Abstract: An alignment system for use in aligning a first object with a second object, which system comprises a transmitter (6) for transmitting a directable signal, mounted on either the first object or the second object, a receiver (8, 9) for receiving the signal, mounted on the other of the first object or the second object and an indicator (12, 13) for indicating that a signal from the transmitter (6) has been received by the receiver (8, 9). Preferably, a single pair of transmitters (6) is mounted on a crane (7), a single pair of receivers (8) is mounted on a prime-mover (3) and a plurality of pairs of receivers (9) are mounted on a chassis (4) at intervals corresponding to positions midway along the lengths of each of a plurality of containers (2) supported by the chassis (4). Alignment of the transmitter (6) with the receiver (8) on the prime-mover (3) activates an indicator (12) for indicating that the movement of the prime-mover (3) is to be slowed.