Previously, I constructed many large graphitic structures by fusing C60 along a particular 5-fold axis. But in addition to the 5-fold axes, one can also fuse two C60s along a particular 3-fold axis to get different kind of fused structures. One can easily see that the topological charges of necks in these two structures are the same, i.e. (-1)x6=0x3+(-2)*3=-6. The total topological charges are, of course, equal to 18x1+(-6)=12. However the relative arrangement for the two C60s are different, staggered for the pure-heptagon neck, while eclipsed for the hexagon-octagon neck. In fact, Diudea and Nagy have already done a lot on this possibility. Read the book for more information.
The following two pictures show two possible ways of coalescence: the neck of the first one consists of a ring of octagons and hexagons alternatively; the second one is a ring of six heptagons, instead.
In principle, one can create a one-dimensional tube by coalescence of many C60s repeatedly.