The maritime industry has witnessed so many incidents where fire has caused serious damage to the life onboard as well as to the assets. One most common reason for fire which emanates in most cases from the engine room is oil leak or spray over the hot exhaust surfaces. There has been many safety developments to combat such fires. These could be fixed foam or hyper-mist systems. However, all such systems will help to extinguish the fire, but cannot prevent it.
Thus, the question remains the same for decades.
Is there any way to prevent such fires?
The maritime industry is continuously identifying new technologies to combat or prevent such fires. One such preventative method is thermal imaging.
MFAME has covered the topic with a case study on how thermal imaging can prevent fires in engine room? There has been cases where a small oil spray upon hot exhaust surface has rendered ships dead without any power. Some top companies have already taken measures to prevent such fires and here is one example where MOL (Mitsui OSK Lines) uses thermal imaging to enhance coal carrier’s safety.
While the above being said, last week MFAME published a news where a cargo ship averted a fire by identifying it on time with the help of thermal imaging. Based on this news, many technical superintendents have raised questions on the usability of such instrument to identify fires.
MFAME took special efforts and approached a condition monitoring specialist and posted those questions. Mr. Rajagopalan, ex-Marine Chief Engineer and Fleet Manager, CEO SVL Services – offered to answer these questions.
Here is it exclusively for MFAME readers!
1. Thermal imaging cameras – can it spot fires from distance or has it to be taken close to suspected fire zones?
Answer: A Fire need not be seen when there is smoke. Thus, with the thermal imaging cameras, a thermal picture taken from a safe distance would reveal the fire spot. In fact a deep study and understanding on thermal pictures, one can locate the seat of the fire. There is no need to go close to the fire.
2. How close should the cameras be? Is there any limitation on the temperature output subject to distance scanned?
Answer: In the case of fire, with thermal imaging, we actually do not measure the exact temperature of the fire zone or spot. In fact, no one would be interested in measuring or knowing the temperature accuracy. All we need to know is the location or the seat of fire. In case of electrical appliances, it is the hot spot or over current spot which we need to investigate. Thus, we only see the contrast between the fire zone & non-fire area – and thus arrive at a conclusion.
3. Is there any ready interpretation of thermal imaged colors and temperatures? Is there any ready guide for end users to understand the thermal image color spectrum?
Answer: Thermal images can come in several color palettes. I t is the choice of a Thermographer to use a particular type of pallette. In general, the lighter the color, higher the temperature. Some examples are given below:
Iron bow-Palette
Sidebars provide the temperature scale in each case
High Contrast palette
Amber Palette
Grey Scale Palette
4. At what color or temperature does an alarm need to be raised?
Answer: One needs to understand the temperature levels the machinery usually operate to raise an alarm. Manufacturers do give some data for the majority of the equipment. In the absence of data, some Thermographers use NETA standards. Infraspection Institute has combined various standards and published some details for usage. Some of them are
- NETA Standard;
- Military based standard;
- Experience based standard and so on so forth.
If anyone is interested, I will be happy to guide. We have given below an extract from NETA standard for reference.
Hope all the questions asked were answered. If you have more questions, please do no hesitate to write to us at: experts@mfame.guru
Our experts are ready to share knowledge and as always consulting experts for technical advice for shipboard problems are FREE when contacted through MFAME. Our experts are always there to guide you!
We specially thank Mr. Rajagopalan, CEO SVL Services for answering the questions and providing illustrations where appropriate. Please feel free to write to us if you look forward to use condition monitoring services.
About the Author:
Mr. Rajagopalan, is the CEO of SVL Singapore services, which has a combined Marine experience of 72 years. The company is specialized in Thermal Imaging, Ultrasound, Vibration & Noise control audits and the company strongly believes that condition based maintenance is always cost effective and can predict faults well before catastrophic failures.
MFAME readers have the privilege to consult Mr. Rajagopalan for FREE. Please contact Mr. Raja or SVL Singapore Services by writing to: experts@mfame.guru
