Man who takes care of the powder cable running to the mucker.

An enclosed platform, similar to an elevator car, used to transport men and miscellaneous material up and down a shaft.

A shaft of concrete or steel which can be sunk through the ground by excavating the ground within the perimeter of the lower edge, with the rate of sinking frequently controlled by compressed air.

Portable platform that rides on a track in a tunnel and is used for passing cars and trains. It has space for two or more tracks, crossovers, and switches, and has sliding and tapered end rails that ride on main-line rails.

Portable tracks used for switching cars. The portable tracks are of sufficient length to accomodate one car when the portable tracks are resting on top of the main-line track. The rails are knife-edged on each end so as a car can be placed on them from the main track. Then these tracks and car can be manually rolled on other rails to the side a sufficient distance to clear the main track.

One of the most pollutant element produced by fuel engines.

A place where elements for immersed tunnels can be fabricated in the dry, and which can be flooded to allow the elements to be floated out and taken away. Generally used for concrete tunnels

Used in environmental assessment to describe the need for caution in proceeding with a project if the environmental effects are not well understood -- in contrast to proceeding until evidence shows that there is a problem

A relatively short, underground room-type opening of large cross-sectional area, generally built to house a special structure such as a hydroelectric power plant, hardened defense facility or storage for waste.

Continuous space within the cross-section of an element, bounded by walls, floor and ceiling. A cross-section may contain many cells, hence multiple-cell box, where for example separate cells may be used for each traffic direction, emergency egress, utilities, supply air and exhaust air.

A below-grade portion of a building. See also basement

Quantity of cement contained in a unit volume of concrete or mortar, preferably expressed as weight per cubic measure (examples : kg/cubic meter, pounds per cubic yard, sacks per cubic yard etc.)

A method of tunnelling whereby the center is left to the last for excavation.

A relatively short, underground room-type opening of large cross-sectional area, generally built to house a special structure such as a hydroelectric power plant, hardened defense facility or storage for waste.

Corners of box section tunnels are often chamfered (bevelled, with the corners missing) to remove unnecessary space where it serves no useful purpose, or thickened to reduce moments and shears (haunches) and to allow dragging anchors to pass more easily over the tunnel.

A building containing toilets, showers, lockers, and clothes-drying facilities for the tunnel crews.

Physical site conditions revealed by excavation to be substantially different from the conditions that could reasonably be anticipated from information in the contract documents. Common basis for litigation by contractor, sometimes resulting in an extra paid by owner.

A combination of chemicals that gel into a semi-solid after they are injected through drilled holes to strengthen incompetent ground (generally soil), or to prevent groundwater from flowing into the excavation.

A combination of chemicals that gel into a semi-solid after they are injected into the ground to solidify water-bearing soils

Any frame capable of lifting a car vertically so a train may pass beneath it; used for passing cars.