Tools and techniques Mechanical excavation thumb|Excavation at the site of the Battle at the Harzhorn (Germany) This describes the use in excavations of various types and sizes of machines from small backhoes to heavy duty earth-moving machinery. Machines are often used in what is called salvage or rescue archaeology in developer-led excavation when there are financial or time pressures. Using a mechanical excavator is the quickest method to remove soil and debris and to prepare the surface for excavation by hand, taking care to avoid damaging archaeological deposits by accident or to make it difficult to identify later precisely where finds were located. The use of such machinery is often routine (as it is for instance with the British archaeological television series Time Team) but can also be controversial as it can result in less discrimination in how the archaeological sequence on a site is recorded. One of the earliest uses of earth-moving machinery was at Durrington Walls in 1967. An old road through the henge was to be straightened and improved and was going to cause considerable damage to the archaeology. Rosemary Hill describes how Geoffrey Wainwright "oversaw large, high-speed excavations, taking bulldozers to the site in a manner that shocked some of his colleagues but yielded valuable if tantalising information about what Durrington had looked like and how it might have been used." Machines are used primarily to remove modern overburden and for the control of spoil. In British archaeology mechanical diggers are sometimes nicknamed "big yellow trowels".
Tools and techniques Mechanical excavation thumb|Excavation at the site of the Battle at the Harzhorn (Germany) This describes the use in excavations of various types and sizes of machines from small backhoes to heavy duty earth-moving machinery. Machines are often used in what is called salvage or rescue archaeology in developer-led excavation when there are financial or time pressures. Using a mechanical excavator is the quickest method to remove soil and debris and to prepare the surface for excavation by hand, taking care to avoid damaging archaeological deposits by accident or to make it difficult to identify later precisely where finds were located. The use of such machinery is often routine (as it is for instance with the British archaeological television series Time Team) but can also be controversial as it can result, in less discrimination in how the archaeological sequence on a site is recorded. One of the earliest uses of earth-moving machinery was at Durrington Walls in 1967. An old road through the henge was to be straightened and improved and was going to cause considerable damage to the archaeology. Rosemary Hill describes how Geoffrey Wainwright "oversaw large high-speed excavations, taking bulldozers to the site in a manner that shocked some of his colleagues but yielded valuable if tantalising information about what Durrington had looked like and how it might have been used." Machines are used primarily to remove modern overburden and for the control of spoil. In British archaeology mechanical diggers are sometimes nicknamed "big yellow trowels".