The Challenges of Electronic Enclosures for US Navy Ships Frank Duvergne 901D, LLC Rel 01

What makes US Navy Shipboard Enclosures so special? Stringent Environmental requirements Shock/Vibration Temperature Water Drip EMI Mission-specific requirements Equipment I/O (Input/Output) HMI (Human Machine Interface)

Why not the same rack everywhere? Ship-related requirements Ship type Available space Cable entry Foundation locations Hatchability Mission-related requirements Equipment type, size and weight Number/types of I/O HMI requirements (display, keyboard) Maintenance requirements TEMPEST requirements

minimize Cost/schedule impact of custom solution Reliance on proven structural frame Modular design Same isolation system for different deck frequencies Modular isolation system to accommodate wide range of payloads Same basic mount dimensions and interface, different characteristics Provisions for growth in number of isolators

Examples of Modular Designs

Different type of Electronics enclosures Hard Mounted Externally isolated, base mounted Externally isolated, bulkhead mounted Internally isolated Consoles

Methods of Construction Welded Bolted Formed metal Machined/extrusion Combination

Rack structure is only part of the solution Proper internal Equipment mounting is key to Shock/vibration mitigation Everything is in the brackets!

MIL-DTL-901E Replaces MIL-S-901D as of June 2017 Evolutionary rather than revolutionary Introduces DSSM (Deck Simulating Shock Machine) as alternate shock vehicle for heavyweight shock test Applies to new programs (e.g. FFG(X))

The key challenge: Thermal Management The challenges Increase of electronics density High max ambient temperature COTS usually not rated for high temperature Cannot cool to lower than max ambient temperature with forced-air cooling! Airborne noise due to fans How to address them Thermal simulation Ducting Control fan speed vs temp Choice of equipment Alternates to forced-air cooling: cold plate, air/water heat exchangers, Thermo-Electric Cooler (TEC).

The “Hosting Solution” approach Provide an integrated solution, based on functional requirements from customer Hosting solution includes Shock isolated enclosure Power supply and distribution: UPS, PDU, Wiring Harness Cooling subsystem HMI I/O Generic computing power Mechanical and electrical interface for mission-specific equipment ( can be installed by customer or by supplier) Advantage: single point of responsibility from design to delivery.