INNOVATION July-August 2013

. 2013 PROJECT HIGHLIGHTS

2012

Cleveland Dam Elevator Installation CWA Engineers with the assistance of EBA, RWDI, Gunn Consultants, and R.F. Binnie & Associates designed and installed an elevator and ducting system inside a new service building down a narrow 60 m underground airshaft for Metro Vancouver. Originally used as an air intake for cone valves at the bottom of the airshaft, the atmosphere in the airshaft was wet and misty. Engineered galvanized ducting and a gutter system were installed to keep the airshaft dry and prevent ice formation in the shaft walls. The dry environment helps extend the service life of the new elevator. The only suitable location for the building was located at the base of an embankment that is seismically unstable. Engineered slope stabilization by use of soil anchors was installed to seismically isolate the slope from the building during a seismic event.

LDPE Lined High Velocity Channels Heber Diversion Dam, a creosote-coated timber crib rock fill dam, on Vancouver Island was dismantled and the river channel rehabilitated. Two temporary LDPE (Low density polyethylene) trapezoidal diversion channels were designed and constructed to divert water around either side of the dam and minimize seepage into the adjacent excavation. The channels were 150 and 185 m long with finished depths ranging from 2.5 m to 4.5 m. The channels were designed to carry the 50-year return period summer flows of 17m 3 /s and 47m 3 /s with design flow velocities up to 7 m/s and design flow depths up to 2.5 m. Gradual bends and cross wave freeboard allowances totaled 1.0 m to 2.0 m. These temporary LDPE lined diversions provide an alternative to large riprap channels for clean or contaminated water diversions. Owner: BC Hydro. Contractor: Quantum Murray LP. Designer: Rick Rodman, P.Eng. (Rodman Hydrotechnical). Material supplier/installer: Western Tank and Lining.

Radio Transmission Power Boost CBC Vancouver’s Radio One programming, broadcast on 88.1MHZ FM Band, has increased

effective radiated power from 20 kW to 100 kW. This project involved the installation of two new Harris Z10 transmitters with a switch- less combiner to provide 12.85 kW transmitter power, together with a new Jampro FMwideband antenna array (eight bays of two panels) and FM constant impedance combiner module.  The antenna array is comprised of upper and lower half antenna systems, each half antenna system (four bays of two panels) employing 8 Arrowhead Crossed Dipole antennas. The RF layout (patch-panel and combiner modules) gives technicians the flexibility to route each transmitter to either the new or existing wideband antennas, improving the robustness of the transmitter site. Project participants: Julie Bergeron, Surren Balendran, Kevin Blackwell, P.Eng. (Morrison Hershfield), Theo Papadam and Dino Zorbas, P.Eng. (ENV-Telcom).

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