15 Jan 2008 10:27:28
tlog
Scull length for a recreational single

Hi All,
I've searched RSR for this but with no luck.
I have a 17 foot recreational single, spread of 159cm and inboards of
88 cm which gives a nice overlap. What should the overall length of
the sculling blades (Cleavers) be for this type of boat given that
it's a/. not as fast as a fine boat and b/. likely to be rowed by
people for pleasure who wont be as fit as a reasonable club rower.
Help appreciated.
Cheers

Roger


15 Jan 2008 11:56:07
Mike Sullivan
Re: Scull length for a recreational single

the working outboard isn't all that critical for recreational
rowing, many scullers don't athletically get to full compression
anyway, and aren't doing 2K races, but if you have
adjustable length sculls and you want to, then
shorten the overall length as much as it will allow you to,
if they are CIIs, you prolly won't get shorter than about
288 cm or so.

your spread and inboard are good, I always find rigging
height to be a problem for club boats as rigging a rec boat
for a big guy means smaller women are pulling into their
chins.


"tlog" <tlog@angelfire.com > wrote in message
news:0ef58699-ae25-4085-985d-3fa8363136cf@p69g2000hsa.googlegroups.com...
> Hi All,
> I've searched RSR for this but with no luck.
> I have a 17 foot recreational single, spread of 159cm and inboards of
> 88 cm which gives a nice overlap. What should the overall length of
> the sculling blades (Cleavers) be for this type of boat given that
> it's a/. not as fast as a fine boat and b/. likely to be rowed by
> people for pleasure who wont be as fit as a reasonable club rower.
> Help appreciated.
> Cheers
>
> Roger




16 Jan 2008 01:06:20
carolinetu
Re: Scull length for a recreational single

On Jan 15, 7:56=A0pm, "Mike Sullivan" <s...@slacSNIP.stanford.edu >
wrote:
> the working outboard isn't all that critical for recreational
> rowing, =A0many scullers don't athletically get to full compression
> anyway, =A0and aren't doing 2K races, but if you have
> adjustable length sculls and you want to, then
> shorten the overall length as much as it will allow you to,
> if they are CIIs, you prolly won't get shorter than about
> 288 cm or so.
>
> your spread and inboard are good, =A0I always find rigging
> height to be a problem for club boats as rigging a rec boat
> for a big guy means smaller women are pulling into their
> chins.
>
> "tlog" <t...@angelfire.com> wrote in message
>
> news:0ef58699-ae25-4085-985d-3fa8363136cf@p69g2000hsa.googlegroups.com...
>
>
>
> > Hi All,
> > I've searched RSR for this but with no luck.
> > I have a 17 foot recreational single, spread of 159cm and inboards of
> > 88 cm which gives a nice overlap. What should the overall length of
> > the sculling blades (Cleavers) be for this type of boat given that
> > it's a/. not as fast as a fine boat and b/. likely to be rowed by
> > people for pleasure who wont be as fit as a reasonable club rower.
> > Help appreciated.
> > Cheers
>
> > Roger- Hide quoted text -
>
> - Show quoted text -

We recently bought some Dreher "Little Big Blades" for our
recreational rowers - the spoons are slightly smaller than normal
cleavers making them somewhat easier for people who are less fit and
strong. They are very light and have nice grips, and are also a bit
cheaper than the racing sculls (always a bonus!). Ours are 288 cm
long with 88 cm inboard and 160 cm span.

Caroline


16 Jan 2008 07:47:03
Re: Scull length for a recreational single

Roger, in an OT manner, Collars in England are very knowledgeable for
Fixed seat oars and maybe rec sliding seats .they have a proud history
and it might be worthwhile contacting them.
Also , I'm not sure that Cleavers are the correct oars for a 17ft rec
- rower,, in the old days "radical" spoons were reserved for "Fast
Gigs" , on slower boats the oars would cavitate ( I refer to John
Cullers book Boats oars and rowing) the same way a fast 19 ft + gig
would run away from ordinary oars. Perhaps you might want consider
using smaller and less "radical' blades, However Collars would be well
positioned to advise.


19 Jan 2008 12:55:49
tlog
Re: Scull length for a recreational single

On Jan 16, 10:47=A0am, mi...@jaywalk.com wrote:
>
Thankyou all for the advice. I'll keep spread and inboard where they
are and get the outboard down below 290cm

Cheers Roger


21 Jan 2008 07:09:51
Jake
Re: Scull length for a recreational single

1) Roger, hope you are well and keeping fit. I look forward to our
next great sculling battle, wherever that will be...

2) This mention of cavitation raises something that has been bugging
me in my sculling. Anybody know if the following is a bad thing:
Should there be a largish hole/ vortex (say 6 inches diameter) , which
then collapses with a vertical (upwards) splash, just after the mid
stroke accompanied by a slurp or sometimes a pop?
This all happens at the back of the blade, say 6 inches behind it. I'd
hate to think I'm wasting boat moving energy making slurps or pops,
and my understanding of cavitation in the context of an underwater
foil is when it drags a bubble of air from the surface.
a) Is this what is happening?
b) Do I need to know about it/ worry about it etc.



21 Jan 2008 07:38:22
Re: Scull length for a recreational single

On 21 Jan, 15:09, Jake <jake.fr...@rya.org.uk > wrote:
> 1) Roger, hope you are well and keeping fit. I look forward to our
> next great sculling battle, wherever that will be...
>
> 2) This mention of cavitation raises something that has been bugging
> me in my sculling. Anybody know if the following is a bad thing:
> Should there be a largish hole/ vortex (say 6 inches diameter) , which
> then collapses with a vertical (upwards) splash, just after the mid
> stroke accompanied by a slurp or sometimes a pop?
> This all happens at the back of the blade, say 6 inches behind it. I'd
> hate to think I'm wasting boat moving energy making slurps or pops,
> and my understanding of cavitation in the context of an underwater
> foil is when it drags a bubble of air from the surface.
> a) Is this what is happening?
> b) Do I need to know about it/ worry about it etc.

Does sound like it TBH. It means the blade is slipping in the water at
midstroke, ie lots of wasted, non-boat-moving work. It's a bit like
your feet slipping backwards when you try to run on soft sand.

You need to have the spoon buried more. You could try dropping the
gate height a bit, which might help.
Kit


21 Jan 2008 16:16:47
mruscoe
Re: Scull length for a recreational single

kdavies@kidare.com wrote:
> On 21 Jan, 15:09, Jake <jake.fr...@rya.org.uk> wrote:
>> 1) Roger, hope you are well and keeping fit. I look forward to our
>> next great sculling battle, wherever that will be...
>>
>> 2) This mention of cavitation raises something that has been bugging
>> me in my sculling. Anybody know if the following is a bad thing:
>> Should there be a largish hole/ vortex (say 6 inches diameter) , which
>> then collapses with a vertical (upwards) splash, just after the mid
>> stroke accompanied by a slurp or sometimes a pop?
>> This all happens at the back of the blade, say 6 inches behind it. I'd
>> hate to think I'm wasting boat moving energy making slurps or pops,
>> and my understanding of cavitation in the context of an underwater
>> foil is when it drags a bubble of air from the surface.
>> a) Is this what is happening?
>> b) Do I need to know about it/ worry about it etc.
>
> Does sound like it TBH. It means the blade is slipping in the water at
> midstroke, ie lots of wasted, non-boat-moving work. It's a bit like
> your feet slipping backwards when you try to run on soft sand.
>
> You need to have the spoon buried more. You could try dropping the
> gate height a bit, which might help.
> Kit

I find this with the right blade more than the left (sculling left over
right) so it's partly due to blade depth. Also, I have noticed that it
seems to develop as the water gets colder in winter and the boat is
moving slower, and can be lessened by lightening the gearing slightly.


30 Jan 2008 01:54:02
Re: Scull length for a recreational single

For our Burgashell R1 scull we set the span at 1cm further outboard on
each side, and suggested that approx 1cm collars were used on standard
racing sculls. Rigging is all about gearing, and this rig leaves the
handles in the same position but with a similar feel due to the lower
running speed of the hull.

I would advise making the rig lighter, so more inboard and less
outboard, moving the pins out, so that the boat feels comfortable to
row at your normal racing scull steady-state rating.

Regarding the cavitation comment... Surely the ideal situation is to
leave the water as you found it, ie. giving as little energy to the
water as possible? This assumption leads to a reasonable answer to
most blade arguments and suggests that popping, collapsing and
exploding are all unhelpful things to be doing with your time.

Nick




On 21 Jan, 16:16, mruscoe <use...@mruscoe.org > wrote:
> kdav...@kidare.com wrote:
> > On 21 Jan, 15:09, Jake <jake.fr...@rya.org.uk> wrote:
> >> 1) Roger, hope you are well and keeping fit. I look forward to our
> >> next great sculling battle, wherever that will be...
>
> >> 2) This mention of cavitation raises something that has been bugging
> >> me in my sculling. Anybody know if the following is a bad thing:
> >> Should there be a largish hole/ vortex (say 6 inches diameter) , which
> >> then collapses with a vertical (upwards) splash, just after the mid
> >> stroke accompanied by a slurp or sometimes a pop?
> >> This all happens at the back of the blade, say 6 inches behind it. I'd
> >> hate to think I'm wasting boat moving energy making slurps or pops,
> >> and my understanding of cavitation in the context of an underwater
> >> foil is when it drags a bubble of air from the surface.
> >> a) Is this what is happening?
> >> b) Do I need to know about it/ worry about it etc.
>
> > Does sound like it TBH. It means the blade is slipping in the water at
> > midstroke, ie lots of wasted, non-boat-moving work. It's a bit like
> > your feet slipping backwards when you try to run on soft sand.
>
> > You need to have the spoon buried more. You could try dropping the
> > gate height a bit, which might help.
> > Kit
>
> I find this with the right blade more than the left (sculling left over
> right) so it's partly due to blade depth. Also, I have noticed that it
> seems to develop as the water gets colder in winter and the boat is
> moving slower, and can be lessened by lightening the gearing slightly.



31 Jan 2008 19:58:54
Re: Scull length for a recreational single

On Jan 15, 10:27 am, tlog <t...@angelfire.com > wrote:
> Hi All,
> I've searched RSR for this but with no luck.
> I have a 17 foot recreational single, spread of 159cm and inboards of
> 88 cm which gives a nice overlap. What should the overall length of
> the sculling blades (Cleavers) be for this type of boat given that
> it's a/. not as fast as a fine boat and b/. likely to be rowed by
> people for pleasure who wont be as fit as a reasonable club rower.
> Help appreciated.
> Cheers
>
> Roger

I'd assume a recreational single would be spending most of his or her
time in various bars working of perfecting their chat-up lines...


01 Feb 2008 19:01:17
John Mulholland
Re: Scull length for a recreational single

<RoCoach@gmail.com > wrote in message
news:91345ad9-6d64-41d6-beb9-5d3a81e69907@n20g2000hsh.googlegroups.com...
> On Jan 15, 10:27 am, tlog <t...@angelfire.com> wrote:
>> Hi All,
>> I've searched RSR for this but with no luck.
>> I have a 17 foot recreational single, spread of 159cm and inboards of
>> 88 cm which gives a nice overlap. What should the overall length of
>> the sculling blades (Cleavers) be for this type of boat given that
>> it's a/. not as fast as a fine boat and b/. likely to be rowed by
>> people for pleasure who wont be as fit as a reasonable club rower.
>> Help appreciated.
>> Cheers
>>
>> Roger
>
> I'd assume a recreational single would be spending most of his or her
> time in various bars working of perfecting their chat-up lines...

Though, at 17 foot tall, the chat-up lines might go straight over the heads
of any potential partners.

--
John Mulholland