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What can we learn fromthe VASA?
Jane Huang
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• The VASA
• 1625 the Swedish king Gustavus Adlophus ordered
  new warships.
• The VASA was built in Stockholm. It was to be
  the mightiest warship in the world, armed with
  64 guns on 2 gundecks.
• During the Vasas maiden voyage in 1628, and
  filled with spectators and foreign diplomats, the
  glorious warship keeled first to one side and
  then to the other side and sank killing 30-50
  people.

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• Dont let the King be your Architect
• The Vasa was specified and respecified by the
  king.
• The boat was midway between a small boat and
  large boat design of the day.
• The keel was originally laid for a small boat
  and then lengthened. Designers tried to make
  her wider but could not change the existing
  design.
• She was therefore long and tall.
• The king heard that a rival boat in Denmark was
  being built with 2 gundecks so he insisted on an
  extra gundeck. This made the VASA top heavy.

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Things arent always as they seem

• If you see the VASA today your first impression
  may be NO WAY!
• The boat looks tall, narrow, top-heavy etc.
• But most of the boats at that time did look that
  way and most were stable.
• Calculations done today on the resurrected ship
  show that the proportions were only slightly off
  by a couple of inches here and there.

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Check the design

• There are no surviving plans for the Vasa,
  because there never were any!
• In those days nobody made detailed drawings.
• Naval architect had a few carefully guarded
  calculation tables and rules of thumb.
• Most of the boat was built on the fly!

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Know what you dont know

• State of practice in those days was rudimentary.
• Calculations of center of mass etc were not known
  or done.
• It was therefore practically impossible to know
  if a design was stable or not.
• It was amazing that more boats didnt sink!!

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Dont ignore data

• Several days before the launch the Vasas
  builders did a very pragmatic stability test on
  the ship.
• 30 sailors ran from one side of the boat to the
  other.
• After three runs, the sailors had to store
  because the boat was heeling too much.
• But the king was out of the country and no one
  else dared postpone the launch.

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Maintain continuity of Architecture

• Principle architect died midway through the
  project.
• Prior to his death, both he and his assistant
  were in charge.
• This illustrates what happens when a single and
  strong point of leadership is lost.

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Are you in a hurry, as usual?

• The Vasa was built in about two years.
• There was a lot of schedule pressure.
• The urgency to get the project finished no doubt
  contributed to some bad decision making.

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Are you focusing on the wrong features?

• Numerous ornate carvings and decorations were
  completed on time for the Vasa.
• Clear example of featuritis.

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When the design is bad

• A criticism of the day is that the shipbuilders
  didnt load enough ballast into the hold to make
  the boat more stable.
• They ACTUALLY crammed in as much as there was
  room for.
• Even if they had added more balast the boat
  would have ridden lower and water would have
  poured through the portals of the lower deck.

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The difference between prototype and product

• Given her experimental design, the Vasa should
  have been considered a prototype not a product.
• When the shipbuilders discovered she was unstable
  during her tests, they should have put her in a
  museum 333 years early.
• BUT it was the Kings boat and cost 4 of the
  countrys income for that year. It was also
  needed for a war.

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References

• http//www.vasamuseet.se/indexeng.html
• Software Engineering Process with the UPEDU,
  Pierre Robillard and Phillippe Kruchten, Pearson
  Education Inc.