brisalta Posted August 25, 2020 #51 Share Posted August 25, 2020 12 hours ago, chengkp75 said: While this is true, it does not reflect a "dirty little secret" that LNG proponents tend to hide. There is a thing called "methane slippage", which is the amount of methane released in transport and transfer operations (like bunkering the ship), and unburned by the diesel engines. And, as we all know from the "cow fart" problem, methane is a major greenhouse gas, with a global warming potential 84 times higher than CO2 over 20 years. Emissions testing of engines is done at "optimal" load (fully loaded), while in real life most engines, particularly ship's engines, will operate at partial load, and variable load (think of maneuvering thrusters), which significantly affects the combustion efficiency, and hence the methane slip. Is LNG a potential move in the right direction? Perhaps. Is it the panacea that LNG proponents claim? Likely not. One of the big reason cruise ships, particularly in the US market, are switching to LNG is not environmental concerns, but cost. What about vessels that use turbines as opposed to reciprocating engines? Link to comment Share on other sites More sharing options...
chengkp75 Posted August 25, 2020 #52 Share Posted August 25, 2020 9 hours ago, brisalta said: What about vessels that use turbines as opposed to reciprocating engines? Gas turbine engines are way less fuel efficient than diesel engines, unless run at full load all the time, which doesn't happen with marine applications. Link to comment Share on other sites More sharing options...
Rare stevenr597 Posted August 25, 2020 Author #53 Share Posted August 25, 2020 7 hours ago, chengkp75 said: Gas turbine engines are way less fuel efficient than diesel engines, unless run at full load all the time, which doesn't happen with marine applications. I thought that the cruise ships use the diesels to power the Electrical Azipod engines. Coral and Island Princess do have gas turbines which take up less space. The major drawback to LNG is that they generate less BTU's than other types of fuel, so power generated is not as great and the ships much carry a larger volume to go the same distance. Link to comment Share on other sites More sharing options...
chengkp75 Posted August 25, 2020 #54 Share Posted August 25, 2020 11 minutes ago, stevenr597 said: I thought that the cruise ships use the diesels to power the Electrical Azipod engines. Coral and Island Princess do have gas turbines which take up less space. The major drawback to LNG is that they generate less BTU's than other types of fuel, so power generated is not as great and the ships much carry a larger volume to go the same distance. Yes, they do use diesels to power electrical propulsion, whether azipod or shafted propulsion motors. (engines are internal combustion, motors are electrical). Yes, Coral and Island have both diesel engines and gas turbines. The gas turbines were originally installed to provide less emissions in ports in Alaska, but it was found that running the gas turbine under low load in port was way too costly, so they are only used when underway at high load. These gas turbines run on diesel fuel, however. LNG has more BTU's per pound than diesel fuel, but less BTU's per gallon (volume), and since an engine only cares about the volume of fuel it gets, not how much that volume weighs, yes it requires more volume to produce the same energy as diesel fuel. 1 Link to comment Share on other sites More sharing options...
voljeep Posted August 26, 2020 #55 Share Posted August 26, 2020 22 hours ago, chengkp75 said: LNG will these new ships still have the same soot problems for the aft cabins as the Royal / Regal / etc. ? Link to comment Share on other sites More sharing options...
chengkp75 Posted August 26, 2020 #56 Share Posted August 26, 2020 19 minutes ago, voljeep said: will these new ships still have the same soot problems for the aft cabins as the Royal / Regal / etc. ? Probably much reduced. There will be less turbocharger cleaning, and if the boilers are LNG as well, then their soot contributions will be greatly reduced as well. 1 Link to comment Share on other sites More sharing options...
suzyed Posted August 27, 2020 #57 Share Posted August 27, 2020 On 8/18/2020 at 3:26 PM, Kamloops50 said: I expect most ships that are under construction will be finished and delivered. The cost of the ship builds is the responsibility of the shipyard . The cruise line only pays a 10% deposit before construction starts. The other 90% is due when the ship is turned over to the cruise line on its delivery date. LOL! That is the exact opposite of what another poster said! Link to comment Share on other sites More sharing options...
suzyed Posted August 27, 2020 #58 Share Posted August 27, 2020 (edited) On 8/24/2020 at 1:58 AM, caribill said: So far they may be delayed, but I doubt they will be cancelled. Once in the fleet they will be the most energy efficient ships they have and thus the lowest cost to Princess per passenger to operate. When these more efficient ships enter the fleet, older (less efficient) ships will leave the fleet. But if they are delayed, there will inevidably be cancellations of some sailings. Edited August 27, 2020 by suzyed Link to comment Share on other sites More sharing options...
caribill Posted August 27, 2020 #59 Share Posted August 27, 2020 2 hours ago, suzyed said: But if they are delayed, there will inevitably be cancellations of some sailings. Do any of the scheduled LNG ships even have bookings available yet? Link to comment Share on other sites More sharing options...
chengkp75 Posted August 27, 2020 #60 Share Posted August 27, 2020 7 hours ago, suzyed said: LOL! That is the exact opposite of what another poster said! Any ship that is currently under construction (steel has been cut) will be completed and delivered. Future ships may be canceled or delayed, unknown at this time. The statement about the financing (10% deposit, 90% upon delivery) is correct, I've been there when the check with all the zero's is turned over to the yard. There are, however, cancellation clauses, and the penalty depends on how far along the construction is. Link to comment Share on other sites More sharing options...
Kamloops50 Posted August 27, 2020 #61 Share Posted August 27, 2020 9 hours ago, chengkp75 said: Any ship that is currently under construction (steel has been cut) will be completed and delivered. Future ships may be canceled or delayed, unknown at this time. The statement about the financing (10% deposit, 90% upon delivery) is correct, I've been there when the check with all the zero's is turned over to the yard. There are, however, cancellation clauses, and the penalty depends on how far along the construction is. Thanks. I've seen Youtube videos where on delivery day they say that the balance of the contract price is transferred to the shipyard. When the Queen Mary was being planned. Cunard was looking for a company that had the financial ability to finance the ship. Link to comment Share on other sites More sharing options...
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