07 - michael kennedy

7/27/2019 07 - Michael Kennedy

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CONDITION BASED MAINTENANCE IN NEW BUILDINGSA SHIP OWNERS PERSPECTIVEDr. Michael(MIKE) B. Kennedy, Hellespont Steamship Corp.

Condition based maint./monitoring (CBM): safety and economics.

CBM encompasses voyage performance, coatings and machinery.

When ordering/building ships include CBM requirements.


2/13

THE SITUATION ONBOARD - WHEN CBM?

Ships are steel, coatings, machines working in a harsh environment.Hundreds of systems and some are too critical to fail.

Condition based maintenance is maintenance when NEEDED.(1) equipment condition is such that it is failing, working unacceptably.

or(2) maintenance delay => much higher operating/mnt costs now/later.

CBM can help minimize off-hire, spares and labor - crew and shore.


3/13

NEW BUILDINGS (NB)

Condition based maintenance req. will be subordinate to commercialnego. but the building spec and maker selection can include CBM.

a. sub-models, features put key items into spec.

b. interfacing and expansion options are important.c. require full documentation including all passwords.d. owner benefits - training time of at least a few days.

A site team can make extensive measurements, photos, nameplatedetails, collect doc/passwords and operating data.a. during operations need many measurements / records.b. photos/movies of operations are "insurance" of coverage.

c. nameplate details ensure correct supply and future pms.d. site team needs to collect all passwords from serv.eng.


4/13

COND. MONITORING - PRACTICE AND EQUIP.

Voyage performance indicators - spd/fuel, load/disch times, etc. Mach. monitoring: lube oil, water, fuel analysis, IPCC, meggers. Steel and paint thickness measurements (photos).

Monitoring is on calendar/hour periods (e.g. monthly lube). Time between data must not exceed failure/repair times. Who does what monitoring and what training is needed?


5/13

THE ALARM MONITORING SYSTEM (AMS)

Tracking temperatures, pressures, etc. against baselines. With planning and a diligent trained crew use existing tools. The AMS is recording but non-alarm data is often not retained.

AMS use common computer equipment and access is via browsers butpassword, usage is not well documented and makers charge high pricesfor additional sensors interfaces, work stations, etc.

With enough data condition monitoring rules can be created usingequipment manuals, shop tests, sea trial and baseline data.Record data with notes to know what data is in what operating mode.


6/13

AMS REQUIREMENTS

1. Alarms must display their ID, description and set points.E.g. MEP.T103 Port Eng. Cyl 3 Exh Temp. 500C > 490C.

2. Full feature (history, graphing) work stations - not only ECR.

3. Measurements should be recorded with the GMT time

4. Retrieval of Sensor History - history 1+ year with zooming.

5. Data Dumping to Memory Sticks. Engineering units/time.

6. AMS config. available for conversions, set points, etc.

7. Screen Printout with User Labeling/File Naming.

8. Alarm rules, e.g. dsch pump > 8 bar for 10+ seconds.

9. Able to add new sensors without needing the makers service.

10. Creation of virtual sensors such as delta pressure.


7/13

NOT AMS CONDITION MONITORING

Photos of the hull, cargo holds/tanks, equip. are common. AMS fortemperatures and pressures. Megger testing for electrics.

Whats left? Vibration, Steel mm, Coating DFT, Cathodic(Voltage), Paint "X"ing.

Clearance (wear down) and vibration measurement and temperatures.

Portable vibration data - journals of rotating mach (document). Vrms, Arms, Shock Pulse all need baselines for operating modes.

Data taking documented and handover made in-situ.a. What positions?

b. What orientation/axis?c. What data collector/sensor config. setup?d. Expected data range (confirms if data collection correct).


8/13

PORTABLE VIBRATION MONITOR REQUIREMENTS

1. Engineering data upload to on board computers doc. format.

2. Save config(scaling, bandwidth) setup for reload.

3. GMT time used - optionally local - watch out for drift.

4. Able to skip data and add extra data without confusion.

5. Sensors matched to equipment (bandwidth adjustable).

6. Calibration shaker or other field verification unit.

7. Digitization, sampling and time on the daily "walk".

8. ISO2372, ISO10816, additional (e.g. SPM), NMEAs, etc.

9. Equip. programming via videos, doc., courses, etc.

10. Data "walks" saved in common formats. Spectra nice.


9/13

NON-VIBRATION CONDITION MONITORING

Hull Steel and Coatings: ultrasonic but equip. (mm vs microns)a. Steel thickness in mm (accuracy about 0.1mm - ignores rust, paint).b. Coating thickness in microns (accuracy 20 microns, ignore rust).

c. Coating quality tricky if chalking or microcracking/failures/blisters. Cathodic (hull/tanks) to determine both voltage level and "speed".

More than 0.850 mv silver/chloride (AgCl) traditional. Speed 1-2 days.

Small local destructive coating tests by knife/scribe (photos).a. X about 100mm by 100mm. Repair (scrape, solvent wipe, paint).b. Look for underpeeling. Too easy X. Surface underneath.

Built-in Machinery Diagnostics plus calc. capacity, temps, press.But how to integrate disparate equip. into a unified scheme?


10/13

AMS/MACH. DIFFICULTIES AND REQUIREMENTS

Serv.Eng immediately via laptops modify machinery setups.a. much harder to understand what is going on. magic parameters.b. service engineers dont usually know PID values.

c. PID but with - cascaded loops and multiple feedbacks. Access data/setup means doc., training and levels of passwords.

a. user passwordb. chief engineer passwordc. service tech password.d. factory password.

Less dials/gauges but more bro wser info if you have passwords.

Set-points, passwords, config., docs needed to make a CBM scheme.

NB plan app. + maker selection to incorp. commissioning proc., doc.


11/13

CBM NEEDS

Data history with consistent recording, baselines, alarm values, etc.

Vibration, visuals, pressure, temps, throughputs, capacities, etc. Data quantity, plotting - quantity and email to shore => Computer.

Condition monitoring via fixed data meas. points at fixed times. Time between data must be short compared to "failure times" Alarm levels relative to failure/repair times incl. material

Total life cycle costs of CBM - CBM is more complex(e.g. training)

Equipment maybe critical and require CBM.


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CONCLUSIONS

1. CBM is more complex than other types of maintenance.

2. NB opportunity: Specs, Maker Selection, Commissioning oversight.

3. Makers must "open" the black box and provide doc., training.

4. Makers/Class find CBM "trouble". Crew, equip. pushed, after sales.

5. Longtime crew can do CBM with existing but need training.

6. Extra equipment can help if it is used correctly and trustfully.7. Complexity => CBM co-exist with Time Sched. and breakdown Mnt.

07 - michael kennedy

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