Engine brake apparatus for a turbocharged IC engine

The engine (1) has a two-stage turbocharger system. The inlet air (23) passes through a low-pressure compressor (17) driven directly (12) by a low-pressure turbine (16), and through a high-pressure compressor (14) driven (15) by two separate high-pressure turbines (13a/b). There are air coolers (26,27) before and after the high-pressure compressor. The engine has a single inlet manifold (5) and two separate exhaust manifolds (6). The braking valve (30) is located downstream of the low-pressure turbine and has a mechanical actuator (31). A control circuit regulates the action of the braking valve, also the action of bypass valves (34a,34b) for the high- pressure turbines.