Alusoria (short form ofnavis lusoria from Latin '"dancing/playful ship"', pluralnaves lusoriae) was type of a small military vessel of the lateRoman Empire that served as atroop transport. It was powered by about thirty soldier-oarsmen and an auxiliarysail. Nimble, graceful, and of shallow draft, such a vessel was used on northern rivers close to theLimes Germanicus, the Germanic border, and thus saw service on theRhine and theDanube. The Roman historianAmmianus Marcellinus mentioned thenavis lusoria in his writings,[1][2][dead link] but not much about it could be learned until the discovery of such boats atMainz, Germany in 1981–82.[3][4][dead link]
In November 1981, during excavation in the course of a construction of a Hilton Hotel at Mainz, wooden remains were found and identified as parts of an old ship. Before construction resumed three months later, the site yielded remnants of five ships that were dated to the 4th century usingdendrochronology. The wrecks were measured, taken apart and, in 1992, brought to theMuseum of Ancient Seafaring (German:Museum für Antike Schifffahrt) of theRomano-Germanic Central Museum (Römisch-Germanisches Zentralmuseum) for further preservation and study.[3]
Scientifically the wrecks were termed "Mainz 1" through "Mainz 5" and generally referred to as the "Mainzer Römerschiffe" (the Mainz Roman ships). They were identified as military vessels that belonged to the Roman flotilla in Germania, theClassis Germanica. The vessels could be classified into two types, namely small troop transports (Mainz 1, 2, 4, 5) termednavis lusoria and a patrol vessel (Mainz 3).[4] Thelusoria is narrower than theactuaria, an earlier and wider type of Roman cargo vessel.
A full-sized reconstructed vessel is on display at the Museum of Ancient Seafaring, Mainz, and serves as a representative of thelusoria. For the reconstruction of this vessel specifically Mainz 1 and 5 served as templates. The replica measures 21.0 by 2.8 m (68 ft 11 in by 9 ft 2 in) while thegunwale measures 0.96 m (3 ft 2 in).[5] Again oak is used. The planks are 2 cm (0.8 in) thick, generally 25 cm (10 in) long and arecarvel-built. Thekeel is only 5 cm (2 in) thick and constructed of planks; it contains a central channel to collect water. There is nokeelson. The frames are placed 33.5 cm (13.2 in) apart corresponding to the measuring unit of apes Drusianus.[4] The frames hold the ship together. The mastframe contains a hole to place the mast. While the ship could be sailed, the main method of propulsion was rowing by one open row of oarsmen on each side. The gunwale displays an outsidefender and is topped by a covering board. The covering board contains the support for the oars. The protective effect of the gunwales is further extended by the shields of the soldiers which were hung on the outside. Boats were steered by a doublerudder aft. Sails have not survived the centuries, so their reconstruction relies on ancient depictions. Alusoria was crewed by the steersman, two men to handle the sail, and about 30 soldiers who manned the oars.[4][dead link]
It has been calculated that the narrow and relatively longlusoria could attain a travel speed of 11 to 13 km/h (6 to 7 kn) and a maximum speed of 18 km/h (10 kn).[2]
The significance of the findings led to the establishment of a specific research center to study Roman ship transport at the Romano-Germanic Central Museum and of the Museum of Ancient Seafaring as its parent division. The latter museum has been in operation since 1994 and displays replicas of thelusoria and the patrol vessel as well as original artefacts.[6] It specializes in Roman shipbuilding and ship transport, in the Germanic provinces and in the whole empire.
After the establishment of the militarycastrum (fort) ofMogontiacum (modernMainz) in 13–12 BC, ships of theClassis Germanica became stationed at its harbor. Mogontiacum soon became the capital of the Roman province ofGermania Superior and ships from its harbor could travel up and down the Rhine and east to the Main river.[3] The military fleet was upgraded when theEmperor Julian increased defensive measures along the Rhine in the 4th century, and Marcellinus reported that the Emperor had 40lusoriae that were used for his troops at Mogontiacum.[1] At that time the border was increasingly threatened, andlusoriae became useful to ship troops to outposts or to points of crisis. Eventually however,Vandals,Suebi, andAlansmoved across the Rhine and sacked Mogontiacum in or about 407. As Roman control ended, the local Roman fleet decayed and, over time, became covered with debris, mud and earth.
TheRegina is a reconstruction of alusoria by students of the Department for Ancient History of theUniversity of Regensburg.[7] Launched in 2004, the boat was used to test its abilities in numerous trips along theNaab andDanube. In 2006, theRegina travelled fromRegensburg toBudapest covering distances of up to 100 km (54 nmi) per day confirming that the vessel was speedy and demonstrating the great mobility the military could achieve by its use.
