The extension of the ‘All Red’ telegraph network to Australia and New Zealand during the 1870s greatly enhanced communication between the centre and periphery, consolidating British imperial expansion and offering the Australasian colonies the opportunity to engage more fully in imperial affairs. For contemporaries, the Trans-Tasman cable between Australia and New Zealand provided the final link in a grand imperial chain of communications, which promised to bolster their significance in world affairs and offset the cultural isolation which appeared to be stifling their development. The cable represented an essential bond between the furthest-flung imperial ‘bridgehead’ (John Darwin) and the cultural and strategic centre of London. In real terms, however, the promises of the new technology of submarine telegraphy failed to live up to expectations. Although quickly integrated into New Zealanders’ dawning cultural nationalist myth, the cable was expensive and underused for many years. Its real significance lies in its symbolic power as a symbol of imperial expansion, and as a case study in the vagaries of technology transfer.