ETO ENGINEER

⭐ #Star (Y) Connection What it is The three #windings of the motor are connected so that one end of each #winding is joined together at a common point (neutral). The other ends connect to the three-phase supply. Characteristics • Phase voltage = Line voltage / √3 (≈ 58% of full voltage) • Starting current is lower (about 1/3 of delta) • Starting torque is lower (about 1/3 of delta) Where it is used • During #motor starting to reduce inrush #current • On light-load start motors • For star–delta starters 🔺 #Delta (Δ) Connection What it is The windings are connected end-to-end in a triangle. Each winding receives the full line #voltage. Characteristics • Phase voltage = Line voltage • Full rated current • Full rated torque • Higher starting current Where it is used • For normal running of the motor • When full torque is required • For motors designed for Δ run ⚡ Star–Delta Starting (Y–Δ) This is a common method to start large motors smoothly. Why it’s used • Reduces starting current to about 30–35% of direct-on-line (#DOL) • Reduces mechanical shock • Protects the electrical network from voltage dips How it works 1. Start in Star → lower voltage on each winding → low current, low torque 2. After a few seconds (motor reaches 70–80% speed)… 3. Switch to Delta → full voltage → full torque for normal running

What R-S-T Means in Three-Phase Electrical Systems R, S, and T are traditional names for the three #phases of an #AC three-phase power system. They are commonly used in Europe, Asia, and especially in industrial and marine electrical installations. 1. What the letters mean The letters do not have special meanings. They simply represent: • R = Phase 1 (L1) • S = Phase 2 (L2) • T = Phase 3 (L3) This naming system was adopted in older European standards and is still widely used. 2. Why R-S-T is used R-S-T helps identify: • the three power lines in a three-phase system, • the phase rotation (R → S → T), • correct connection of motors, generators, switchboards, and #MCCs. Maintaining the correct order (R-S-T) is important for equipment that depends on rotation direction, such as motors and pumps. 3. Relation to modern designations Today, international standards (#IEC) prefer: • L1, L2, L3 But R-S-T is still common in: • marine systems, • generator panels, • industrial switchgear, • old European installations. #RST

On 15 March 2025, the gas carrier Gaschem Homer experienced a loss of #propulsion and #steering while manoeuvring in the Port of Brisbane, Queensland. The Australian Transport Safety Bureau (#ATSB) investigated the incident and released its final report on 19 November 2025. What Happened • The vessel was departing its berth and performing a turning manoeuvre in the harbour channel. • During this manoeuvre, the ship suffered a complete electrical #blackout, leading to a loss of propulsion and rudder control for approximately two minutes. • The blackout occurred when the bow thruster was engaged, causing a sudden increase in electrical load. Cause of the Blackout • The ship had three auxiliary diesel generators. • Before departure, two generators were left in manual mode instead of automatic, contrary to safe operating practice. • When the #bowthruster load increased, one generator overloaded and tripped. • The other #generators did not automatically take over the load because they were not configured in the auto mode, resulting in a total loss of electrical power. • No injuries or damage occurred, but the loss of control inside a confined harbour channel was classified as a serious #incident. ATSB Findings • The vessel’s Safety Management System (SMS) used generalized fleet-wide procedures that did not reflect the specific requirements and power system configuration of Gaschem Homer. • Pre-departure checks were too generic and did not clearly define responsibilities or steps for generator mode verification. • The crew relied heavily on memory rather than structured, ship-specific procedures — which increased the risk of error. • The incident occurred due to a combination of inadequate procedures, improper generator configuration, and insufficient adaptation of #SMS to vessel-specific systems. Actions Taken After the Incident • The operator updated its risk controls and procedures. • Checklists were rewritten to require generators to be in AUTO mode before manoeuvring. • A power consumption matrix was introduced to manage electrical loads during port operations. • Training for engineers was enhanced, focusing on generator management and load-sharing principles. Why This Matters • The event highlights how even short power losses during #manoeuvring can create significant risks. • Safety procedures must be updated, ship-specific, and easy to use. • Proper load management and #generator mode selection are essential for safe navigation, especially in restricted waters. Official Sources • ATSB news release: https://www.atsb.gov.au/media/news-items/2025/gas-carrier-loss-propulsion-highlights-importance-date-and-usable-procedures • Full ATSB report (PDF): https://safety4sea.com/wp-content/uploads/2025/11/ATSB-Loss-of-propulsion-Gaschem-Homer-2025_11.pdf #news

Loose Wire on Containership Dali Leads to Blackouts and Contact with Baltimore’s Francis Scott Key Bridge Date: November 18, 2025 Key Points: • A single loose #wire in the electrical system of the 984-foot long #containership Dali caused an electrical blackout. • The #blackout led to the vessel losing both propulsion and steering while passing near the Francis Scott Key Bridge (Key Bridge) in Baltimore, and the ship contacted the bridge structure. • The incident occurred on March 26, 2024; the bridge collapse followed, resulting in the deaths of six highway workers. • The investigation revealed that the wire-label banding prevented the wire from being fully inserted into a terminal-block spring-clamp, causing an inadequate connection which triggered a #breaker to trip. • During the series of events: after the first blackout the ship’s heading swung toward Pier 17 of the Key Bridge; despite efforts by pilots and shoreside dispatchers, the loss of #propulsion close to the bridge made avoiding the collision impossible. • The size of the #ship and the lack of bridge design counter-measures for large ocean-going vessels contributed to the severity of the event. For example, an earlier collision by the ship Blue Nagoya in 1980 (390 ft long) caused only minor damage; the Dali was about ten times the size. • As a result of the investigation, NTSB issued a series of safety recommendations to multiple parties including the United States Coast Guard, the Federal Highway Administration, bridge-owners nationwide, and electrical-component manufacturers. • #NTSB emphasised that this incident was preventable, and that implementation of the recommendations is essential to avoid similar tragedies in the future. 🔗 Link to the news ➡️ https://www.ntsb.gov/news/press-releases/Pages/NR20251118.aspx #news

MSB Maintenance #MSB #DD #DryDock

Gel batteries (#GEL) are a type of sealed lead-acid battery in which the electrolyte is thickened into a gel by adding silica. They belong to the #VRLA (Valve Regulated Lead Acid) family — maintenance-free, sealed batteries with pressure-relief valves. Advantages of Gel #Batteries • Sealed and maintenance-free — no water topping-up, minimal gas emission. • Long service life — typically 6–12 years in standby applications. • Deep-cycle capable — handle deep discharges better than AGM batteries. • Vibration resistant — suitable for marine environments. • Safe — very low risk of acid leakage. • Wide operating temperature range — around −20 to +50 °C (model-dependent). Disadvantages • More expensive than AGM or flooded lead-acid batteries. • Lower charge current tolerance — require precise charge control. • Sensitive to overcharging, especially at high temperatures. Typical Applications • Marine systems (emergency power, communication systems). • #UPS (Uninterruptible Power Supplies). • Solar and off-grid power systems. • Electric vehicles and medical equipment. Charging Parameters Proper charging is critical for long battery life: • Bulk/Absorption voltage: 14.0–14.4 V (for a 12 V battery). • Float #voltage: 13.5–13.8 V. • Charge current: typically 0.1C (10% of capacity). • Temperature compensation: about −3 mV/°C per cell. How to Identify a Faulty Gel Battery • Significant capacity loss (over 30% drop). • Strong voltage drop under load. • #Battery gets unusually warm while charging. • Swelling of the case (critical sign). • High internal #resistance during testing.

Shore Power Supply ⚡️⚠️ (short instruction) #DD #DryDock #ShoreConnection

Shore Power Supply ⚡️⚠️ #DD #DryDock #ShoreConnection

Terasaki ANU-1 OCR Checker The ANU-1 is a dedicated test instrument from Terasaki for verifying the functionality of Over-Current Relays (#OCRs) in circuit breakers. • Typical model reference: “AC110-240 V ANU-1 OCR Checker”. • It is described as “compact and portable” for field-testing OCRs (over-current releases) in industrial/utility installations. What functions does it check? ANU-1 is capable of checking the following: • Long time-delay trip (pickup and time) • Short time-delay trip (pickup and time) • Instantaneous trip (pickup current) • Ground-fault trip (pickup and time) • Pre-trip alarm function (for breakers with a pre-alarm before full trip) So if you are dealing with breakers (or ACB/OCR combinations) that have multiple stage over-current protection, this instrument is very useful. Key Specifications & Features • Supply voltage: AC 110-240 V (50/60 Hz) version. • Power consumption: Approximately 7 VA. • Single connector interface for the OCR under test (simplifies field connection). • Clear LCD display showing the function, phase output and trip signal indicators. • Light weight (in one rental listing: ~1 kg) and portable carrying case. Typical Use Cases — Relevant to your site work Given your context (ships, switchgear, protection systems), here’s how this tool comes in handy: • If you need to verify the OCR section of a breaker (especially the over-current release unit) after settings changes or installation, the ANU-1 lets you simulate fault currents and trip times. • On board a vessel, especially when you have ACBs (#aircircuitbreakers) with OCRs, this tool helps confirm that the over-current protection is still within spec (pickup/trip time) and that the pre-trip alarm (if present) is functioning. • For maintenance or commissioning of switchgear, you can use the ANU-1 to validate the OCR without having to fully load the circuit or create actual fault conditions — saving risk and downtime. Important Usage & Safety Notes A few key cautions pulled from the manual and associated documentation: • Before testing, isolate the #breaker under test (ensure upstream circuit breaker is open, remove control power, etc.). • After testing or changing OCR settings, return settings to original values. Failure to do so may cause fire or burnout. • The instrument itself is electronic; avoiding shock, dropping or mechanical damage is important. • Make sure during connection that the current being applied does not exceed permissible values for the OCR or wiring (excess current may damage the breaker or the tester). • Ensure the device is connected properly, power off while connecting/disconnecting to avoid inadvertent trip. How this relates to your environment (ships, switchgear, etc) Given your work with marine electrical systems, parallel generators, #protection etc, here’s how this tool could support you: • On board ship #switchgear with #ACBs that include OCRs, you can carry the ANU-1 to check OCR functionality in situ after maintenance or fault events. • When you suspect an over-current protection issue (e.g., nuisance trips, no trip when expected) in a breaker’s OCR unit, you can use the #ANU-1 to measure pickup/trip values and compare to the breaker/OCR spec. • If the breaker’s #OCR has undergone setting changes (for example to adapt to changed loading conditions), you can validate those changes using the ANU-1 to ensure compliance with protective requirements. • In a #vessel environment, where downtime is critical and fault simulation is high risk, using a dedicated OCR tester like this reduces the need for full fault injection or burning equipment.

The green discs are #varistors (MOV – Metal Oxide Varistors). They are mounted across the #transformer terminals as overvoltage protection devices. Their purpose: • absorb #voltage spikes and surges (lightning, switching spikes, generator noise); • #protect the transformer windings and downstream electronics; • clamp the voltage to a safe level by diverting excess energy to ground. ✅ Why there are three of them, and why they are connected to ground You normally place one #MOV on each phase, connected: Phase → MOV → Ground This way, any surge on any #phase is discharged safely to ground. This is a standard arrangement in: • marine control equipment, • power supplies, • #UPS input filters, • automation transformers. ✅ How to know if a varistor is faulty ✅ 1. Visual inspection A bad MOV usually shows: • cracks in the disk, • dark burn marks, • pieces of coating missing, • a burnt smell, • swelling. ✅ 2. #Multimeter test A good MOV shows very high #resistance at low voltage. If your meter shows: • Low resistance (a few ohms) → the MOV is shorted (failed) • Normal infinite resistance → likely OK (or open-circuit, which also means no protection) You cannot fully test the MOV without high-voltage equipment, but a shorted MOV is easy to detect. ✅ 3. Symptoms in the system If a MOV is shorted: • #breakers/ fuses blow, • transformer hums heavily, • input voltage drops, • the device won’t power up. If a MOV is open-circuit: • the system works normally • but you have no surge #protection anymore. ✅ How to check if the #transformer itself is healthy • Measure winding resistance (similar between phases if 3-phase). • Check no-load current (should be small). • Measure output voltage under load. • Ensure no #overheating.

A Multipurpose Controller (#MPC) in a #MAN B&W main engine is a modular electronic controller used in the ME-engine control and safety system. It is part of the ECS (Engine Control System) and handles specific control tasks, depending on how it is configured. ✅ Main purpose of the MPC The MPC is essentially a #PLC-type module placed inside the #Engine Control Room (ECR) cabinet or local control cabinets. Each MPC is assigned one or more functions, such as: ✅ Typical functions of MPC modules on MAN ME engines Depending on the engine type (ME, ME-C, ME-B), MPCs may handle: 1. Fuel Injection Control • Controls the Hydraulic Cylinder Units (#HCUs) • Controls timing and quantity of injection • Receives feedback from #MOP sensors, #FIVA valves, pressure sensors 2. Exhaust Valve Control • Commands opening/closing via hydraulic oil distributor • Monitors valve position feedback 3. #Cylinder Lubrication Control • Controls Alpha Lubricators • Adjusts cylinder oil feed rate based on load, #SFOC, sulfur level 4. Safety Monitoring • Monitors critical sensors: • Scavenge air pressure • Exhaust temp • Fuel rail pressure • Hydraulic oil pressure • Turning gear position • Can initiate slowdown, shutdown, or load reduction 5. Starting Air System Control • Controls air start valves • Monitors starting air distributor signals 6. Auxiliary Systems • Maneuvering commands • Governor interface • Shaft generator logic (on some setups) ✅ Communication The MPC communicates with: • #DCU (Diesel Control Unit) on each cylinder • #ECS Main Controller (#SIGMA, #CoCoS, or later versions EICU) • Scavenge air temp controller • Bridge and ECR interfaces • Communication is typically via redundant #CANbus or MAN proprietary bus. ✅ Hardware features • Modular I/O board (analog & digital) • #CPU board • Power supply section • Rugged design for vibration & heat • Hot-swappable in some engine versions ✅ Typical number of MPCs A typical #ME engine has several MPCs, e.g.: • MPC-A – Fuel system • MPC-B – Exhaust valves • MPC-C – Safety & protection • MPC-L – Cylinder lubrication (Names differ by project and wheelhouse specification.) ✅ If you are troubleshooting Common MPC issues include: • “MPC Communication Lost” • “MPC I/O Board Error” • Faulty 24V supply • CAN bus errors • Loose connector pins • Firmware mismatch after replacement

Replacing a synchronous motor on an anemometer ℹ️ Related article ➡️ The anemometer gives false readings. Troubleshooting https://www.eto-engineer.com/2023/09/the-anemometer-gives-false-readings.html #anemometer

Can 24.34VDC batteries be used to calibrate a 24VDC pressure transmitter? #Span #Zero #calibration #pressuretransmitter #pressure #transmitter

The replacement interval for bearings in marine electric #motors depends on operating conditions, motor design, and maintenance quality. On average, bearings in marine motors last between 20,000 and 40,000 hours under normal temperature and acceptable vibration levels. For motors exposed to heavy loads or #vibration (such as winches), the service life may be reduced to 10,000–20,000 hours. Open Bearings require regular lubrication, usually every 2,000–4,000 operating hours. Marine-grade anti-emulsion greases, such as Mobil Polyrex EM or SKF LGHP 2, should be used since they resist moisture and salt. #Bearing condition should be monitored through vibration Analysis and temperature measurement. These checks are recommended at least once a month. If vibration exceeds 4.5 mm/s RMS or temperature rises above 95°C, the bearing should be replaced. Even if the motor operates normally, bearings are typically replaced every 4–5 years, or after about 30,000 hours of service. For critical equipment, such as main pumps or engine room ventilation #motors, bearings are often renewed during each major #overhaul. If a #motor has been idle for a long time, bearings may suffer from corrosion or “sticking.” Before starting, the shaft should be rotated manually to ensure it turns freely. #Bearings wear out faster under certain conditions, such as moisture ingress, overheating, shaft misalignment, rotor imbalance, excessive belt tension, or use of incorrect grease.

A #temperatureswitch is a device that monitors temperature and activates (or deactivates) an electrical circuit when a certain preset temperature is reached. 🔧 How it works: • Inside the #switch, there’s a temperature-sensing element (like a bimetallic strip, thermistor, or gas-filled bulb). • When the temperature rises or falls to the setpoint, the #sensor changes shape or #resistance. • This action opens or closes electrical contacts — turning equipment on or off automatically. ⚙️ Typical functions: • Turn cooling #fans on when a system gets too hot. • Turn #heaters off when a set temperature is reached. • Trigger #alarms when overheating occurs. 🧩 Types: 1. Mechanical temperature switch – uses a bimetal or expansion element (no power needed). 2. Electronic temperature switch – uses a thermistor or RTD and electronic circuit for precise control. 🛠️ Applications: • #Engine and #motor protection • #HVAC systems • Industrial process control • #Overheat #protection in generators or pumps

A #floatlevelswitch is a type of sensor used to detect the level of liquid in a tank or vessel. It works by using a floating element (the float) that rises and falls with the liquid level. When the float reaches a certain point, it activates or deactivates an electrical switch, sending a signal to a control system or alarm. Here’s a breakdown of its main parts and working principle: ⚙️ Main Components 1. Float – A buoyant object that moves with the liquid surface. 2. Stem or Arm – Connects the float to the switch mechanism. 3. #Switch mechanism – Usually a magnetic reed switch or micro switch that opens or closes the circuit based on float position. 4. Housing – Protects the internal parts; may be stainless steel, plastic, or brass depending on the application. 🔍 Working Principle • When the #liquid #level rises, the float moves upward. • This movement changes the state of the internal switch (e.g., from open to closed). • The signal can be used to: • Start or stop pumps • Trigger alarms • Control valves • Protect equipment from dry running or overflow ⚡ Types of Float Level #Switches 1. Vertical type – Mounted from the top or bottom of a tank; float moves up/down along the stem. 2. Horizontal type – Mounted from the side; float swings inward/outward as the level changes. 3. Cable type – Float is attached to a flexible cable; used in large tanks or sumps. 4. Multi-point type – Detects multiple liquid levels with several switches on one stem. 🧰 Applications • Ballast #tanks • Freshwater and fuel oil tanks • Bilge systems • Cooling systems • Sewage treatment plants • Hydraulic oil reservoirs ⚠️ Common Problems • #Float stuck due to debris or corrosion • Magnetic failure (in reed switch type) • Incorrect installation angle • Electrical connection failure

Working at #Heights: Safe Use of Fall Restrainers and Fall Arresters Working at heights poses serious risks and requires strict adherence to safety procedures. According to the UK Department of Transport (UK DoT) definition, any work conducted above 2 meters with a potential risk of falling qualifies as “working at heights.” For such tasks, a permit to work and appropriate fall protection equipment are mandatory. There are two main types of fall protection systems, each serving a distinct purpose: 1. #FallRestrainer – A safety system (such as a safety belt or harness with a lanyard) designed to prevent a worker from reaching a position where a fall could occur. 2. #FallArrester – A system with a body harness designed to stop a fall that has already started safely. The Safety Officer determines whether a restrainer or arrester is required, depending on the nature of the job and the associated risks. For instance, work in elevated areas without guardrails or operations overboard (e.g., rigging the accommodation ladder) require the use of a fall arrester with a full body harness. Donning and Inspection Before using any fall protection system, the equipment must be carefully inspected. The user must ensure that: • Belts, straps, metal components (D-rings, hooks, etc.), and lanyards are free from damage or corrosion. • The retractable lifeline operates smoothly and locks properly when tested. • The safety harness is worn tightly, checked by another crewmember, and the hook of the arrester is properly engaged. The stronghold (anchorage point) on the ship must be inspected to ensure it is structurally sound, has no sharp edges that could damage the lanyard, and can withstand a load of at least 500 kg. Only a full-body #safety #harness (not a safety belt) can be used with a fall arrester. #Fall Clearance Distance When setting up a fall arrester system, the fall clearance distance must be calculated correctly. This distance should exceed the total distance a worker might fall before being stopped by the system. It includes: 1. Length of the lanyard 2. Length of the deployed energy #absorber (once activated) 3. Worker’s height 4. Safety factor (for vessel motion or protruding fittings) An overhead anchoring point is preferable since it provides less fall distance compared to anchoring from the floor. Maintenance When not in use, fall arresters, safety harnesses, and belts must be stored in a dry room, away from sunlight and chemicals. They must not be hung by their metal parts. Monthly inspections should follow the manufacturer’s manual, checking for: • Rust or structural failure, • Paint, grease, or salt buildup (cleaning required), and • Completeness of all components. Some manufacturers may require annual servicing, which must be arranged accordingly. All inspections and maintenance activities are recorded in the Planned Maintenance System (#PMS). A fall arrester must be replaced every five years. Rescue Procedures In the event of a fall, immediate recovery of the crewmember is essential. The person must not be left hanging, as suspension trauma can occur — a condition where blood pools in the legs, reducing circulation to the brain and vital organs. After #rescue: • The worker should be placed in a sitting position (never laid flat) for at least 30 minutes to stabilize blood flow. • Medical supervision should follow. • The #fallarrester and harness used during the incident must be discarded, as internal damage may not be visible. Proper inspection, maintenance, and understanding of fall #protection systems are essential for preventing serious injuries or fatalities during work at heights. Every crewmember must ensure that their fall restrainer or arrester is in good working condition and used according to procedures. Safety begins with preparation — a moment of care can prevent a lifetime of regret.

🧠 What Is the Kalman Filter? The #Kalman #Filter is a mathematical algorithm used to estimate the true state of a dynamic system that is affected by noise and uncertainty. In simple terms, it’s a smart way to combine predictions from a model with noisy sensor measurements to obtain the most accurate possible estimate of what’s really happening. 🔍 Basic Idea At every time step, the filter performs two main actions: 1. Prediction: It predicts the next state of the system based on the previous state and a mathematical model. 2. Correction (Update): It compares this prediction with a new measurement from a sensor and adjusts the prediction depending on how much it trusts the sensor vs. the model. This process repeats continuously, giving a constantly updated “best guess” of the system’s true state — even when measurements are noisy or incomplete. ⚙️ Why It’s Called “Kalman Filter” The name comes from Rudolf Emil Kalman, an American engineer and mathematician of Hungarian origin, who introduced the filter in his 1960 paper: “A New Approach to Linear Filtering and Prediction Problems.” It’s called a filter because it literally filters out noise from data — extracting the most probable signal from uncertain or fluctuating measurements. Kalman’s method became world-famous after being used in the Apollo space program to help guide spacecraft to the Moon. 📊 Where It’s Used The #KalmanFilter is widely applied in: • #Navigation systems (#GPS, inertial sensors, #autopilots); • Aerospace and marine control systems; • #Robotics and object tracking; • Signal processing and sensor fusion; • Economics and data prediction. Anywhere you have uncertain measurements and need reliable estimates — you’ll often find a Kalman Filter. ⚖️ The Kalman Gain — the Heart of the Filter The #KalmanGain, usually denoted as K, determines how much the filter should trust the new measurement compared to the predicted value from the model. It’s a weighting factor — balancing the reliability of the model and the #sensor. 🔧 Intuitive Explanation • If the sensor is accurate (low #noise), the Kalman Gain K becomes large, and the filter trusts the measurement more. • If the sensor is noisy, K becomes small, and the filter trusts the prediction more. 🚢 The Extended Kalman Filter estimates the vessel's heading, position and velocity in each of the three degrees of freedom - #surge, #sway and #yaw. Il also incorporates algorithms for estimating the effect of sea current and waves The Extended Kalman Filter uses a mathematical model of the #vessel. The mathematical model itself is never a 100% accurate representation of the real vessel. However, by using the Extended Kalman filtering technique, the model can be continuously corrected. The vessel's heading and position are measured using the gyrocompasses and position-reference systems, and are used as input data to the #SDP system. These measurements are compared with the predicted or estimated data produced by the mathematical model, and the differences are then used to update the mathematical model to the actual situation.

Fear and Loathing in the Engine Room. Feel the atmosphere 🤯 #EngineRoom #ER

🧩 A puzzle of diagrams scattered across various manuals (Main Control Console, Main Engine, Wiring diagrams) and information from the MOP. Not all the diagrams are included (I didn't attach any minor ones related to the 24VDC power supply). ➡️ For reference. I've replaced these #converters on other vessels, so keep this in mind. 💡 Note how the #MOP tells you where the problem lies (in the cable or in the #sensor). Unfortunately, this isn't enough to give a complete picture, as at least three signal #amplifier converters are involved in the circuit. Perhaps in the future, all the components will be shown, but then the ETO won't be needed anymore. 🤷‍♂️ Or is that right? 😅 #troubleshooting #turbocharger #RPM