Transcript planing boats - Goldbelt Heritage Foundation

TLINGIT INGENUITY &
TECHNOLOGY
GOLDBELT HERITAGE FOUNDATION
INVESTIGATING TLINGIT ECOLOGICAL
KNOWLEDGE
What does it take to thrive
in Southeast Alaska?
Focused observation over generations
Trust for inherited wisdom from ancestors
Qualitative oral record
Life-encompassing moral code
Respect for the interconnectedness of everything
(awareness of the metaphysical)
What else?
• Deep understanding of ecological conditions
• bedrock geology
• surficial geology & soils
• climate
• marine ecology & oceanography
• vegetation
• fish & marine invertebrates
• wildlife
• human relations
• Ability to move great distances for trade, safety, and defense (navigation, transportation)
• Fishing technology & gear
• Food preservation
Transportation
Southeast Alaska requires
inter-coastal waterway
travel in difficult conditions
(low visibility, wave and
wind variability)
Knowledge of the Interior
navigation
Good relationships for
trade, design of canoes
came from Haida
Understanding Boat
Technology
DISPLACING BOATS
PLANING BOATS
Bottom is a flat line to stern
At rest, uses hydrostatic lift (buoyancy)
Hull below water, at high speed “appears trapped” behind
a bow wave
Speed limited by waterline and displacement weight
At speed, uses hydrodynamic lift
Relies more on hydrostatic lift
Hull comes almost entirely out of water at high speeds
Speed determined by distance between bow and stern
waves
DRAFT
AS SPEED
Powerboats need high power engine to overcome
gravity to plane
DRAFT
AS SPEED
Higher resistance because bow is trying to climb waves
while stern is being sucked back down by dynamic forces
Are Tlingit canoes planing or displacing boats?
In this picture, huge amount of the hull is below the waterline (not able to be
seen)
Displacing hull speed video: https://www.youtube.com/watch?v=3lffCqqluYI
Planing boat demonstration: https://www.youtube.com/watch?v=hyME1EDreNg
Specialized Features of
Boat Hulls
Rocker
Forward flotation/extended forward floatation
Wave blocking devices
Bulbous bows and bow wave dispersion devices
C-shaped double ender
Rockers
Flat bottom boats do not
have rockers
In Southeast Alaska, the
design is necessary to
withstand the waves and
wind
Does the Chief Shake
canoe have a rocker?
In addition to rockers, many of
these early engineering devices are
seen in most boats today
Extended forward flotation
devices
Wave dispersion devices
Large bulbous bows to draw
boat up onto the wave
Elsewhere in Alaska….
Based on the shape, what
are these boats used for?
Water-line length?
Rocker?
Forward bow flotation?
Bulbous bow structure?
More influences on today’s
technology
Tools
• Adze
• Halibut hooks
Food Preservation techniques:
• Drying
• Smoking
• Oils
• Fermentation
Food Preservation
SMOKING:
• Region-dependent wood use
• Cottonwood in Chilkat region (Klukwan)
• Alder throughout Southeast
• Alder contains toxins that help eliminate
bad bacteria during smoking process
• Smoking also evaporates water (preventing
growth of bacteria)
• Aas Kwaani-the Tree People communicate
with one another (evidence in oral
narratives)
• chemical communication between root
systems
• one alder will alert the grove to raise
levels of toxins when deer are grazing
nearby
Food Preservation
DRYING:
• Water removal inhibits growth of microorganisms (evaporation through
sun or wind drying)
OIL AS A PRESERVATIVE:
• Hooligan and seal oils were used to preserve fats and meat
• Prevents oxygen from reaching the meat, depriving bacteria of basic
needs
Food Preservation
FERMENTATION:
•
Occurs in oxygen-deprived environments
•
Metabolic process that converts sugars into acids, alcohols, or
gases
•
Wine and beer fermentation is relatively safe and controllable
because adding yeast means that the yeast outcompetes other
microorganisms
•
Fermentation of meat is more high-risk and can be fatal if done
wrong
Fermentation Continued
Bio-preservation adds lactic acid
When the fish muscle drops below a
pH of 4.5 it greatly inhibits microbial
growth
Traditionally, fish pits were dug and
plant material and sticks were
added into the pit
Today, plastic gallon jugs and bags
are used
Increased risk of Botulism caused
by the Botulinum bacteria which
thrives in anaerobic environments
Images & References
Slideshow modified from Henry Hopkins, Helen Watkins, and Fred White’s presentation during
pilot class
Wikimedia Commons Images:
• Albacore Dinghy-Dabbler 2005
• Imperial War Museums A-724-Royal Navy Officer Tomlin 1940
• Archimedes; Principle-Finot 2006
• Carving adze-Waldo Brown 1910
• Walrus meat-Ansgar Walk 1999
Tlingit canoe-SMU Central University Library 1887
Chief Shake’s canoe-University of Washington Libraries 1916
Halibut Hook-FishEx Alaska Seafood