Plug and feather
Encyclopedia
Plug and feather, also known as plugs and wedges, feather and wedges, wedges and shims, pins and feathers and feather and tare refers to a technique and a three-piece tool set used to split stone.
ian times. With this simple mechanical technique, the stone was first measured and marked. Bronze
plugs and feathers were then driven into grooves which had been previously cut with a chisel
and mallet
.This was the most common method used by the Egyptians for quarrying limestone
and sandstone
. Evidence of this method for cutting obelisks in the quarries
of Aswan
can clearly be seen. The technique was also used by the Romans
.
On Dartmoor
, Devon
, England, the process is known as feather and tare and it was used from around 1800 to split the large blocks of granite
found on the ground there. It was, for instance, used to make the rails for the Haytor Granite Tramway
in 1820.
In New England, the plug and feather technique is first mentioned in The New-England Farmer; Or, Georgical Dictionary(1790) by Samuel Deane. Deane wrote "... another method of breaking rocks, which ought to be generally known, and which sometimes turns out cheaper, is this: Drill two holes in a stone, ranging with the grain, when that can be discovered with the eye. Then filling each hole with two semi-cylindrical pieces of iron, drive along steel wedge between them. the stone will thus be split open. And commonly, very regular shaped pieces for building may be obtained." (page 268-269) In 1803, Governor Robbins was part of a committee tasked with building a new state prison. In a chance encounter in the same year, Robbins came into contact with Mr. Tarbox who was using a modified version of the plug and feather method described by Deane. Instead of using only two holes, Tarbox drilled as many holes as was necessary, spacing them six to eight inches apart. Robbins hired Tarbox to teach the quarrymen at the Quincy Massachusetts quarries his technique. Within a year, the price of quarried stone was cut in half. The method spread quickly and became the basis of the modern plug and feather method still used today.
Circa 1803, according to William Pattee's History of Old Braintree and Quincy (1878) Josiah
Bemis, George Stearns, and Michael Wild developed a splitting method similar in concept to the plug and feather method. This technique (referred to by modern researchers as the "Flat Wedge Method") for splitting stone entailed cutting slots in a shallow line into the stone using a cape chisel
struck with a large hammer. Small, flat metal wedges were then driven between shims made of sheet iron. The method of feathers and plugs began to be employed around this time, and spread rapidly throughout the region. Evidence of stone split with both methods indicate the evolution of this technique. The method using the cape chisel created long rectangular slots, whereas the newer method, using a plug drill, left round holes.
The plug and feather method is still widely in use today.
Description
Each set consists of a metal wedge (the plug), and two shims (the feathers). The feathers are wide at the bottom, and tapered and curved at the top. When the two feathers are placed on either side of the plug, the combined width of the set is the same at both ends.Technique
Multiple sets of plug and feathers are typically used to split a single, large piece of stone. The stone is first examined to determine the direction of the grain. After the location of the intended split is chosen, a line is scored on the surface of the stone. A number of holes are then cut or drilled into the stone face along the scored line approximately 10 – 20 cm apart. Plug and feather sets are then inserted in the holes with the "ears" of the feathers facing the direction of the desired split. The plugs are then struck with a small stone maul in sequence. An audible tone from the wedges changes to a 'ringing sound' when the wedges are tight. Between each series of strikes, a pause of several minutes allows the stone to react to the pressure. Eventually a crack appears along the line that was scored on the surface and the stone splits apart.History
Variations of the plug and feather method have been used since ancient EgyptAncient Egypt
Ancient Egypt was an ancient civilization of Northeastern Africa, concentrated along the lower reaches of the Nile River in what is now the modern country of Egypt. Egyptian civilization coalesced around 3150 BC with the political unification of Upper and Lower Egypt under the first pharaoh...
ian times. With this simple mechanical technique, the stone was first measured and marked. Bronze
Bronze
Bronze is a metal alloy consisting primarily of copper, usually with tin as the main additive. It is hard and brittle, and it was particularly significant in antiquity, so much so that the Bronze Age was named after the metal...
plugs and feathers were then driven into grooves which had been previously cut with a chisel
Chisel
A chisel is a tool with a characteristically shaped cutting edge of blade on its end, for carving or cutting a hard material such as wood, stone, or metal. The handle and blade of some types of chisel are made of metal or wood with a sharp edge in it.In use, the chisel is forced into the material...
and mallet
Mallet
A mallet is a kind of hammer, usually of rubber,or sometimes wood smaller than a maul or beetle and usually with a relatively large head.-Tools:Tool mallets come in different types, the most common of which are:...
.This was the most common method used by the Egyptians for quarrying limestone
Limestone
Limestone is a sedimentary rock composed largely of the minerals calcite and aragonite, which are different crystal forms of calcium carbonate . Many limestones are composed from skeletal fragments of marine organisms such as coral or foraminifera....
and sandstone
Sandstone
Sandstone is a sedimentary rock composed mainly of sand-sized minerals or rock grains.Most sandstone is composed of quartz and/or feldspar because these are the most common minerals in the Earth's crust. Like sand, sandstone may be any colour, but the most common colours are tan, brown, yellow,...
. Evidence of this method for cutting obelisks in the quarries
Quarry
A quarry is a type of open-pit mine from which rock or minerals are extracted. Quarries are generally used for extracting building materials, such as dimension stone, construction aggregate, riprap, sand, and gravel. They are often collocated with concrete and asphalt plants due to the requirement...
of Aswan
Aswan
Aswan , formerly spelled Assuan, is a city in the south of Egypt, the capital of the Aswan Governorate.It stands on the east bank of the Nile at the first cataract and is a busy market and tourist centre...
can clearly be seen. The technique was also used by the Romans
Ancient Rome
Ancient Rome was a thriving civilization that grew on the Italian Peninsula as early as the 8th century BC. Located along the Mediterranean Sea and centered on the city of Rome, it expanded to one of the largest empires in the ancient world....
.
On Dartmoor
Dartmoor
Dartmoor is an area of moorland in south Devon, England. Protected by National Park status, it covers .The granite upland dates from the Carboniferous period of geological history. The moorland is capped with many exposed granite hilltops known as tors, providing habitats for Dartmoor wildlife. The...
, Devon
Devon
Devon is a large county in southwestern England. The county is sometimes referred to as Devonshire, although the term is rarely used inside the county itself as the county has never been officially "shired", it often indicates a traditional or historical context.The county shares borders with...
, England, the process is known as feather and tare and it was used from around 1800 to split the large blocks of granite
Granite
Granite is a common and widely occurring type of intrusive, felsic, igneous rock. Granite usually has a medium- to coarse-grained texture. Occasionally some individual crystals are larger than the groundmass, in which case the texture is known as porphyritic. A granitic rock with a porphyritic...
found on the ground there. It was, for instance, used to make the rails for the Haytor Granite Tramway
Haytor Granite Tramway
The Haytor Granite Tramway was a unique granite-railed tramway running down from Haytor Down, Dartmoor, Devon. The tramway was built in 1820 to carry Haytor granite, which was of fine grain and high quality, down from the heights of Dartmoor for the construction of houses, bridges and other...
in 1820.
In New England, the plug and feather technique is first mentioned in The New-England Farmer; Or, Georgical Dictionary(1790) by Samuel Deane. Deane wrote "... another method of breaking rocks, which ought to be generally known, and which sometimes turns out cheaper, is this: Drill two holes in a stone, ranging with the grain, when that can be discovered with the eye. Then filling each hole with two semi-cylindrical pieces of iron, drive along steel wedge between them. the stone will thus be split open. And commonly, very regular shaped pieces for building may be obtained." (page 268-269) In 1803, Governor Robbins was part of a committee tasked with building a new state prison. In a chance encounter in the same year, Robbins came into contact with Mr. Tarbox who was using a modified version of the plug and feather method described by Deane. Instead of using only two holes, Tarbox drilled as many holes as was necessary, spacing them six to eight inches apart. Robbins hired Tarbox to teach the quarrymen at the Quincy Massachusetts quarries his technique. Within a year, the price of quarried stone was cut in half. The method spread quickly and became the basis of the modern plug and feather method still used today.
Circa 1803, according to William Pattee's History of Old Braintree and Quincy (1878) Josiah
Bemis, George Stearns, and Michael Wild developed a splitting method similar in concept to the plug and feather method. This technique (referred to by modern researchers as the "Flat Wedge Method") for splitting stone entailed cutting slots in a shallow line into the stone using a cape chisel
Chisel
A chisel is a tool with a characteristically shaped cutting edge of blade on its end, for carving or cutting a hard material such as wood, stone, or metal. The handle and blade of some types of chisel are made of metal or wood with a sharp edge in it.In use, the chisel is forced into the material...
struck with a large hammer. Small, flat metal wedges were then driven between shims made of sheet iron. The method of feathers and plugs began to be employed around this time, and spread rapidly throughout the region. Evidence of stone split with both methods indicate the evolution of this technique. The method using the cape chisel created long rectangular slots, whereas the newer method, using a plug drill, left round holes.
The plug and feather method is still widely in use today.
See also
- MasonryMasonryMasonry is the building of structures from individual units laid in and bound together by mortar; the term masonry can also refer to the units themselves. The common materials of masonry construction are brick, stone, marble, granite, travertine, limestone; concrete block, glass block, stucco, and...
- StonemasonryStonemasonryThe craft of stonemasonry has existed since the dawn of civilization - creating buildings, structures, and sculpture using stone from the earth. These materials have been used to construct many of the long-lasting, ancient monuments, artifacts, cathedrals, and cities in a wide variety of cultures...
- Non-explosive demolition agentsNon-explosive demolition agentsNon-explosive demolition agents are commercial products that are an alternative to explosives in demolition, mining, and quarrying. To use non-explosive demolition agents in demolition or quarrying, holes are drilled in the base rock like they would be drilled for use with conventional explosives...
, another way of splitting stone
External links
- Using Plug and Feathers Video of a stone block being split with plug & feathers
- Drilling and splitting Video explaining the process from drilling, placing supports and use of plug & feathers; with timing
- Different methods for splitting stone using hand tools Includes photographs of the tools and the different type of quarry marks left by the tools.
- Video of Brazilian stonemason showing the ancient technique of splitting stone without feathers and wedges