What are the safety requirements for the bow of bulk carriers during ship safety inspection?
2023-08-22
Bulk carrier is the most common type of ship in sea transportation. Chapter XII of the SOLAS Convention "Additional Safety Measures for Bulk Carriers" is dedicated to the effectiveness of the hull structure, cargo hold, ballast tank and dry space water ingress alarm device and pump system. etc. made additional requirements. In this issue, a relevant defect of a bulk carrier is used as an introduction to understand the special requirements of the Convention for spaces between the collision bulkhead and the forwardmost cargo hold of a bulk carrier.
Problem discovery
Vessel description: Vessel XX, Flag State: Marshall Islands, Vessel type: Bulk Carrier, Gross tonnage: 43,672, Keel laid down: 16.12.2015.
On August 9, 2023, the Nantong Maritime Safety Administration PSCO conducted a PSC inspection on the "XX" ship berthing at Nantong XX Wharf, and found many defects. During the inspection on the bridge, the security inspectors found that the control of the ballast piping system in the ship's bow tank When the remote control panel of the valve is turned to the "REMOTE CONTROL" position, it cannot be operated remotely, which does not meet the requirements of the convention. The defects are as follows:
THE DEWATERING VALVES INSTALLED IN BOSUN STORE AND F.P.T BULKHEAD OUT OF ORDER AS UNABLE TO BE OPERATED REMOTELY FROM BRIDGE.
The valves on the bow storage room and the bulkhead of the bow compartment cannot be remotely operated from the bridge.
The remote control panel for the control valve of the ballast piping system in the forepeak tank installed on the bridge
The inspection found that it cannot be controlled remotely, and the relevant control valve does not operate
The forepeak tank refers to the small tank located at the front of the ship, usually storing ballast water, which is used to help balance the ship, that is, to adjust the bow and stern trim, abbreviated as F .P .T .
The fore peak tank is located in front of the collision bulkhead of the ship, which can prevent the damage of the bow from flooding and flooding other cabins. It is often used as a ballast water tank to adjust the trim of the ship.
In the case of strong wind and waves, the crew cannot go to the bow of the ship through the open deck to open the control valve of the ballast piping system. If the remote control fails, the water in the fore peak cannot be discharged. , the entire ship may also face the risk of sinking.
Convention related requirements
1. Alarm devices for water ingress in ballast tanks and dry spaces
(1) Regulation 12.1.2 of Chapter XII of the SOLAS Convention requires audible and visual alarms for any ballast tank forward of the collision bulkhead: for any ballast tank forward of the collision bulkhead required by Regulation II-1/12 When the liquid level in the tank reaches not more than 10% of the tank capacity, an audible and visual alarm should be issued. An alarm override device can be installed to be activated when the cabin is used;
(2) Regulation 12.1.3 of Chapter XII of the SOLAS Convention requires audible and visual alarms for any dry space or empty space that extends any part forward of the forwardmost cargo hold: in any part other than the chain locker that extends to the forwardmost part In any dry space or empty space forward of the cargo hold, an audible and visual alarm should be given when the water level is 0.1 m above the deck. When the capacity of the enclosed space does not exceed 0.1% of the ship's maximum displacement, such alarms need not be installed.
Water level detectors and sewage wells installed in the dry space ahead of the foremost cargo hold
2. The effectiveness of the pump system
(1) Regulation 12, Part B-2, Chapter II-1 of the SOLAS Convention requires for the fore peak collision bulkhead valve: a pipe may pass through the collision bulkhead below the bulkhead deck for the purpose of The liquid in the fore peak tank is handled, but the pipe must be equipped with a screw-down valve that can be operated above the bulkhead deck, and the valve body is to be fixed on the collision bulkhead in the fore peak tank. The Administration may permit the valve to be located on the aft side of the collision bulkhead, provided that it is readily accessible under all operating conditions and that the valve is located in a space other than a cargo space. All valves shall be made of steel, bronze or other approved plastic materials, and ordinary cast iron or similar materials shall not be used.
(2) Regulation 13, Chapter XII of the SOLAS Convention on the effectiveness requirements of the pumping system (applicable to bulk carriers): the ballast water used for discharge and pumping of ballast tanks located in front of the collision bulkhead on bulk carriers and other Any equipment extending partly to the bilge of dry spaces forward of the forwardmost cargo hold shall be capable of controlling its operation from within an accessible enclosed space. The enclosed space is to be accessible from the navigating bridge or the main engine control station without passing through the exposed freeboard deck or superstructure deck. If the piping for these tanks or bilges passes through the collision bulkhead, devices operated by remotely actuated valves are also acceptable as an alternative to the valve controls specified in regulation II-1/12, provided that such valve controls The location of the device complies with the provisions of this article. After July 1, 2007, all bulk carriers shall meet the above requirements.
In summary: the screw valve is set on the collision bulkhead, and the valve can be opened and closed by remote control in the navigation bridge or engine room centralized control room, or can be opened and closed in the enclosed space, and the enclosed space should be controlled from the navigation bridge or the main engine. station access without passing through the exposed freeboard deck or superstructure deck.
Check points
1. Whether there is a water level detector in the relevant place, whether the installation position meets the requirements, and whether the sound and light alarm is displayed in the cab.
2. The water level indicator should be able to be powered by two independent power sources. An alarm should be given in the event of main power failure.
3. The valves for discharging and pumping ballast water from ballast tanks located forward of the collision bulkhead and bilge water from any part of them extending to dry spaces forward of the forwardmost cargo tank are to be remotely controlled from the centralized control room.
4. Check whether the relevant valve is in the correct open or close position.
5. Check whether the pumping system can discharge the liquid in the space normally.
6. Check whether the crew knows the meaning of the alarm and is familiar with the operation of the system.
Common Defects
1. The crew is not familiar with the principles and functions of the effectiveness of the pump system and the operation steps of the equipment.
2. The drainage valve is faulty, and the remote control operation is invalid.
3. The identification serial number of the remote switch button on the control panel is inconsistent with the local identification serial number of the remote control valve.
4. There are defects in the pump system used for drainage in relevant places, and drainage cannot be realized.
5. After the fore peak tank was drained, the override switch of the alarm device was not reset in time, resulting in the loss of monitoring of the water level in the space.
6. The water level detectors in the relevant places are damaged, faulty, falsely alarmed, and the installation location does not meet the requirements.
7. There are sundries in the sewage well, and the drainage pipe is blocked.
8. Malfunction or failure of the water ingress alarm system.