The Roman navy operated hundreds if not thousands of warships over a period of nearly nine hundred years, but very little is known about those ships. The written sources mention plenty of types of warships, but without providing much extra information. Artistic representations exist in significant numbers, but only one of them clearly identifies the type of ship being portrayed.
Pitassi's approach to this problem is to start from the physical limitations of an oar-powered warship - the amount of space needed for each rower, the length and angle of the oars and the efficiency of different arrangements (generally speaking two men each with their own oar provide more power than two men on a single oar). He then takes the visual representations of warships and tries to produce plans that combine the identifiable features in the art with different possible arrangements of rowers and oars. Finally he produced models of many of the types of ships to see if the plans work in practice. This final step eliminated one or two possible designs when it became clear that the different ranks of rowers would clash.
The analysis can get quite technical. One example of this is Pitassi's attempts to work out the arrangement of rowers in a sexteres, a warship with six men in each rowing position on each side of the boat. Three different arrangements of oars are examined, two with the ship as a trireme (three rows of oars on each side) and one as a bireme. The amount of space required for each rower, the angle at which the oars would have hit the water and the amount of mechanical power available in each arrangement are examined (the innermost rower limits how far the oar can move, with each rower nearer to the outside of the boat making a reduced contribution to each stroke). All three arrangements are illustrated, and eventually Pitassi decides on the bireme arrangement as being more practical and best matching a possible representation of a sexteres in Roman art.
This is a fascinating approach to take, and produces some very convincing reproductions of Roman warships. The model building stage proves to be more important than I would have though, eliminating some possible designs that looked practical on paper, and also gives Pitassi some excellent illustrations. This book comes highly recommended.
Part 1: Interpretation
1 - Sources
2 - Interpreting the Sources
3 - Ship Fittigsn
Part II: The Ships
4 - The Earliest Types: Eighth to Fourth Centuries BC
5 - Naval Ascendancy: Third and Second Centuries BC
6 - Civil Wars and Imperial Fleets: First Centuries BC and AD
7 - Height of Empire: Second and Third Centuries AD
8 - The Late Empire: Fourth and Fifth Centuries AD
9 - Terminus
Appendix I: Service Lives of Ship Types
Appendix II: Types of Roman Warship
Appendix III: Gazetteer: Where to See Roman Boats and Ships
Appendix IV: Glossary of Nautical Terms Used
Author: Michael Pitassi