<p>First (2) and second (3) side spars form an edge round a cable-retaining part (5). A base unit (4) connects the side spars. Connecting sections (CS) (6,7) use mechanical linking elements (MLE) (11) to link a first (1) cable-carrying device (CCD) to a second CCD (1'). The MLE link the first CCD to one end overlapping on the CS with complementary MLE for the second CCD.</p>