Re: How wide should a tender be for comfortable rowing?
Hi Ken,
with its clean entry and exit flow, is part of the reason. I don't
have the plans in front of me, but the waterline beam is quite a bit
less than the 45" beam at the rails. I think the boat is sort of a
poor man's Thomaston Galley, having no sailing rig or motor mount.
The photos on this page give some sense of the difference in waterline
and overall beam:
http://www.kolbsadventures.com/robote_8.htm
On the other hand, my 19'-6" Long Light Dory has much less than 39"
waterline beam, especially when lightly loaded. With just me and a
little fishing gear aboard, I'll bet it's not much over 26"-28", since
the bottom panel is only 24" wide at its maximum breadth. This page
gives some idea of the bottom width compared to the overall beam:
http://www.kolbsadventures.com/long_dory_7.htmI think you'd have to
really load this boat down to get it to 39" waterline beam.
Jon Kolb
www.kolbsadventures.com/boatbuilding_index.htm
> Robote is based on his tiny little WeeVee that is less than 8 feetlong yet
> has the same "no chines in the water" design. This feature, and notwist in
> the bottom panels, are what Jim attributes the great rowingcharacteristics
> of these boats.Robote is definitely a fine rowing machine, and no doubt the v-bottom,
with its clean entry and exit flow, is part of the reason. I don't
have the plans in front of me, but the waterline beam is quite a bit
less than the 45" beam at the rails. I think the boat is sort of a
poor man's Thomaston Galley, having no sailing rig or motor mount.
The photos on this page give some sense of the difference in waterline
and overall beam:
http://www.kolbsadventures.com/robote_8.htm
On the other hand, my 19'-6" Long Light Dory has much less than 39"
waterline beam, especially when lightly loaded. With just me and a
little fishing gear aboard, I'll bet it's not much over 26"-28", since
the bottom panel is only 24" wide at its maximum breadth. This page
gives some idea of the bottom width compared to the overall beam:
http://www.kolbsadventures.com/long_dory_7.htmI think you'd have to
really load this boat down to get it to 39" waterline beam.
Jon Kolb
www.kolbsadventures.com/boatbuilding_index.htm
Hi Ken,
ROBOTE has an overall beam of 42.5 inches, not 48, as measured to
the outside of planking.
The ROBOTE waterline beam is also 42.5 inches at a designed maximum
displacement of 610lbs, while draft is 9 inches, and the chines are
just touching the water in level trim. This would be when carrying a
passenger and some gear.
However when carrying a solo rower, at the designed displacement of
320lbs, the draft is 7 inches, the chines are above the water and
the waterline beam lies between 38.5 and 39.5 inches.
I say between 38.5 and 39.5 as I am only eyballing the reduced plan
included in the book and not a blueprint, and of course some boats
will be heavier and sit lower than others. It does show the 39
inch "rule" though (+ or - a bit). If I correctly recollect
comparisons made a while ago, then ROBOTE is very close to the
Bolger CRYSTAL in waterline dimension and proportion.
The double chined Michalak WOOBOO is just a litlle bigger in size
than ROBOTE, and has more beam as it's intended to sail in
addittion to rowing well. It's maximum beam from the blueprint is
48.5 inches with the upper chine just immersing at a passenger and
gear carrying 600lbs displacement. However, again, at a lighter solo
crew displacement the waterline beam is reduced to not much more
than 40 inches only. I'd say that it's within the 39 inch plus or
minus "rule".
Michalak's WEE VEE also evolved into his VOLE. At similar length it
is wider so is not as deep for a similar displacement, but in other
aspects you mention it is the same. Solo crew would see it at about
a 48 inch WLB so it is better for sailing, but definately not for
rowing. Displacement links draft to WLB; change one and you change
the other, all else remaining unchanged as much as possible. Jim
Michalak talks of the deep draft of WEE VEE probably helping to make
it a good rower, but he could just as much talk about the WLB -
thing is, WEE VEE makes a good rower at about 39 inches WLB, and
VOLE doesn't at 48inches.
(Jon: incidently JM says the 7.5 feet long VOLE is not a good
tender. It's too clunky wide at 5 feet overall beam.)
Graeme
--- Inbolger@yahoogroups.com, Kenneth Grome <bagacayboatworks@...>
wrote:
ROBOTE has an overall beam of 42.5 inches, not 48, as measured to
the outside of planking.
The ROBOTE waterline beam is also 42.5 inches at a designed maximum
displacement of 610lbs, while draft is 9 inches, and the chines are
just touching the water in level trim. This would be when carrying a
passenger and some gear.
However when carrying a solo rower, at the designed displacement of
320lbs, the draft is 7 inches, the chines are above the water and
the waterline beam lies between 38.5 and 39.5 inches.
I say between 38.5 and 39.5 as I am only eyballing the reduced plan
included in the book and not a blueprint, and of course some boats
will be heavier and sit lower than others. It does show the 39
inch "rule" though (+ or - a bit). If I correctly recollect
comparisons made a while ago, then ROBOTE is very close to the
Bolger CRYSTAL in waterline dimension and proportion.
The double chined Michalak WOOBOO is just a litlle bigger in size
than ROBOTE, and has more beam as it's intended to sail in
addittion to rowing well. It's maximum beam from the blueprint is
48.5 inches with the upper chine just immersing at a passenger and
gear carrying 600lbs displacement. However, again, at a lighter solo
crew displacement the waterline beam is reduced to not much more
than 40 inches only. I'd say that it's within the 39 inch plus or
minus "rule".
Michalak's WEE VEE also evolved into his VOLE. At similar length it
is wider so is not as deep for a similar displacement, but in other
aspects you mention it is the same. Solo crew would see it at about
a 48 inch WLB so it is better for sailing, but definately not for
rowing. Displacement links draft to WLB; change one and you change
the other, all else remaining unchanged as much as possible. Jim
Michalak talks of the deep draft of WEE VEE probably helping to make
it a good rower, but he could just as much talk about the WLB -
thing is, WEE VEE makes a good rower at about 39 inches WLB, and
VOLE doesn't at 48inches.
(Jon: incidently JM says the 7.5 feet long VOLE is not a good
tender. It's too clunky wide at 5 feet overall beam.)
Graeme
--- Inbolger@yahoogroups.com, Kenneth Grome <bagacayboatworks@...>
wrote:
>that's almost 4
> Hi Graeme,
>
> Jim Michalak designed Robote, reportedly a wonderful rowboat
> feet wide and 14 feet long:long yet
>
>http://www.duckworksbbs.com/plans/jim/robote/index.htm
>
> Robote is based on his tiny little WeeVee that is less than 8 feet
> has the same "no chines in the water" design. This feature, andno twist in
> the bottom panels, are what Jim attributes the great rowingcharacteristics
> of these boats.water. Robote
>
> I think Bolger's "rule" applies only when the chines are in the
> and WeeVee don't drag any chines in the water and that's probablywhy they
> are such a good rowboats even though they are both wider thanthe "Bolger
> rule".
>
> Sincerely,
> Ken Grome
> Bagacay Boatworks
> www.bagacayboatworks.com
Hi Graeme,
Jim Michalak designed Robote, reportedly a wonderful rowboat that's almost 4
feet wide and 14 feet long:
http://www.duckworksbbs.com/plans/jim/robote/index.htm
Robote is based on his tiny little WeeVee that is less than 8 feet long yet
has the same "no chines in the water" design. This feature, and no twist in
the bottom panels, are what Jim attributes the great rowing characteristics
of these boats.
I think Bolger's "rule" applies only when the chines are in the water. Robote
and WeeVee don't drag any chines in the water and that's probably why they
are such a good rowboats even though they are both wider than the "Bolger
rule".
Sincerely,
Ken Grome
Bagacay Boatworks
www.bagacayboatworks.com
Jim Michalak designed Robote, reportedly a wonderful rowboat that's almost 4
feet wide and 14 feet long:
http://www.duckworksbbs.com/plans/jim/robote/index.htm
Robote is based on his tiny little WeeVee that is less than 8 feet long yet
has the same "no chines in the water" design. This feature, and no twist in
the bottom panels, are what Jim attributes the great rowing characteristics
of these boats.
I think Bolger's "rule" applies only when the chines are in the water. Robote
and WeeVee don't drag any chines in the water and that's probably why they
are such a good rowboats even though they are both wider than the "Bolger
rule".
Sincerely,
Ken Grome
Bagacay Boatworks
www.bagacayboatworks.com
> Jon,
>
> particularly for a boat design that has a specification high on the
> list for solo rowing, PCB indicates that about a 39 inch waterline
> beam is the maximum. For example, see the PCB write-ups on JUNE BUG
> & PIRATE RACER for mention of the 39. The 15 feeet 6 inches long
> FEATHERWIND, a much earlier flat bottomed single chine boat, mostly
> meant for sailing though, is only 42 inches on the bottom. It's
> flared sides give a waterline beam of only about 46+ inches at her
> designed displacement of 700lbs yet PCB says " ..she's too wide on
> the bottom to be a really good rowboat.." He does go on to say that
> under oars " she's not to be sneered at and a GOOD MAN could
> certainly get over a mile in twenty minutes in her in a DEAD CALM."
>
> I've not seen PCB's detailed explanation of what seems to be the
> 39 "rule"; explanation of why exactly it is a rule, if he's ever
> published it. I suspect that the 39 inches WLB is a rule of thumb
> that delivers an optimum balance between the conflicting
> requirements for stability and load carrying on the one hand versus
> speed limiting resistance on the other. It must apply to all hull
> cross section types too. Take a look at PCB's dory, Vee-bottomed,
> multichined, round bilged, and round bottomed boats intended for
> solo rowing - few go very much wider than 39 inches WLB.
>
> The more rounded bottom boats should have less wetted surface, so
> less surface drag, as well as less chine turbulence than flat
> bottomed boats. The more Vee-bottomed boats should have more wetted
> surface, but less to nil chine drag. That the 39 inch (+ or - a bit)
> WLB limit apparently applies to all types of bottom shape, of
> whatever length, is a puzzle to me. It seems to indicate that drag
> from wave making and form necessitate this width. At rowing speed
> the resistance is supposed to be mostly from wetted surface drag
> (skin friction).
>
> Now there's a puzzle I'd like explained.
>
> Graeme
--- Inbolger@yahoogroups.com, catboat15@... wrote:
What do you mean you HAD a Bolger Car Topper? Don't you still have it?
Nice to hear from you.
Nels
>well. Then
> I had a Bolger Car Topper with four foot beam and it rowed quite
> had a Fred Shell Swifty that was six feet wide and that wasdifficult to row.
> (bought a little 2 cycle "kicker" for that one.Hi John,
>
>
> Bolger, Payson Car topper
> 14-9 foot Swifty
> John Meacham
>
What do you mean you HAD a Bolger Car Topper? Don't you still have it?
Nice to hear from you.
Nels
Jon,
particularly for a boat design that has a specification high on the
list for solo rowing, PCB indicates that about a 39 inch waterline
beam is the maximum. For example, see the PCB write-ups on JUNE BUG
& PIRATE RACER for mention of the 39. The 15 feeet 6 inches long
FEATHERWIND, a much earlier flat bottomed single chine boat, mostly
meant for sailing though, is only 42 inches on the bottom. It's
flared sides give a waterline beam of only about 46+ inches at her
designed displacement of 700lbs yet PCB says " ..she's too wide on
the bottom to be a really good rowboat.." He does go on to say that
under oars " she's not to be sneered at and a GOOD MAN could
certainly get over a mile in twenty minutes in her in a DEAD CALM."
I've not seen PCB's detailed explanation of what seems to be the
39 "rule"; explanation of why exactly it is a rule, if he's ever
published it. I suspect that the 39 inches WLB is a rule of thumb
that delivers an optimum balance between the conflicting
requirements for stability and load carrying on the one hand versus
speed limiting resistance on the other. It must apply to all hull
cross section types too. Take a look at PCB's dory, Vee-bottomed,
multichined, round bilged, and round bottomed boats intended for
solo rowing - few go very much wider than 39 inches WLB.
The more rounded bottom boats should have less wetted surface, so
less surface drag, as well as less chine turbulence than flat
bottomed boats. The more Vee-bottomed boats should have more wetted
surface, but less to nil chine drag. That the 39 inch (+ or - a bit)
WLB limit apparently applies to all types of bottom shape, of
whatever length, is a puzzle to me. It seems to indicate that drag
from wave making and form necessitate this width. At rowing speed
the resistance is supposed to be mostly from wetted surface drag
(skin friction).
Now there's a puzzle I'd like explained.
Graeme
--- Inbolger@yahoogroups.com, "jonny_stone2002" <jonathan@...>
wrote:
particularly for a boat design that has a specification high on the
list for solo rowing, PCB indicates that about a 39 inch waterline
beam is the maximum. For example, see the PCB write-ups on JUNE BUG
& PIRATE RACER for mention of the 39. The 15 feeet 6 inches long
FEATHERWIND, a much earlier flat bottomed single chine boat, mostly
meant for sailing though, is only 42 inches on the bottom. It's
flared sides give a waterline beam of only about 46+ inches at her
designed displacement of 700lbs yet PCB says " ..she's too wide on
the bottom to be a really good rowboat.." He does go on to say that
under oars " she's not to be sneered at and a GOOD MAN could
certainly get over a mile in twenty minutes in her in a DEAD CALM."
I've not seen PCB's detailed explanation of what seems to be the
39 "rule"; explanation of why exactly it is a rule, if he's ever
published it. I suspect that the 39 inches WLB is a rule of thumb
that delivers an optimum balance between the conflicting
requirements for stability and load carrying on the one hand versus
speed limiting resistance on the other. It must apply to all hull
cross section types too. Take a look at PCB's dory, Vee-bottomed,
multichined, round bilged, and round bottomed boats intended for
solo rowing - few go very much wider than 39 inches WLB.
The more rounded bottom boats should have less wetted surface, so
less surface drag, as well as less chine turbulence than flat
bottomed boats. The more Vee-bottomed boats should have more wetted
surface, but less to nil chine drag. That the 39 inch (+ or - a bit)
WLB limit apparently applies to all types of bottom shape, of
whatever length, is a puzzle to me. It seems to indicate that drag
from wave making and form necessitate this width. At rowing speed
the resistance is supposed to be mostly from wetted surface drag
(skin friction).
Now there's a puzzle I'd like explained.
Graeme
--- Inbolger@yahoogroups.com, "jonny_stone2002" <jonathan@...>
wrote:
>foot in
> Hi all,
>
> I am shortly going to be starting to build a tender of about 8
> length. I don't mind how boxy she looks, and volume is useful forlaod
> carrying etc, but is there a max width I should be aware of,beyond
> which rowing becomes more awkward?. I know that the Tortoise forallowed
> example is just over 3 feet wide. yet the 8x4 sheet would have
> it to be built at up to about 4 feet wide. Is there a reason forthis
> or can I make the boat as wide as the wood will allow?
>
> Jon
>
I had a Bolger Car Topper with four foot beam and it rowed quite well. Then
had a Fred Shell Swifty that was six feet wide and that was difficult to row.
(bought a little 2 cycle "kicker" for that one.
Bolger, Payson Car topper
14-9 foot Swifty
John Meacham
************************************** See what's free athttp://www.aol.com
[Non-text portions of this message have been removed]
had a Fred Shell Swifty that was six feet wide and that was difficult to row.
(bought a little 2 cycle "kicker" for that one.
Bolger, Payson Car topper
14-9 foot Swifty
John Meacham
************************************** See what's free athttp://www.aol.com
[Non-text portions of this message have been removed]
> I am shortly going to be starting to build a tender of about 8 foot inI don't know what is too wide, but I did feel that the Elegant Punt
> length. I don't mind how boxy she looks, and volume is useful for laod
> carrying etc, but is there a max width I should be aware of, beyond
> which rowing becomes more awkward?.
was too narrow at 3'7". She's pretty high sided, and a lower boat of
that width might be better.
--- Inbolger@yahoogroups.com, "GarthAB" <garth@...> wrote:
beam, but it also depends on the depth amidships, the height of the
rowing thwart, the height and arm length of the rower.
Rubens Nymph is an enlarged version of Nymph created by increasing the
beam a full foot, while Big Tortoise is an enlarged Tortoise by
increasing the length and leaving the beam the same. Both changes were
to increase the load carrying capacity of the original, but since
Nymph is multi-chine, it seems the decision was to increase the beam.
Both Torti can use the same length oars.
Choosing a tender also involves other decisions. Storing on board or
towing. Weight and launching ease. Stability. Attractiveness. (Ugly
can be better:-) Whether one wants to sail it. How crowded the
anchorage maybe. (I am considering a Payson Pirogue - that uses a paddle.)
Bolger even suggested in one article - towing a large enough tender
that it can be tented over for sleeping in.(CARTOPPER) That way you
had an extra guest room. It supposedly rows well as do the others
mentioned.
Nels
>Dynamite suggests starting off with an oar length 1 1/2 times the
> I think you can go as wide as you like -- just make oars long enough
> to row comfortably. There are a number of different oar-length
> formulas, which you can probably find by Googling around a bit.
>
beam, but it also depends on the depth amidships, the height of the
rowing thwart, the height and arm length of the rower.
Rubens Nymph is an enlarged version of Nymph created by increasing the
beam a full foot, while Big Tortoise is an enlarged Tortoise by
increasing the length and leaving the beam the same. Both changes were
to increase the load carrying capacity of the original, but since
Nymph is multi-chine, it seems the decision was to increase the beam.
Both Torti can use the same length oars.
Choosing a tender also involves other decisions. Storing on board or
towing. Weight and launching ease. Stability. Attractiveness. (Ugly
can be better:-) Whether one wants to sail it. How crowded the
anchorage maybe. (I am considering a Payson Pirogue - that uses a paddle.)
Bolger even suggested in one article - towing a large enough tender
that it can be tented over for sleeping in.(CARTOPPER) That way you
had an extra guest room. It supposedly rows well as do the others
mentioned.
Nels
I think you can go as wide as you like -- just make oars long enough
to row comfortably. There are a number of different oar-length
formulas, which you can probably find by Googling around a bit.
One thing about making a wider tender is: it's just more boat. The
Tortoise or a Mouseboat you can pick up and carry under one arm like a
suitcase. A Rubens Nymph or a Michalak Vole (I just finished one, so
this is on my mind) -- they weigh substantially more. If you need to
cartop or lift or handle it in any way, it's more of a job.
We trailer our Cormorant (31') and carry the dinghy in the big boat's
cockpit till we get to the launch site, so each trip involves lifting
it out, and then back in at the end. If you can leave your dinghy in
the water all season, it's not much of an issue.
All best,
Garth
to row comfortably. There are a number of different oar-length
formulas, which you can probably find by Googling around a bit.
One thing about making a wider tender is: it's just more boat. The
Tortoise or a Mouseboat you can pick up and carry under one arm like a
suitcase. A Rubens Nymph or a Michalak Vole (I just finished one, so
this is on my mind) -- they weigh substantially more. If you need to
cartop or lift or handle it in any way, it's more of a job.
We trailer our Cormorant (31') and carry the dinghy in the big boat's
cockpit till we get to the launch site, so each trip involves lifting
it out, and then back in at the end. If you can leave your dinghy in
the water all season, it's not much of an issue.
All best,
Garth
--- Inbolger@yahoogroups.com, "jonny_stone2002" <jonathan@...> wrote:
>
> Hi all,
>
> I am shortly going to be starting to build a tender of about 8 foot in
> length. I don't mind how boxy she looks, and volume is useful for laod
> carrying etc, but is there a max width I should be aware of, beyond
> which rowing becomes more awkward?. I know that the Tortoise for
> example is just over 3 feet wide. yet the 8x4 sheet would have allowed
> it to be built at up to about 4 feet wide. Is there a reason for this
> or can I make the boat as wide as the wood will allow?
>
> Jon
>
Hi all,
I am shortly going to be starting to build a tender of about 8 foot in
length. I don't mind how boxy she looks, and volume is useful for laod
carrying etc, but is there a max width I should be aware of, beyond
which rowing becomes more awkward?. I know that the Tortoise for
example is just over 3 feet wide. yet the 8x4 sheet would have allowed
it to be built at up to about 4 feet wide. Is there a reason for this
or can I make the boat as wide as the wood will allow?
Jon
I am shortly going to be starting to build a tender of about 8 foot in
length. I don't mind how boxy she looks, and volume is useful for laod
carrying etc, but is there a max width I should be aware of, beyond
which rowing becomes more awkward?. I know that the Tortoise for
example is just over 3 feet wide. yet the 8x4 sheet would have allowed
it to be built at up to about 4 feet wide. Is there a reason for this
or can I make the boat as wide as the wood will allow?
Jon