 The Act stipulated that the railway and the dock could only be opened together, not independently, and that had to be within five years.In fact the seam at the St Davids pit proved more elusive than expected, and was finally found in June 1832 at a depth of 660 feet, the deepest in Wales at the time.The delay meant that the works could not be completed within the authorised time, and a second Act was obtained allowed a time extension; it also permitted the use of steam locomotives on the line.