River travel

In the past, people here have posted URLs for seagoing
bikes, which look like pretty toys.

But has anyone actually ridden such a thing? And would
it be at all realistic to use for regular transport on
a journey of 15-20 miles that's primarily river
(specifically, the Tamar from around Gunnislake to
locations in Plymouth)?

My gut feeling is that upstream at least would tend to
call for an engine. Anyone with real-life knowledge/
experience?

--
Nick Kew

In article , Nick Kew wrote:
In the past, people here have posted URLs for seagoing
bikes, which look like pretty toys.

But has anyone actually ridden such a thing? And would
it be at all realistic to use for regular transport on
a journey of 15-20 miles that's primarily river
(specifically, the Tamar from around Gunnislake to
locations in Plymouth)?

My gut feeling is that upstream at least would tend to
call for an engine. Anyone with real-life knowledge/
experience?

I have no real experience, but would be dubious about
using one at sea.

http://www.shuttlebike.com/ says cruising speed
3.5 knots (6 km/h), maximum speed 5.5 knots (10 km/h)
Looking at a map of Plymouth, tidal stream is likely
to vary a lot depending exactly which locations you
want to get to and whether you can time your journey
for slack water or have to get there at a set time.

http://www.bhpc.org.uk/oldnews/Issue63.pdf has an
article by someone who tried a Speed Ross on one
(on a lake), which doesn't sound a huge success
(he managed 2-3mph when the prop wasn't tangled
in weed, and the Ross steering didn't turn far
enough).

Nick Kew wrote:
In the past, people here have posted URLs for seagoing
bikes, which look like pretty toys.

But has anyone actually ridden such a thing? And would
it be at all realistic to use for regular transport on
a journey of 15-20 miles that's primarily river
(specifically, the Tamar from around Gunnislake to
locations in Plymouth)?

My gut feeling is that upstream at least would tend to
call for an engine. Anyone with real-life knowledge/
experience?


Why not go for one of the pedal powered boats out there? At least the
fundamental vehicle, a boat, is designed for use on water whereas a
bicycle is not. Either way 15-20 miles is a long way by human powered
boat downstream let alone upstream.

--
Tony

"I did make a mistake once - I thought I'd made a mistake but I hadn't"
Anon

in message , Nick Kew
') wrote:

In the past, people here have posted URLs for seagoing
bikes, which look like pretty toys.

But has anyone actually ridden such a thing? And would
it be at all realistic to use for regular transport on
a journey of 15-20 miles that's primarily river
(specifically, the Tamar from around Gunnislake to
locations in Plymouth)?

My gut feeling is that upstream at least would tend to
call for an engine. Anyone with real-life knowledge/
experience?

I strongly suspect a light rowing skiff would be better. Pedalling is a
very efficient way of turning muscle energy into rotational motion, but
even the best propellers are not very efficient in turning rotational
motion into actual movement of the boat.

I've done a lot of rowing (including against fast tides); I have used a
pedalo but only under fairly calm conditions.

--
(Simon Brooke) http://www.jasmine.org.uk/~simon/

;; may contain traces of nuts, bolts or washers.

On Mon, 10 Oct 2005 09:04:47 +0100, Simon Brooke wrote:

My gut feeling is that upstream at least would tend to call for an
engine. Anyone with real-life knowledge/ experience?

I strongly suspect a light rowing skiff would be better.
I strongly suspect something with sails would be good too!

Thinking about it, water has a much higher drag than air.
If you're trying to move a vehicle through water via human power,
as you say you want something with as streamlined a hull as possible,
and probably nicely polished like a rowing skiff.
I'm sure Pete Clinch has a bike rack for his sea kayak somewhere though :-)

I'm sure you can't get a human powered boat, pedal or otherwise, up on the
plane.

Not a great sailor, but a fast sailing dinghy minimises wetted hull area.
Can't remember if it is the leaning over which does this, or just getting
it properly up to speed.

And hence powered watercraft like hydrofoils/Sea Cats. Minimise wetted
area and you cut drag dramatically.


Veering wildly off-topic, I read an interesting article in a trade
magazine recently, about the use of computational fluid dynamics in
cycling. I know that wind tunnels are commonly used in pro cycling.
This article was talking about simulations of a team of cyclists, for time
trialling. Comment was this is not in common use now, but in a few years
may well make the difference between first and second place.
Who knows, I might be recruited by a top cycling team yet!

"John Hearns" wrote:

I'm sure you can't get a human powered boat, pedal or
otherwise, up on the plane.

These guys can:

http://www.humanpoweredboats.com/Pho...rofoilHPBs.htm

James Thomson

Truth is stranger than fiction.

Someone on the GLLUG list posts a link about some science-fiction,
on evolutionary software development putting all programmers out of a job.
I follow the link, then another and find:
http://www.foilkayak.com/ a hydrofoil kayak

On Mon, 10 Oct 2005 10:36:59 +0200, James Thomson wrote:

These guys can:

http://www.humanpoweredboats.com/Pho...rofoilHPBs.htm

Oh no. Its bad enough to have helmet threads on u.r.c. let alone
bouyancy aids.

http://www.humanpoweredboats.com/Pho...PBs/AvaAva.jpg




ps. That's a joke, right? I wouldn't go anywhere near a kayak or a sailing
dinghy sans bouyancy aid. And I used to have a lid firmly on the
head when doing any white-water stuff.

John Hearns wrote:
Truth is stranger than fiction.

Someone on the GLLUG list posts a link about some science-fiction,
on evolutionary software development putting all programmers out of a job.
I follow the link, then another and find:
http://www.foilkayak.com/ a hydrofoil kayak

Just wondering whether a hydrofil is illegal on rowing eights.. that
would be seriously fast..

...d

John Hearns wrote:

I'm sure you can't get a human powered boat, pedal or otherwise, up on the
plane.

There are now hydro-wing kayaks, see http://www.foilkayak.com/

As the site states, "Hydrofoil kayaking demands a certain level of
fitness", so you needn't apply unless you're a strong paddler with good
wing technique, but it *is* possible.
A rowing skiff may well have problems because there's too much of a
return pause between the strokes, where a kayak has a closer rhythm to
help make up for the reduced power of a single stroke. Another
advantage of the kayak is that the freedom of the paddle allows use of
hydrodynamic lift from wing paddles which are individually more
efficient, but need a rather contrived technique which wouldn't work too
well with a fixed rollock (I'm guessing, I don't really know anything
much about rowing).

The IHPVA page sends you to http://lancet.mit.edu/decavitator/ for a
pedal powered foil, if you insist on doing it that way. This has the HP
water record at the moment at 18.5 knots

Not a great sailor, but a fast sailing dinghy minimises wetted hull area.
Can't remember if it is the leaning over which does this, or just getting
it properly up to speed.

The leaning is just a natural reaction to the wind pushing it from the
side. AFAICT best speed is on the level (aside from anything else
leaning the boat tends to mask the sail as it is pushed over, limiting
the power you can get from it).

Pete.
--
Peter Clinch Medical Physics IT Officer
Tel 44 1382 660111 ext. 33637 Univ. of Dundee, Ninewells Hospital
Fax 44 1382 640177 Dundee DD1 9SY Scotland UK
net http://www.dundee.ac.uk/~pjclinch/