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

2. 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)

3. 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

4. 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

5. Examples of Modular Designs

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

7. Methods of Construction
Welded
Bolted
Formed metal
Machined/extrusion
Combination

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

9. 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))

10. 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).

11. 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.