SEACON » Blog » SEACON 24-/48 Channel HYDRALIGHT Connector Combines Precise Performance Specifications with Cost Savings

SEACON 24-/48 Channel HYDRALIGHT Connector Combines Precise Performance Specifications with Cost Savings


International Ocean Systems May/June 2016

TE Connectivity’s (TE) SEACON high-count optical wet-mate connector enables customers to optimise their network infrastructure reliably and cost-effectively


In 1964 SEACON established its first manufacturing division within what would become the SEACON Group. By 1968, the San Diego, USA, company was manufacturing Marsh & Marine electrical connectors for industry and specialised connectors for classified military applications. Over time, SEACON expanded its customer base and manufactured connectors for worldwide oceanographic research, military and marine oil and gas (MOG) exploration and production markets.


Nearly a half-century later, SEACON is well-known as standing for underwater connectors, with decades of experience in electrical, optical and hybrid (electrooptical) dry- and wet-mate connectors. The company has evolved from modest quarter to be part of TE, one of the leaders in sources of MOG connectivity solutions in mission-critical and harshenvironment applications.


The current SEACON suite of connectors has evolved from a single product in 1968 to more than 25 product ranges and 30,000-plus separate connector types and configurations in the standard range. These include many industrystandard and industry/technology leading connectors such as the WetCon, Micro WetCon, Rubber Molded, Minicon, HydraLight, OptiCon and G3 connector ranges. In July 2014, SEACON was acquired by TE. TE’s MOG portfolio includes more than 2500 underwater electrical and fibre optic connectors and offers complete system solutions to provide a wide range of advanced connectivity options.


New products come about in a number of ways. Some are developed as a natural progression of the manufacturer’s existing product line. Others develop as a result of industry initiatives, where a customer approaches a manufacturer with unusual – even unique – performance requirements on its wish list. The story of the HydraLight 24-/48-channel connector illustrates the latter scenario.

In 2010, a well-known subsea services company approached SEACON with a unique set of requirements. At a time when the industry standard for underwater mateable connectors was eight channels, the customer required a 48-channel connector for use in a sensing project. The 48 channels had to be enclosed in a single connector body (although this later changed to a 24-channel requirement). The optical power requirement was higher than the usual 200 milliwatts.

Connector back reflection values were highly critical in the customer’s sensing application. At the time this customer approached SEACON, the standard eightchannel HydraLight connector contained an ultra physical contact (UPC) configuration, which averaged a back reflection reading of -50dB, with a minimum of -30dB. The HydraLight, with angled physical contacts (APC), would guarantee the absolute value of -45dB back reflection on each optical channel.



SEACON met with the customer and launched the new product’s engineering design phase. To meet the new requirement, SEACON decided to utilise an existing small-profile, wet-mateable fibre optic connector, developed for offshore downhole sensing and telemetry. The smallprofile contact package was the ideal baseline design for two reasons. It offered a high number of optical channels in a small footprint, and APC contacts met the desired return loss criterion of less than -45dB. The design phase took approximately a year and a half of monthly design reviews with the customer, who provided periodic strategic input. The design phase included the following elements:

  • Front-end engineering and design (FEED) study
  • Detailed design of connector assembly
  • Prototype verification testing
  • Failure mode effects and criticality analysis (FMECA)
  • Connector qualification testing. Stringent SEACON qualification testing included the following parameters
  • Helium leak
  • Mate-demate cycles
  • Thermal shock
  • Wetmates in simulated turbid seawater
  • Hydrostatic pressure
  • Shock and vibration
  • Drop testing
  • Accelerated life testing (simulating 25-year service life conditions)

Each eight-channel HydraLight has eight positions where a single optical ferrule can be inserted. SEACON miniaturised the contacts such that each HydraLight connector tube could accommodate six optical channels, versus a single channel per tube, for a total of 48 (six channels x eight positions) separate channels. While the design was based on 48 channels, six months into the design phase the customer opted for two 24-channel connectors, based on redundant connector philosophy.
The only change required in the 24-channel configuration was to populate only four of the eight positions. In reality, each HydraLight can work at any variation from
one to 48 channels.

The delivered pair of 24-channel connectors met all customer requirements. HydraLight 24-/48-channel connector features include:

  • APC contacts configurable to a maximum of 48 channels per connector.
  • Uses synthetic mineral oil as pressure compensation fluid, for maximum protection against contamination during mating process, where fibre is connected to fibre inside an oil-filled chamber.
  • Field-proven sealing mechanisms (dualchamber mating environment).
  • ROV operable.

The connector’s design ratings are:

  • Depth 23,000 feet (7000 metres).
  • Design life: 30 years, when used within its rated number of to 250 mate/de-mate cycles.
  • Maximum optical back reflection of -45dB per channel.
  • Maximum optical insertion loss of 0.5dB per channel.


Increasing the fibre optic channel count within the SEACON HydraLight connector enables customers to optimise their network infrastructure reliably and cost-effectively. Historically, operators had been compelled to use connectors containing a maximum of eight channels each. Now, with the addition of HydraLight 8-, 12-, 16-, 24- or 48-channel connectors, all having identical outside dimensions and utilising the patented joinedchamber technology, customers have greater flexibility for their system configuration designs. This ability also drives indirect cost savings derived from reduction in connectors and associated framework with housing multiple connectors. HydraLight 48-channel connectors enjoy the same economy of scale as illustrated in the 24-channel example.

As the market for 48-channel connectors matures, users may even adapt this customer’s approach of two 24-channel HydraLight connectors to a pair of 48-channel variants, with proportionate cost savings. TE, TE Connectivity, SEACON and Hydralight are trademarks.

About the Author

Michael Mulcahy is a former US Navy officer and former Sea Technology magazine managing editor. He has written more than 100 articles for international ocean engineering publications. His interests include undersea connectors and cables, marine engineering, naval architecture, commercial diving, remotely operated vehicle operations and ship salvage engineering. He is a graduate of the University of North Carolina at Chapel Hill.