Fire Safety Question

[cruiseguy2500]

Hello! I am wondering if cruise ships have a typical firemain system like commercial vessels where there are hydrants on each deck? Or do they rely on the watermist system for the staterooms and only use hydrants for the bridge level and the upper deck? Thank you.

[shof515]

they are hydrants and places to hook up a hose it. it is usually hidden behind some kind of panel or some other door. i seen a few out in the open on the outside decks

[Elaine5715]

1 hour ago, cruiseguy2500 said:

Hello! I am wondering if cruise ships have a typical firemain system like commercial vessels where there are hydrants on each deck? Or do they rely on the watermist system for the staterooms and only use hydrants for the bridge level and the upper deck? Thank you.

Bonus points for an original question!  If you like this type of information about ships, search for posts by @Heidi13 and @chengkp75 and welcome to CC where we cruise and critic...

[Heidi13]

2 hours ago, cruiseguy2500 said:

Hello! I am wondering if cruise ships have a typical firemain system like commercial vessels where there are hydrants on each deck? Or do they rely on the watermist system for the staterooms and only use hydrants for the bridge level and the upper deck? Thank you.

 

Fire regulations require a fire main system and hydrants, so that 2 jets of water can be applied at any point on the ship. The hoses, which can be up to 60', must be attached to different hydrants.

 

Any sprinkler system or hi-fog system is in addition to the required hoses and extinguishers.

[chengkp75]

To add to Andy's post, the fire main system must be able to produce 100psi at the hose nozzle on the highest deck.  We routinely had the Honolulu fire department visit the ship whenever in port, to learn to liaise and cooperate with us in case of a fire, and they were routinely amazed at the amount of equipment the ship had, and the capabilities of the ship's equipment.  They always stated that the ship generated more pressure on the firemain than they could, so connecting their trucks to our system was not really feasible, unless the ship loses all power, but they would be used for boundary cooling on the outside of the ship.

 

The firemain system on cruise ships is different than commercial ships, in that each deck will not only have hydrants and hoses on each deck, but each deck will have a "ring main" that circles the deck to feed the hydrants from various sources.  This allows for isolating sections of the firemain that may be damaged by a fire, and keep pressure on the rest of the system.  There are isolating valves for these ring mains at each fire zone boundary. 

Edited January 28 by chengkp75

[ldubs]

3 hours ago, chengkp75 said:

To add to Andy's post, the fire main system must be able to produce 100psi at the hose nozzle on the highest deck.  We routinely had the Honolulu fire department visit the ship whenever in port, to learn to liaise and cooperate with us in case of a fire, and they were routinely amazed at the amount of equipment the ship had, and the capabilities of the ship's equipment.  They always stated that the ship generated more pressure on the firemain than they could, so connecting their trucks to our system was not really feasible, unless the ship loses all power, but they would be used for boundary cooling on the outside of the ship.

 

The firemain system on cruise ships is different than commercial ships, in that each deck will not only have hydrants and hoses on each deck, but each deck will have a "ring main" that circles the deck to feed the hydrants from various sources.  This allows for isolating sections of the firemain that may be damaged by a fire, and keep pressure on the rest of the system.  There are isolating valves for these ring mains at each fire zone boundary. 

 

100 psi is respectable and was the standard at the my FD as it produced the best spray patterns from the adjustable fog nozzles in use.  It was difficult but management by one person on a 1 1/2" line.  Not possible without a crew on a 2 1/2" line being moved about.  

 

Out of pure curiosity are the hose stations wet or dry pipe?  

[chengkp75]

1 hour ago, ldubs said:

 

100 psi is respectable and was the standard at the my FD as it produced the best spray patterns from the adjustable fog nozzles in use.  It was difficult but management by one person on a 1 1/2" line.  Not possible without a crew on a 2 1/2" line being moved about.  

 

Out of pure curiosity are the hose stations wet or dry pipe?  

The rule of thumb on ships is 1 person for every inch or part of an inch of hose diameter, so 2 on an 1 1/2" hose, 3 on a 2 1/2" hose.  Think about working a 2 1/2" fully charged hose around the machinery in an engine room.  The firemain is dry pipe, since it is sea water, and you don't want this corrosive element in the pipes at all times. 

[Heidi13]

1 hour ago, ldubs said:

 

100 psi is respectable and was the standard at the my FD as it produced the best spray patterns from the adjustable fog nozzles in use.  It was difficult but management by one person on a 1 1/2" line.  Not possible without a crew on a 2 1/2" line being moved about.  

 

Out of pure curiosity are the hose stations wet or dry pipe?  

 

On my older ships the fire main was pressurised with salt water and on newer ships it was filled with fresh water. Except for topping up pressure, if the fire pumps cut in, it switched over to sea water.

 

Therefore, when we were testing fire hoses or using them for wash down, we contacted the Engineers to isolate the sea water.

[MBP&O2/O]

I remember one lad on our MN Officers Fire Fighting Course who failed to hold the hose pipe correctly. The pressure in the pipe literally lifted him off the ground. 🤭

[ldubs]

8 hours ago, chengkp75 said:

The rule of thumb on ships is 1 person for every inch or part of an inch of hose diameter, so 2 on an 1 1/2" hose, 3 on a 2 1/2" hose.  Think about working a 2 1/2" fully charged hose around the machinery in an engine room.  The firemain is dry pipe, since it is sea water, and you don't want this corrosive element in the pipes at all times. 

 

Thanks.  Our structural firefighting nozzles on 2 1/2" lines flowed 250 gpm at 100 psi nozzle pressure.  Impossible for one person unless stationary.  I like your rule of thumb.