July 28, 2025
Use of Engine/Shaft Power Limiters in Pilotage Waters
The U.S. Coast Guard Sector Delaware Bay has observed an increase in vessels entering the COTP Zone with Engine Power Limiters (EPLs) or Shaft Power Limiters (ShaPoLis). This MSIB clarifies requirements for their safe and compliant use and aligns with pre-arrival pilot questionnaires.
International Standards and Override Authority: Masters and Officers in Charge of a Navigational Watch (OICNW) must understand that EPLs ShaPoLis are equipped with override functionality, permitted by IMO Resolution MEPC.335(76) to ensure safety. Clear override procedures and authorization, including the time required to achieve full power, must be documented in the Onboard Management Manual (0MM) and/or Safety Management System (SMS). This information must be provided to the pilot
in advance.
Pilot Card Requirements: Updated pilot cards for vessels with EPLs ShaPoLis are mandatory and must include:
1. Procedures for accessing power reserves.
2. Time required to override the limiter.
3. The ship’s maximum unlimited (design) power and limited power for all maneuvering RPMs.
4. Impact of the EPL ShaPoLi on engine responsiveness to throttle changes (e.g., Half Ahead to Full Ahead).
Accurate maneuvering characteristics and limitations are crucial, especially in restricted waters, and should comply with IMO Resolution A.601(15), “Provisions and Display of Maneuvering Information on Board Ships.”
Pilot Information Requirements (33 CFR § 164.11(k)): Pilots must be informed of the vessel’s draft, maneuvering characteristics, unique features, including the presence and type of EPL/ShaPoLis (Electronic, Mechanical, etc.), and any abnormal conditions affecting safe navigation. Masters and OICNW must also explain how these systems affect maneuvering, and the procedures and time required for overriding. This should be done before pilot boarding.
Specific Requirements within the COTP Zone Delaware Bay:
• Mandatory Updated Pilot Card and Wheelhouse Poster: If the pilot card and wheelhouse poster do not reflect the vessel’s maneuvering characteristics with the EPL ShaPoLis system installed, the system must be overridden before entering U.S. territorial waters.
• Mandatory Disablement North of Benjamin Franklin Bridge: All vessels transiting north of the Benjamin Franklin Bridge must disable their EPL ShaPoLis prior to pilot embarking.
• Override Readiness: Masters and OICNW must be prepared to immediately override the system at any time if a safety concern arises. If overriding or disabling is not feasible, notify the COTP immediately.
Masters and OICNW are reminded that the use of EPLs ShaPoLis must never impair safe and effective maneuvering, especially in narrow, winding, or heavily trafficked waters. Precise control is essential in these areas. This MSIB is issued for public information and notification.