CNG Technology – Safety First

Hurricane Jeanne

EnerSea’s first and foremost priority will always be to take a proactive approach to safety in all designs and operations. Numerous safety features and systems have been included in the VOTRANS™ design and operating procedures, many of which are extensions from existing gas facility and vessel design principles and practices. In the evolution of our current VOTRANS designs, EnerSea completed a variety of safety and risk studies that have provided insight for the design of EnerSea’s CNG vessels which will meet class society requirements including:

  • VOTRANS CNG Containment Structural Integrity Assessments
  • Vessel HAZID Studies
  • Vessel HAZID Register – updated regularly
  • Cold Jet Studies for Containment System
  • Comparative Risk Assessment between EnerSea’s CNG system and LNG operations
  • Vessel Inspectability (In-service Inspection Plan)
  • Fire and Explosion
  • Escape, Evacuation and Rescue
  • Gas Dispersion Analysis

Additionally, ABS required that EnerSea’s system be benchmarked against gas shipping alternatives to ensure an equivalent or better level of safety compared to the historic safe operating performance of LNG. ABS Consulting (ABSC) performed a series of risk studies aimed at providing a holistic approach to risk assessment for EnerSea’s CNG vessel. The Comparative Risk Assessment compared the risks associated with complete transportation systems in the form of Liquefied Natural Gas (LNG) and EnerSea’s CNG marine transport. The total system can be categorized into seven analogous phases summarized as:

LNG Value Chain CNG Value Chain
Liquefaction Compression and Refrigeration
Loading Loading
Port Departure Departure from Loading Buoy
Transit Transit
Port Arrival Arrival at Discharge Buoy
Discharging Discharging
Regasification Warming and Decompression

The fundamental conclusion drawn from the study is that risks associated with the two options are comparable, although distributed differently between the phases of the operation, and that the two gas transport technologies of CNG and LNG have the same order of risk overall.