Thirty year Roadmap for Navy power systems to support railguns and lasers

The US Navy has a roadmap to align electrical power system developments with warfighter needs and enable capability based budgeting. It is meant to be a living document, updated biannually, that invites innovation and guides investment by DOD, government, industry, and academia to achieve synergistic advances in naval power systems. Recommendations have been provided based on available information, engineering judgment, and projected requirements. The historic timelines for major component and large system development such as the gas turbine engine and IPS can take up to about 20 years to transition to the fleet whereas smaller subsystems such as the LHD 8 hybrid electric drive can take up to 8 years. During the same length of time, the Navy 30 year Shipbuilding Plan changes, ship programs are initiated and terminated and threats to our security change constantly. This TDR proposes multiple paths to continue providing targets in the face of uncertainty.

This is a 95 page document. Naval Power Systems Technology Development Roadmap PMS 320 by the Electric Ships Office that is directing the Future of Ships Power. Advanced sensors, railguns and lasers will need a lot more power but that power will need to be compact and light.

The Navy has jjust installed a first prototype railgun on a navy catamaran. The Navy has installed their prototype railgun on a 1500 ton military catamaran called the joint high speed vessel aka JHSV. Lance M. Bacon reports this development at the Navy Times and Sam LaGrone at UNSI. The JHSV has 600 tons of excess payload capacity, but Zumwalt Navy destroyers have 20 tons of excess payload capacity. The railgun will need to be made more compact to be installed on the destroyers. The Destroyers at 14500 tons are bigger than the JHSV. The Destroyers are already filled with other systems.

The railgun also uses 34 mega joules of power to launch a 23-pound projectile to distances greater than 100 miles at speeds topping Mach 7 (better than 5,300 mph). While Zumwalt-class destroyers will generate roughly 78 mega joules (twice the power the railgun needs), most destroyers have in reserve less than one-third of the power the railgun needs. And there are a whole bunch of limitations on what can be done inside the ship to add power generators. Developers will house power generators in con-ex boxes during the JHSV demonstration, but a permanent power solution will be needed before the railgun lands in the fleet.

The target is 2018 for installation of a combat railgun on a US Navy destroyer.

Long term trends directly leading the development of Naval Power Systems are expected to continue. In general, they are:
* Navy platforms will require more electric power, on demand, to meet the needs of ever improving mission systems.
* The power density of the electric power system will need to continue improving to meet the increasing demand in the same foot print.
* Economic realities will force the Navy to keep current platforms in service longer than originally planned
* These platforms will be looked upon to service advanced weapons and sensors due to emerging threats.

A fundamental tenet in technology development and transition is to have the right technology, at the right time, for the right task. Under this construct, the overall capabilities present the “right task” and the Roadmap presents the “right technologies, at the right time” to sync up with the planned shipbuilding cycle. This roadmap promotes communication and collaboration and eliminates the need for industry to guess where the Navy is headed.

Technological superiority is critical to maintaining the US Navy’s position as the world’s premier naval force. This roadmap supports that technological superiority by focusing and directing investments and developments. It integrates the investments of the Navy, other DoD, and Industry with the innovative power of Academia. It tells all of our stake holders where we see our needs in the future to the extent that those needs can be forecast today.

Mid-Term (2023-2032) Development Recommendations

Mid-term development recommendations are dominated by NPS EDMs for the DDG(X) and LCS(X). Time phasing of NPS development for the mid-term is critical. Engineering Development Modules (EDMs) supporting the Milestone B FY 2030 and 2031 ships should be completed and ready for testing by approximately FY2025. Thus, any EDMs requiring development will be POM-20 or POM-21 issues. Any Science and Technology (S and T) development required needs to begin in FY-15 or 16. The following
mid-term development recommendations are provided:

* An EDM focused on MVDC
o Because of increases in loads, the FY2030 combatant will require more generation capacity than can be provided using a segregated plant on a DDG 51 hull.
o To provide power to all of the loads, DC power distribution appears to be appropriate technology. Previously conducted shipyard studies have shown the advantages of DC power distribution in the long term.
o The additional generation and distribution requirements indicate this ship will have some sort of integrated power system. A goal of this EDM is to conduct the necessary investigation into the loads, physical integration and power
requirements studies to determine if the system is a mechanically or electrically integrated NPS.
o In order to support MVDC for a FY2030 ship, EDM efforts must initiate in the early FY20s timeframe. Prior to the EDM, FNCs have to start in FY2015 and work towards full scale demonstrators in FY2020. These activities will support AoAs in the FY2025 / FY2027 timeframe.

A 2031 DDG(X) Naval Power System target delivery date 2026 that may require:
* Modular Capability (Based on the development timelines, it is recommended that the naval power systems currently under
development for insertion on the FY 30 and 31 medium and small surface combatants be compatible and enable “modular capability.)
* An advanced high power density propulsion motor and motor drive system
* An advanced high power density power generation system
* Advanced circuit protection
* Fully integrated advanced Energy Magazine
* High efficiency prime movers with energy recovery capability
* Advanced NPS power management controls

* A 2030 LCS(X) Naval Power System target delivery date 2025

From generators, to storage, to cables and breakers – All power components are planned

Far-term (2033-2042) Requirements Analysis

Anticipating both required capabilities and available technologies in the far-term involves additional uncertainty, but certain trends have become evident that build upon the assessments performed for the mid-term. It is expected that additional directed energy weapons requiring even more power will become available in the far-term as well as higher powered improved sensors and rail guns of increased size and capability. It is likely that Navy platforms will have many of these systems operating simultaneously, that the Navy will introduce additional modular ships with modular payloads, and that electric power systems will be required to continue to improve in the following areas:
* Provide improved power system flexibility
* Power system simplification will be desirable (less parts reduce cost)
* Power system cost reductions will be desirable
* Power system volumetric and gravimetric density increase will be desirable
* Power system modular upgradeability

Far-term (2033-2042) Development Recommendations

The following supporting product and system developments will be required in the far term:

* Build and test a solid state energy recovery system
o Advanced materials that can support waste heat scavenging hold promise as additional sources of power on future ships.

* Build and test a full scale 500kW fuel cell power generation system capable of using logistic fuels
o The use of logistic fuels present in the Navy today is a critical requirement for widespread adoption of fuel cells as a prime mover on future Navy ships. This effort builds on the body of knowledge achieved by the navy and industry thus far in powering fuel cells from marine diesel and other distillate fuels.
o Innovation here could potentially lead to wider adoption of fuel cells aboard future Navy ships and even allow multiple, smaller point of use type prime movers.

* Build or adopt advanced electrical cables for shipboard use
o Drastically reduce distributed system weight for cables
o Reduce bend radius for the same ampacity
o Increase maximum ampacity per cable

* Build and test advanced innovative electrical distribution system circuit protection
o Eliminate centralized load centers/switchboards (inline circuit
protection, converters, etc.)
o Reduce electrical distribution system weight
o Reconfigurable power transmission paths

* Promote D&I for advanced wide bandgap semiconductor devices
o Emergent technologies that could be the target of D&I funding should be monitored

* Eliminate separate Ethernet cables
o Combine Ethernet/control signals over power lines
o Transmit Ethernet/control signals wirelessly

SOURCES – Electric Ship Power Roadmap, UNSI, Navy Times