Shaft Power & Torque Monitoring System in Marine Industry: Enhancing Performance, Safety, and Compliance
The efficiency of a ship’s propulsion system is directly linked to how well the power transmitted through the propeller shaft is monitored and controlled. Among the most advanced technologies that have become integral to modern shipping is the Shaft Power and Torque Monitoring System (SPTMS). This system measures, records, and analyzes the torque, power, and rotational speed of the ship’s main propulsion shaft. It plays a vital role in fuel optimization, machinery protection, and ensuring compliance with the latest international maritime regulations such as SOLAS and IMO efficiency standards (EEXI & CII).
In this article, we will explore what shaft power and torque monitoring systems are, the different types available, their importance in ship operations, their link to international maritime regulations, and the need for proper servicing.
What is a Shaft Power & Torque Monitoring System?
A Shaft Power & Torque Monitoring System is a precision measurement system installed on a vessel’s propulsion shaft. It continuously monitors three key parameters:
Torque – The twisting force applied by the engine to the shaft.
Rotational Speed (RPM) – The number of revolutions per minute of the shaft.
Shaft Power – The effective power transmitted from the main engine to the propeller, calculated as torque × speed.
By analyzing these parameters, the system provides real-time insights into propulsion efficiency, fuel consumption, and potential mechanical stress on the propulsion shaft.
Importance of Shaft Power & Torque Monitoring
1. Fuel Optimization and Energy Efficiency
Fuel is one of the largest operational costs for any ship. Monitoring shaft power helps optimize engine loading, ensuring fuel is consumed efficiently and unnecessary wastage is minimized.
2. Compliance with IMO Regulations
The IMO’s EEXI (Energy Efficiency Existing Ship Index) and CII (Carbon Intensity Indicator) regulations require vessels to demonstrate energy efficiency. Shaft power monitoring provides the essential data for proving compliance during audits and inspections.
3. Machinery Protection
Torque monitoring prevents shaft overloading, misalignment damage, or excessive vibration, protecting the main engine, shaft, and propeller.
4. Performance Monitoring
The system provides data that can be analyzed over time to detect deterioration in hull or propeller performance due to fouling, helping to schedule hull cleaning or propeller polishing at the right time.
5. Operational Safety
Abnormal readings trigger alarms that help crew take immediate corrective actions, thereby preventing accidents and breakdowns.
Types of Shaft Power & Torque Monitoring Systems
Several technologies are used in marine shaft power monitoring systems:
Strain Gauge Systems
Use strain gauges bonded to the shaft surface to measure deformation.
Provide highly accurate torque readings.
Require careful installation and calibration.
Optical Sensor Systems
Use laser or optical sensors to measure torsional vibration and shaft twist.
Provide non-contact monitoring, reducing wear and maintenance.
Magnetostrictive Systems
Rely on magnetic sensors detecting changes in the shaft’s magnetic properties under stress.
Rugged and suitable for harsh marine environments.
Hybrid Systems
Combine strain gauges and non-contact sensors for redundancy and accuracy.
Each type is chosen based on vessel size, propulsion system design, and regulatory requirements.
Compliance with SOLAS and IMO
SOLAS Requirements: While SOLAS primarily addresses safety, it requires effective monitoring of propulsion machinery and alarms for abnormal operations. Shaft torque monitoring contributes to compliance by preventing overload and ensuring safe propulsion performance.
IMO’s Energy Efficiency Regulations:
EEXI (Energy Efficiency Existing Ship Index): Effective since 2024, it mandates ships to measure propulsion efficiency. Shaft power monitoring systems provide certified shaft power data for EEXI calculations.
CII (Carbon Intensity Indicator): Requires continuous monitoring of CO₂ emissions per ton-mile. Shaft power data, coupled with fuel consumption data, forms the backbone of CII reporting.
Thus, shaft power and torque monitoring systems are not only tools for operational safety but also essential instruments for meeting environmental regulations.
Integration with Other Ship Systems
Modern shaft power monitoring systems can be integrated with:
Engine Control Systems – To optimize load distribution.
Alarm Monitoring Systems (AMS/ERAMS) – For real-time fault detection.
Ship Energy Efficiency Management Plans (SEEMP) – To provide accurate reporting for compliance.
Bridge Displays – To assist navigators in adjusting speed and load for fuel-efficient voyages.
Maintenance of Shaft Power & Torque Monitoring Systems
To maintain accuracy and reliability, shaft power monitoring systems require regular servicing:
Annual Checks: Calibration of sensors, testing alarm limits, and verification of data output.
Five-Yearly Surveys: In-depth inspection, recalibration, replacement of worn components, and certification as per class and IMO requirements.
Software Updates: Updating software and digital interfaces for compatibility with ship systems.
Data Validation: Ensuring recorded data aligns with vessel performance logs for EEXI and CII reporting.
Consequences of Faulty Shaft Power Monitoring
Failure to maintain shaft monitoring systems can result in:
Overloading of main engine and shaft damage.
Reduced efficiency and higher fuel costs.
Failure to comply with IMO audits, leading to penalties.
Inability to track carbon intensity, affecting vessel ratings under CII.
Increased risk of breakdowns and unplanned downtime.
Conclusion
The Shaft Power & Torque Monitoring System is no longer just an advanced option; it has become a necessity for modern ships aiming to comply with international environmental and safety standards. From preventing shaft overloads to ensuring compliance with IMO’s stringent efficiency regulations, these systems safeguard machinery, reduce operational costs, and improve vessel performance.
Ftron Technology provides complete solutions for shaft power and torque monitoring systems. We offer annual services, five-yearly surveys, supply, repair, maintenance, and certification of all major types of shaft power monitoring systems. With our expertise, shipowners can ensure their vessels operate efficiently, safely, and in compliance with SOLAS and IMO requirements.
FAQs on Shaft Power & Torque Monitoring Systems
Q1: Why is shaft power monitoring important for EEXI compliance?
A1: EEXI requires ships to measure propulsion efficiency. Shaft power monitoring provides certified data necessary for compliance calculations.
Q2: How does torque monitoring protect the propulsion system?
A2: Torque sensors detect overloading or misalignment, preventing potential damage to the main engine, shaft, or propeller.
Q3: Are there different types of shaft power monitoring systems?
A3: Yes, systems include strain gauge, optical sensor, magnetostrictive, and hybrid designs, each suitable for different vessel types and operating conditions.
Q4: How often should these systems be calibrated?
A4: Calibration is recommended annually, with complete recalibration and certification during five-yearly surveys as per class society rules.
Q5: Can Ftron Technology provide certification for shaft power systems?
A5: Yes, Ftron Technology supplies, maintains, repairs, and certifies shaft power & torque monitoring systems in accordance with IMO and SOLAS regulations.
📌 Post Name: Shaft Power & Torque Monitoring System in Marine Applications
