Fortaleza Metro.
East Line 3

Four 6.92 m (22.7 ft) mixed ground Robbins Earth Pressure Balance Machines (EPBs) will excavate for one of Brazil's largest tunnel projects, Line 3 of the Metro Fortaleza. Line 3 will connect souteastern areas of Fortaleza with the downtown, and transport thousands of daily passengers. The machines will excavate sections of tunnel ranging from 4.3 km (2.7 mi) to 5.8 km (3.6 mi).

The four EPBs are designed for Brazil's complex geology with mixed ground cutterheads and additive injection capabilities. Each machine will also be equipped with Robbins continuous conveyor systems for efficient muck removal.

Ingemey's work in the project involved the geometric definition of the segment and design and calculation of the thrust structure.

The following summarizes the characteristics of the ring.

Ø external	6.60 m
Ø internal	6.00 m
Segment thickness	30 cm
Average length	1.5 m
Ring's segments	5 + 1
Key Segment	22.5º
Dovela tipo	67.5º
Regular Segment	15.000 kN