Entera Opens Trenchless Technology Division

As the demand for steel casing underneath major highways and railroads grew, the need to employ our own ABM was apparent. In mid-2019 we put it to work in north Toronto where we installed a 48” by 40m tunnel under the CN rail corridor. 

Our next opportunity, and the one highlighted in the pictures, was a challenge that was turned down by many other contractors. A 1.2m diameter tunnel, 178m long, installed under the busiest stretch of highway in the world, Highway 401 at Highway 427. The first trying task began with the excavation of the shafts. The area available to install the south shaft was to small to employ the standard trench box method as it was sandwiched between an on-ramp and an off-ramp for the 401 with high priority utilities on 3 sides. The shaft on the north side was located on a steep embankment with serious property line constrictions. An alternate method was employed. 

With an assist from our parent company, Somerville, a pilot hole had been pre-drilled through the rock employing directional bore technology. Once our auger bore machine was installed in the south shaft, it was time to get turning! This is where our perseverance was put to the test. The ground conditions were inconsistent at best. Shale, pockets of muck and solid limestone seams were mixed throughout the bore. The rock had been tested at 150+ mPa. The real challenge wasn’t just the strength of the rock but that the ground condition would not remain consistent. Constant communication with different tooling manufacturers and geotechnical experts at our disposal our crew adapted on the fly. Multiple cutter heads were brought to bear and replaced regularly as the ground dictated what drill heads worked best for each substrate encountered.

The jack and bore across the 401 was ultimately successful and was still completed ahead of schedule. That experience hardened Entera’s resolve and ultimately paved the way for another tightly scheduled bore under highway 404 which finished ahead of schedule as well. More projects in 2019/2020, included 2 tunnels 6 underneath very busy Metrolinx railroads.

On all projects, we have employed a fully equipped and regulatory compliant rescue team that practices regularly with the crew.

We are always seeking ways to improve our operations and become more efficient, recently we added an On-Target Steering system. This will allow us to install casing Pipe on precise angles giving us opportunities to have the sending and receiving shafts at different grades and is used in storm and sanitary sewer applications.

Entera continues to grow, we continue to broaden our horizons with trenchless technology as another infrastructure installation method we have mastered, and we are excited to offer as a service.