GRUPA WOLFF has supplied lighting fixtures and an explosive gas detection system to the repaired submarine ORP “Orzeł”. Due to the danger of hydrogen explosion, the requirements set by the crew of the submarine for the lighting fixtures were very high. In addition to ensuring a safe use of the fixtures in the second zone of the hydrogen explosion risk, compact fixtures with a modular design had to be applied to allow an easy maintenance and replacement of damaged components. Also the luminous flux should not blind the crew during the operations conducted.
The fixture housing should be made of aluminium, without any addition of copper, with powder-applied epoxy anti-corrosive coating. It should be resistant to shocks and vibrations and have an effective radiator dissipating heat excess from the LEDs and the whole electronics – comments Sebastian Słaboszewski (GRUPA WOLFF) who coordinated the supply of lighting fixtures and the explosive gas detection system for the ORP ORZEŁ.
For the control system, a reliable industrial stabilized power supply unit should be applied and the fixture must be protected against effects of short circuits and overloads by means of adequate safeguards. The lighting fixture should be characterised by low harmonic distortions potentially affecting the operation of the entire electric system supplied by a bank of batteries. This is particularly important for an electrically self-contained unit.
Since the number of all the lighting fixtures mounted on the submarine exceeded 300, they had to meet certain legally binding safety standards and efficiency standards. Also the height of the fixture was an important selection criterion, considering the limited space of the submarine. It was extremely important in view of the small mounting height (up to 2 metres) and the necessity to fit the new fixtures in place of the old ones as «hidden» in the soffit – ends the enumeration Słaboszewski.
Finally, the investor decided to use the compact and modular Vaporgard fixtures since only they met all the above requirements of the submarine’s crew and repair works contractor.
Detection of Hydrogen in Battery Cavities
The above mentioned replacement of two sets of batteries (120 links each) supplying the submarine ORP ORZEŁ necessitated a modernization of the hydrogen detection system in the battery cavities. In view of the working conditions prevailing under water, the most important criterion for choosing the detection system was simplicity and robustness.
The stationary detection system included 47K series passive hydrogen detectors, as based on the catalytic combustion technology, and multi-channel control units of the GasGard XL type.
The tasks of the system include continuous monitoring of the hydrogen concentration in the battery cavities and transfer of information to the command post with the alarm trigger function. The control unit provides power to the sensors and signal amplification sections and to the display that shows the measured gas concentration, alarm thresholds, output signals of alarm devices and diagnostic messages in the self-test function – explains Mateusz Adamski (MSA Safety – producer of gas and flame detection systems) and continues: – In line with the standards prevailing in the Navy, the system gives the user the hydrogen concentration in percent by volume, with simultaneous indication of each of the nine sensors. On this basis, the crew of the submarine is able to determine quickly the degree of the risk associated with the hydrogen fumes emitted during the battery charging and take appropriate measures to ensure the safety.
At the threshold of 2.5% by volume of hydrogen concentration, the GasGard XL control units transmit an alarm signal to the command post of the submarine and at the same time, audible and visual signals are triggered. On this basis, the battery charging is cut off immediately by means of battery automatics (or the manual trigger function) in order to prevent their excessive gassing. The GasGard XL control units have also their own backup batteries allowing to sustain the operation of the detection system for 30 minutes after a power failure. In addition to equipment supplies, MSA also provides maintenance and calibration of the detection system – ends Adamski.
SCOPE OF WORK: selection and supply of lighting fixtures and a hydrogen detection system for a submarine
LOCATION: Poland, Pomeranian Province