My understanding too, they broke it down to the smallest part, then set up an assembly line with each line building 1 part, then mass assembling then. roman crews practiced on the beach while the ships were built. They used the corvus ( raven in latin ) in battle, a 35 foot bridge with a spike on it that was lowered from the bow onto another ship. It allowed the roman to basicly turn a sea fight into an infantry fight. In 260bc at Mylae the roman won the first of several naval battles with carthage with the new fleet. However the corvus made the ships top heavy and they lost more ships to storms than to battle and after 254bc it was abandoned ( the romans much more experienced at sea warfare now could live without it )