The Collaborative International Dictionary of English v.0.48:

Shipping \Ship"ping\, n.
   1. The act of one who, or of that which, ships; as, the
      shipping of flour to Liverpool.
      [1913 Webster]

   2. The collective body of ships in one place, or belonging to
      one port, country, etc.; vessels, generally; tonnage.
      [1913 Webster]

   3. Navigation. "God send 'em good shipping." --Shak.
      [1913 Webster]

   Shipping articles, articles of agreement between the
      captain of a vessel and the seamen on board, in respect to
      the amount of wages, length of time for which they are
      shipping, etc. --Bouvier.

   To take shipping, to embark; to take ship. [Obs.] --John
      vi. 24. --Shak.
      [1913 Webster]

WordNet (r) 3.0 (2006):

shipping articles
    n 1: a contract between crew and captain of a ship [syn:
         articles of agreement, shipping articles]

Bouvier's Law Dictionary, Revised 6th Ed (1856):

SHIPPING ARTICLES, contr. mar. law. The act of congress of July 20, 1790, s.
1, directs that a master of any vessel bound from a port in the United
States to any foreign port, or of any vessel of fifty tons or upwards, bound
from a port in one state to a port in any other than at adjoining state,
shall, before he proceed on such voyage, make an agreement in writing or in
print, with every seaman or mariner on board such vessel, (except such as
shall be apprenticed or servant to himself or owners) declaring the voyage
or voyages, term or terms of time, for which such seaman or mariner shall be
shipped.
     2. And by sect. 2, it is required that at the foot of every such
contract, there shall be a memorandum in writing, of the day and the hour on
which such seaman or mariner who shall so ship and subscribe, shall render
himself on board to begin the voyage agreed upon.
     3. This instrument is called the shipping articles. For want of which,
the seaman is entitled to the highest wages which have been given at the
port or place where such seaman or mariner shall have been shipped for a
similar voyage within three months next before the time of such shipping, on
his performing the service, or during the time he shall continue to do duty
on board such vessel, without being bound by the regulations, nor subject to
the penalties and forfeitures contained in the said act of congress; and the
master is further liable to a penalty of twenty dollars.
     4. The shipping articles ought not to contain any clause which
derogates from the general rights and privileges of seamen, and if they do,
such clause will be declared void. 2 Sumner, 443; 2 Mason, 541.
     5. A seaman who signs shipping articles, is bound to perform the
voyage, and he has no right to elect to pay damages for non-performance of
the contract. 2 Virg. Cas. 276.
     Vide, generally, Gilp. 147, 219, 452; 1 Pet. Ad. Dec. 212; Bee, 48; 1
Mason, 443; 5 Mason, 272; 14 John. 260.