When I was a young boy at sea as a junior watch-keeping engineer, I was taught to scan the various temperature and pressure gauges on the main engine control panel regularly. I also learned the value of touching various components with the back of my hand as I walked by them, and this soon became second nature.
This is an article on checking the temperatures of engine room components as part of the duties of a watch keeping engineer.
Here we shall evaluate the use of a handheld infrared thermometer use in the engine room. We begin then with an overview of the components which require temperature monitoring and control.
Engineroom Components Temperature Monitoring and Control
An Overview of Temperature Monitoring and Control: Steam Turbines and Auxiliary Equipment
Starting from the top of the engineroom:
The purpose of the deaerator is to remove dissolved gases such as oxygen and carbon dioxide from the feed water, by passing the feed water through bled steam. The deaerator is also used to prevent surge in the system, acting as a feed water heater and storage tank.
Temperature checks required:
- Steam inlet and outlet temperatures
- Feed water inlet and outlet temperatures
Dial temperature gauges are normally used to record these temperatures.
Application of handheld infrared thermometer: as the steam and feed water piping is insulated, there would be little use for the infrared thermometer.
Lube oil header tank
Lube oil is bled from the system and pumped to the header tank at the top of the engineroom, running back down to the main sump. Its function is to provide oil under gravity feed to the main turbine bearings in the event of loss of oil supply.
Temperature checks required:
- Lube oil inlet and outlet temperatures
Normally recorded using temperature gauges.
Application of handheld infrared thermometer: the infrared thermometer could be used to record the temperature of oil in the tank, as well as the oil inlet and outlet temperatures.
Here we have the control station and control board that houses numerous temperature and pressure gauges.
Looking aft from the control station, the insulated tops of the steam turbines are visible with their interconnecting insulated pipework.
The turbine temperature checks required are:
- Superheated steam inlet to HP turbine
- Steam temperature inlet to IP turbine
- Steam inlet temperature to LP turbine
These are normally recorded on 10” rigid stem dial gauges that can be easily read from a distance whilst performing watch-keeping duties.
Application of handheld infrared thermometer: once again all the steam pipes are heavily insulated against heat loss, so there would not be any use for the infrared thermometer.
The main seawater circulating pumps, feed water pumps, and centrifuges are fitted at this level along with the lube oil cooler. Under the plates are the main condenser and hotwell.
Temperature checks required are:
- Main condenser feed water outlet temperature.
- Seawater inlet and outlet from condenser.
- Seawater inlet from shipside seachest.
- Lube oil inlet and outlet from cooler.
- Seawater inlet and outlet from cooler.
- Lube oil inlet and outlet from LO centrifuge heater.
- Hotwell feed water outlet temperature.
These are normally recorded on rigid stem dial temperature gauges; all forming part of the engineroom log and closely scrutinized by the Chief Engineer to ensure the turbines are running at maximum efficiency.
Application of handheld infrared thermometer: the temperatures of these components could be recorded using the handheld infrared thermometer, although the plates would have to be lifted to get at the hotwell; a very hot and arduous job and, I speak from experience.
As a young junior engineer I had to trace out all the pipelines under the bottom plates as part of my training, wearing a rubber wet-suit! I then had to draw out these pipelines, color them with crayons and present it to the Second Engineer. I did discover a steam leak whilst undertaking this exercise, and was nominated to replace the gasket at the next port, as reward for all my crawling about on oily tank tops.
Anyway I digress, which is a problem with being Irish and an old sea dog. The use then of the infrared thermometer for the aforementioned components would be suitable.
Thrust block (Michell/Kingsbury Bearing)
The thrust block is used to transmit the drive shaft thrust through the mounting bolts into the ships structure. It consists of a arrangement of pads and plates, their clearance being maintained and dictated by oil pressure.
A temperature rise could mean oil pressure/filter problems, shaft alignment, or excessive revolutions as prevalent in rough seas.
Temperature checks are: oil inlet and outlet.
Normally large 10” dial rigid stem temperature gauges are used.
The sense of touch using back of hand to gauge the temperature of the thrust bearing housing always gave a good indication that all was well. (This was also true for vibration check).
Application of handheld infrared thermometer: the handheld infrared thermometer could be used to check oil inlet and outlet temperatures, along with monitoring the outer bearing housing temperature.
Tunnel shaft bearings
These are normally white metal bearings and lubricated by splash lubrication.
Temperature checks are: oil temperature
This is normally displayed on a dial gauge, but also through sense of touch by hand. An increase in temperature could indicate shaft misalignment, but normally is due to oil starvation. (Check oil level gauge)
Application of handheld infrared thermometer: the handheld infrared thermometer could be used to check the bearing temperature.
Normally no thermometer used here, only touch by hand. A hot stern gland indicates the gland being too tight. The gland packing ring should be slackened until a small trickle of water emanates from gland.
Application of handheld infrared thermometer: excellent prospect for a handheld infrared thermometer when used to record the actual temperature of the gland.
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Please read on to examine some types and specifications of handheld infrared thermometers.
Handheld Infrared Thermometers Function
There are numerous types of Infrared handheld thermometers; however a small compact one that will fit into the boiler-suit top pocket or belt holster is ideal for engineroom use. Some compact digital infrared thermometers are shown below along with their relevant specs:
Specifications of Omega Stick Infrared Pyrometer Model No. OS643
- Approximate Dims: 8” x 11/2”
- LCD Display: °C and °F
- Detection Element: Thermopile
- Laser 1mW
- Power Supply: 4 x AAA Batteries
- Accuracy: +/- 3%
- Temperature range 32° to 500°F (0° to 260°C)
- Carry case: pouch
- Price: £57 ($90)
Specifications for Fluke Digital Infrared Thermometer Model No Fluke 62
- Temperature range: -20°F to 932°F (-30°C to 500°C)
- Accuracy: +/- 1.5%
- Emissivity: preset to 0.95
- LCD Display: °F or °C
- Distance to spot: up to 2m
- Dimensions: 6” x 4” x 1½”
- Weight: 7oz
- Power: 9v Battery
- Price: £81 ($128)
- Carry case: holster
Specifications of Digikey infrared digital thermometer Model No. 290-1427-ND
- Temperature Range: -4°F to 572°F (-20°C to 300°C)
- LCD: °F and °C
- Power: 9V battery
- Cover: Pouch
- Price: £51 ($80)
Summary of Handheld Infrared Thermometers use in Engine Rooms
As can be seen from the section on monitoring of the temperature of engineroom components, there are numerous components that require temperature monitoring, either by touch, temperature gauges, pyrometers or pocket thermometers. A handheld infrared thermometer would complement these methods through confirming temperatures, but not replacing them.
A number of these temperatures are duplicated on the main control board, situated at the control station, where the watch-keeping engineer can see at a glance if there is a rise or fall in temperature. Any dramatic change in temperature should always be investigated, and having a handheld infrared thermometer in your pocket would add to the confirmation of a suspected faulty temperature gauge reading.
We marine engineers have all seen broken or inaccurate temperature gauges in the engineroom, and when there are no spare gauges onboard to replace them, the infrared thermometer would be of great significance.
The three models illustrated are easily carried in a small leather case in the top pocket of the boiler suit, or in a belt holster, being battery operated are completely portable and do not require an external power source.
I think as a retired marine engineer, I would still use the back of my hand as an initial check for excess heat on un-insulated piping and bearings – old habits die hard. Nonetheless, I can see a hand held infrared thermometer being used to monitor a component whose temperature is found to be rising by the above sense of touch method, where no fixed temperature measurement is possible.
However, the young engineers of today have been brought up with new digital technology, so they would probably get to be familiar with the handheld infrared thermometer use in engine rooms.
Handheld infrared thermometers for engine room use and dial thermometers
Images: S.M. Gauge Co., Ltd.