Engineering Survey Projects

Hudsons Bay Mining & Smelting Co.

1994-1996 (Mine Audit and Control Surveys and Shaft Plumbing)

Underhill was contracted to carry out high precision mine surveys and to audit the surveying operations at two HBMS mine sites in Flin Flon, Manitoba. The surveys included 4 km of precise 3-D traverse along ramps ranging from 0 to 24% grades. These traverses were supplemented with multiple gyroazimuth observations. The gyrotheodolite was also used to transfer azimuths between levels down a 670m shaft. This shaft was plumbed using optical and mechanical techniques. As with most mine sites, conditions were less than optimal. Despite the conditions, we obtained sub-decimeter accuracy in the traverses (95% confidence) and centimetre accuracy in the shaft plumbing.

The audit was a thorough review of all surveying operations in the mine. This included an assessment of: instruments and equipment, conditions, field practices, reduction techniques, and personnel. The purpose of the traverses was to direct critical excavation in mine expansion. However, at the same time we carried out our traverses, we tied into local mine control and thus were able to assess the quality of the mine control. The results of this comparison were also included as part of the audit.

H.A. Simons International Ltd./Howe Sound Pulp and Paper Ltd.

1988 - 1991 (Port Mellon Mill Expansion)

Underhill was contracted to provide consulting survey services for this 1 Billion Dollar mill expansion. Project included establishment of a pillared mill control network and grid, structural layout, and as-build, road layout and grades, legal surveys, and precise engineering surveys.

Sandwell Inc. / Western Pulp Limited Partnership

1990 - 1992 (Woodfibre Pulp Mill Upgrade / Expansion Surveys)

Underhill supplied engineering survey services for the design, layout, control, and as-built of structures and other facilities in this project.

H.A. Simons (International) Ltd. / Western Pulp Limited Partnership

1984 - 1987 (Woodfibre Pulp Mill Upgrade / Expansion Surveys)

Underhill was contracted to provide consulting survey services for the establishment of a monumented control network, layout of contractor specific control, as-builts of contractors work, general layout work, topographic surveys, earthwork volumes, structural deformation monitoring, and various legal surveys.

B.C. Hydro

1989 - 1992 (Wahleach Tunnel Diversion Project)

Underhill was contracted to supply consulting survey services for the revitalization of BC Hydro's Wahleach Tunnel penstock. The project involved design and establishment of precise survey networks both above and under ground. Various engineering as-built surveys were required during the project. Precise deformation measurement and analysis surveys on existing penstock raise. Establishment of control for aerial mapping.

1989 (Louisiana Pacific 230 KV Transmission Line)

Underhill was engaged to prepare ground profiles for a proposed transmission line. The project involved establishing control along the route, clearing and profiling the line. The survey data was formatted to the clients proprietary format in the field and delivered to their head office for processing and plotting at regular intervals throughout the project.

1988 (Aiyansh to Stewart 138 KV Transmission Line)

This project involved establishing control along the route, clearing and profiling the line. A software package was developed to take data from a total station instrument and automatically reformat it into the clients format, to be utilized by their in-house software for the reduction and processing of the data. The developed package was also used to screen the input data for possible errors.