Rare A&L_Ont Posted November 14, 2012 #26 Share Posted November 14, 2012 Our tour guide told us they were the BRT's (Big Round Things) and were for decoration only. So we all began calling them the BRT's. The engineers on board would love to do away with those BRTs because they increase drag and weight - thus it's more expensive to move the ship with them. But that's an expensive task and won't happen. The turbine on the Island and Coral is one reason they are used in Alaska, they also have 2 heavy fuel generators which produces most of the electricity the ship normally runs on. If the two diesel generators can't produce enough power they'll turn on the turbine which is much much more expensive to run but also much cleaner. This is exactly the explanation that we were told too. When on the Island Princess the BRTs were also one more item that we watched the deck crew wash clean. Andrew Link to comment Share on other sites More sharing options...
jackieo Posted November 14, 2012 #27 Share Posted November 14, 2012 Hi All I thought they only used them when Captain Kirk was onboard. yours Shogun I was thinking they belonged to Jon Luc Pick Your Nose from the Next Generation. Engage, make it so Mr Data! Link to comment Share on other sites More sharing options...
VOR Posted November 14, 2012 #28 Share Posted November 14, 2012 I was watching sailaway on the Ft. Lauderdale webcam on Sunday and was watching the Coral Princess depart. I noticed way up high on the smoke stack on back of ship what looked like two huge jet engines. I thought, is that for real? I did some research and the wikipedia entry for the Coral says the propulsion is two fixed pitch propellers driven by two diesel engines and two General Electric LM 2500 engines. I looked up the GE engines and they are described as turbo jet engines used on several cruise ships for power generation. Wow! Can anybody who has sailed on the Coral tell us what that sounds like? On Saphire this spring, one of the officers called BUST's in a lecture. That stands for big useless shiny things Link to comment Share on other sites More sharing options...
kross9 Posted April 3, 2018 #29 Share Posted April 3, 2018 We just finished a cruise on the Coral Princess. Very quiet ship. I was also told that the jet engine looking cylinders were just decoration, but I am guessing they are actually air intakes. The gas-turbine is located near the ship's funnel on the deck 15. Really interesting set up. Supposed to provide less exhaust emission. The ship has the one gas-turbine up, and two diesel electric engines in the lower engine hold. I have seen the General Electric gas turbines (LM 2500) before. The ones I saw were in pods (or frames) and were to be mounted on a US Navy ship. The engines are very similar to jet engines (I think jet engines are basically gas turbines). We cruised to the Panama Canal, and hit stops in Aruba, Cartagena, Panama City, Costa Rica, and we missed the stop in Ocho Rios Jamaica. The wind gusts were 40 knots that day, and we were unable to make the port call. Otherwise the trip was great, and I really enjoyed the ship. Link to comment Share on other sites More sharing options...
pablo222 Posted April 3, 2018 #30 Share Posted April 3, 2018 . Very quiet ship. I was also told that the jet engine looking cylinders were just decoration, but I am guessing they are actually air intakes. The gas-turbine is located near the ship's funnel on the deck 15. Really interesting set up. Supposed to provide less exhaust emission. The ship has the one gas-turbine up, and two diesel electric engines in the lower engine hold. . I'm pretty sure they added a third diesel electric genset during a (major) dry dock. Supposedly if one diesel was down for maintenance, they had to run the turbine, which was rediculously expensive. Link to comment Share on other sites More sharing options...
chengkp75 Posted April 3, 2018 #31 Share Posted April 3, 2018 The gas turbines were installed to reduce emissions while in port, and while cruising certain ecosystems, like Alaska. However, they found that running the gas turbines for hotel load was extremely costly in fuel, and the Wartsila's were way over powered for hotel load, so they did add a third, smaller diesel generator. Link to comment Share on other sites More sharing options...
Rare stevenr597 Posted April 3, 2018 #32 Share Posted April 3, 2018 The Coral and Island Princess used a jet powered steam turbine for propulsion. I believe they are the only two ships that Princess has with this power source. These ships need less space for the engine room, and because of this, and some other innovations, especially on the Coral Princess, they have more space/passenger than most other ships in their class. The replicas on the smoke stack is to symbolize their propulsion system. Link to comment Share on other sites More sharing options...
chengkp75 Posted April 3, 2018 #33 Share Posted April 3, 2018 The Coral and Island Princess used a jet powered steam turbine for propulsion. I believe they are the only two ships that Princess has with this power source. These ships need less space for the engine room, and because of this, and some other innovations, especially on the Coral Princess, they have more space/passenger than most other ships in their class. The replicas on the smoke stack is to symbolize their propulsion system. It is not a jet powered steam turbine, it is a gas turbine (jet engine) powering a generator. There is no steam involved. And since the turbine is in the funnel, it cannot provide propulsion directly, it merely provides electricity to power the electric propulsion motors, as do the diesel generators. Link to comment Share on other sites More sharing options...
Rare gdlamberth Posted April 3, 2018 #34 Share Posted April 3, 2018 We just finished a cruise on the Coral Princess. Very quiet ship. I was also told that the jet engine looking cylinders were just decoration, but I am guessing they are actually air intakes. The gas-turbine is located near the ship's funnel on the deck 15. Really interesting set up. Supposed to provide less exhaust emission. The ship has the one gas-turbine up, and two diesel electric engines in the lower engine hold. I have seen the General Electric gas turbines (LM 2500) before. The ones I saw were in pods (or frames) and were to be mounted on a US Navy ship. The engines are very similar to jet engines (I think jet engines are basically gas turbines). We cruised to the Panama Canal, and hit stops in Aruba, Cartagena, Panama City, Costa Rica, and we missed the stop in Ocho Rios Jamaica. The wind gusts were 40 knots that day, and we were unable to make the port call. Otherwise the trip was great, and I really enjoyed the ship. Can you tell us a bit more about your trip? LA to FLL? What were the MUTS, What cabin were you in? How'd you like it? We're doing the same trip FLL-LA in three weeks. Link to comment Share on other sites More sharing options...
mo&fran Posted April 3, 2018 #35 Share Posted April 3, 2018 It is not a jet powered steam turbine, it is a gas turbine (jet engine) powering a generator. There is no steam involved. And since the turbine is in the funnel, it cannot provide propulsion directly, it merely provides electricity to power the electric propulsion motors, as do the diesel generators. The exhaust from the gas turbine engine is still quite warm, so it could be used to heat water, possibly steam, to use for something, including powering generators. Link to comment Share on other sites More sharing options...
rkacruiser Posted April 3, 2018 #36 Share Posted April 3, 2018 These two "engine-like" objects must not have much, if any, use. When alterations were made to sister Island Princess, they were removed. Link to comment Share on other sites More sharing options...
Rare Hlitner Posted April 3, 2018 #37 Share Posted April 3, 2018 I thought they used those things to take care of the chair hogs. When they caught a chair hog, they were sentenced by the Staff Captain and then loaded into one of the two tubes (that look like jet engines). They are then blasted out one end (kind of like the circus act where they fired a person out of a canon) and no more chair hog :). Rumor has it they are also used for those who violate the smoking policy...but they are only launched on a darn night. Hank Link to comment Share on other sites More sharing options...
chengkp75 Posted April 3, 2018 #38 Share Posted April 3, 2018 The exhaust from the gas turbine engine is still quite warm, so it could be used to heat water, possibly steam, to use for something, including powering generators. Yes, I'm not sure if they use a waste heat boiler on the exhaust from the gas turbine. Most cruise ships don't bother to reclaim this energy from the diesel exhaust the way that most cargo ships do, so I'd be surprised if they do it for the gas turbine. The ships all have oil fired boilers used to heat water, provide heat for the accommodations, and to heat the fuel used in the diesel engines, which needs to be heated to about 250*F before it can be injected in the engine. Some cargo ships will use waste heat from their engine exhaust to generate steam to drive a steam turbine, but I've yet to see one on a cruise ship. Link to comment Share on other sites More sharing options...
mo&fran Posted April 3, 2018 #39 Share Posted April 3, 2018 Yes, I'm not sure if they use a waste heat boiler on the exhaust from the gas turbine. Most cruise ships don't bother to reclaim this energy from the diesel exhaust the way that most cargo ships do, so I'd be surprised if they do it for the gas turbine. The ships all have oil fired boilers used to heat water, provide heat for the accommodations, and to heat the fuel used in the diesel engines, which needs to be heated to about 250*F before it can be injected in the engine. Some cargo ships will use waste heat from their engine exhaust to generate steam to drive a steam turbine, but I've yet to see one on a cruise ship. I thought that i read that the GE LM2500 engines used in the RCI Radiance class and Celebrity Millennium class were combined cycle engines, which means they capture on use the waste heat. Link to comment Share on other sites More sharing options...
Rare Hlitner Posted April 3, 2018 #40 Share Posted April 3, 2018 Funny thing about steam. We still remember cruising on the old SS Fairwind (Sitmar) which was powered by 4 Steam Turbines. We recall it being a relatively quiet ship (with little vibration)....but this was many years ago. But that ship did operate for about 47 years. We also recall touring one ship's galley where all the stoves were heated by superheated steam. Perhaps this is going back to the future. Hank Link to comment Share on other sites More sharing options...
chengkp75 Posted April 4, 2018 #41 Share Posted April 4, 2018 I thought that i read that the GE LM2500 engines used in the RCI Radiance class and Celebrity Millennium class were combined cycle engines, which means they capture on use the waste heat. I think you are mistaking a "combined cycle" plant which captures waste heat from the gas turbine to produce steam for a steam turbine, with a CODAG plant (Combined Diesel And Gas turbine). Even the manufacturer of the overall plant, Wartsila, calls these CODAG plants. Some CODAG plants couple the gas turbine directly to the propulsion plants, some to a generator. Link to comment Share on other sites More sharing options...
chengkp75 Posted April 4, 2018 #42 Share Posted April 4, 2018 Funny thing about steam. We still remember cruising on the old SS Fairwind (Sitmar) which was powered by 4 Steam Turbines. We recall it being a relatively quiet ship (with little vibration)....but this was many years ago. But that ship did operate for about 47 years. We also recall touring one ship's galley where all the stoves were heated by superheated steam. Perhaps this is going back to the future. Hank Many ships will have their "tilting pans" (large pressure cookers) and soup kettles still heated by steam, and the steam tables in the buffet and the galley plating lines are steam heated as well. Link to comment Share on other sites More sharing options...
chengkp75 Posted April 4, 2018 #43 Share Posted April 4, 2018 Due to the high cost of jet fuel for the turbine engines, they are used only when the ship must make high speed to reach ports early in an emergency.Fuel consumption for each turbine is US$60,000 for 24 hours operation. For maintenance purposes, the turbines are "fired up" a few times a month, for a few minutes. Engine noise is minimal in the ship's public areas. While you are correct that the gas turbines eat a lot of expensive fuel, I'm not sure they use jet fuel (I don't know for sure what Princess does), as most marine gas turbines run on diesel fuel, since it is compatible with the diesels as well. Using diesel fuel in the gas turbine drops the relative costs considerably. And to put things in perspective, the Wartsila 12V46 diesel engines burn $27,000 per 24 hours at full load. The diesel is rated at 25,000 hp, while the gas turbine is 33,000 hp. The cost today of HFO used in the diesel engine is $351/mt, marine gas oil (diesel fuel) is $598/mt, and Jet A-1 is $1320/mt (all per metric ton). The diesel uses 170 grams/hp-hr of fuel, and the gas turbine uses 169 grams/hp-hr. So, using these figures, the diesel engine costs $0.06/hp-hr on heavy fuel, $0.10/hp-hr on diesel fuel, and the gas turbine costs $0.10 on diesel fuel or $0.22 on jet fuel. These fuel consumption figures are based on ISO conditions and are at rated power, and the efficiency of the gas turbine falls of dramatically at lower loads compared to the diesel, so trying to run one of these gas turbines in port (33% load) would only reduce the fuel consumption by 40-50%. Link to comment Share on other sites More sharing options...
Kenswing Posted April 4, 2018 #44 Share Posted April 4, 2018 I bet it's a sight when they hit the afterburners.. lol Link to comment Share on other sites More sharing options...
chengkp75 Posted April 4, 2018 #45 Share Posted April 4, 2018 I bet it's a sight when they hit the afterburners.. lol Not so much. The full power of the gas turbine (about 2/3rds of the combined diesels) only takes you from about 18-19 knots to 22 knots. Link to comment Share on other sites More sharing options...
Lucky TGO Posted April 4, 2018 #46 Share Posted April 4, 2018 They were designed to indicate that the ship has a gas turbine engine. Hi Pam, Your probably right but I like the water skiing answer better...:):):) Tony Link to comment Share on other sites More sharing options...
ctompkins Posted April 4, 2018 #47 Share Posted April 4, 2018 They only fire them up for water skiing demos. Hahaha, I have not noticed them, but will now! The signup sheet for water skiing will be our first stop once on board Apr. 20! Link to comment Share on other sites More sharing options...
Recommended Posts
Please sign in to comment
You will be able to leave a comment after signing in
Sign In Now