ÁLVARO FLEITES MARCOS Université de Caen Normandie
4. De la conferencia de prensa del 9 de septiembre a los primeros pasos hacia un acuerdo
CT 1P CT 2P CT 3P CT 4P CT 5P SLOP P
CT 1S CT 2S CT 3S CT 4S CT 5S CT 1C
CT 2C CT 3C CT 4C CT 5C
SLOP S
Channel 1
Channel 2
Channel 3
Issue: Final Draft - November 2007 IMO No: 9323948
4.3.3 OVErFILL aLarM SySTEM Manufacturer: Saab Marine Electronics
Type: Saab TankRadar STaR
The overfill or high level alarm duties are undertaken within this unit, along with level monitoring and temperature measurements. The combined unit meets all the international regulations regarding independent high level measurement and alarm.
The unit is radar-based with no moving internal tank parts, and is based around two completely separate systems contained in one unit. Thus there are two separate signals into two channels all independently working and designed around two separate intrinsically safe systems. Each system is separately wired with its own power supply.
Automatic self-testing is incorporated in the CCR panel to ensure reliable function and meet the regulations governing testing and the unit operation.
The alarm panel is situated in the ship’s control centre on the cargo control panel.
The set points for each tank are at 98% which are non-adjustable after the installation of the unit and final manufacturer’s settings are programmed into the system.
Section 4.3.3 - Page 2 of 2
Issue: Final Draft - November 2007 IMO No: 9323948
Deck Operating Manual
Maersk Nautica
Section 4.3.4 - Page 1 of 3 Illustration 4.3.4a Gas Detection Alarm Panels
ALARM ACCEPTED
BUZZER SILENCE
ACCEPT
RESET BUZZER LAMP
TEST ON/OFF
OMICRON
LOW GAS ALARM HIGH GAS ALARM
GAS ALARM SYSTEM OGS 2.1/4-3-1
LOW GAS ALARM HIGH GAS ALARM LOW GAS ALARM HIGH GAS ALARM LOW GAS ALARM HIGH GAS ALARM LOW GAS ALARM HIGH GAS ALARM
1. FPT
3. NO.1 WBT FORE S
5. NO.1 WBT AFT S
7. NO.2 WBT FORE S
9. NO.2 WBT AFT S
LOW ALARM HIGH ALARM ACCEPTED
FLOW FAILURE ACCEPTED
DISABLED
AUTOMATIC
CALIBRATION
BUZZER SILANCE
ACCEPT/
RESET BUZZER POWER
RESTORE
LAMP
TEST ON/OFF
PURGE
CONNECTION CONTROL
UP
SAMPLE SELECTOR
SAMPLE-POINT
DOWN
DIM DIM
MANUAL
ACTIVE
MANUAL MODE MANUAL SAMPLING
GAS SAMPLING SYSTEM OGS 3.1/25
OMICRON
11. NO.3 WBT FORE S
13. NO.3 WBT AFT S
15. NO.4 WBT FORE S
17. NO.4 WBT AFT S
19. NO.5 WBT FORE S
21. NO.5 WBT AFT S
23. ER WBT TANK (S) FWD
25. ER AFT STBD
2. NO.1 WBT FORE P
4. NO.1 WBT AFT P
6. NO.2 WBT FORE P
8. NO.2 WBT AFT P
10. NO.3 WBT FORE P
12. NO.3 WBT AFT P
14. NO.4 WBT FORE P
16. NO.4 WBT AFT P
18. NO.5 WBT FORE P
20. NO.5 WBT AFT P
22. ER WBT (P) FWD
24. ER WBT AFT PORT
SYSTEM FAILURE NO.1 HC SENSOR 2ND PLAT. M.
% LEL
SYSTEM FAILURE NO.2 HC SENSOR FLOOR PORT
% LEL
SYSTEM FAILURE NO.3 HC SENSOR
FLOOR M.
% LEL
SYSTEM FAILURE NO.4 HC SENSOR FLOOR STBD
% LEL
SYSTEM FAILURE NO.1 H2S SENSOR
FLOOR. M.
PPM
NO.2 H2S SENSOR FLOOR. PORT
PPM
SYSTEM FAILURE
LOW CONTENT LOW LOW CONT.
LOW GAS ALARM HIGH GAS ALARM LOW GAS ALARM HIGH GAS ALARM
SYSTEM FAILURE NO.3 H2S SENSOR
FLOOR. STBD PPM
OXYGEN SENSOR FLOOR. M.
% VOL.
SYSTEM FAILURE
Issue: Final Draft - November 2007 IMO No: 9323948
4.3.4 GaS dETECTION SySTEM
Manufacturer: Omicron
Model: OGS 3.1/25 (for ballast tanks and void spaces) Model: OGS 2.1 ( for the pump room)
description
The Omicron Gas Sampling System is a gas detection system, which monitors and detects explosive gases in the ballast tanks and other spaces.
The main system monitors for hydrocarbon explosive gases in the ballast tanks and void spaces. The system has twenty-five (25) external sampling points and one internal point for sampling the atmosphere inside the detector cabinet itself. Of these sampling points twenty-five (25) are designated to cover the ballast tanks, there are two sample points per ballast tank, one in the fore peak tank and none in the upper void space. The sampling points are each fitted with a non-return valve.
The alarm settings for ballast tanks and other spaces are as follows.
Low alarm HC 10% LEL High alarm HC 38% LEL
The pump room system monitors for hydrocarbon, O2 and H2S content using eight (8) sensors; four (4) hydrocarbon combustible (LEL measurement), three (3) for hydrogen sulphide and one (1) for oxygen. The pump room detector cabinet has eight (8) sample points, seven in the bottom platform, 1 H/C in O/B platform and one internal point for sampling the atmosphere inside the cabinet itself.
Pumproom Alarm Settings Low Alarm High Alarm
Combustible HC 10% LEL 30% LEL
Toxix H2S 10ppm 15ppm
Toxic 02 19.5% Vol 17.5% VOL
The gas detection system is an automatic scanning, permanently installed gas detection system. The automatic scanning function ensures that the detector is connected to the different sampling points in a predetermined sequence.
After a sample has been drawn and analysed the sample point is purged. This avoids unnecessary quantities of dust, dirt, salt and moisture being drawn into and retained in the individual sample pipes in the system and avoids the necessity of in-line filters which are a known source of faults. At the end of each sampling sequence the air in the gas cabinet is analysed, during this phase GAS CABINET CHECK is displayed on the LCD screen.
The sampling system has three modes of operation:
• Automatic
• Manual
• Calibration
A gas cylinder, with a gas mixture of known composition, is connected to the system for regular calibration of the gas alarm instrument, as well as checks on the operation of the system.
The gas detection system consists of four primary units:
display units
The display unit contains all the control and checking functions of the system and is located in the SCC. The display unit is divided into two parts - the gas alarm panel and the operating panel. The gas alarm panel is activated when a gas alarm situation is detected. The sampling point number, alarm level and the actual gas detector in alarm are displayed.
The operating panel continuously displays the last sampling point and measured value.
detector Cabinet unit
The detector cabinet is situated in the foam room and contains all functions for gas detection and transportation of the test samples, as well as an internal sampling point for monitoring internal gas leakage. The power to the detector cabinet will automatically be shut off should gas be detected in the cabinet.
The hydrocarbon gas detection for the ballast spaces is carried out by a SEARCHPOINT OPTIMA PLUS infra-red gas detector,
The pump room sensors are as follows:
HC Sensepoint Combustible 0-100% LEL H2S Sensepoint Toxic 0-50ppm
O2 Sensepoint 1-25%
External alarm panels
The function of this panel is to indicate alarms/faults visually and audibly on the bridge.
pipe System
The pipe system transports the test samples from sampling points to the detector cabinet and incorporates shut-off valves and flame traps, which are located at the detector cabinet.
It is important that the control/instrument air supply to the system is never isolated during the normal operation of the control units. The individual sampling line isolation valves must also remain open during normal sampling operations, these are located in the foam room.
Special attention should be made to the ballast tank sampling system. When individual ballast tanks are filled, each sample point in that tank must be disabled from the scanning cycle at the control unit and disconnected by a ball valve. When disconnected, the display unit will send a counter air pressure flow down the line, this is sufficient to ensure that no water can enter the system, which might otherwise cause damage. The non-return valve on each sample tube is a back-up in case the disabling is not carried out.