Editing Cable layer (section)

=== Repeaters ===
When [[coaxial cable]]s were introduced as submarine cables, a new issue with cable-laying was encountered.  These cables had periodic [[repeater]]s inline with the cable and powered through it.  Repeaters overcame significant transmission problems on submarine cables.  The difficulty with laying repeaters is that there is a bulge where they are spliced in to the cable and this causes problems passing through the [[sheave]].  British ships, such as HMTS ''Monarch'' and [[CS Alert (1961)|HMTS ''Alert'']] solved the problem by providing a trough for the repeater to bypass the sheave.  A rope connected in parallel to the repeater went through the sheave which pulled the cable back in to the sheave after the repeater had passed.  It was normally necessary for the ship to slow down while the repeater was being laid.<ref name="Haigh">K. R. Haigh, ''Cableships and Submarine Cables'', pp. 211–214, Adlard Coles, 1968 {{oclc|497380538}}.</ref>  American ships, for a time, tried using flexible repeaters which passed through the sheave.  However, by the 1960s they were also using rigid repeaters similar to the British system.<ref name="NewScientist">[https://books.google.com/books?id=d_XOKdeyXrYC&pg=PA716 "Two new British cable ships completed"], ''New Scientist'', No. 240, p. 716, 22 June 1961.</ref>

Another issue with coaxial repeaters is that they are much heavier than the cable.  To ensure that they sink at the same rate as the cable (which can take some time to reach the bottom) and keep the cable straight, the repeaters are fitted with parachutes.<ref name="NewScientist"/><ref name="Haigh"/>{{rp|212}}