• Electric Utility Distribution System Planning

East End Road Utility Relocation Homer Electric Association, Homer, AlaskaThe Department of Transportation (DOT) elected to upgrade East End Road in Homer, Alaska. Before the new road could be constructed, the impacted utilities along the old road would require relocation.

Homer Electric Association (HEA) contracted with D&L to design a final relocation. D&L prepared the final relocation plan, prepared construction technical specifications and provided construction support. The corridor along East End Road contains many different utility facilities, including power, communication, water, sewer, and gas.

Upgrading the road created conflicts with these existing facilities. HEA began the preliminary design of the new distribution system and tasked D&L with completing the design and preparing necessary construction plan drawings and bid documents. This project replaced the existing overhead distribution system with an underground double circuit feeder (express and distribution) and a relocated overhead system as terrain and other facilities allowed. It required working in cooperation with DOT, the road designer, as well as telephone, cable, and natural gas utilities. The final design of the underground system incorporated a joint trench shared by multiple utilities. Cordova Airport Feeder Cordova Electric Cooperative, Cordova, AlaskaProject consisted of design and construction management of a new underground distribution feeder to the Cordova Airport. This is a unique underground project adjacent to an existing roadway and wetlands. Crossing of multiple drainages and standing water required horizontal borings in selected areas.

Trenching sections were required to match-up with the borings. Underground vaults located in the roadway fills were installed flush with the slope to allow for standard road maintenance.

An existing underground cable needed to remain in service during construction for supply to the airport and navigational lighting. Close coordination with DOT/PF and the airport was essential. Fort Wainwright Feeder 10 Rebuild Doyon Utilities, Fort Wainwright, AlaskaProject consisted of the design of a new heavy distribution feeder through the center of the Post.

This feeder will be the backbone for new electrical loads and a re-distribution of existing loads. Ten separate distribution feeders presently supply the electrical needs of the Post and are essentially the same as originally constructed over 50 years ago. This heavy conductor feeder is the beginning of an upgrade of the whole system. O’Malley Road Underground Installation Of 12.5 kV Distribution & 34.5 kV Sub-Transmission Lines Chugach Electric Association, Anchorage, AlaskaThis project consisted of the design for an overhead to underground relocation of 12.5 kV distribution and 34.5 kV sub-transmission lines. Designs for overhead and underground secondary services, sections of overhead 12.5 kV and overhead double and triple circuit 12.5/34.5 kV were also part of this project. Road crossings required extensive use of horizontal borings for the length of the project. The underground installation was in preparation for a 138 kV transmission line we were also designing.

Plans for road re-grading and widening along the O’Malley Road Corridor necessitated substantial coordination with DOT. Walden Point Line Extension Metlakatla Power & Light, Metlakatla, AlaskaThis project involved the preparation of a complete design package including field staking and construction documents for a 35 kV line extension from the Metlakatla Power House to the Walden Point Ferry Terminal, from the Walden Point Ferry Terminal, across Revillagigedo Channel via submarine cable to Mountain Point Substation on the Ketchikan Public Utility system. Pole assemblies were based on RUS specifications for 35 kV construction and RUS recommendations for raptor protection.

Electric Utility Distribution System Planning

Terra Southwest Williamsport To Pile Bay Communications Line General Communications, Williamsport, AlaskaFor this project Dryden & LaRue designed a fiber optic communications line from Williamsport in Cook Inlet to Pile Bay on Lake Iliamna. The terrain traversed by this line is largely mountainous. Typical aerial and buried plant standards (primarily from United States Department of Agriculture, Rural Utility Systems (RUS) and GCI) were used in compiling the construction units for this project. The plant standards were utilized in conjunction with Design Criteria developed by Dryden & LaRue in response to the expected environmental conditions in this region of Alaska.