page_title: Trip hammer
section_title: Greco-Roman world
hierarchical_section_title: Trip hammer / Early history / Europe / Greco-Roman world
caption_attribution_description: English: Carreg Pumsaint This standing stone is near the entrance to Dolaucothi gold mine. There is a legend of five travelling saints who rested against this stone and were frozen in place. Merlin freed them but their impressions were left in the stone. The nearby village is called Pumsaint - meaning five saints. The only problem is that examining the stone reveals only four indentations. Archaeologists suggest that the indentations were made on the stone because it was used for grinding ore during the Roman gold mining operations.
context_page_description: A trip hammer, also known as a tilt hammer or helve hammer, is a massive powered hammer. Traditional uses of trip hammers include pounding, decorticating and polishing of grain in agriculture. In mining, trip hammers were used for crushing metal ores into small pieces, although a stamp mill was more usual for this. In finery forges they were used for drawing out blooms made from wrought iron into more workable bar iron. They were also used for fabricating various articles of wrought iron, latten, steel and other metals.
  One or more trip hammers were set up in a forge, also known variously as a hammer mill, hammer forge or hammer works. The hammers were usually raised by a cam and then released to fall under the force of gravity. Historically, trip hammers were often powered hydraulically by a water wheel.
  Trip hammers are known to have been used in Imperial China since the Western Han dynasty. They also existed in the contemporary Greco-Roman world, with more evidence of their use in medieval Europe during the 12th century. During the Industrial Revolution the trip hammer fell out of favor and was replaced with the power hammer.
context_section_description: The main components for water-powered trip hammers – water wheels, cams, and hammers – were already known in Hellenistic times. Early cams are in evidence in water-powered automata from the third century BC. One Greek automaton in particular, a flute player whose mechanism was described by the Banu Musa but can be "reasonably" attributed to Apollonius of Perge, functions on the principle of water-powered trip hammers.
  The Roman scholar Pliny (Natural History 18.97) indicates that water-driven pestles had become fairly widespread in Italy by the first century AD:
  The greater part of Italy uses an unshod pestle and also wheels which water turns as it flows past, and a trip-hammer [mola]".
  While some scholars have viewed this passage to mean a watermill, recent scholarship argues that mola must refer to water-powered trip hammers which were used for the pounding and hulling of grain. Their mechanical character is also suggested by an earlier reference of Lucius Pomponius (fl. 100-85 BC) to a fuller's mill, a type of mill that has been operated at all times with falling stocks. However, it has been pointed out by recent scholarship that the translation of Pomponius' fragmentary text could be faulty, and relies on translating "mola", which is often thought to mean either a mill or millstone, to instead refer to a water powered trip hammer. Grain-pounders with pestles, as well as ordinary watermills, are attested as late as the middle of the 5th century AD in a monastery founded by Romanus of Condat in the remote Jura region, indicating that the knowledge of trip hammers continued into the early Middle Ages.
  At the Italian site of Saepinum excavators have recently unearthed a late antique water mill that may have employed trip hammers for tanning, the earliest evidence of its kind in a classical context.
  The widest application of trip hammers seems to have occurred in Roman mining, where ore from deep veins was first crushed into small pieces for further processing. Here, the regularity and spacing of large indentations on stone anvils indicate the use of cam-operated ore stamps, much like the devices of later medieval mining. Such mechanically deformed anvils have been found at numerous Roman silver and gold mining sites in Western Europe, including at Dolaucothi (Wales), and on the Iberian peninsula, where the datable examples are from the 1st and 2nd century AD. At Dolaucothi, these trip-hammers were hydraulic-driven and possibly also at other Roman mining sites, where the large scale use of the hushing and ground sluicing technique meant that large amounts of water were directly available for powering the machines. However, none of the Spanish and Portuguese anvils can be convincingly associated with mill sites, though most mines had water sources and leat systems which could easily be harnessed. Likewise, the dating of the Pumsaint stone to the Roman era did not address that the stone could have been moved, and relies on a series of interlinked probabilities which would jeopardize the conclusion of a Roman dating should any of them unravel.
caption: The regular indentations on the Carreg Pumsaint and similar mortar blocks are believed to stem from mechanically-operated trip hammers.[1]
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