Our Team Carries Us Forward

With over two decades spent tunneling in the challenging geotechnical conditions of the Pacific Northwest, the J.W. Fowler team has developed a unique capability to self-perform a wide variety of tunneling, trenchless, and shaft-sinking methods including slurry microtunneling with deep water retrieval, earth pressure balance tunneling, SEM tunneling, hard rock tunneling, open face conventional tunneling with rib and lagging or liner plate, sliplining, cast-in-place concrete liner, frozen ground excavations, segmentally lined caissons, pipe ramming, and auger boring.


Pilot Tube Guided Boring

Pilot Tube Guided Boring (PTGB) is one of the most popular and cost-effective trenchless methods to accurately install steel casing for underground utilities, waterlines, and sanitary sewers. Typical installation diameters range from 12-inch to 48-inch diameter with lengths ranging from 50-feet to 500-feet.

This method combines the pinpoint accuracy of the pilot tube installation to control line and grade with the excavation process of horizontal auger boring.
Pilot tube-guided boring is becoming more common for probing for obstructions prior to larger tunnel installation and can be combined with pipe ramming for accurately installing casings in excess of 48-inch.

Auger Boring

Auger boring is a trenchless technology method used to install steel casing pipe in a variety of soil conditions ranging from dry sand and clay to solid rock formations with the proper cutting head on the auger. Installation diameters are typically 24-inch to 60-inch diameter with drive lengths of up to 500-feet.

This process results in a horizontal bore by jacking the steel casing through the earth from a main shaft to a reception shaft. Spoil/muck is removed from inside of the casing by means of a rotating auger. The rotating auger carries the excavated material back through the casing pipe to the main shaft for removal.

Shaft Excavation

Shafts are installed at a variety of depths and sizes in just about every type of ground condition. Shaft support of excavation can vary depending on depth and ground conditions. Common methods include soldier pile/lagging, sheet pile, secant piles, slurry walls, and ground freezing. New technologies in shaft excavation continue to be developed like the Vertical Shaft Machine (VSM) method which installs shafts under the groundwater table via remote mechanical excavation.


I found James W. Fowler Co. to be a true and valued partner by identifying project challenges and offering innovative solutions, often prior to the beginning of construction, and without impacting the successful and timely completion of the project.
Marty Noble
King County Construction Manager (Retired)
J.W. Fowler staff worked closely with City of Portland staff and the design firm to prepare a constructible design that would meet our needs. They were able to help us shave more than $15,000,000 (33%) from the overall estimated cost of the project.
H. Scott Clement, PE
Former Balch Consolidation Conduit Program Manager, City of Portland Environmental Services
Fowler's depth of knowledge and experience helped make the project successful and a pleasurable experience. Fowler believes in and contributed to a "partnership" approach to project management.
Jim McWade
Former Project Manager, CH2MHILL

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