I used to think any cruise ship ran on 12 volts DC.
I assume you mean any cruise ship FIRE alarm system?
Well, because most vehicles and boats ran on 12VDC, I thought cruises did the same thing as well.
A cruise ship is a whole different ballgame. I doubt they could get by with only 12 volts. It would be a large and massive boat with a lot of decks so I donāt think 12 volts will cut it.
A cruise ship carries the equivalent in crew and passengers of the population of a small city. 12 volt DC power distribution is totally impractical. Think for a moment about the 10 or 12 restaurants all with commercial cooking, ventilating, and refrigeration equipment. Those draw lots of power and are not available to run on 12 volts DC. Then there are the HVAC system, elevators, lighting systems, etc.
Typical cruise ships have multiple 3 phase diesel or turbine generators feeding a high voltage AC distribution system. Distribution as high as 11,000 volts is used in the modern ships. In older ships 6,600 volts was common. Substations in electrical rooms are around the ship to step the high voltage down to 480, 240, and 120 volts for local use.
Just do a Google search on ācruise ship power distributionā for more answers.
Iāve been on a three cruises; all Norwegian Cruise Line. Iāve noticed that most newer ships in their fleet (Norweigian Breakaway-beyond) have strobe lights in them, branded by Consilium. As for the PA system tones, older NCL ships do a 950hz tone, some ships like the Epic do a slower 900hz tone, and the newer ships do a 1000hz tone. Iām curious to know what would happen if you pressed a call point, or if a smoke detector is activated. On the Norwegian Escape, Iāve seen some Roshni sounders in common areas, though Iām unsure if those are actually connected to the call points (thereās a video somewhere on YouTube of them going off when the emergency doors are shutting). I imagine it sends a signal to the bridge, and if itās in a stateroom itāll probably set off the smoke detectorās sounder base (depending on if it has one).
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[quote=AlarmObsessed post_id=87484 time=1597176797 user_id=3104]
On the Norwegian Escape, I've seen some Roshni sounders in common areas, though I'm unsure if those are actually connected to the call points (there's a video somewhere on YouTube of them going off when the emergency doors are shutting).
[/quote]
Are these sounders located near doors?
[quote=randomperson post_id=87489 time=1597203474 user_id=3878]
[quote=AlarmObsessed post_id=87484 time=1597176797 user_id=3104]
On the Norwegian Escape, I've seen some Roshni sounders in common areas, though I'm unsure if those are actually connected to the call points (there's a video somewhere on YouTube of them going off when the emergency doors are shutting).
[/quote]
Are these sounders located near doors?
[/quote]
Somewhat. Aside from the Roshnis and Yodalarms found in the kitchens at Garden Cafe, I recall seeing a Roshni in the casino, though it was probably about 40 feet from the emergency door.
This isnāt on the Escape, itās on the Getaway, a sister ship with a similar design. You can hear the Roshni doing a sweep tone as the doors close.
[quote=AlarmObsessed post_id=87484 time=1597176797 user_id=3104]
On the Norwegian Escape, Iāve seen some Roshni sounders in common areas, though Iām unsure if those are actually connected to the call points (thereās a video somewhere on YouTube of them going off when the emergency doors are shutting). I imagine it sends a signal to the bridge, and if itās in a stateroom itāll probably set off the smoke detectorās sounder base (depending on if it has one).
[/quote]
Call points are usually a silent alarm sent to whoeverās responsible for investigating the situation. This is done to avoid panic, especially in larger cruises.
While Iām not sure about the specifics, I wouldnāt be surprised if other fire protection systems activate (i.e. doors closing or HVAC cutting off).
I think most new Fincantieri-built ships use 1750hz, so it varies quite a bit between makers
Also, for modern cruise ships, thereās a HUGE fire suppression system with hundreds of agent containers installed onboard to provide protection for the engine compartment and the pump room. Different from ones installed in buildings, most marine suppression systems can be operated manually only. Theyāre considered as not the first and most urgent choice for containing a fire outbreak but the last choice to save the ship from a burndown.
old discussion but most of the times, the roshnis are connected to other stuff like emergency doors and watertight doors.
Iāve also seen them connected to the fire suppression systems in the restaurants.
Iāve seen from videos that most ships have some sort of combo alarm indicator, which consists of a cluster of speakers and a stack of lights/strobes indicating fire alarm, agent release, mechanical failure, phone call etc.