https://archeologie-sel.inrap.fr/Archeologie-du-Sel/Les-sites/Hallstatt-Autriche
Salt mining in the Hallstatt region (Austrian Alps) can be traced back to the Neolithic period, with the discovery of salt springs.
From the Bronze Age onward, mining activity developed; miners dug vertical shafts, up to 200 meters deep, to access the rock salt. The oldest traces of this type of mining date back to the 14th century BCE. Equipped with bronze picks, the miners dug through the clay layer to reach the salt.
From the Iron Age onward, shafts were dug at an angle into the mountain to more easily reach the salt layers, and extraction rooms were built. The salt and rock debris, tools, human remains, and fragments of clothing and textiles found during various excavation campaigns allow us to reconstruct the lives of the mining community that lived there. With the large-scale development of salt mining, a precious commodity destined for a vast supra-regional market, a wealthy and organized society emerged, as evidenced by the valuable objects found in the graves of the cemetery associated with this mine: this is known as the “Hallstatt culture.” Faced with competition from another deposit located in Hallein (Salzburg), the Hallstatt site declined around the 5th century BC.
https://www.nhm.at/hallstatt/en/salt_mine/bronze_age/transport_flow/carrysacks
The well-known carrysacks are among the most beautiful and fascinating finds from the mine. They were used to transport the salt through the galleries. We know of five such carrysacks.
Construction method
All carrysacks were made in the same way […], although displaying differences in handiwork. The basic form is a piece of hide cut in an hourglass shape, folded and sewn together laterally. The rim is hemmed over and reinforced with thongs. Two flanking wooden frame elements provide vertical reinforcement. The wide shoulder strap is also made of hide and fixed at both ends to the lower part of the carrysack, to be supported on the right shoulder. Tests have shown that the length of the strap must have been precisely adapted to the individual stature; this is why the strap is not firmly knotted with the carrysack, but wrapped several times around the strips of wood – a Bronze Age quick release fastener. A short wooden stick extends over the left shoulder; the stick is fastened to the upper part of the carrysack and has to be pulled down during carrying.
Use
The disadvantages of this construction, namely the excessive strain on one shoulder and habitual use of one hand, coupled with being off-balance are compensated for by one big advantage: the carrysack, weighing up to 30 kilos, can be emptied quickly and easily by dropping the stick away from the shoulder. This is however only an advantage if the carrysack is used without interruption over an extended period.
Evidence of the organizational structure in the mine
The bespoke construction of the individual carrysacks is highly functional and suggests a strict division of labour, as well as a continuous work flow. These items clearly show the highly structured nature of Bronze Age mining, of which they are not the only example. This quest for efficiency can be detected at various stages in the mining process of the time. From a present-day perspective, this rigid organisation can only be explained by the objective of minimizing nonproductive down time. An objective which only seems sensible if the quantity of salt produced keeps up with the optimised work flow. In other words, optimised mining logistics will only pay off if it is possible to produce considerable amounts of salt in a continuous fashion.