Hotel Service Unit 4 Q1

A bilge high level alarm is a safety device installed on ships to monitor the water level in the bilge, which is the lowest compartment on a ship where water collects. The primary function of this alarm is to alert the crew when the bilge water level reaches a predetermined high level, indicating a potential flooding or water ingress issue.  

1. Bilge High-Water Sensor – Skyhawk Oversea Year-Round Boat Monitoring System

2. Bilge Water Level Alarms – ASAP Supplies

Key Components:

• Sensor: A float switch or other type of sensor is placed in the bilge to detect the water level.   1. Bilge Water Level Alarms – ASAP Supplies www.asap-supplies.com
• Control Unit: This unit processes the signal from the sensor and triggers the alarm when the water level reaches the set point.
• Alarm: An audible and/or visual alarm is activated to alert the crew of the high bilge water level. The alarm may be located in the engine control room, on the bridge, or in other designated areas.   1. USCG High Water Alarm and Sensor – Blue Guard Innovations www.bluebgi.com

Purpose and Importance:

• Early Warning: The bilge high level alarm provides an early warning of potential flooding or water ingress, allowing the crew to take immediate action to investigate the source of the water and initiate corrective measures.
• Preventing Flooding: By alerting the crew in time, the alarm helps prevent flooding, which can lead to stability problems, damage to machinery and equipment, and potentially compromise the safety of the vessel.   1. Cargo hold flooding | Water ingress from cargo & bilge lines – Britannia P&I Club britanniapandi.com
• Safety Compliance: The installation and proper functioning of bilge high level alarms are mandatory under various international regulations, including SOLAS (Safety of Life at Sea) and MARPOL (Prevention of Pollution from Ships).

Typical Alarm Activation Points:

• Engine Room Bilges: The alarm may be set to activate at different levels, depending on the specific vessel and its design. However, a common practice is to have alarms at two levels:
  • A warning alarm at a lower level to indicate the need for attention
  • A main alarm at a higher level, indicating a more critical situation requiring immediate action
• Cargo Holds and Other Spaces: Similar alarm levels may be used in cargo holds or other spaces where bilge water can accumulate.

Response to Alarm:

• Upon activation of the bilge high level alarm, the crew should:
  • Immediately investigate the source of the water ingress
  • Take necessary action to stop the ingress (if possible)
  • Start bilge pumps to remove the excess water
  • Inform the bridge team or other relevant personnel
  • Monitor the situation closely and take further action as required

By providing a timely alert of rising bilge water levels, the bilge high level alarm plays a vital role in maintaining the safety and integrity of the vessel, preventing potential flooding, and ensuring compliance with safety regulations.  

1. Design and Development of a Bilge alarm System for Ships? | 4 Answers from Research papers – SciSpace

There are a couple of methods commonly used to test a bilge high level alarm switch, depending on the type of switch installed:

1. Float Switch:

This is a common type of bilge high level alarm switch. It consists of a float attached to a lever arm that operates a switch mechanism.  

1. Automatic Bilge Switches – BoatUS

• Manual Lifting of the Float:
  • Locate the float switch in the bilge.
  • Carefully lift the float to simulate a high water level.
  • Observe if the alarm sounds and any indicator lights activate on the control panel.
  • If the alarm does not activate, there may be a fault with the switch, wiring, or control unit.
• Pouring Water:
  • If accessing the float directly is difficult, carefully pour water into the bilge until it reaches the level where the float should trigger the alarm.
  • Observe for alarm activation.
  • Take caution not to overfill the bilge or cause any damage.

2. Electronic/Capacitance Switch:

These switches use electronic sensors to detect the presence of water or changes in capacitance caused by rising water levels.  

1. How does capacitive level sensing work? – Gill Sensors & Controls

Test Button or Function:

• Some electronic bilge alarms have a built-in test button or function on the control panel.
• Press the test button or activate the test function to simulate an alarm condition.
• The alarm should sound and any indicator lights should activate.

• Simulating Water Presence:
  • If a test function isn’t available, consult the manufacturer’s instructions for specific testing procedures.
  • In some cases, it might be possible to simulate water presence by carefully placing a damp cloth or sponge near the sensor.

Additional Considerations:

• Safety First: Always exercise caution when working around electrical equipment and bilge water. Ensure the power supply to the alarm system is isolated or disconnected if necessary.
• Regular Testing: Bilge high level alarms should be tested regularly as part of the ship’s planned maintenance system (PMS) to ensure their proper functioning.   1. Onboard Alarms – Part II | Steve D’Antonio Marine Consulting stevedmarineconsulting.com
• Maintenance and Repairs: If any faults are detected during testing, report them to the responsible personnel for repair or replacement.
• Documentation: Record the results of the test in the appropriate logbook or maintenance record.

Remember, testing the bilge high level alarm is an essential safety measure that helps ensure the early detection of potential flooding and allows for prompt action to prevent damage and protect the vessel and its crew.Sources and related content

A diesel engine cooling water high temperature alarm probe is a safety device that monitors the temperature of the engine’s cooling water system. Its primary function is to trigger an alarm when the cooling water temperature exceeds a predetermined safe limit, indicating a potential overheating issue.  

1. VDO Diesel Engine Water Temperature Sensor 120C alarm generator part transmision universal brand origin electric sensor – AliExpress.

Key Components:

• Temperature Sensor: The probe itself contains a temperature sensor, typically a thermistor or a resistance temperature detector (RTD), which measures the temperature of the cooling water at a specific location in the system.
• Control Unit: The sensor is connected to a control unit or alarm module, which processes the temperature signal and compares it to the set alarm point.   1. CN203214162U – Marine diesel engine cooling system overtemperature alarm device – Google Patents patents.google.com
• Alarm: When the temperature exceeds the set limit, the control unit activates an audible and/or visual alarm to alert the operator of the potential overheating condition.   1. VDO Diesel Engine Water Temperature Sensor 120C alarm generator part transmision universal brand origin electric sensor – AliExpress www.aliexpress.com

Purpose and Importance:

• Preventing Engine Damage: Overheating can cause severe damage to a diesel engine, including warped cylinder heads, seized pistons, and bearing failure. The high temperature alarm provides an early warning, allowing the operator to take immediate action to prevent catastrophic damage.   1. Failure Analysis for Warped or Pitted Cylinder Heads – Highway and Heavy Parts highwayandheavyparts.com
• Safety: In some cases, engine overheating can lead to fire or other hazards. The alarm helps to mitigate these risks by prompting timely intervention.   1. What Causes a Car to Catch on Fire? – Progressive www.progressive.com
• Operational Efficiency: Maintaining proper cooling water temperature is crucial for optimal engine performance and fuel efficiency. The alarm helps ensure the engine operates within its designed temperature range.   1. Why Is The Cooling System Important For The Engine | Mike’s Auto Service Center www.mikeasc.com

Typical Installation:

• Location: The probe is typically installed in the engine’s cooling water outlet or at a critical point in the system where temperature monitoring is essential.
• Sensor Type: The specific type of sensor used (thermistor or RTD) depends on the engine manufacturer’s recommendations and the temperature range being monitored.

Response to Alarm:

• Upon activation of the high temperature alarm, the operator should:
  • Immediately reduce engine load or shut down the engine if necessary.
  • Investigate the cause of the overheating, which could include issues like coolant leaks, thermostat malfunction, or restricted flow.
  • Take necessary corrective actions, such as replenishing coolant, repairing leaks, or replacing faulty components.
  • Monitor the engine closely until the temperature returns to a safe range.

Regular Maintenance:

• The high temperature alarm probe, like other safety devices, should be regularly tested and calibrated to ensure its accuracy and reliability.
• The sensor and wiring should also be inspected for any signs of damage or corrosion.

In conclusion, the diesel engine cooling water high temperature alarm probe is a vital safety device that protects the engine from overheating, ensuring its longevity, safety, and efficient operation.

Testing a diesel engine cooling water high temperature alarm probe involves simulating an overheating condition to verify that the alarm activates as intended. Here’s a general method for testing the probe:

Safety Precautions:

• Isolation: Ensure the engine is shut down and the electrical power supply to the alarm system is isolated or disconnected to prevent electrical hazards during testing.
• Coolant Temperature: Allow the engine to cool down sufficiently before working near the cooling system to avoid burns.   1. Testing a cooling system – Apex Tools www.apexinds.com
• PPE: Wear appropriate personal protective equipment, such as gloves and safety glasses.

Testing Procedure:

1. Locate the Probe: Identify the high temperature alarm probe in the engine’s cooling water system. It’s typically installed near the engine’s coolant outlet or at a critical point in the system.
2. Disconnect the Probe: Carefully disconnect the electrical connector from the probe.   1. Tips For Replacing the Engine Coolant Temperature Sensor – CarParts.com www.carparts.com
3. Apply Heat:
   • Hot Water: Use a heat gun or immerse the probe tip in a container of hot water, gradually increasing the temperature. Monitor the temperature using a thermometer.
   • Direct Heat (with caution): If permissible by the manufacturer’s instructions, you can carefully apply direct heat to the probe using a heat gun. Exercise caution to avoid damaging the probe or surrounding components.
4. Observe Alarm Activation: As the temperature rises, observe the alarm panel or control unit for the activation of the high temperature alarm. The alarm should sound and any associated indicator lights should illuminate when the temperature reaches the set alarm point.
5. Verify Alarm Set Point: Compare the temperature at which the alarm activates with the specified set point in the engine’s documentation or alarm system settings. If there’s a significant discrepancy, recalibration or adjustment may be necessary.
6. Reconnect the Probe: After the test, allow the probe to cool down and then reconnect it to the electrical connector.

Additional Considerations:

• Alternative Testing Methods: Some engine control systems may have built-in test functions to simulate alarm conditions without physically heating the probe. Consult the manufacturer’s instructions for specific testing procedures.
• Documentation: Record the results of the test, including the date, time, alarm activation temperature, and any observations or corrective actions taken.
• Regular Testing: Incorporate high temperature alarm probe testing into the ship’s planned maintenance system (PMS) to ensure its continued reliability.

Important Notes:

• Always follow the engine manufacturer’s recommendations and safety guidelines when working on the cooling system or testing alarm probes.
• If any faults or discrepancies are detected during testing, report them to the responsible personnel for further investigation and repair.
• Remember that the high temperature alarm is a critical safety device that helps protect the engine from damage. Regular testing and maintenance are vital to ensure its proper functioning and contribute to the safe and efficient operation of the vessel.   1. The Crucial Role of Engine Overheat Alarms: Protecting Your Vehicle and Your Investment tabratrading.com

An oil mist detector is a critical safety device installed in the crankcase of large diesel engines, particularly those found on ships. Its primary function is to continuously monitor the concentration of oil mist within the crankcase and trigger an alarm if it reaches a potentially dangerous level.  

1. Oil Mist Detector & Monitoring System｜MEIYO ELECTRIC Co.,Ltd.

2. Oil Mist Detector | DAIHATSU DIESEL

How it works:

• Oil mist is a fine aerosol of lubricating oil suspended in the air within the crankcase.   1. Oil mist nature and abatement. How does it work? – Tecnosida www.tecnosida.com
• If a bearing or other component overheats or fails, it can generate excessive oil mist.
• When this oil mist mixes with air in the right concentration, it creates a highly flammable and explosive atmosphere.   1. G26 Ambient Oil Mist Detector – Green Instruments greeninstruments.com
• The oil mist detector uses optical sensors or other technologies to measure the concentration of oil mist in the crankcase.   1. Oil Mist Detector & Monitoring System｜MEIYO ELECTRIC Co.,Ltd. www.meiyoelc.co.jp
• If the concentration exceeds a preset alarm threshold, typically set at 2.5% of the Lower Explosive Limit (LEL), the detector triggers an alarm, alerting the crew to the potential hazard.

Purpose and Importance:

• Early Warning: The oil mist detector provides an early warning of potential crankcase explosions, allowing the crew to take immediate action to prevent a catastrophic event.   1. G26 Ambient Oil Mist Detector – Green Instruments greeninstruments.com
• Preventing Engine Damage: By detecting excessive oil mist, the detector can help identify and address underlying mechanical problems before they lead to severe engine damage.
• Safety of Personnel and Vessel: Crankcase explosions can be extremely dangerous, causing significant damage to the engine, injuries to personnel, and even loss of the vessel. The oil mist detector is a crucial safety measure to mitigate these risks.   1. Crankcase explosion – Wärtsilä www.wartsila.com2. G26 Ambient Oil Mist Detector – Green Instruments greeninstruments.com
• Regulatory Compliance: The installation and proper functioning of oil mist detectors are mandatory under various international regulations, including SOLAS (Safety of Life at Sea).

Types of Oil Mist Detectors:

• Crankcase Oil Mist Detectors (OMDs): These are installed directly inside the crankcase and continuously monitor the oil mist concentration at various points.   1. oil mist detectors – Oceantech Shipping & Trading Ltd ost.gr
• Ambient Oil Mist Detectors: These are installed in the engine room or other enclosed spaces to detect oil mist leaks from the crankcase or other sources.

Response to Alarm:

• Upon activation of the oil mist alarm, the crew should:
  • Immediately reduce the engine load or stop the engine, if possible.
  • Investigate the cause of the high oil mist concentration.
  • Take necessary corrective actions, such as repairing leaks or addressing mechanical issues.
  • Continue monitoring the oil mist concentration until it returns to a safe level.

Regular Maintenance:

• The oil mist detector should be regularly tested, calibrated, and maintained according to the manufacturer’s instructions and the ship’s planned maintenance system (PMS).

In summary, the oil mist detector is a vital safety device that helps prevent crankcase explosions and protects both the engine and personnel on board. Its early warning capability allows for timely intervention, ensuring the safe and efficient operation of the vessel’s machinery.  

1. G26 Ambient Oil Mist Detector – Green Instruments

2. SPECS – Oil Mist Detection Systems – Technava

Testing an oil mist detector is crucial to ensure its proper functioning and timely detection of potential crankcase explosions. Here are the common methods employed for testing:

1. Functional Test:

• This test verifies the basic operation of the detector and its associated alarm system. It typically involves:
  • Simulating an Alarm:
    • Most oil mist detectors have a built-in test button or function that simulates an alarm condition.
    • Activating this test function should trigger the alarm, indicating that the detector, wiring, and alarm system are working correctly.
  • Power Failure Simulation:
    • Disconnecting the power supply to the detector should also trigger an alarm, ensuring that it can detect power loss and alert the crew.

2. Sensitivity Test:

• This test assesses the detector’s ability to accurately measure oil mist concentrations and trigger the alarm at the appropriate threshold. It involves:
  • Using a Test Gas: A calibrated test gas with a known concentration of oil mist is introduced into the detector’s sampling system.
  • Observing Response: The detector’s reading and alarm activation are observed and compared to the known concentration of the test gas.
  • Calibration Check: If the detector’s response deviates significantly from the expected value, it may require recalibration or adjustment.

3. Smoke Test:

• This is a simple test that can be performed to verify the detector’s response to smoke particles, which can sometimes mimic the behavior of oil mist.
• Smoke Source: A small amount of smoke is generated near the detector’s sampling point, typically using a cigarette or a specialized smoke generator.
• Alarm Activation: The detector should trigger an alarm in response to the smoke, demonstrating its sensitivity to particulate matter.

Additional Considerations:

• Manufacturer’s Instructions: Always refer to the specific manufacturer’s instructions for the oil mist detector being tested, as there might be additional or specific testing procedures recommended.
• Regular Testing: Oil mist detectors should be tested regularly as part of the ship’s planned maintenance system (PMS) to ensure their continued reliability.
• Maintenance and Repairs: If any faults or discrepancies are detected during testing, they should be promptly reported and addressed by qualified personnel.

Safety Precautions:

• Isolation: Ensure the engine is shut down and necessary isolation procedures are followed before working on or near the oil mist detector.
• Ventilation: Provide adequate ventilation in the engine room during testing, especially when using smoke or test gases.
• PPE: Wear appropriate personal protective equipment, including gloves and eye protection.

By conducting regular and thorough testing of oil mist detectors, ship operators can ensure the early detection of potential crankcase explosions, promoting the safety of personnel and the vessel itself.