prolonge

from WordNet (r) 3.0 (2006)

prolonge
    n 1: a rope fitted with a hook and used for towing a gun
         carriage

from The Collaborative International Dictionary of English v.0.48

Prolonge \Pro*longe"\, n. [F. See {Prolong}.] (Field Artillery)
   A rope with a hook and a toggle, sometimes used to drag a gun
   carriage or to lash it to the limber, and for various other
   purposes.
   [1913 Webster]