2. A system according to claim 1 wherein the rod bundle forming station includes a gathering tub to which the rod is delivered in the form of a series of rings, said apparatus at the rod bundle forming station including means for positioning an empty carrier with the mandrel thereof projecting within the gathering tub to guide said rings of rod onto the carrier and form a rod bundle supported on the base platform of the carrier.

3. A system according to claim 2 wherein the means for positioning an empty carrier includes a shuttle carriage for moving an empty carrier under the gathering tub, an elevator device for raising the empty carrier into rod bundle forming position, and means on the base platform of the carrier for registry with the elevator device.

4. A system according to claim 1 wherein the rod bundle forming station includes an elevated gathering tub to which the rod is delivered in a series of rings, said overhead power and free conveyor being arranged at the rod bundle forming station with means for stopping a load carrying unit in a carrier detaching position and in a carrier resuspending position, said apparatus at the rod bundle forming station including means for detaching and moving a empty carrier beneath the gathering tub, elevator means for raising the empty carrier to a rod bundle forming and receiving position in which the mandrel of the empty carrier projects within the gathering tub and guides rings of rod onto the carrier to form a rod bundle supported on the base platform of the carrier, and for lowering the loaded carrier.

5. A system according to claim 1 wherein the rod bundle forming station includes an elevated gathering tub to which the rod is delivered in a strand formed into a series of rings; the overhead power and free conveyor being arranged with a station adjacent to one side of the gathering tub at which a load carrying unit can be stopped to detach an empty rod bundle carrier therefrom and with a second station adjacent to the opposite side of the gathering tub at which a load carrying unit can be stopped to resuspend a loaded rod bundle carrier thereon; said apparatus at the rod bundle forming station including carrier shuttle mechanism transversely moveable between said stopping stations, the shuttle mechanism including means for supporting a pair of rod bundle carriers in side-by-side relation with one of said supported carriers located at one of said stopping stations and the other supported carrier located beneath the gathering tub; and elevator means beneath the gathering tub for raising an empty carrier from the supporting means of the shuttle mechanism to a rod bundle forming and receiving position in which the mandrel of the empty carrier projects within the gathering tub and guides rings of rod onto the carrier to form a rod bundle supported on the base platform of the carrier, and for lowering the loaded carrier back onto the supporting means of the shuttle mechanism for movemEnt thereby to said second stopping station.

6. A system according to claim 5 wherein said shuttle mechanism includes means for raising and lowering the supporting means for detaching and resuspending a rod bundle carrier from a load carrying unit.

7. A system according to claim 6 wherein said shuttle mechanism is operable while a carrier is held in said rod bundle forming and receiving position by the elevator means.

8. A system according to claim 1 wherein the means for detachably suspending the rod bundle carrier includes a suspension element at the outer end of the mandrel structure.

9. A system according to claim 1 wherein the rod bundle carrier is provided with handling elements on the base platform thereof engageable by complimentary handling elements forming part of the carrier handling apparatus.

10. A system according to claim 1 wherein the mandrel structure comprises a plurality of beams extending longitudinally of the mandrel axis and arranged radially about the mandrel axis, the outer ends of the beams forming a tapered nose portion.

11. A system according to claim 1 wherein the carrier handling apparatus includes a table, means for moving the table into engagement with the base platform of a rod bundle carrier suspended from a load carrying unit to detach the carrier therefrom, means for securing the base platform of the carrier to the table, and means for rotating the table and carrier between a position in which the base platform of the carrier is horizontal and a position in which the base platform is substantially vertical.

12. A system according to claim 11 wherein the table and the base platform of the carrier are provided with interengageable elements for fixing the position of the carrier relative to the table.

13. A system according to claim 11 wherein the table is mounted on a base moveable transversely to the path of travel of the overhead conveyor.

14. A system according to claim 11 wherein the intermediate station is for performing a compacting and banding operation and the apparatus thereof includes a compacting head moveable relative to the base platform of a rod bundle carrier engaged by the apparatus, and banding apertures in the base platform of the carrier to facilitate the application of bands to a rod bundle supported thereby.

17. A system according to claim 16 wherein the means for detachably suspending the rod bundle carrier includes a suspension element at the outer end of the mandrel structure.

18. A system according to claim 16 wherein the rod bundle carrier is provided with handling elements on the base platform thereof engageable by complementary handling elements forming part of the carrier handling apparatus.

19. A system according to claim 16 wherein the mandrel structure comprises a plurality of beams extending longitudinally of the mandrel axis and arranged radially about the mandrel axis, the outer ends of the beams forming a tapered nose portion.