SS NOBSKA
Bringing her home
Assignments
Nautical Quiz
A selection of physical and mathematical problems related to
steamships.
Physics, mathematics and geography classes might want to
explore these.
These assignments are most relevant in the context of the
paragraph that led to them.
Engines
- E1) Gas pressure
- If steam enters the first stage of NOBSKA's triple expansion
engine at 200 lbs, what are the initial
pressures in the intermediate and low pressure cylinders?
- E2) Mechanical arms
- Give a reason why the stroke is equal in all four cylinders
of NOBSKA's steam engine.
Based on your answer, what can you say about
the relative driving forces
produced by each of the pistons?
- E3) Engine types
- How many power strokes, and why, does each cylinder of
a diesel, two-stroke and steam (be careful) reciprocating
engine make, to turn a propeller 200 revolutions per minute?
- E4) Energy
- Describe the difference between the internal and external
reciprocating combustion engines.
Is the type of fuel burned determinate?
Navigation
- N1) Time & distance
- Traditionally the elapsed time for counting the marked knots as
they run out, to determine
a vessel's speed in miles of 6080 feet, is 28 seconds
(don't ask!).
Calculate the distance between the knots in the log line.
- N2) Geometry
- With the nautical mile defined as one minute of arc
on the terrestial sphere and measuring 6080 feet.
Calculate the earth's diameter in statue miles of 5280 feet.
Design
- D1) Equilibrium
- Describe the function of a vessel's watertight bulkheads.
What can you say about the volume of the separated compartments?
- D2) Communicating vessels
- Research how her bulkhead design contributed to the
sinking of the "Titanic".
- D3) Mechanical moments
- Give two reasons why NOBSKA was ballasted after some
heavy machinery was taken out in Baltimore.
Then refine your answer by eliminating one of your reasons
(hint - write down NOBSKA's beam and draft, and think
about a floating board supporting a stone near one end).
- D4) Conversion
- With some cars and cargo aboard an Island Line steamer
displaced 275,000 gallons of water.
How much did the vessel weigh in long tons of 2240 lbs?
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