échelle de drague

OBS: [Illustration :] Passerelle et échelle pour l'excavation de la drague n° 4.

CONT: The mining dredges were land-locked floating machines, digging the ponds that allowed them to float - and thus move - across the area to be mined. The floating dredge most commonly operated in the North was the California-type, also known as bucket-line dredge. This type of dredge used a continuous line of buckets (called the ""digging ladder"") to scrape the bottom and edge of the pond.
CONT: Parks Canada is issuing a Call for Tenders for the supply, fabrication and installation of a new foundation for the digging ladder at Dredge no. 4 National Historic Site of Canada in Dawson City, Yukon.
CONT: The depth of digging is controlled by changing the angle of the digging ladder through a running rigging system extending from a winch on the port side.