Big Scale Collaboration: A Great Success

Recently, Sandvik and our customer Cementation Americas joined forces to achieve one of the largest raise’s completed in the Northern Hemisphere ever: a massive raise boring shaft, 7.965 meters in diameter. It proved to be a successful and zero-harm project taking place at the Solvay Soda Ash Mine at Green River, Wyoming (US).

It all started with a request from Cementation Americas to excavate a shaft with an increasing concrete liner thickness as the depth of the shaft increased. Soon, the Sandvik Raise Boring team and Cementation Americas found that a totally new solution was needed, which turned out to mean a record-breaking raise bore diameter.

“Innovations are at the very core of our business, and when given the chance to design, engineer, and manufacture a flexible reaming head, we were both excited and eager to transform our extensive knowledge and years of field expertise into a productive solution", says Neil McPhee, Product Line Manager Raise Boring for Canada at Sandvik Mining and Rock Solutions.


The raise boring shaft at Solvay Mine

Initially, the concept of achieving this was proposed by a pilot slash raise with a raise bore drill, and then slash from the top down to accomplish the differing diameters and accommodate the correct concrete liner thickness. When discussing alternative options, the end results instead landed in a full raise bored shaft solution with variable diameters for each section of the shaft.

Working closely together, Cementation Americas and the Sandvik Raise Boring team designed, engineered, and manufactured a reaming head with the ability to cut back into desired diameters, rather than having to manufacture different diameters of outside wings. The final design was an impressively large reaming head that allowed for five diameter options – spanning from 8,133 to 7,461-meter diameters – and consisting of 12 individual sections and 46 cutters.

The planning of the project started back in 2020, and the reamer was ready to be shipped out to the Solvay Green River mine in October 2021. Following the completion of the pilot hole by the end of December 2021, the reamer started first collaring, with a conclusion of a smooth and problem-free assembly with zero issues.

The project completed successfully earlier this year without any incidents or harm to operators. ​

“The success of this project is the result of great collaborations by all parties involved, as well as a customer-focused drive to find the best technical solution for Solvay", says Neil McPhee.


Solvay is a global leader in soda ash, with nine major soda ash and bicarbonate plants, of which Green River in Wyoming, US is one. The company produces soda ash and sodium bicarbonate from trona, a naturally occurring mineral, to serve the glass, chemicals, detergents and food industries, among others.

Location: Solvay Mine, Green River, Wyoming, USA
Type of mine: soda ash and sodium bicarbonate from trona
Drill rig: Strata 950 Raise Drill with 16" stem 14" rods
Reamer weight: 62 tons (136 000 lbs)
Hole length: 429 m (1407 ft)
Hole diameter at starting point: 7,965 m (26,12 ft)
Hole diameter at completion: 7,461 m (24,48 ft)​

Drill phase 1:
Reaming starts at diameter 7,965 m (26,12 ft) for 179 m (588 ft), before the reamer is lowered down and cut back to rearrange the saddles ​

Drill phase 2:
Continue reaming at diameter 7,629 m (25,02 ft) for 87 m (285 ft), before the reamer is once again lowered down and cut back to rearrange the saddles​

Drill phase 3:
Continue reaming at diameter 7,461 m (24.47 ft), until completion.