Liner wear monitoring: from periodic spot checks to routine self-diagnosis. Cylinder liner wear is a core indicator of the technical health of a two-stroke low-speed diesel engine, and its measurement must follow the technical specifications in the engine manufacturer's maintenance manual.
The current standard method requires manual measurement with an internal micrometer at defined heights — usually near piston top dead centre, mid-stroke and bottom dead centre — in two orthogonal directions, fore-and-aft and port-to-starboard, from which maximum wear, roundness and cylindricity are calculated. That traditional approach has clear limitations:
- Dependent on manual work: measurement accuracy is easily affected by operator skill and by environmental conditions;
- Requires removal of the cylinder head: the job is complex and time-consuming, and is normally carried out only at piston overhaul intervals, typically every three to four years;
- Measurement frequency is far too low: wear trends cannot be captured as they develop, so predictive maintenance is unsupported.
For more economical and efficient whole-life engine management, the industry needs to move liner wear inspection from an overhaul add-on to a frequent, routine monitoring task.
The logical route is to carry it out together with each routine scavenge port inspection, usually performed monthly. This substantially increases the density of data collected and allows early abnormal wear or signs of cold corrosion to be detected in good time.
The practical limits of the external service model
Some owners commission third-party service providers to carry out precision measurement through the scavenge port, but in practice that model faces three constraints:
1. High cost: specialist travel, working hours and transport of dedicated equipment make each visit expensive;
2. Data gaps: long intervals between inspections prevent a continuous condition curve from being built, weakening trend analysis;
3. Slow response: where performance drops suddenly or abnormal vibration occurs, liner condition data cannot be obtained immediately to support fault tracing.
A better answer: CLDM enables accurate measurement by the crew
The CLDM (Cylinder Liner Diameter Measurement) system, developed by Dr. E. Horn GmbH of Germany, offers a breakthrough for these problems.
This high-precision, multi-point self-centring measurement system is designed for two-stroke low-speed diesel engines with bores of 350 mm and above. It supports fast, highly repeatable in-situ measurement of liner diameters at different heights and orientations through the scavenge port, without removing the cylinder head. Its core advantages come down to three zeroes:
- Zero dismantling: work is carried out directly through the scavenge port, avoiding heavy tooling and downtime;
- Zero external dependency: after brief training, crew members complete the full measurement independently, with no waiting for shore-based specialists;
- Zero data delay: measurement and analysis happen together, with standardised reports generated immediately to support fast decisions.
CLDM uses HORN's proprietary high-precision position-sensing technology and includes automatic calibration for the specific bore, ensuring consistency over the long term.
The accompanying software automatically calculates wear, roundness, cylindricity and other key parameters, and produces inspection reports that meet classification society requirements — CCS, LR and ABS among them — covering both repair verification and condition record-keeping.
CLDM is not only an advance in measuring equipment but an upgrade in maintenance thinking: it moves liner condition monitoring from passive response to active control, making frequent, low-cost and highly reliable in-house inspection possible.
In an era of shipping that demands safety, efficiency and compliance in equal measure, CLDM is becoming an indispensable technical foundation for the intelligent engine room.
We can propose a measurement package and application guidance tailored to your engine type and maintenance regime, and help you assess the return on investment and practical results. Contact Tecway for product documentation, case references and trial arrangements.
About Tecway
Tecway International Limited was founded in Hong Kong in 1993 and is a leading technical consultant and quality agent for the global maritime industry. Over more than three decades it has built five core business areas: marine equipment, petrochemical storage and transport, diesel and gas engines, marine technical services and maritime consultancy, serving markets across China, Southeast Asia, the Middle East and Europe.
Tecway is committed to the diesel and internal combustion engine sector, supplying products such as the Cylinder Liner Diameter Measurement system (CLDM) together with technical support. Our fast-response service network covers everything from sales consulting and installation through commissioning, training and after-sales service.
We also focus on the low-carbon transition of shipping companies, providing EU ETS and FuelEU compliance consulting, shipping green hydrogen project support, smart-ship dry-docking, export solutions for Chinese-made marine equipment and FGSS services.