Editor’s note: This blog post was last updated Oct. 30 2017, to provide links to Policy Letter 17-07’s References (a) and (b). 

The Office of Commercial Vessel Compliance announced the release of two policy letters addressing issues associated with testing of machinery alarms on small passenger vessels.

Policy Letter 17-08: Inspection of Machinery Alarms on Small Passenger Vessels
Neither Subchapter T nor Subchapter K provides regulatory requirements for safety shutdowns or alarms on main propulsion units except for the requirements associated with alarms for wet exhaust when cooled by other than the engine cooling system. Current regulations in Subchapter T and K require vessels to have gauges to indicate water temperature, lubricating oil pressure, and propulsion engine revolutions per minute. New emissions control and performance requirements for prime movers have changed the level of sophistication of the basic engine package such that newer basic engine packages frequently have more alarms and safety devices installed that are not required by regulation.

This policy letter provides guidance to assist owners and operators of small passenger vessels, and Coast Guard field units with the inspection of machinery on small passenger vessels. Specifically, this policy interprets “test of machinery alarms” in 46 CFR 176.804(i) and 115.804(i) and clarifies the discretionary language for “additional testing or inspections deemed reasonable and necessary” under 46 CFR 176.840 and 115.840. Owners and operators of vessels with microprocessor based propulsion controls or vessels of unusual design with Design Verification Test Procedures should follow existing procedures.

Enclosure (1) to Policy Letter 17-08 provides instructions for standardizing the documentation of MISLE Activities related to testing of machinery alarms/shutdowns.

Policy Letter 17-07: Required Plan Review And Design Verification Testing On Small Passenger Vessels
The regulations do not clearly address the appropriate level of review required for the broad array of propulsion control systems found on small passenger vessels, nor is there established guidance identifying which plans are required for the initial design review and subsequent testing under 46 CFR 115.804 or 46 CFR 176.804. The lack of guidance has resulted in OCMIs applying inspection criteria inconsistently between zones and raising concern within the industry.

This policy letter is to assist vessel owners and operators of small passenger vessels and Officer(s) in Charge, Marine Inspection with the plan review and testing of propulsion control systems that use microprocessors.

Reference (a) Policy Letter 17-07: Plan Review Guide E2-23: MSC Guidelines for Electrical Plans – Small Passenger Vessels, dated 26 July 2017

Reference (b) Policy Letter 17-07: CG-ENG-3 Memorandum: “Microprocessor and Computer based Propulsion Engine Control Systems on K and T Vessels,” dated 07 June 2017

This blog is not a replacement or substitute for the formal posting of regulations and updates or existing processes for receiving formal feedback of the same. Links provided on this blog will direct the reader to official source documents, such as the Federal Register, Homeport and the Code of Federal Regulations. These documents remain the official source for regulatory information published by the Coast Guard.