1. A hybrid electrical and mechanical ship propulsion and electric power
system, comprising:
a first mechanical power plant configured to exclusively drive a first propeller via a first shaft;
a second electrical power plant configured to exclusively drive a second propeller via a second shaft; wherein the second electrical power plant includes a high temperature superconductor (HTS) motor interconnected to the second shaft; and
a first electrical network to which the HTS motor is connected in order to energize the HTS motor to drive the second propeller via the second shaft.
2. The ship propulsion and electric power system of claim 1 further including at least one electric weapons system interconnected to and powered by the first electrical network.
3. The ship propulsion and electric power system of claim 2 further including a second electrical network configured to power the ship service electric system; wherein the second electrical network is connected to a disconnect switch which is also connected to the first electrical network; the disconnect switch configured to connect and disconnect the first power network and the second power network.
4. The ship propulsion and electric power system of claim 3 wherein the second electrical power plant includes at least one HTS generator connected to the first power network via a first switchgear.
5. The ship propulsion and electric power system of claim 4 wherein the at least one HTS generator is a high inertia HTS generator.
6. The ship propulsion and electric power system of claim 5 wherein the first mechanical power plant includes at least one gas turbine or diesel engine prime mover
interconnected to a main reduction gear, and wherein the main reduction gear is connected to the first shaft to drive the first propeller.

7. The ship propulsion and electric power system of claim 6 further including at least
one ship service turbo-generator or diesel generator interconnected to the second electrical
power network.
8. The ship propulsion and electric power system of claim 7 further including a second
switchgear connecting at least one pulsed power load to the first electrical network.
9. The ship propulsion and electric power system of claim 8 wherein the first mechanical power plant is configured to be installed in a first engine room of the ship and the second electrical power plant is configured to be installed in a second engine room on the ship.
10. The ship propulsion and electric power system of claim 9 wherein in the second engine room on the ship there is included the at least one HTS generator of the second power plant.
11. The ship propulsion and electric power system of claim 10 wherein the HTS motor is mounted in the second engine room lower in a hull of the ship than the at least one HTS generator.
12. The ship propulsion and electric power system of claim 11 wherein the HTS motor in the second engine room is mounted lower in the hull of the ship than the main reduction gear in the first engine room.
13. The ship propulsion and electric power system of claim 12 wherein the main reduction gear is interconnected to the first shaft at a first angle and the HTS motor is interconnected to the second shaft at a second angle, and wherein the first angle is greater than the second angle.
14. The ship propulsion and electric power system of claim 13 further including a controller configured to operate the ship propulsion and electric power system in at least two modes of operation.

15. The ship propulsion and electric power system of claim 14 wherein, in a first mode, the controller is configured to connect the at least one HTS generator and the at least one pulsed power load to the first electrical network via the first switchgear and the second switchgear, respectively, and wherein the controller is configured to open the disconnect switch to isolate the first electrical power network from the second electrical power network, thereby enabling the first electrical network to power the HTS motor to drive the second propeller via the second shaft and to simultaneously power the at least one pulsed power load.
16. The ship propulsion and electric power system of claim 15 wherein in the first mode the controller is further configured to operate the first mechanical power plant to drive the second propeller via the second shaft.
17. The ship propulsion and electric power system of claim 14 wherein, in a second mode, the controller is configured to connect the at least one HTS generator to and disconnect the at least one pulsed power load from the first electrical network via the first switchgear and the second switchgear, respectively, and wherein the controller is configured to close the disconnect switch to connect the first electrical power network to the second electrical power network, thereby enabling the first electrical network to supply power to the second electrical power network and to simultaneously power the HTS motor to drive the second propeller via the second shaft.
18. The ship propulsion and electric power system of claim 17 wherein in the second mode the controller is further configured to operate the first mechanical power plant to drive the second propeller via the second shaft.
19. The ship propulsion and electric power system of claim 14 wherein, in a third mode, the controller is configured to disconnect the at least one HTS generator and the at least one pulsed power load from the first electrical network via the first switchgear and the second switchgear, respectively, and wherein the controller is configured to close the disconnect switch to connect the first electrical power network to the second electrical power network, thereby enabling the second electrical network to supply power to the first

electrical power network and to simultaneously power the HTS motor to drive the second propeller via the second shaft.
20. The ship propulsion and electric power system of claim 19 wherein in the third mode the controller is further configured to terminate operation of the first mechanical power plant and to allow the second propeller via the second shaft to feather.
21. A high temperature superconductor (HTS) rotating machine having a longitudinal axis and having a first rotational inertia, comprising:
a cylindrical stator assembly disposed about the longitudinal axis; a cylindrical rotor assembly disposed within the stator assembly and configured to rotate within the stator assembly about the longitudinal axis, the rotor assembly comprising:
at least one HTS winding assembly which, in operation, generates a magnetic flux linking the stator assembly; and
a cylindrical electromagnetic shield disposed about the at least one HTS winding assembly, wherein the cylindrical electromagnetic shield has a second rotational inertia; and
a cryogenic cooling system for cooling the at least one superconducting winding assembly of the rotor assembly;
wherein the second rotational inertia is at least eighty percent (80%) of the first rotational inertia.
22. The high temperature superconductor (HTS) rotating machine of claim 21 wherein the at least one HTS winding comprises N pole pairs, p.
23. The high temperature superconductor (HTS) rotating machine of claim
22 includes a radius, R1, from the longitudinal axis to the at least one HTS winding.
24. The high temperature superconductor (HTS) rotating machine of claim 23
wherein the cylindrical electromagnetic shield has a thickness, t, and wherein thickness
t > 50% of R1/p.

25. The high temperature superconductor (HTS) rotating machine of claim 24
wherein the cylindrical electromagnetic shield comprises metal.
26. The high temperature superconductor (HTS) rotating machine of claim 25
wherein the metal may comprise one or more of copper, steel, lead, gold, tungsten, and
spent uranium.
27. A turbo-generator, comprising:
a turbine;
a shaft interconnected at a first end to the turbine; and
a high temperature superconductor (HTS) rotating machine connected to a second end of the shaft and having a longitudinal axis and a first rotational inertia; the HTS rotating machine, comprising:
a cylindrical stator assembly disposed about the longitudinal axis; a cylindrical rotor assembly disposed within the stator assembly and configured to rotate within the stator assembly about the longitudinal axis, the rotor assembly comprising:
at least one HTS winding assembly which, in operation, generates a magnetic flux linking the stator assembly; and
a cylindrical electromagnetic shield disposed about the at least one HTS winding assembly, wherein the cylindrical electromagnetic shield has a second rotational inertia; and
a cryogenic cooling system for cooling the at least one superconducting winding assembly of the rotor assembly;
wherein the second rotational inertia is at least eighty percent (80%) of the first rotational inertia.
28. The turbo-generator of claim 27 wherein the at least one HTS winding
comprises N pole pairs, p.

29. The turbo-generator of claim 28 includes a radius, R1, from the longitudinal
axis to the at least one HTS winding.
30. The turbo-generator of claim 29 wherein the cylindrical electromagnetic shield has
a thickness, t, and wherein thickness t > 50% of R1/p.
31. The turbo-generator of claim 30 wherein the cylindrical electromagnetic shield comprises metal.
32. The turbo-generator of claim 31 wherein the metal may comprise one or more of copper, steel, lead, gold, tungsten, and spent uranium.
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