Fire safety has been a major item to be focused on during PSC inspections. By going through some common detainable PSC deficiencies, the Association has found a great many cases of detention involving defective ventilating systems in machinery spaces. To promote safe operation of ships, this article gives a general picture of the deficiencies to be aware of during PSC inspections and outlines the regulations on designing of machinery space ventilation systems and the importance of its proper maintenance.

I. Ventilating systems and fire hazards

The number of fire accidents has been on the rise in recent years with increasing loss of property and life caused. Statistics show that ship fires rank No.4 in the total number of maritime accidents and No.1 in the amount of damage caused. The engine room, often regarded as the “heart” of a ship, is a large space where most machineries are located. With the complicated structure there and all the inflammable materials, fires that break out in the engine room are often hard to be detected and extinguished, and if rapidly spread on board, may escalate to cause serious consequences.

Ventilation systems in machinery spaces are usually designed to include mechanical supply and natural/mechanical exhaust of air. Large quantities of fresh air are brought into engine room or other spaces by fans and then through air ducts distributed to different levels from top to bottom for machinery air consumption. The air left goes up after being heated and then gets discharged into the outlet, which is often on the upper level of the machinery space so that air can be ventilated using the negative pressure created while the ship is sailing.

The air ducts, closing devices in funnels and dampers are key equipment in preventing air from entering the space if a fire breaks out and play a decisive role in the effectiveness of large fire extinguishing system in the engine room.

II. SOLAS requirements

Regulation 35, Chapter II-1 of the SOLAS Convention provides that “machinery spaces of category A shall be adequately ventilated so as to ensure that when machinery or boilers therein are operating at full power in all weather conditions including heavy weather, an adequate supply of air is maintained to the spaces for the safety and comfort of personnel and the operation of the machinery. Any other machinery space shall be adequately ventilated appropriate for the purpose of that machinery space.”

Regulation 4, Chapter II-2 Probability of ignition:

4.2.2.2 The ventilation of machinery spaces shall be sufficient under normal conditions to prevent accumulation of oil vapour.

Regulation 5, Chapter II-2 Fire growth potential:

5.2 Control of air supply and flammable liquid to the space

2.1 Closing appliances and stopping devices of ventilation

2.1.1. The main inlets and outlets of all ventilation systems shall be capable of being closed from outside the spaces being ventilated. The means of closing shall be easily accessible as well as prominently and permanently marked and shall indicate whether the shut-off is open or closed.

2.1.2. Power ventilation of accommodation spaces, service spaces, cargo spaces, control stations and machinery spaces shall be capable of being stopped from an easily accessible position outside the space being served. This position shall not be readily cut off in the event of a fire in the spaces served.

2.1.3. In passenger ships carrying more than 36 passengers, power ventilation, except machinery space and cargo space ventilation and any alternative system which may be required under regulation 8.2, shall be fitted with controls so grouped that all fans may be stopped from either of two separate positions which shall be situated as far apart as practicable. Fans serving power ventilation systems to cargo spaces shall be capable of being stopped from a safe position outside such spaces.

2.2 Means of control in machinery spaces

2.2.1. Means of control shall be provided for opening and closure of skylights, closure of openings in funnels which normally allow exhaust ventilation and closure of ventilator dampers.

2.2.2. Means of control shall be provided for stopping ventilating fans. Controls provided for the power ventilation serving machinery spaces shall be grouped so as to be operable from two positions, one of which shall be outside such spaces. The means provided for stopping the power ventilation of the machinery spaces shall be entirely separate from the means provided for stopping ventilation of other spaces.

2.2.3. Means of control shall be provided for stopping forced and induced draught fans, oil fuel transfer pumps, oil fuel unit pumps, lubricating oil service pumps, thermal oil circulating pumps and oil separators (purifiers). However, paragraphs 2.2.4 and 2.2.5 need not apply to oily water separators.

2.2.4. The controls required in paragraphs 2.2.1 to 2.2.3 and in regulation 4.2.2.3.4 shall be located outside the space concerned so they will not be cut off in the event of fire in the space they serve.

2.2.5. In passenger ships, the controls required in paragraphs 2.2.1 to 2.2.4 and in regulations 8.3.3 and 9.5.2.3 and the controls for any required fire-extinguishing system shall be situated at one control position or grouped in as few positions as possible to the satisfaction of the Administration. Such positions shall have a safe access from the open deck.

2.3 Additional requirements for means of control in periodically unattended machinery spaces

2.3.1. For periodically unattended machinery spaces, the Administration shall give special consideration to maintaining the fire integrity of the machinery spaces, the location and centralization of the fire-extinguishing system controls, the required shutdown arrangements (e.g. ventilation, fuel pumps, etc.) and that additional fire-extinguishing appliances and other fire-fighting equipment and breathing apparatus may be required.

2.3.2. In passenger ships, these requirements shall be at least equivalent to those of machinery spaces normally attended.

III. Major deficiencies

The stopping devices for skylights and ventilators are an important part of the firefighting system and any deficiencies in these devices may affect the integrity of sealing in the event of a serious fire in the engine room. Past inspections have therefore focused on engine room ventilation systems and defective systems have become a regular detainable item. The Association has followed up with some cases of ship detention and found inadequate understanding in maintenance of ventilation systems in machinery spaces. Some common detainable items include:

• the automatic closing arrangement not effective;
• crew not familiar with the switch at the top of the funnel;
• the stopping devices of engine room ventilators not active;
• louver of the funnel poorly closed, which may lead to exchange of oxygen when extinguishing fire with CO₂;
• open/closed of engine room ventilator switches marked wrong;
• fire doors such as doors of the engine room and the steering gear room cannot self-close or are kept open with ropes or hooks;
• funnels and ventilators with holes of corrosion;
• damper blade cylinder leaked;
• fans controls jammed, meaning inadequate testing and maintenance work.

These deficiencies are to remind owners and ships to carry out periodic testing and maintenance in accordance with requirements of the management system. The fittings together with their controls should be effective. For regular inspections of fire dampers, it is important to ensure that they are correctly marked with open/closed indications, that the locking pins are freely removable and that the handles are fully operable.

IV. Proper maintenance

With PSC inspectors worldwide getting more professional and meticulous, PSC inspections are performed to restrict and exclude low-standard ships, to ensure safe navigation and to prevent pollution of the marine environment, and to support the competent flag state administrations. Effective means of control of the engine room ventilation system are vital to ship fire prevention and the safety of lives and properties, and so it is recommended to carry out maintenance and preparation for inspections from the following aspects.

(1) In addition to the maintenance, emergency drills and trainings in accordance with requirements of applicable international conventions and the safety management system, ships should be prepared by carrying out self-inspections, especially on defective items that have previously been found to avoid being issued with ISM-related deficiencies.

(2) Ship companies should step up effective management and provide strong shore-based support to the vessel, so as to effectively prevent or reduce detainable deficiencies including fire safety deficiencies.

(3) For deficiencies found during the PSC inspections, reporting, analyzing and correction in accordance with the SMS procedures should be conducted. Corrective actions should be taken in a timely manner with designated responsible persons supervising the implementation.

For more information, please contact Managers of the Association.