Detailed analysis of a 2,000-year-old bronze warship ram has shed new light on how the object was created and used.
Discovered by British divers off the coast of Tobruk, Libya, in 1964, the Belgammel Ram weighs 20kg (44lb) and would have been part of a small Greek or Roman warship called a tesseraria. The 65cm (2’2″) ram is a type known as a proembolion, meaning it would have been fixed to the upper level of the bow, and was used to break the oars of enemy ships.
Until now it had not been clear how the metal object had been cast, and the details of its date, composition, and the origin of its materials were unknown. Extensive tests using modern scientific techniques, led by Dr Nic Flemming of the National Oceanography Centre, has provided clues to all of these matters, however.
In a study recently published in the International Journal of Nautical Archaeology, radiocarbon dating of burnt wood found inside the ram, together with stylistic analysis of the images of birds and tridents used to decorate the artefact, suggest a date of between 100 BC and AD 100.
Micro-drilled samples of metal have revealed that the composition of the bronze is 87% copper, 6% tin, and 7% lead, while the fact that these concentrations vary throughout the casting indicate that the Belgammel Ram was cast in one piece and cooled as a single object.
Further examination of the metals used to make the ram have also hinted at where its materials were sourced. While previously isotope analysis of lead was only capable of identifying a general location in the Mediterranean, recent advances in this technology have allowed the team to narrow this down much more accurately. The lead used to make the Belgammel Ram is thought to have come from a particular district of Attica in Greece called Lavrion.
‘We have learned such a huge amount from the Belgammel Ram and have developed new techniques which will help us unpick future mysteries,’ said Nic Flemming . ‘We will never know why the ram was on the seabed near Tobruk – there may have been a battle in the area, a skirmish with pirates, or it could be that it was cargo from an ancient commercial vessel, about to be sold as salvage.’
He added: ‘The fragments of wood inside the ram show signs of fire, and we now know that parts of the bronze had been heated to a high temperature since it was cast which caused the crystal structure to change. The ship may have caught fire and the ram fell into the sea as the flames licked towards it. Some things will always remain a mystery. But we are pleased that we have gleaned so many details from this study that will help future work.’
In 2007 the last remaining member of the dive group that found the ram decided that the artefact should be returned to museum in Libya. This was achieved in 2010, with the help of the British Society for Libyan Studies. Although the Libyan uprising of 2011 resulted in many battles in the area around the museum, the building suffered no damage and the Belgammel Ram remains safe.