A valve train assembly includes: at least one dual body rocker arm having a first body, a second body, and a latching arrangement for latching and unlatching the first body and the second body, the latching arrangement being biased to an unlatched configuration; and an actuator arrangement external to the rocker arm for controlling the latching arrangement, the actuator arrangement being arranged so that a default setting thereof is to cause the latching arrangement to be in a latched configuration.