A roadheader, also called a boom-type roadheader, road header machine, road header or just header machine, is a piece of excavating equipment consisting of a boom-mounted cutting head, a loading device usually involving a conveyor, and a crawler travelling track to move the entire machine forward into the rock face. The cutting head can be a general purpose rotating drum mounted in line or perpendicular to the boom, or can be special function heads such as jackhammer-like spikes, compression fracture micro-wheel heads like those on larger

tunnel boring machine A tunnel boring machine (TBM), also known as a "mole" or a "worm", is a machine used to excavate tunnels. TBMs are an alternative to drilling and blasting methods and "hand mining", allowing more rapid excavation through hard rock, wet or dry so ...

s, a slicer head like a gigantic chain saw for dicing up rock, or simple jaw-like buckets of traditional excavators.

History

The first roadheader patent was applied for by Dr. Z. Ajtay in Hungary, in 1949. It was invented as a remote operated miner for exploitation of small seam, close walled deposits, typically in wet conditions.

Types

Cutting Heads: * Transverse - rotates parallel to the cutter boom axis * Longitudinal - rotates perpendicular to boom axis

Uses

Roadheaders were initially used in coal mines. The first use in a civil engineering project was the construction of the

City Loop The City Loop (originally called the Melbourne Underground Rail Loop or MURL) is a piece of rapid transit, underground commuter rail infrastructure in the Melbourne central business district, central business district (CBD) of Melbourne, Vict ...

(then called the Melbourne Underground Rail Loop) in the 1970s, where the machines enabled around 80% of the excavation to be performed mechanically. They are now widely used in such as tunneling both for

mining Mining is the Resource extraction, extraction of valuable geological materials and minerals from the surface of the Earth. Mining is required to obtain most materials that cannot be grown through agriculture, agricultural processes, or feasib ...

and municipal government projects, building wine caves, and building cave homes such as those in Coober Pedy,

Australia Australia, officially the Commonwealth of Australia, is a country comprising mainland Australia, the mainland of the Australia (continent), Australian continent, the island of Tasmania and list of islands of Australia, numerous smaller isl ...

. On February 21, 2014, Waller Street, just south of Laurier Avenue collapsed into an 8m-wide and 12m-deep sink-hole where a roadheader was excavating the eastern entrance to

Ottawa Ottawa is the capital city of Canada. It is located in the southern Ontario, southern portion of the province of Ontario, at the confluence of the Ottawa River and the Rideau River. Ottawa borders Gatineau, Gatineau, Quebec, and forms the cor ...

's LRT

O-Train The O-Train is a light rail system in Ottawa, Ontario, Canada, operated by OC Transpo. The O-Train system consists of three lines, all of which are fully Grade separation, grade-separated. As of March 2025, one line is currently being extended an ...

tunnel. A similar incident occurred in June 2016, when a sink-hole opened up in Rideau Street during further construction of the tunnel, and filled with water up to a depth of three metres. The

CBC CBC may refer to: Media * Cadena Baja California or Grupo Cadena, a radio and television broadcaster in Mexico * Canadian Broadcasting Corporation, Canada's radio and television public broadcaster ** CBC Television ** CBC Radio One ** CBC Music ** ...

reported that one of Rideau Transit Group’s 135-tonne roadheaders was in a part of the tunnel where the flooding was the deepest. Three roadheaders were used in the construction of the O-Train.

Projects utilizing roadheaders

* Boston's Big Dig * Ground Zero Cleanup * Addison Airport Toll Tunnel * Fourth bore of

Caldecott Tunnel The Caldecott Tunnel is a four-bore highway tunnel through the Berkeley Hills between Oakland and Orinda, California. Its four bores carry California State Route 24. Named after Thomas E. Caldecott, former mayor of Berkeley, it opened in ...

* Malmö City Tunnel *

Line 1, Ottawa

References

External links

{{Commons category, Roadheaders
An article on underground home design and construction, with a section on use of roadheader machines

Ripping head roadheader Video
Engineering vehicles Mining equipment Excavating equipment