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CRALEY Fibre™ 7km underground river link, Washington state, USA.




CRALEY Fibre 7km underground river link in Snohomish County, Washington State, USA.

CRALEY Group, Snohomish County Public Service District No. 1 (SnoPUD) and IMCO Construction facilitated the installation of a 7KM (4.3miles) CRALEY Fibre link and 48 fibres in a tunnel of hydroelectric generation in the state of Washington, USA.

SnoPUD, the power generation and distribution company in Snohomish County, WA, had a very specific challenge: replacing its existing fiber optic link between the Jackson hydroelectric power station and the Culmback dam on Lake Spada. These facilities also provide drinking water supply to more than 600,000 residents and service businesses in the territory.

The pipeline infrastructure of a water company, by design, reaches where people, buildings and assets are, providing interconnections for the delivery of water.

"This can be very useful when you want to implement fiber optic links. Whether connecting two facilities, a rural community, a business in a remote location or providing "backhaul" for mobile phone poles, the existing water infrastructure can be used to provide a much faster and more economically viable solution than traditional techniques "

Andy Harris, CEO of CRALEY Group

This technique was used by SnoPUD to improve their communication in the installation they have in a rural area and difficult to access. SnoPUD has a tunnel of 4 meters (13 feet) in diameter, or "underground river", which was drilled through solid rock granite mountain, which carried water directly between the two facilities that require the communications connection. The SnoPUD engineering team contacted CRALEY Group to design a solution that could use this tunnel as a conduit to supply the fiber optic link.

Working in close collaboration with SnoPUD, CRALEY Group designed an CRALEY Fibre™ solution to provide a secure communications link in the tunnel, capable of supporting the entry and exit zones, the high flow velocities and the high pressures.

The solution included a continuous section of CRALEY Fibre™ for drinking water, 48 fibers Messenger Pipe, which entered and exited through two individually designed PFM pressure fittings and was fixed to the walls of the tunnel at regular intervals.

"SnoPUD has relied on our current vibration system for control, monitoring and telemetry, and CRALEY'S Fibre™ solution to provide high-speed data through our tunnel provided an ideal alternative: the other option was to settle 12 miles along the difficult mountainous terrain up to the Culmback Dam, which was estimated at more than 2 million dollars. The CRALEY Fibre™ solution was manufactured, delivered and installed in a tight timing ".

Brad Spangler, SnoPUD Senior Manager and project lead


Together with the new fiber optic link, SnoPUD is now able to improve the operational safety of its water and energy facilities.

The "pipe-in-a-pipe" solution from CRALEY Fibre™ proved to be the optimal and most cost-effective means to provide an end-to-end direct link between the two facilities.

The chief engineer of CRALEY Group, Neil Smith, worked closely with the SnoPUD contractor, IMCO, and completed 1.6km (1 mile) per day, completing the installation in a week.

"This is an example of flexibility and the benefits of the CRALEY Fibre™ solution, and I am proud that, despite the adverse weather conditions and the imminent closure of the tunnel in 14 days, the installation was completed within budget in just 7 days . My thanks and appreciation to all the members of the excellent team of gropu SnoPUD, IMCO and CRALEY, who carried out this project on time and within budget ".

Andy Harris, CEO of CRALEY Group

A unique project?

No, these requirements are almost always necessary in rural and geographically difficult regions; where existing communications are very poor and traditional installation techniques slow, problematic and have a prohibitive cost. It is in these same circumstances that CRALEY Fibre™ provides a great benefit.

CRALEY Group is already involved in similar projects in South America and Eastern Europe and believes that there will be many more around the world, to provide profitable fiber optic links within the hydraulic tunnels and large rivers or underground aqueducts.

Click image to view:

The mountainous granite terrain of Lake
Snohomish County SnoPUD Logo.png
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