Product Development Process: HydroActive Bulkhead Seals


Stage 1: Identifying the Challenge & Solution

Customer Challenge/Requirements:

On Thursday, October 12, 2000, while refueling at a port in Aden, Yemen, the USS Navy destroyer Cole (DDG-67) was attacked by two suicide bombers navigating a small motorboat full of explosives. The damage was extensive as can be seen in an photo from an article published in 2007. The USS Cole had to be physically transported to the US for repairs. Upon further investigation it was determined that a bulkhead seal had failed which compromised the ships ability to contain the influx of water into adjacent compartments.  Only the skilled and heroic actions of the crew saved the USS Cole and others on the ship.

Conventional bulkhead seals continuously wear and may not be ready when needed. The United States Navy sought a better bulkhead seal design to protect its fleet and sailors. The above US Navy photograph above taken from, represents what is needed to stop a bulkhead seal that does not properly function from leaking.

Mide’s Solution:

Through a Navy small business innovative research (SBIR) award, Mide proposed a novel solution to the existing bulkhead shaft seal problem. Mide proposed a non-contacting seal that would only activate when a compartment was flooded, meaning the seal would always be ready for use when needed in an emergency for the ship. This design eliminated the maintenance required for the contacting seals that were currently in use and provided the Navy with 100% reliability.

Stage 2. Engineering the Solution



  • Lip seal displacement and wear
  • HydroActive foam force and performance
  • Shock and Vibration survivability
  • Thermal distribution



  • 1/8th size prototype to validate functionality
  • Different lip seal geometry
  • HydroActive foam optimization



  • 1000+ Hour Operational Testing
  • Shock MIL-S-910D, Grade A
  • Vibration MIL-STD-167-1A
  • Foreign Fluid Compatibility
  • Shaft to Bulkhead Misalignment



  • Military approved and commercial versions.
  • In house production and assembly (ISO 9001: 2008)
  • ABS, DNV, BV, & Lloyds Type approvals
  • Service team for installation

Result/Current Status:

Mide’s bulkhead seals were rigorously tested and met the United States Navy’s stringent requirements, making them the premiere option for the U.S. Navy’s fleet. Mide’s HydroActive seals are currently installed on over 52 Navy vessels, including the USS Arleigh Burke Class (DDG 51), the USS Independence Class (LCS 2), the USS Freedom Class (LCS 1), and the USS San Antonio Class (LPD 17).  These seals are reducing maintenance and lifecycle costs for the Navy, while also providing the reliability needed to help ensure the safety of our warfighters. Mide has also transitioned the technology to a commercial product. 

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