The several, we had ran for more than 3 hours each and without a hitch at Long Beach. Any of these three ways to collect current will be easier to build, to maintain and to operate on a home layout than as one or more modules of a modular layout. Yet it was with modules that the whole system was developed and the specifications for modules provide a pretty fool proof, satisfactory way whereby cars and locomotives can run over as many or as few modules as exist at the time without problems. NCat's specifications apply equally to modular or permanent layouts. These are the items.
Installation is a separate matter.
Fortunately the first lineside pole design proved quite satisfactory and has been in use since. In the mid-1980s Don Spencer simplified this design which, though easier to make, does not operate satisfactorily in all situations. In the earlier days when only pantographs were in use as current collectors, connections between modules were made through loops in the contact wires at each end of a module. When trolley poles started to be used, this was changed to a design that functions for trolley poles as well as pantographs. Also, when trolley poles were used, the system of just crossing the overhead wires over turnouts and crossings necessitated frogs and x-ings in the overhead wire.