In the first month of operation, the company applied to the Board of Trade for permission to run the line as a light railway and this was granted on 11 March 1880. A maximum speed of was specified, and it was to be worked by one engine in steam. Operation of the swing bridge was achieved using an Annett's key, which was attached to the staff, which the working engine was required to carry. Passenger traffic for the first ten years was fairly static, at around 76,000 journeys per year, but goods traffic doubled to reach . The next ten years saw a steady increase, with passenger journeys rising to 100,000 by 1900, while of minerals and of parcels were carried. In order to cope with the increase, another locomotive was ordered from Sharp Stewart in 1893. It was of a similar design to the originals, but slightly longer, and with a 2-4-2 wheel arrangement. It carried the name "Southwold" and the number 1, as its predecessor had done.