Model Boat Building

Model Subs – How does the model get the radio signal

howardelliot — Sun, 02 Mar 2008 17:54:21 +0000

How does the model get the radio signal
when its underwater?
We aren’t worried about the technical details.
We do know the radio signal penetrates
fresh water as deep as most people are willing
to take their boats. Heavy chlorine content
in a swimming pool will limit the signal
depth depending on signal strength and
frequency.
Salt water is pretty well impenetrable given
the typical low power and relatively
high-frequency of the R/C units. Crafty sub
modelers have figured out ways to run their
boats in salt water by allowing the radio
receiver’s antenna to remain above the surface.
How do
you see
the sub
or tell
what
its
doing?
In murky water, we sub drivers spend a lot
of time at periscope depth and on the surface,
with short, shallow dives. In clear water,
especially where you can see the bottom,
the models look great underwater. Unlike
a “target” (surface boat in sub-speak),
subs offer that important 3rd dimension to
give some extra excitement. There are also
electronic and mechanical devices available
from several manufacturers to help your
model maintain depth and trim (tilt or level
of the sub.)
How much do they cost?
How much do you want to spend?
A basic, complete beginner sub starts around
$200 and is designed for the backyard pool.
Kits for more functionally capable subs begin
around US$350. For a kit sub, you’ll
also need radio,
batteries,
speed control,
paint,
adhesive s ,
and any accessories
that
you may
want. Figure
on $700 -
$800 by the
time you
have your
sub in the water. Large scale sub kits can
cost as much as $1,500 without radio, but
remember, the real things start at about half
a billion and go up from there. So model
subs are a pretty good value!
How do you
keep the
water out?
Model subs,
just like the
real ones,
have a watertight
and
pressure resistant
compartment
(pressure
hull)
where all the stuff that hates water (motor,
radio, etc.) lives. The parts of the model
that don’t have to be dry are free-flooding,
with holes or slots to allow the water in and
out. Of course, you need to get inside the
pressure hull for assembly and servicing.
Plus, the mechanical connections to operate
the rudders and diving planes need to
get out. These openings in the pressure hull
are typically sealed with o-rings and gaskets.
Some models use custom-fitted hand built
pressure hulls, but nowadays a lot of hobbyists
use commercially available, manufactured
units called WTCs or Water Tight Cylinders.
How do they go under water?
There are two basic ways that model subs
dive: dynamic and static. Dynamic boats
dive by the use of forward motion and angle
on the diving planes. When the model
stops, the boat floats back to the surface
which can be a decided advantage when
there is a failure of the battery or other
equipment! The disadvantage is that the
speed required to submerge, is much faster
than scale (realistic speed).
Static divers actually take water into compartments
called ballast tanks to increase
their weight or reduce their buoyancy. They
are just like the above described dynamic
models only much easier to control under
water: The model can dive at a slower, more
scale speed. Many static boats can take on
enough water to allow them to sink statically,
without forward motion and actually
hover at a fixed depth!
OK, now the boat is sinking, how does it
come back up?
Sinking is such an ugly word! We prefer to
say “diving,” thank you. With a dynamic
diver, you reduce throttle and/or elevate the
dive planes. As the model slows, it will rise
or by elevating the planes the boat surfaces
due to the motion of the water! Static boats
either pump the water out of the ballast
tanks, or blow it out with some form of compressed
gas.
How deep can they go?
In fresh water, the depth is limited by the
strength of the pressure hull and the
operator’s nerves. Typically, most model
subs never get below 10-15 feet. Certainly
some models have gone much deeper than
this.
Torpedoes?
Absolutely!
But unarmed
of course.
Larger model
subs launch
t o r p e d o e s
AND missiles
using the
same sort of
compressed
gas that blows the model submarine’s ballast
tanks.
What happens if it doesnt come back up?
Many model subs have fail-safe systems
incorporated into their construction. These
can range from sophisticated electronic devices
that actuate an emergency ballast system
to mechanical weights that are dropped
to allow the boat to float to the surface.
Otherwise, you either go swimming or hire
a diver.
How fast do they go?
Most will move along at about walking
speed, with some of the smaller modern
shapes getting close to 10 mph.
An entry level R/C sub like
this SubTech Albacore can
cost about $500 – $700
depending on accessories.
Most model subs use a
watertight compartment or
“WTC” to keep the radio and
operating gear dry.
If your sub doesn’t surface you have to be
prepared to write it off or go for a swim!
This torpedo is being fired
from a model submarine!

Building a LEGO ROV Using the MindStorms Robotics Kit

howardelliot — Tue, 08 Jan 2008 17:16:16 +0000

1
Building a LEGO ROV Using the MindStorms Robotics Kit
Amos G. Winter, Tufts University
Mentors: Paul McGill, Bill Kirkwood
Summer 2001
Keywords: LEGO, ROV, MindStorms, RCX
ABSTRACT
This paper discusses the design and creation of a Remotely Operated Vehicle
(ROV) that runs off the LEGO RCX and is primarily made out of standard LEGO
components. With the power of the RCX, the ROV has the ability to collect data and
control itself autonomously. It is simple enough to construct that it has the possibility of
being used as a classroom project. Furthermore, it is a prototype for a new LEGO kit
which could be produced as a model of MBARI’s (the Monterey Bay Aquarium Research
Institute) real ROV Tiburon.
INTRODUCTION
Three years ago LEGO introduced a new line of kits, called “MindStorms,” that
focused on robotics. At the heart of these kits is the RCX, a completely programmable
LEGO “brick” with three power outputs and three sensor inputs. LEGO produces a
variety of sensors to attach to the inputs and three different kinds of motors, as well as
lights for connection to the power outputs. The RCX runs off six AA batteries, enabling it
2
to deliver 9 Volts (each battery 1.5V, hooked in series) to the motors. It can also be run
off a 120V outlet with a 120VAC to 12VAC converter.
Figure 1: RCX
The RCX is programmed through IR (infrared). The IR is sent from a tower
hooked up to a computer and received by the RCX through its IR receivers. There are a
variety of programming languages that can be used with the RCX. These including
LEGO’s own program which they sell with MindStorms, Not Quite C, and ROBOLAB
which is sold with LEGO’s educational robotics kits. ROBOLAB is ideal for this project
because the programming is graphically based instead of text based. This enables
children who are not able to read to use it. ROBOLAB is also based on LabVIEW, a
powerful data acquisition program, and retains many of LabVIEW’s capabilities.
Although the MindStorms kit is a wonderful way to teach kids about robotics, it is
limited to a dry environment, such as a classroom floor. The current kit is not capable of
going underwater, and the components would be quickly destroyed if they got wet. This
limitation gave rise to the project of developing an underwater LEGO ROV. By making a
3
new LEGO kit that allows the RCX to be used underwater, many new possibilities open
up for MindStorms.
MBARI is interested in developing a LEGO ROV because the kit could be sold as
an educational toy through the Monterey Bay Aquarium. Furthermore, the LEGO ROV
could be modeled after Tiburon, MBARI’s in house designed, real ROV. Tiburon would
provide advertising for the kit, which would be good publicity for the Aquarium and
MBARI.
The main goal of the project was to first and foremost develop a LEGO ROV that
ran off the RCX. Furthermore, the ROV was to be a prototype for a new LEGO kit to be
used in conjunction with MindStorms. The kit had to keep as many LEGO components
unchanged as possible. It would include waterproof motors, waterproof sensors, and a
tether to connect these components to a control box that worked with the RCX. This way
the ROV could be controlled manually, autonomously by the RCX, or using a
combination of both. The ROV also had to retain simplicity in its construction as to leave
open the possibility of it being built as a classroom project. All its non LEGO parts had to
be made from easily attainable materials and built using common tools.
MATERIALS AND METHODS
MOTORS
The RCX is capable of outputting a maximum of 700mA and 9V through each of
its power outputs. This translates into 6.3 Watts, which is a very small amount of power.
Because of this limited power supply, LEGO manufactured motors are the most efficient
to use for the ROV because they are already rated for such a low power level.
4
Additionally, if LEGO decides to produce the ROV as a kit in the future, they already
have the motors in production. The motors used for the project can be purchased from
LEGO’s educational distributor, www.pitsco.com.
Figure 2: LEGO motor used
The motors are waterproofed through a similar method as described in the book
Build Your Own Underwater Robot, by Harry Bohm and Vickie Jensen. First, the motor
is taken out of the LEGO casing. Next, an APS film canister is used as the motor housing.
A hole, slightly smaller than the shaft size, is drilled in it using a #49 drill. After sealing
up all the holes in the motor with either tape or hot glue, Vaseline is packed around the
shaft. When the motor is pressed into the housing, the Vaseline is spread out on the inside
face, making the seal through which the shaft passes. Because the Vaseline layer is so
thin and tightly packed between the face of the motor and the inside face of the housing,
and because the hole in the housing makes a snug fit around the shaft, a sufficient seal is
made. The rest of the motor housing cavity is filled with 3M Scotchcast which hardens
into a dense rubber. An APS film canister fits into LEGO dimensions perfectly, so a
LEGO motor brace is easily built around the motor to make it LEGO compatible.
5
Figure 3: Waterproof Motor Setup Figure 4: Finished Waterproof Motor in LEGO brace
PROPULSION
Remote control model boat props are used to propel the ROV. The props are
called “3/16” Drive Dog Props” and can be found at the hobby supplier http://hobbylobby.
com. These props are used because they are very cheap ($1.05 to $1.30 each), work
much better than cropped airplane propellers (the props suggested in “Build Your Own
Underwater Robot”), and glue perfectly onto LEGO axels. With one motor connected to
one prop, the size “3” prop is the most efficient to use. With one motor connected to two
props, size “2” is the most efficient.
Figure 5: Prop Glued onto LEGO Axel
A serious problem encountered while developing the ROV was getting enough
vertical thrust to push it underwater. The solution is to put two outrigger thrusters on the
6
sides of the ROV where the water flow is much less restricted. One motor runs both
vertical propellers. To reduce power loss in the drive train caused by the churning of the
surrounding water, small 45o bevel gears are used. These gears work very well because
they don’t have teeth that extend outside the face of the gear, thus the teeth don’t paddle
the water as much as other LEGO gears. They are also made for 90o turns in the drive
train. For the horizontal thrusters, two motors, each with a prop directly connected, are
mounted on the back of the ROV. This way, to move the ROV forwards, the motors both
spin forwards. To move backwards, both motors spin backwards, and to turn, the motors
spin in opposite directions. With this configuration, the ROV is capable of moving in
three dimensions.
Figure 6: Thruster Configuration Figure 7: Close-up of Vertical
Thruster and Bevel Gears
7
To try to further increase the efficiency of the vertical thrusters, ducted props
were designed and constructed. The thruster housings have the exact dimensions of an
8X8X4 (LXWXH) LEGO cube. They also have a ledge around the outside so that
LEGOs can be attached and built around them. The #2 “Drive Dog Prop” fits within the
housing, with the LEGO axel going through two bracing holes. The housing is made of
two pieces that press fit together. Its semi-circular shape helps capture the unique contour
of Tiburon’s foam pack, if it were to be used in a Tiburon kit.
Figure 8: Solid Works Drawing of Thruster Housing
UNDERWATER SENSORS
The RCX reads sensors by sending out 5V and then reading the voltage drop over
the sensor. The resulting voltage goes into a 10 bit A/D converter, so 0V = 0, 5V = 1023.
In order for the ROV to be able to collect data or react to its environment, it needs
sensors. Temperature and pressure sensors are important to include in order to collect
data. A light sensor fills the third sensor port on the RCX so the ROV can react to
changes in light, as in the case of getting too close to a wall.
8
The standard LEGO temperature sensor is easily adapted to the ROV because it is
already waterproofed. It has the ability to read –20oC to 50oC in increments of 0.01, or
the equivalent temperatures in Fahrenheit, as specified in the program.
The standard LEGO light sensor can be made waterproof by drilling small holes
in the bottom, and then injecting 3M Scotchcast through a syringe into them. The
Scotchcast covers the small circuit board inside and fills in the gap between the circuit
board and the sensor housing, making a seal. In ROBOLAB, light sensor reads a 0 to 100
scale; 0 being total dark, 100 being total light.
Figure 9: Bottom of Light Sensor, Showing Scotchcast Injection Holes
The pressure sensor is the most difficult sensor to make because LEGO does not
currently produce one. The circuit design used is adapted from an air pressure sensor
found at http://www.alynk.com/usr/gasperi/pressure.htm. In ROBOLAB, the pressure
sensor is programmed as a light sensor, so it reads 0 to 100 counts. The water pressure
sensor design differs from one on the internet in that a 75k instead of a 100k resistor is
used as the gain for the second op-amp. This does is makes the sensor read 5 counts at the
water surface instead of 0, so an immediate change is seen as the ROV submerges. The
water sensor also differs from the air sensor in that it uses a 15 psi gage sensor instead of
a 30 psi max differential sensor. This way the pressure sensor is ideal for use up to one
9
atmosphere (14.7 psi) which translates to 33.9 feet under water. The 15psi gage sensor
can be ordered directly from its manufacturer, Lucus Novasensor, by calling 800-962-
7346. The part number for the sensor is: NPC-410-015G-3L.
Figure 10: Circuit Diagram of Pressure Sensor
The sensor is waterproofed by casting it in 3M Scotchcast, leaving only the
pressure tube (which comes waterproof) exposed. LEGOs are used to make the mold for
the Scotchcast in order to keep the sensor in LEGO dimensions. To enable the sensor to
attach to other LEGOs, two LEGO plates are left bonded into the Scotchast
Figure 11: Pressure Sensor Circuit Board Figure 12: Sealed, Finished Pressure Sensor
10
CONTROL
In manual operation, the RCX delivers a constant 9V to each of its power outputs,
and the ROV’s motors are controlled by switching the current flow with Double Pole
Double Throw (DPDT) rocker switches. When the rocker switch is in its neutral position,
no current flows. When it is switched forward, the current flows and the motor turns
forwards. When the DPDT switch is switched backward, the poles are reversed, resulting
in the current flowing backwards, making the motors turn backwards. Additionally, in
each motor’s control circuit is a manual override Double Pole Single Throw (DPST)
switch to give the RCX direct control of the motor. With this switch, autonomous control
can be turned on and off for each motor individually, so the operator has the option of the
RCX controlling one function while another function is controlled manually. One
application of this ability would be the ROV hovering. The RCX would monitor the
pressure and adjust the vertical thrusters while the operator could still manually drive in
the horizontal plane.
Figure 13: Circuit Diagram of Motor Control Switches
11
The general control box design is a container for the RCX that is held with two
hands on either side. The top has the two horizontal motor control switch sets in reach of
the thumbs in addition to three subroutine switches. Each subroutine switch hooks
directly into one of the sensor inputs, and so when it is tripped it shorts out that input. In
the ROBOLAB program a shorted input will return the max value of the sensor
programmed to be hooked up to that input. When that max value is reached, the program
can be triggered to do a task. This makes it possible for a manual switch to run a
subroutine. The front of the box has the connection to the tether as well as the vertical
motor control switch set which is in reach of the index fingers. Additionally the box has
an AC adapter input on its left side. The box itself is made from a waterproof box
produced by “Otter Box.” It has a clear top so the LCD screen can be easily seen while
operating the ROV. The top is hinged and opens so the RCX can be popped in and out.
The boxes are available directly through the company at www.otterbox.com.
Figure 14: Top View and Front View of Control Box
12
The tether is made from two, six conductor Ethernet wires held together with zip
ties. Each motor and each sensor needs two conductors, which add up to a total of twelve.
The connections between the tether and a motor or sensor are sealed by being cast in 3M
Scotchcast.
UNDERWATER VIDEO CAMERA
A small video camera is on the larger, Tiburon ROV. This is made from a cheap
internet camera. This camera is ideal because all the circuitry is contained on one small
circuit board. To waterproof the camera, it is cast in 3M Scotchcast in a LEGO mold to
keep the LEGO compatibility. A flat lens is over the original camera lens to adjust for the
light refraction from water to air.
BUOYANCY
A problem with taking LEGOs underwater is that they tend to trap air. This
causes problems when the ROV goes deep and the air compresses. This means that if the
ROV is slightly positively buoyant at the surface, it becomes negatively buoyant a few
feet below. To help correct this problem, syntactic foam is used for the floatation inside
the ROV’s foam pack, which is a hollow chamber on the top of the vehicle. Syntactic
foam is most effective because it does not compress as the pressure increases underwater,
and thus provides a constant amount of lift. To balance out the lift from the foam, weights
are on the bottom of the ROV. The weights are made from shrink wrap filled with lead
13
shot. By putting a lot of weight on the bottom of the ROV, and a lot of floatation on the
top, the center of gravity is lowered towards the bottom and the center of buoyancy is
raised towards the top. This makes the ROV very stable and resistant to rolling over.
Figure 15: Syntactic foam (white) inside the ROV
The syntactic foam does not completely solve the problem of the ROV becoming
negatively buoyant underwater. Additionally, the Ethernet cable used for the tether is
negatively buoyant, so the farther it goes underwater, the more it makes the ROV sink.
To totally solve the problem of the ROV sinking, syntactic foam chunks are attached to
the tether to make it float. Through testing, it is determined that 0.63in3 of foam makes
one foot of tether neutrally buoyant. To totally fix the problem of the air compressing
inside the ROV and making it negatively buoyant, an increasing amount of foam is added
along the tether from the ROV to the control box. This way the tether becomes more
buoyant as the ROV goes deeper, balancing out the loss of lift from the compressed air
inside the LEGOs. This keeps the ROV almost perfectly neutral at any depth.
14
RESULTS
The result of this project is an ROV that is fully maneuverable in three
dimensions in 0 to 29 feet of water. The ROV is powered solely by the RCX and is
primarily made out of standard LEGO components. Additionally, it has the capability of
performing autonomous functions, as in the case of monitoring the pressure sensor and
adjusting its thrusters to hover. This ROV is very compact, containing a limited number
of components, which makes it ideal to be produced as a kit.
Figure 16: Finished ROV
The ROV also has the ability to be used as a scientific tool because of its data
collection capabilities. It can collect data to see changes over time, or compare data from
two different sensors, as in the case of temperature versus depth. To test the ROV, two
data collection programs were written; one to see how the pressure changes over one
minute of time and one to compare temperature versus pressure. Another useful feature of
ROBOLAB is that it can plot data directly, or export it into a spreadsheet program like
15
Microsoft Excel. Both tests were conducted in the MBARI test tank. The results can be
seen in the figures below.
Figure 17: Pressure versus Time During One Minute of Hovering
(Y axis labeled “Light” because of pressure sensor programmed as light sensor)
Figure 18: Temperature versus Pressure (graphed in Excell)
Temperature vs Pressure
66
67
68
69
70
71
72
0 20 40 60 80 100 120
Pressure (Counts)
Temperature (F)
Temperature
(Fahrenheit)
16
The other ROV built is a model of Tiburon. This ROV differs from the other one
in that it has the on-board video camera, ducted thruster housings, and is much bigger.
Although this ROV looks a lot more appealing, it doesn’t perform as well in the water. It
is not powerful enough to easily move vertically. The ducted thruster housings are not
efficient because axel supports in them block too much water flow. This problem can be
easily solved by supporting the axel on only one side, and making the supports much
thinner. With some redesign, the thruster housings should be very effective. Their
compatibility with other LEGOs makes them desirable to put in a kit. The underwater
video camera works very well, even with no additional light source on board the ROV.
Figure 17: Finished Tiburon ROV
CONCLUSIONS/RECOMMENDATIONS
This project proved that a LEGO ROV can be built primarily with standard
LEGO components and be powered only by the RCX. The ROV is capable of being
controlled in three dimensions and operating to a depth of 29 feet. It also has the power to
perform autonomous functions, such as hovering and data collection. The small ROV
could easily be built in a classroom. All the custom parts were made from common
17
materials with no special tools. If the ROV were to be made in a classroom, I would
recommend a middle school or high school class to do it because of the dexterity and
dangerous tools needed to make some of the parts. Most importantly, the ROV is fun!
People of all ages helped test it, and everyone, from toddlers to sixty year olds, loved it.
If LEGO decided to produce the ROV as a kit, I would recommend they stick to a
design closer to the small ROV because it is a much simpler package with significantly
fewer parts than the Tiburon ROV. Ideally, the kit would be a combination of both
ROVs, with a low number of pieces like the smaller one, but with the shape and feel of
Tiburon with the thruster housing “bricks.” I would also recommend a neutral tether with
extra floatation that can be clipped on if necessary. Floatation and weighted “bricks”
should be part of the kit to make construction easier. Any combination of the ROVs
comprising a kit would undoubtedly be successful because taking MindStorms
underwater would open up numerous learning and playing possibilities.
ACKNOWLEDGEMENTS
I would like to thank the following people for their help in making this project
possible: Paul McGill, Bill Kirkwood, Larry Bird, John Ferreira, Hans Thomas, Mark
Sibenac, Drew Gashler, Nicole Tervalon, Clark Brecht, Zorba Pickerill, Carolyn Todd,
Craig Okuda, Jim Scholfield, Farley Shane, Cindy Hanrahan, George Matsumoto, Chris
Rogers, and Todd Walsh.
18
References:
Bohm, H.,V. Jensen (1999). Build Your Own Underwater Robot and Other Wet Projects.
Westcoast Words
Gasperi, M. (1998). MindStorms RCX Sensor Input Page.

http://www.alynk.com/usr/gasperi/lego.htm

To learn about how the Stampeders built their own boats in order to complete the final 500 miles of the journey to Dawson city.

howardelliot — Fri, 04 Jan 2008 16:45:58 +0000

Title: Building Boats
Objective: To learn about how the Stampeders built their own boats in order to complete the final 500 miles of the journey to Dawson city.
Materials:
Part One: Graph paper
Part Two: Model Boat Building Materials (popsicle sticks, cardboard, glue, milk cartons, fabric, dowels, tape, string, etc.)
Time: 2 hours
Lesson Description:
1. Begin by saying:
We’ve finally made it over the mountains. The good news is we don’t have to walk any more! The bad news there is a lake and 500 miles of river between us and Dawson City, the “City of Gold,” and either we build our own boat or hire someone to build us a boat.
2. Read the following excerpt from Gold! The Klondike Adventure:
The Dyea and Skagway trails ended at adjoining mountain lakes whose emerald-green waters fed into the Yukon. No boats waited along the shores of Lake Lindeman or nearby Lake Bennett to carry passengers to the Klondike. It was up to each man to build his own vessel and find his way 500 miles downriver to Dawson…By the spring of 1898, 30,000 people were camped along the frozen lakes at the foot of the passes. In just a few months the Stampeders had transformed this once-quiet valley into a bustling boat-building center. Acres of stumps stood where forests had once grown. (p. 47, Ray)
Continue by telling your class: 109
The lake is still frozen but we need to be ready to go as soon as the ice breaks. If we build our own boats we’ll need to make our own boards. That requires a long and tiring process call whipsawing. First one places a fresh cut log on a raised platform called a sawpit. Then begins the destruction of many a good friendship. One partner stands on the top of the sawpit while the other partner stands below. Each hold the end of a long, jagged-tooth saw and the fun begins. The partners have to work in perfect synchronicity pushing and pulling the saw. With each stroke of the saw the partner below gets a face full of sawdust while the person on top quickly developed an aching back from leaning over. Partners often yelled and cursed one-another convinced the other wasn’t doing his share of the work.
In class today we are gong to build models of the boats we plan to take down the river. First we have to design our boats. Think about the type of boat you could build that would withstand 500 miles of travel through white water rapids, flat open lakes, carry 2,000 pounds of gear, and be easy to build.
Part One: Designing the boats
1. Ask your students what are some features they might want to include in their boat design? Record some of the student ideas. Then pass out graph paper to the students.
2. Explain they’ll need to draw two perspectives of the boat—a top view and a side view. They’ll want to make certain to design their boat to be symmetrical and include a line of symmetry in the design.
After students have had a chance to finish their designs move onto Part Two. (Part One is usually done on one day and Part Two is started the next.)
Part Two: Building the boats
1. Begin by saying:
You’ve had a chance to design your boats. Today we try to build them.
2. Show the students where the materials are laid out. You may want to assure your students that their model may not reflect their design. Often times the materials available don’t allow for exact replicas of the designs.
110
Students who finish early can create the supplies to load on the boats.
111

Building an Arctic Boat

howardelliot — Fri, 04 Jan 2008 16:37:44 +0000

Scientific American Frontiers . Coming to America . Teaching Guide . Building an Arctic Boat – High School. PDF | PBS
Activity 1: Grades 9-12
Building an Arctic Boat
An umiak (oo-mee-ak) is an open arctic boat that has
been used since earliest times by the Inuit. Its frame is
constructed of thin pieces of wood (called stringers) that
are lashed together. This type of construction produces a
flexible structure that easily withstands the force of
crashing waves. The stringers are covered by seal or
walrus skin. Known as a family boat, or “women’s boat,”
the umiak has traditionally been used to transport all
sorts of things, including weapons, clothing, people,
dogs, sleds and tents.
This activity page will offer:
l A hands-on experience in shaping a model umiak hull
l An exploration of boat balance
l An understanding of how ballast helps keep a boat upright
Weighed Down
Not only does the umiak have a large carrying capacity, but it is also
extremely stable. This stability arises from its shape and low center of balance.
To further increase stability, rocks are placed in the bottom of the hull. In this
activity, you’ll observe how added weights can make a boat model less likely
to capsize.
Materials
l Balsa wood
l White glue
l Tissue paper
l Clay
l Large nail or bolt
l Bowl filled with water
Scientific American Frontiers . Coming to America . Teaching Guide . Building an Arctic Boat – High School. PDF | PBS
Procedure
Part One – Building the Model
1. Work in teams of two. Examine the frame of a model umiak shown here.
2. Use stringers of balsa wood and white glue to construct this model
frame. Let dry.
3. When the frame has dried, cover it with tissue paper. Use a light coating
of white glue to attach the paper to the frame. Let dry.
4. When the covering is dry, you can waterproof the paper by painting it
with a very dilute solution of white glue. Let dry overnight.
Part Two – Exploring Stability
1. Place your model boat into a bowl filled with water. Observe how it
floats.
2. Remove the model from the bowl. Secure a large lump of clay to one of
the sides of the boat. Place the boat back in the bowl. What happens
now?
3. Place a large nail or bolt in the bottom of the hull. How does this added
weight affect the stability of the boat?
Questions
1. Although a block of aluminum sinks, the boat you shaped from
aluminum foil floated. Explain.
2. What happened when the lump of clay was added to the side of the
boat?
3. How did the extra weight placed in the bottom of the hull affect the
boat?
Inquiry Extension
How does the amount of weight placed in the hull affect stability? Can you add
too much weight? Develop a strategy for inquiry that would explore this
variable. Share your design with your instructor. With your instructor’s
permission, perform your investigation.
Fictional Log
Think back to the earliest sailors of umiaks. Suppose you were a village elder
who recorded the travels of this prehistoric band. Write a fictional account of
your journey as you crossed the Atlantic Ocean along the edge of the polar ice
sheet. Make sure that you create this essay through the eyes and
understanding of an individual who lived more than 10,000 years ago!
Western and Eastern Versions
There are two distinct types of umiaks. The Western Arctic umiak is a
streamlined slender boat often used in hunting. The Eastern Arctic umiak is a
larger, bulkier boat used mostly in transportation of goods, homes and
families. Research the differences in these boats and construct a model of each
Scientific American Frontiers . Coming to America . Teaching Guide . Building an Arctic Boat – High School. PDF | PBS
type. Use these models to compare and contrast the differences in use and
design.
Row, Paddle or Sail?
Prior to the advent of outboard engines, umiaks could be propelled in several
ways. Depending on the situation, the boat could be rowed, paddled or sailed.
Each type of propulsion had advantages and disadvantages. Compare and
contrast these different ways of propelling the boat. What situations would
warrant the use of each method? Which method of propulsion was best used to
travel great distances? Why?
Web Connection
Umiak Construction and Form

http://www.rockisland.com/~kyak/umicon.html

The site offers an overview of umiak form and construction.
Good Old Boat: Is Your Boat Stable?

http://www.boatus.com/goodoldboat/stability.htm

This site offers an introduction to boat stability that explores the shape and
design of typical sailboat hulls.
Native Watercraft: Umiaks

http://www.civilization.ca/aborig/watercraft/wau03eng.html

This site includes illustrations of different types of umiaks.
Academic Advisors for this Guide:
Suzanne Panico, Science Teacher Mentor, Cambridge Public Schools, Cambridge, MA
Anne E. Jones, Science Department, Wayland Middle School, Wayland, MA
Gary Pinkall, Middle School Science Teacher, Great Bend Public Schools, Great Bend, KS
Cam Bennet Physics/Math Instructor Dauphin Regional Comprehensive Secondary School
Dauphin, MB Canada
Scientific American Frontiers . Coming to America . Teaching Guide . Building an Arctic Boat – High School. PDF | PBS
…………………………………………………………………………………………………………
Activity 1: Grades 9-12
Building an Arctic Boat
ANSWERS
Part Two – Exploring Stability
1. Place your model boat into a bowl filled with water. Observe how it floats.
2. Remove the model from the bowl. Secure a large lump of clay to one of
the sides of the boat. Place the boat back in the bowl. What happens
now?
(The boat capsizes and sinks.)
3. Place a large nail or bolt in the bottom of the hull. How does this added
weight affect the stability of the boat?
(It increases the model’s stability.)
Questions
1. Although a block of aluminum sinks, the boat you shaped from aluminum
foil floated. Explain.
(The design of the hull displaced enough water to produce a
buoyant force that was greater than the weight of the boat.)
2. What happened when the lump of clay was added to the side of the boat?
(The boat became unstable and tipped over.)
3. How did the extra weight placed in the bottom of the hull affect the boat?
(It increased the model’s stability, and the boat was less likely to
tip.)

Wooden Boat News

howardelliot — Fri, 04 Jan 2008 16:30:06 +0000

Wooden Boat News
The Winterton Boat Building and Community Museum Newsletter
September 2006
Planning For Our Future
The Winterton Boat Building Museum has been mandated to preserve and exhibit the design, construction and use of small inshore fishing boats that were so much apart of pre-confederation life in Winterton. This work has been possible through the efforts and collaboration of various individuals spanning a period of over 20 years. Today, because of the extensive work of folklorist David A. Taylor, committed community volunteers, and through the donations of artifacts and information from town residents, much of the knowledge of Winterton boats and boat building is being preserved.
Now the WBBCM has set its sights on a larger goal. The museum wishes to develop a Provincial focus and capture the history of wooden boats throughout Newfoundland and Labrador. The museum wants to become the center of wooden boat building knowledge and history in the Province. A tale that tells the story of not only the Winterton Rodney, but also of the Gander River Boat, the South Coast Dory, the MicMac Canoe, and of other traditional wooden boats from regions all over the Province. This will be accomplished through a dynamic program, which incorporates boat collection and construction activities, interpretive exhibits, innovative programming, and partnering with like-minded groups and individuals. It is imperative that the knowledge of traditional wooden boats and boat building in Newfoundland and Labrador be preserved for future generations.
The Winterton Heritage Advisory Board, together with the Town of Winterton is poised to become the center for the collection and preservation of this vital piece of our Province’s heritage. With the help of ACOA and ITRD we have begun to action the above; Planning Resources Inc. has completed Phase 1 of our Long Term Growth Framework, and we are now half way through Phase 2, which will outline an action plan to go forward, based on the above concepts.
Note: We have repeated this article from our previous newsletter because we have updated our database of contacts and felt this article would be interest to the many new friends of the Museum.
Boat Builders of Newfoundland and Labrador
In Newfoundland and Labrador, where fishing and water-borne transportation have always been of great importance, boats represent an integral part of the culture. Even though boat building and boat use has been widespread in the Province, little information has been collected and preserved about the details of boat building and boat builders. We want to establish a network of contacts to assist in this collection and preservation; if you are a traditional wooden boat builder, (either full size or model) know of someone who is or was, or, if you are just an interested individual, please contact us. (see contact information at the end)
Over the past several years many individuals have expressed sincere interest in what we are doing and offered their assistance and support. If we have not taken advantage of the offers it is not because you have been forgotten or overlooked but because we have been busy with funding and other issues which are needed to move this mammoth project forward. We anticipate by late fall and into 2007, we will be reaching out by various means, including this newsletter, for contributions of time, information, ideas etc; and we are sure we will be able to count on your support.
Boat Building in Winterton
We are pleased to announce the republication of Boat Building in Winterton, Trinity Bay, Newfoundland by David A. Taylor. This book is Dr. Taylor’s Master of Arts in Folklore thesis on traditional boat building and the boat builders of Winterton. This book maybe purchased by money order from the museum at a cost of $30.00 CAN plus shipping and handling. Postage and handling rates are available on our website or by calling our office.
Intangible Heritage Conference
The Winterton Boat Building and Community Museum was invited to take part in the Celebrating Our Living Heritage Conference, which took place from June 7-10, 2006 at Memorial University of Newfoundland. During the conference, Frank French gave a short presentation about how we are preserving traditional boat building skills at the museum and our plans for the future. As well, Fred and Melvin Green demonstrated some traditional boat building skills through the partial completion of a rodney. During this conference we met many people who are interested in working with us to preserve traditional boat building in our Province.
CBC Crosstalk
The museum will be participating in CBC Radio’s Crosstalk. Anne Budgell will be interviewing Fred, Melvin, Frank and Dr. David Taylor on September 15 at 1:30 pm Newfoundland Time. If you would like to phone in and ask a question or make a comment on traditional boat building, the number in St. John’s is 722-7111 or 1-800-563-8255 in Canada and the U.S. If you miss the live broadcast you can listen to it on the web at www.cbc.ca/radionoonnl/ by clicking the media button and then clicking listen live.
Inshore Fishing Grounds Research
Patty Wells, a PhD student in the Archaeology Unit at Memorial University, will be conducting research on the inshore fishing grounds in the Winterton area. Through interviews with fishermen she will document the location of markers, fishing grounds, and trap berths. These are important locations that are a part of how Newfoundlanders of European decent understood or made their particular seascape. Wells believes that the seascape is not simply the sum of its physiological characteristics, but that it is constructed or understood in particular ways by members of a culture. This is determined by peoples’ traditions and how they use or occupy the sea.
Seascapes have meaning, memory and legend associated with them; they can be experienced in different ways by different groups, and the subtleties of peoples’ knowledge of seascapes lend them a particular character. By understanding how modern inshore fishermen create their seascapes, Wells wishes to explore models for how prehistoric peoples in Newfoundland may
have similarly constructed their cultural seascapes. This research will aid in her interpretation of Dorset Palaeoeskimo (ca 2000-1200 years ago) material culture in Newfoundland. Furthermore, with the essential end of the inshore fishery, the traditional nature and knowledge of these places in the seascape will disappear as fewer people visit and depend upon them for their livelihood. The recording of principal locations in the seascape will ensure the retention of this important aspect of Newfoundland’s intangible heritage.
Winterton Boat Building and Community Museum
P.O. Box 59
Winterton, NL
A0B 3M0
Phone: (709) 583-2044
Fax: (709) 583-2099
www.woodenboat.ca
wintertonmuseum@persona.ca

BOATBUILDING – Produce a Half Model of a Small Craft to Scale

howardelliot — Fri, 04 Jan 2008 16:26:39 +0000

10841 version 4
21-Apr-04
1 of 4
BOATBUILDING
Produce a half-model of a small craft to
scale
 New Zealand Qualifications Authority 2004
level: 4
credit: 10
final date for comment: March 2005
expiry date: December 2006
sub-field: Boating Industries
purpose: People credited with this unit standard are able to prepare
for the production of a small craft to scale; produce
templates to scale; and manufacture the half-model.
They are able to work from a supplied design in the form of
drawings and offsets.
entry information: Recommended: Unit 10840, Draw full sized hulls, decks, and
superstructures from corrected offsets, or demonstrate
equivalent knowledge and skills.
accreditation option: Evaluation of documentation and visit by NZQA and
industry.
moderation option: A centrally established and directed external moderation
system has been set up by the Boating Industry Training
Organisation.
special notes: 1 Definitions
small craft is a boat of up to eight metres in length
when built full size;
half-model is a model split vertically from bow to stern.
2 Range: scale – 1:10 or less;
craft – deck, superstructure, hull, rudder,
keel;
hull – hard chined or round bilged.
10841 version 4
21-Apr-04
2 of 4
BOATBUILDING
Produce a half-model of a small craft to
scale
 New Zealand Qualifications Authority 2004
3 The following apply to the performance of all elements
of this unit standard:
a All required equipment must be set up, started up,
operated, and shut down in accordance with the
manufacturer’s and organisation’s documented
procedures;
b All work practices must meet recognised codes of
practice and documented worksite health and
safety procedures for personal, product, and
worksite health and safety, and must meet the
obligations of current legislation, including the
Health and Safety in Employment Act 1992, and
its subsequent and delegated legislation.
4 This unit standard can be assessed off job.
Elements and Performance Criteria
element 1
Prepare for the production of a small craft to scale.
performance criteria
1.1 Interpretation of supplied drawings and offsets establishes datum lines to
design requirements.
Range: datum lines – centre line, water lines, baselines.
1.2 Selection of tools, and equipment enables job specifications to be achieved.
10841 version 4
21-Apr-04
3 of 4
BOATBUILDING
Produce a half-model of a small craft to
scale
 New Zealand Qualifications Authority 2004
1.3 Selection of materials for templates and finished model enables job
specifications to be achieved.
Range: template materials – timber and/or metal and/or composites.
Evidence is required for at least one.
examples of finished model materials include but are not limited to
- solid timber, reconstituted timber, metal, composites (including
foam plastic).
1.4 Scale selection matches job requirements.
element 2
Produce templates to scale.
performance criteria
2.1 Produced templates are dimensioned to the selected scale.
2.2 Vertical station templates are evenly-spaced and correspond to within 0.25
millimetres of fair lines
Range: at least four vertical templates.
2.3 Horizontal templates correspond to within 0.25 millimetres of fair lines, and are
horizontal at the water line.
Range: at least one horizontal template.
element 3
Manufacture the half-model.
performance criteria
3.1 The water line is marked in accordance with design requirements.
3.2 The model’s external shape corresponds to within 0.25 millimetres of
templates.
10841 version 4
21-Apr-04
4 of 4
BOATBUILDING
Produce a half-model of a small craft to
scale
 New Zealand Qualifications Authority 2004
3.3 Faired lines cross grid lines in all three views at the same points.
3.4 The completed model’s bow points in the specified direction.
Comments on this unit standard
Please contact the Boating Industry Training Organisation training@bia.org.nz if you wish
to suggest changes to the content of this unit standard.
Please Note
Providers must be accredited by the Qualifications Authority or a delegated interinstitutional
body before they can register credits from assessment against unit standards
or deliver courses of study leading to that assessment.
Industry Training Organisations must be accredited by the Qualifications Authority before
they can register credits from assessment against unit standards.
Accredited providers and Industry Training Organisations assessing against unit
standards must engage with the moderation system that applies to those standards.
Accreditation requirements and an outline of the moderation system that applies to this
standard are outlined in the Accreditation and Moderation Action Plan (AMAP). The
AMAP also includes useful information about special requirements for providers wishing
to develop education and training programmes, such as minimum qualifications for tutors
and assessors, and special resource requirements.
This unit standard is covered by AMAP 0136 which can be accessed at

http://www.nzqa.govt.nz/site/framework/search.html.

Hello world!

howardelliot — Fri, 04 Jan 2008 15:42:17 +0000

Welcome to WordPress.com. This is your first post. Edit or delete it and start blogging!