Robbins Deploys First Crossover TBM in Mexico City
New Machine Designed for Variable Ground Conditions
Tunnel machine manufacturer Robbins has launched the first of its new Crossover TBM series machines on a project in Mexico City.
The 28.5-foot XRE TBM was assembled onsite, beginning the project on the Túnel Emisor Poniente II (TEP II) project in August. The TEP II is a major wastewater project by joint venture contractor ALDESA/PROACON/RECSA. The 3.7-mile tunnel will wind through variable conditions, including competent and weathered volcanic rock, soft sand and clay. The “crossover” TBM was selected for the project because it handles two modes: rock and earth pressure balance. Standard TBMs can lose efficiency in such varied conditions, but the Crossover TBM is specially designed and field tested to handle such changes. Features include a single-direction cutterhead for abrasive ground conditions and specialized gearboxes for addition torque at low rpm conditions, like fault zones and soft ground, and high rpm for rock boring.