Shipbuilding [602]
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Usage:     BUILD galley "Name of ship"
or         BUILD roundship "Name of ship"

Requires:  at least three workers [11]
	   50 wood [77] for a galley, 100 wood for a roundship

Time:      250 worker-days for a galley, 500 for a roundship

To begin construction of a ship, the shipbuilder should unstack from
beneath other characters and issue one of the BUILD orders.  One-fifth
of the lumber is required to start construction.  The rest is deducted
as progress on the ship is made (the second fifth at 20% completion,
the third fifth at 40% completion, etc.)

The shipbuilder and his workers will be placed inside the new ship.

As soon as the required number of worker-days has been invested in
construction, the ship will be christened and declared seaworthy.

To resume construction of a partially completed ship, first enter the
ship, then issue the either "build galley" or "build roundship".

Ships may only be built in a port city.