Fighting ships with five rows of oars - penteras - were introduced in the Roman Navy Fleet before the 1st Punic War (264 - 241 B. C.) in connection with the fact that Carthaginians had obtained multi-tier heavy ships boards of whose, defended by a whole forest of oars, were not inaccessible for a ram strike of comparatively light Roman biremes. In a short period of time Romans introduced into their fleet 120 such vessels. A single rower managed an oar. The number of oars in one row reached to 25. The length of the pentera was nearly 45 m and the total number of oars reached 250. Rowers of the third and the fourth rows took their places in a closed crinoline - 'parodos'. Rowers of the lower row were placed one above the other in a hull of the ship. Coordinated rowing of such a great number of oars was reached by account of joining of oars of one row with the help of a common cable and a use of locking lugs limiting the value of one oar movement. The bow and the stern of the pentera were decorated by the acroter (extensions of posts). A shed gallery with a banister under which a boat was hanged surrounded the stern part of the ship. The pentera had two masts with fighting tops. The sail rigging consisted of large square sails used only at passages with fair winds.