Unattended machinery spaces: Class notations E0 and AUT – clarifications on the annual survey

With the merger of two sets of class rules and the harmonization of the survey scope for the class notations regarding unattended machinery spaces – E0 (from DNV), AUT and AUT-nh (from GL) – we have encountered a need to clarify the understanding of the annual survey scope for these notations. This news describes the basis for the notation and the annual survey scope. Plus, it provides some practical guidance for how to best prepare for the survey.

Basis for the notation requirement and follow-up

The fleet in service rules for periodically unattended machinery spaces is based on SOLAS requirement Ch.II-1, Reg.46:

“The arrangements provided shall be such as to ensure that the safety of the ship in all sailing conditions, including maneuvering, is equivalent to that of a ship having the machinery spaces manned. … Measures shall be taken to the satisfaction of the Administration to ensure that the equipment is functioning in a reliable manner and that satisfactory arrangements are made for regular inspections and routine tests to ensure continuous reliable operation. … Every ship shall be provided with documentary evidence, to the satisfaction of the Administration, of its fitness to operate with periodically unattended machinery spaces.”

Periodically unattended machinery spaces – annual survey scope

The objective of the annual survey is to ensure that sensors and alarms considered essential for safe, unattended operation are functioning and tested regularly. This includes the functionality of extension (remote) alarms according a planned test regime which should be documented in on-board test records. 

As not all sensors and alarms can be tested during the annual survey, a documented periodical testing performed by crew is essential for the surveyor to decide on the scope of the actual testing. 

Due to differences during class approval of the notations, there has been different practices in documenting evidence of periodical testing to class. For example, while the E0 notation has a requirement for approval of a specific test plan, which is used actively as part of the annual survey, the AUT notation does not have this approval requirement.

To enhance the effectiveness of the surveys, we need to align the documentation on board the vessels with E0 and AUT notations and establish an alternative documentation of the periodical tests performed for the vessels where an approved test plan is not available. 

Preparation for a successful survey (EO, AUT, AUT-nh) – DNV GL recommendations

The documented testing of essential sensors and alarms will be important when deciding on the test scope during the annual survey for the notation.

Provide documented evidence of the periodical testing in an understandable manner for the surveyor to review. 

  • Evidence of periodically testing should preferably be in the format of the E0 list (I260 – Field instruments periodic test plan, DNV GL rules Pt.6, Ch.2, Sec.2, Table 2), i.e. showing the date when the required E0 alarms were last tested. 
  • Alternatively, the enclosed template plan may be used as a basis to establish a periodical test plan.  

What to include in the periodical test plan

The periodical test plan shall focus on tests related to safety-critical functionality: 

  • Parameters requiring shutdown
  • Parameters requiring independent alarm prior to shutdown (depending on vessel keel laying date, main class requirements for remote operation/automatic start, etc., may be overlapping with requirements for unmanned machinery spaces)
  • Parameters requiring standby start (sensor independent of alarm and shutdown functionality) 
  • Parameters requiring alarm according to SOLAS Ch.II-1, Reg.47 (fire precautions, see below)
  • Parameters requiring alarm according to SOLAS Ch.II-1, Reg.48 (flooding)

In addition, SOLAS Ch.II-1, Reg.47 and 48 require the following to be documented:

  • Boiler air supply casing and exhaust (high temperature where applicable)
  • High temperature in scavenging air belts for propulsion machinery
  • Crank case oil mist detector
  • Bilge wells

To ensure the test results are reliable, the equipment used for the tests and the sensors is assumed to be calibrated. The periodical test plan may therefore also be useful for documenting calibration.