A 2,000-year-old Jewish ritual bath weighing around 25 tonnes has been lifted intact from an archaeological site in Israel in an unusual conservation operation involving a 300-tonne crane.
The ancient mikveh, or ritual purification bath, was discovered during excavations at the Carmei Gat neighbourhood of Kiryat Gat, where archaeologists uncovered evidence of a previously unknown Jewish settlement dating to the Second Temple period.
Rather than dismantling the structure, conservation specialists decided to remove the entire four-metre-wide bath from the ground in one piece to protect it while development work continues around the site.
The operation required two weeks of preparation, extensive reinforcement and a crane capable of lifting up to 300 tonnes.
The mikveh has now been transported to temporary state storage at Beit Guvrin. Once construction in the neighbourhood is completed, officials plan to return it to Carmei Gat and display it in a public open space close to where it was discovered.
Previously unknown Jewish settlement
The ritual bath was uncovered during an Israel Antiquities Authority (IAA) excavation funded by the Israel Land Authority as part of archaeological investigations ahead of development in the area.
Its discovery provided evidence for a Jewish community living there approximately 2,000 years ago.
Archaeologists also recovered stone measuring vessels from the settlement. Such objects were widely used among Jewish communities during the Second Temple period because, under Jewish ritual law, stone vessels were regarded as not susceptible to ritual impurity.
The combination of the vessels and the purpose-built purification bath provided researchers with particularly strong evidence for the identity of the ancient settlement's inhabitants.
According to excavation directors Elena Kogan-Zahavi, Ma'an Margolis and Shira Lipshitz, the discovery fills what had previously been a gap in the archaeological record.
“The Jewish settlement we discovered here is the first and only one known in this area,” they said.
While numerous Jewish settlements dating from the Roman period are known from the Judean Lowlands, they said no comparable settlement had previously been identified in the transitional region between the Judean Lowlands and the northern Negev.
Evidence uncovered during the excavation suggests the community was abandoned around the time of the Bar Kokhba Revolt against Roman rule in the second century AD.
Settlement at the site resumed only about 500 years later, during the Byzantine period, when archaeologists believe it was occupied by a different population.
Moving 25 tonnes of archaeology
Preserving the mikveh presented conservation specialists with an unusual problem.
The structure remained embedded in the ground and weighed approximately 25 tonnes. At around four metres across, it was also too wide to be moved using conventional transport equipment.
Four members of the IAA's conservation team spent approximately two weeks preparing it for removal.
They first excavated around the entire structure, exposing its exterior while ensuring that the ancient masonry remained stable.
Specialists then carried out closely spaced drilling beneath the bath. Steel beams were inserted through the resulting openings, creating a supporting framework beneath the ancient structure and allowing it to be separated from the ground without dismantling it.
The mikveh's surviving ancient plaster posed an additional challenge.
Vibrations produced while lifting the bath and transporting it by road risked causing the plaster to crack or detach from its walls. Conservators therefore covered vulnerable surfaces with gauze and adhesives before lining and reinforcing the structure with protective foam.
Only after the bath had been stabilised could the lifting operation begin.
300-tonne crane brought in
Although the ancient structure itself weighs about 25 tonnes, its position meant a much larger crane was required.
Because the crane had to stand some distance from the archaeological remains, engineers brought in equipment with a maximum lifting capacity of approximately 300 tonnes.
The entire mikveh was then raised from the ground and lowered onto a specialised transporter designed to carry unusually wide loads.
Moving it to Beit Guvrin required further logistical planning. Roads had to be temporarily closed to ordinary traffic, while escort vehicles travelled in front of and behind the lorry carrying the ancient structure.
For the conservation team, the operation left little margin for error.
“The moment you lift a structure like this, there is no turning back,” said Eyal Kaho, a senior conservator with the Israel Antiquities Authority who led the operation.
“If it falls apart, we have lost the mikveh. Therefore, you have to think about every detail in advance.”
Kaho, who has worked for the antiquities authority for 36 years, said operations involving irreplaceable archaeological remains remained stressful despite his decades of experience.
“The day before an operation like this, you don't sleep,” he said. “You are under pressure, because the responsibility is yours and there is no price for mistakes.”
The operation was completed successfully, with the ritual bath surviving the lift and journey intact.
Ancient structure to return home
The mikveh will remain in temporary storage while development of the new neighbourhood continues.
It is eventually expected to make a second journey back to Carmei Gat, where it will be incorporated into a public area in the centre of the neighbourhood.
The plan will allow the ancient bath to be displayed close to its original archaeological context rather than being permanently removed to a museum.
Officials say residents will ultimately be able to see physical evidence of the Jewish community that occupied the area roughly two millennia before the construction of the modern neighbourhood.
The wider archaeological excavations at Carmei Gat have been financed by the Israel Land Authority, with approximately 28 million shekels allocated to rescue archaeology associated with development in the area.
Sources : IAA