How do I prepare an EEXI Technical File using NavCad?

Modified on Thu, 17 Sep at 8:51 AM

Applies to: NavCad Premium Edition 2023 and later

Prerequisites

Before running the EEXI utility to generate a Technical File, the NavCad project must be fully configured:

Hull data at summer load line condition (not ballast or design draft EEXI is defined at summer load line).
Propulsor data: propeller type, series, and geometry matching the installed propeller.
Engine data: engine model power curve entered as IC Engine Object data include the MCR (maximum continuous rating) power and RPM.
Speed–power curve: run resistance and propulsion predictions. Aligned prediction from model test or sea trial is recommended for highest fidelity.

Open the EEXI Assessment: Tools | Utilities | EEXI Assessment [Premium].
Enter vessel category (e.g., RoRo Passenger, Bulk Carrier, Tanker), length between perpendiculars (LPP), and breadth.
Set the engine limiter value if one is installed or being evaluated.
Click Build to run the EEXI calculation. NavCad computes the reference speed, EEXI score, and required EEXI threshold for the vessel category.
Review the Engine load plot this shows the propeller power demand curve (red), the engine power curve (blue), and the reference power line (green). The EEXI reference speed is where the reference power line intersects the demand curve.
To generate the Technical File: click View and Save Technical Report. The report is formatted for EEXI documentation purposes.

Engine power limiter: The simplest corrective measure. NavCad models the effect of the limiter on the reference power and speed, allowing evaluation of the minimum limiter setting needed for compliance.
Propeller repitch: Changing propeller pitch shifts the power demand curve, altering the equilibrium condition. NavCad's propulsion analysis can evaluate the effect of pitch change before committing to physical repitching.
Hull modification: Fitting a bulbous bow or other drag-reducing modification shifts the resistance curve. NavCad can model estimated drag reductions and their impact on the EEXI score.