In this study, a novel decentralised fault-tolerant control strategy is developed for a class of interconnected nonlinear time delay systems with unmeasurable state variables and actuator faults by using dynamic event triggering mechanism. The interconnected system model includes nonlinear time delay functions and unstructured uncertainties, which could be identified by the radial basis function neural networks approximation technique. The adaptive nonlinear observer is designed for each interconnected subsystem to obtain the estimated values of unmeasurable state variables and unknown system faults simultaneously. Then, a decentralised fault-tolerant tracking controller is designed for the considered interconnected time delay systems using both backstepping control procedures and a dynamic event triggering mechanism, which has the smaller event trigger frequency by comparing the traditional static event-triggered control scheme, such that the tracking error signals converge to a small neighbourhood near the origin and all the signals of the closed-loop system are globally bounded. Finally, a chemical reactor example is given to illustrate the feasibility and significance of the designed control scheme.