a little spring when you extract.
One test you can do is to sit with blade up then push handle down quickly, then
repeat with fast cadence three of four times. If the scull bounces in the gate,
you may may some flex. I.ve done this test in a Hudson and also a guy at
Peterborough at HoTrent did it in a KIRS that was left by NZ team after the 99
Worlds - both failed.
Tony
Ottawa RC
Tony Curran
Just thought of another "feature" of wing riggers. They give the user the
opportunity to place the rigger on the boat, be it scull or sweep. That is the
owner can play with the work point. Now, in traditionally rigged boats, the work
point is just about fixed, the only thing adjustable is front stops beyond work
point and foostretcher.
I mention this because it has become obviuos to me that some crews are not giving
this enough thought. There are several examples of international crews that have
set the riggers such that the weight in the boat is either to far astern or too
far in the bow.
Examples, '96 Olys. I suggest in W1x Silken Laumen, LM4- Canada and Ireland, '97
World Augbillette (.sp) LM8+, and 2k Olys W2- Canada and M1x Waddell, had weight
too far astern because the bow would come out of the water too far, beyond the V,
and hence attempt to plane which they cannot do - hence boat will no go as fast as
it could. Also 2k Olys M1x Porter had his weight too far in to the bow, as the
stern would not dip, as they all did, and his bow would dip too severely.
I guess this has all got to do with Center of Gravity which maybe a listening
boatbuilder could explain. Carl....
Tony
Ottawa RC
Mike De.Petris
scrisse al povero All :
s> 1X entry in the Olympics, and his oarlocks were adjustusted to the very
s> top of the pin. That would, I believe, put very different stresses on the
s> pin than in my case where there are no spacers under the oarlock (and of
s> course he is much bigger and much much stronger than I). Some boat
s> builders can customize the wing rigger to the size of the rower and that
s> may reduce flex of the pin.
We usually change pins of our sculling boats with pins for sweep boats,
adapting the riggers for them, the reason is always find the rigging too low,
and we use the right boat to carry the rower's weight.
On our "good" boats whe have backstays, but it may be that even with an
higher oarlock and so longer leverage to flex the pin, the sweep pins are
stronger, so do not need the backstays, the problem is the sum of the
pin/rigger/shell flex/torsion.
Ciao, ** *Mike* ** www.interware.it/users/mike/ mi...@interware.it
--
Ti sento, bellissima statua sommersa.... mi ami o nooooo ?
http://www.studver.uu.nl/triton/rsr/ _*#RSR# Faces*_
http://www.interware.it/users/mike/rowing.html
http://www.triesterivista.it/
*************** _*#Webmaster# TrieSteRivista*_ ***************
*************** _*#Coordinatore# TRieSTeNet*_ ***************
*************** _*#Moderatore# ATARI.ITA*_ ***************
--
Atarian ST -TS! 2:333/608(FidoNet) bbsgate.interware.it
Mike De.Petris
(2:333/608.1) scrisse al povero All :
a> the bow ball whilst its upside down on the rack. See how much travel you
a> have on the bow ball before the full weight of the boat resists.
This is a bit strange, hasn't the bow to push into the water ? So don't you
need stiffness in the other direction ? Try to lift the boat from the bowball
with the boat upright instead!
Carl Douglas
writes
>In uno strano messaggio del 10 Apr 01 s-mayna...@ku.edu (2:333/608.1)
>scrisse al povero All :
> s> 1X entry in the Olympics, and his oarlocks were adjustusted to the very
> s> top of the pin. That would, I believe, put very different stresses on the
> s> pin than in my case where there are no spacers under the oarlock (and of
> s> course he is much bigger and much much stronger than I). Some boat
> s> builders can customize the wing rigger to the size of the rower and that
> s> may reduce flex of the pin.
>
>We usually change pins of our sculling boats with pins for sweep boats,
>adapting the riggers for them, the reason is always find the rigging too low,
>and we use the right boat to carry the rower's weight.
>On our "good" boats whe have backstays, but it may be that even with an
>higher oarlock and so longer leverage to flex the pin, the sweep pins are
>stronger, so do not need the backstays, the problem is the sum of the
>pin/rigger/shell flex/torsion.
Some interesting points raised here.
Putting the gate to the top of the pin imposes much higher torsional
loads on the rigger, & bending loads on the pin, than having it lower
down.
The linear deflexion of a cantilever (e.g. the pin) is proportional to
the cube of the distance of the load centre from the mount. So, Mike,
if those longer pins are still 12mm diameter, then the fact that they
are "rowing pins" will be of no help - they will not be stronger, nor
will they be stiffer, & they will bend quite a lot when the gates are at
the top (& the pitch will go "off" even more). The rigger will also
twist more.
As for backstays - these are only helpful for the early part of the
stroke arc. What is not generally appreciated is that the peak load is
usually not achieved much before the mid stroke, by which point the
effect of the backstay in stabilising the pin is much reduced. And, of
course, backstays increase aerodynamic drag & add weight.
Now - the business of water clearance, & aerodynamic & water-spray drag:
A wing rigger might have some theoretical advantage over a saxboard-
mounted rigger in leaving the saxboard clean for water flow, but that is
offset by the fact that the rigger tubes on the wing are always much
larger in diameter & the saxboard of a wing-riggered boat may be lower,
allowing water into the boat more easily.
The wing need larger tubes (if it is to be anything like as stiff as a
well-designed 2-stay conventional rigger) because, due to its longer
tubes (the cube law again) & less-ideal structural layout, the design is
inherently less stiff. These larger tubes increase aerodynamic drag,
further raised if backstays are also needed to keep the pin stiffer.
A well-designed sax-mounted rigger (AeRoWing - see our websites) reduces
water interference by streamline-shaping of the feet & the
location/alignment of the rigger stay.
As for optimising the rigger position, mentioned by Tony earlier:
A boatbuilder who denies you choice of rigger specification, take it or
leave it, clearly doesn't understand rowing & rowers. The riggers we
make for our boats - & for the much larger number of boats of other
makes for which we also supply riggers - are made to the exact
requirements of each client. We position the pin for height, span/TD &
work position exactly as requested, as is the customers' right.
It amazes me that there should be any other way of doing it. I would
simply point out that the cost of new riggers, or rigger frames, to get
the optimum rowing position & trim for you or your crew is very small in
comparison with the cost of the boat & of the training, feeding & travel
costs of an unsuccessful rowing season.
Cheers -
Carl
Carl Douglas Racing Shells -
Fine Small-Boats/AeRoWing low-drag Riggers/Advanced Accessories
Write: The Boathouse, Timsway, Chertsey Lane, Staines TW18 3JZ, UK
Email: ca...@carldouglas.co.uk Tel: +44(0)1784-456344 Fax: -466550
URLs: www.carldouglas.co.uk (boats) & www.aerowing.co.uk (riggers)
Carl Douglas
writes
>In uno strano messaggio del 10 Apr 01 acu...@nortelnetworks.com
>(2:333/608.1) scrisse al povero All :
> a> Another way to test the stiffness of a boat is to just try to lift it by
> a> the bow ball whilst its upside down on the rack. See how much travel you
> a> have on the bow ball before the full weight of the boat resists.
>
>This is a bit strange, hasn't the bow to push into the water ? So don't you
>need stiffness in the other direction ? Try to lift the boat from the bowball
>with the boat upright instead!
Mike -
Tony's method is a good way to test initial stiffness of a hull since
the weights of different hulls are fairly similar. Unless there is
something very unusual about a particular boat, it should show equal
stiffness for the first stage of bending in either direction.
With their large open sections you may find that the bending curve for
eights loaded in the conventional way is slightly non-linear because,
when the saxboards are thus put into compression, being high but narrow
they may begin to buckle (become wavy) to a small extent. For that
reason many eights have a lip or flange at the top of the sax - making
the sax L-shaped tends to prevent it from going out of shape under
longitudinal compression.
If, beyond a certain (but still realistic) load, a boat's stiffness
becomes much lower in one direction than the other, that is either due
to buckling & other deficiencies in the parts of the structure under
compression, or to actual separation of parts which are under tension.
Tony Curran
Carl Douglas wrote:
> As for optimising the rigger position, mentioned by Tony earlier:
> A boatbuilder who denies you choice of rigger specification, take it or
> leave it, clearly doesn't understand rowing & rowers. The riggers we
> make for our boats - & for the much larger number of boats of other
> makes for which we also supply riggers - are made to the exact
> requirements of each client. We position the pin for height, span/TD &
> work position exactly as requested, as is the customers' right.
Carl,
I know very well that you offer to place the Work Point where the buyer wants it
when you make riggers. My question really was about signifiacance of the Work
Point in relation to the CoG. Most boats place work point inline with the rib. Is
this rib placed at the CoG of the boat? Or what is the significance of the
location of the Work Point, of which I set myself up in the boat to be about 10cm
in front of (approximately in line with the centre of the seat). Or is the work
point fixed - ie where the rib is and the work infront of and behind the Work
Point is defined by the position of the rib, in which case wing rigged boats are
stuffed because they don't have a rib (I believe its the former). Or is the rib
just a point of reference?
Of the three pairs of riggers I've had from you for various boats, dimension F,
measured from the centre line thru the attachment bolt, has always been ordered as
zero (though I do understand the significance of being fore or aft of that
position - affects catch position). Unfortunately I don't have deep enough pockets
to order three riggers (with different values for F) for my boat which I can test
and make informed decision - and I'm sure your not going to give them away. So you
buy whay you know with least risk.
Tony
Ottawa RC
Carl Douglas
>
>
>Carl Douglas wrote:
>
>> As for optimising the rigger position, mentioned by Tony earlier:
>> A boatbuilder who denies you choice of rigger specification, take it or
>> leave it, clearly doesn't understand rowing & rowers. The riggers we
>> make for our boats - & for the much larger number of boats of other
>> makes for which we also supply riggers - are made to the exact
>> requirements of each client. We position the pin for height, span/TD &
>> work position exactly as requested, as is the customers' right.
>
>Carl,
>
>I know very well that you offer to place the Work Point where the buyer wants it
>when you make riggers. My question really was about signifiacance of the Work
>Point in relation to the CoG. Most boats place work point inline with the rib.
>Is
>this rib placed at the CoG of the boat? Or what is the significance of the
>location of the Work Point, of which I set myself up in the boat to be about
>10cm
>in front of (approximately in line with the centre of the seat). Or is the work
>point fixed - ie where the rib is and the work infront of and behind the Work
>Point is defined by the position of the rib, in which case wing rigged boats are
>stuffed because they don't have a rib (I believe its the former). Or is the rib
>just a point of reference?
Why do I always get the easy questions ;^( ?
If we are considering a conventionally-riggered boat, the most efficient
(lightest & stiffest) rigger arrangement will put the pin pretty much in
line with the main shoulder. That keeps the main stay short but gives a
satisfactorily wide angle between the main & aft rigger stays. Designs
which put the main shoulder further to the bow & result in a spread
rigger stay layout lead inevitably to more-flexible & heavier riggers &
do none of the alleged favours for the boat. Similarly, closing the
angle between main & aft stays by moving the main shoulder astern
(making the riggers look more like aft-mounted wings) again increases
rigger flexibility & weight.
Positioning the pin (which determines the dimensions to which the
riggers must be built) is in the first place a matter for the expertise
& discretion of the boat-builder, who ought to know at what trim the
boat will perform at its best. However, since the crew moves by the
same distance in an eight as a single, it is clear that correct
positioning of the pin & the crew is much more sensitive & important for
a single than for any other shell. Indeed, pin position for an eight
can be pretty much wherever you want it, because moving it (& with it
the crew's C of G) a couple of inches either way will make only a minute
difference to the boat's trim. So the best reason for re-setting the
pin position in an eight is that guys in it are so long in the leg that,
unless the pin is moved towards the bow, they can't move their
stretchers far enough astern to achieve an adequate forward reach for
the catch.
Singles are a different matter. Getting the pin position wrong for a
sculler may significantly affect the boat's trim, & scullers' techniques
tend to vary a lot more than rowers': some like to get a very long
catch while others have the opposite preference, yet their bodies will
come to identical positions; some have long legs & short bodies while
others are more stocky. So we like, if possible, to see a sculler &
discuss their technique & physique before establishing the rigging
specification for their new single. Which is why rig specification is
always a client choice with us, whether we are making riggers for our
own boats or for those made by others.
That said, the position of the main shoulders in any shell must be
established in conjunction with the overall structural design of the
shell & should be optimised for the "typical crew". Actually, this does
not (if intelligently done) compromise rigger layout since all the range
of realistic pin positions can then be comfortably accommodated in
rigger manufacture without producing silly geometries.
Some closing notes (as they say about beer tasting):
1. Don't over-confuse sliding position with position of C of G. If a
sculler likes their feet high in the boat they'll need to move the
slides astern to achieve the same reach since they'll sit more upright
at the catch, but their C of G does not move as far astern as that slide
adjustment might suggest & they may use a bit more layback to achieve
the same stroke length
2. The trim of a boat is important but, particularly in singles, it may
be transiently but very visibly affected by checked catches even though
it may be correct for the rest of the stroke & recovery
3. Maybe the boat-builder got it wrong, & the boat really does run
better with its bows up in the air or under water. None of us knows
everything.
Happy Friday 13th!