Why Use Turbine Engines in Ships?
ฝัง
- เผยแพร่เมื่อ 10 ม.ค. 2021
- Thanks to a question from Ever443, we are looking into why a ship might be designed to use a gas turbine engine.
The two Wiki pages I recommend in this video are
Gas Turbine
and
Marine Propulsion - ยานยนต์และพาหนะ
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Retired Navy Guy here, stationed on two lm2500 ships, a cruiser and destroyer. I am an Engineman and dealt directly with the propulsion plant. The controllable pitch propellers allow the engines power output to be matched to an efficient fuel consumption. Ball park figures for LM2500 propulsion plant is about 30-35 gallons per minute cruising at 13 knots including having 2 allison gas turbine generators producing around 4-5 megawatts of power. Going to flank 3 speed from a dead stop would take about 90 seconds when all 4 lm2500's were online. That's moving 9600 tons of steel over 32+ knots through the water. At those speeds, we would exceed 500 gallons per minute of fuel consumption. To have similar performance with a diesel powered engine, the weight penalty and the shear volume of space would not make for a good combat ship. Also a lm2500 could be changed out in about 36 hours when one goes bad. To get several large diesels up to operating temperature IAW navy policies takes several hours where as the gas turbine ships could go from cold to hot within minutes, usually less than 3. Also the fuel quality did not need to be as good as with modern diesels. A small amount of water in the fuel for a diesel blows off the injector tips where as the gas turbines don't care. An important point when your fuel tanks are also your ballast tanks. Yes folks, as you burn fuel you replace it with sea water so your ship get heavier as you burn fuel. So those are some of the design considerations that went into turbine powered combat ships. Great ships, great job. Thanks!
Thanks for pointing out the power density advantage. I'm claiming that's something that combat ship design engineers consider.
If memory serves acoustics of diesels versus gas turbine engines also plays a factor when it comes to ship’s mission & selecting propulsion systems for it. Acoustics with regard to sonar and adversaries hunting us.
That’s cool. I didn’t know they replaced the fuel with water as it was burned. Is there a bladder system or is water just separated from fuel before it’s burned?
This informative comment is too good for the TH-cam comments section. Thanks for leaving it
US Marine engineer here. The vast majority of merchant ships at sea today are powered by slow speed diesels (under ~120RPM). These engines are direct coupled to the propeller to completely omit the complexity and cost of reduction gearing. My personal experience is on US flagged container vessels ranging in power from 35,000- 85,000 horsepower.
The one 85,000hp, 11 cylinder, 800mm bore plant I worked on had three turbochargers. The center turbocharger was equipped with shutoff butterfly valves to block it off, therefore increasing exhaust flow through the other two for higher scavenge air pressure and much improved fuel efficiency at lower sailing speeds (15-20 knots or so). If engine rpm and load started approaching the turbocharger's 10,000 rpm limit, the third turbo would be brought back online. Usually above 88-90 shaft rpm or 22 knots or so. The ship was a little over 300m in length
Merchant ships have less of a concern for power density, and a higher priority of fuel consumption and cost. We're typically burning residual fuel oil thats considerably cheaper than diesel. Factor in the added construction cost of power turbines and reduction gearing and thats why you just don't see this propulsion style outside of navy vessels. They can just flip the bill to the tax payer
Great info from an insider. Thanks!
With regards to how fast it can come up from warm iron, leaving port after say a 16 hour stay, typically about 15 minutes to blow down and prelube the engine properly. from your first slow ahead bell (about 25 rpm) to full ahead (about 65 rpm or so) might take one minute to settle out, but sea speed 65rpm to max rpm goes on an electronically controlled load up program that varies in time. id say about 30 minutes or so typically, which is fine for a merchant vessel. but dead stop to max power very quickly, a gas turbine would be a much better option
PontiacPOWA, wow! 31.5 “ bore, 120 rpm, 85,000 hp. Curious what the stroke is. I’d like to see this beast.
@@Mrsournotes Not my video, but a good walk around. Same engine as what i was talking about just with more cylinders and an extra turbocharger
th-cam.com/video/rm9SjAJ_ki8/w-d-xo.html
the residual fuel burning does not leave any soot on the turbines? how often do they need desooting?
I was on a turbine powered cruise ship back in 2008, GTS Radiance of the Seas. Since turbines work best at full power, the captain kept the throttles up even though the seas were rough. We were doing 23kts up the Inside Passage in Alaska and the sea was so rough that there were 6ft waves in the swimming pool. Those of us hanging out in the hot tub thought it was hilarious, but the rest of the pax were not amused.
en.wikipedia.org/wiki/Radiance-class_cruise_ship
Wow......12 years.....12 years of great videos! Thank you!
Why gas turbines in the US Navy? Because all the support fleet ships in a carrier group have to keep up with the carriers.
JayZ, if you want, I'm a retired PO2 EOOW from the RCN- I've got some of the experience needed. LM2500 on a CPF is 25 000 SHP (x2), and the cruse engine is the Pielstick Diesel Engine at 6000 SHP to propel the ship. That's close to the same as the US Perry class ships, or Type 23 (UK). It's called CODOG- Combination of Diesel _or_ Gas Turbine. CPF will go about 16 kts on the 6000 SHP, and about 30 kts on the 50 000 SHP of unitized.
If you want pure gas turbine, the closest RCN ships were the Sisters of the Space Age, or Tribals, which had COGOG with a FT4 A4 as the boost engine, and FT 12 (original)/ 570KF (post TRUMP) as the cruise engine on each shaft, no cross connection. So, at under 12 kts, you had some interesting things with regards to fuel consumption. My AMOC (4th class Marine) ticket is ex HMCS Algonquin/Huron. Generators were Solar Saturn 750 KW x3, and a 1 MW Detroit V16 Turbo'd engine. There were also 2 of the Rover (ack !) 86 hp prewet pumps.
Usual plant operation would be 2x 570's, Detroit, & one SSGT. That would be up to about 17 kts (depending on if on Huron or 'Gonk).
FT4 was set to full power by a screwdriver dependent on the air density.
Why use GT? Because to operate a 30 000 shp steam plant took 8 of us, to run the GT plant would be 6. (both can be done with less...). The Y-100 steam plant used on the Cadilac's had 12 or 13 on watch at any time, and needed something like 8.
The Y-100 plant would be 1000 tons of the ship weight (roughly 2500 ton ships). The GT plant would be perhaps 1/2 that weight. The total plant weight including fuel on a 280 would be more than 1500 tons, but a substantial portion of that would be fuel (nearly 1000 tons of fuel, from memory...) 280's were quite a bit heavier than the Cadilac's, near enough double. (5" gun vs 2x3", 2 helo's vs 1...)
listening to the flight idle -> full power, power mode change over was less than 5 minutes. It was supposed to be done via change of notice for power, rather than via order speed, if ordered to "maximum" speed by telegraph, EOOW confirms what the OOW wants...the turbine when just spinning the shaft is generally closer to flight idle than ground idle. I don't remember any particular restrictions on going from idle-full power, just the mode switchover time.
On PRO with the 21 000 HP steam turbine plant, I had 5 minutes to go from immediate NFP to full power. We could get from 40-90 (which would be 10%>80% power) in well under a minute. The boiler op would have to be on the ball, but it certainly was possible.
Fuel- we're burning the same fuel in gas turbines as in diesels (and post 1985, in boilers too...), in the form of F-76/Marine Gas Oil. That's all that the USN/RCN/RN burn... It isn't until you get to low speed diesel engines that burning crap fuel is OK, because once you are in crosshead diesel's (generally something like 10 000 HP or more) then the lubrication systems are seperate, so you don't contaminate your crankcase oil with cylinder goo. TBN (Total Base Number) is in reference to that in crankcase oils.
From a historic point,
There is a write up in the pre 1952 Model Engineer about the MGB that was the first marine use of a gas turbine. I have a copy of it downstairs somewhere...
Peach
Need to correct you. The FFG-7 or OHP class frigates couldnt be CODOG. The 2 LM2500s were for propulsion and the 4 diesels for power generation only.
The biggest advantage to turbine propulsion on naval vessels is that you can carry entire spare engines on-board ready to be installed.
In huge cargo ships they use now 2 stroke diesel engines that direct drive the propeller to avoid gearbox losses
Since 1899
You should know that they have what's called a reversible pitch propeller not to be confused with the Variable pitch propeller. The reversible works the same as a Variable pitch propeller does but the main difference is a reversible pitch propeller can fully reverse the pitch of the blades without changing the direction or the RPMs of the propeller shaft itself this eliminates the usage of a gear reduction box as well. Most big ships for the most part are of direct drive using a fixed pitch propeller because they're simply too big to maneuver by themselves in ports and harbours which requires the assistance of tugs. Also out in the ocean there's no need for them to reverse at will and also it takes them many miles to come to a complete stop. A lot of the time the ship will coast to an anchorage point that's not far from the harbour and will wait for tugs to arrive to help guide it into the harbour and it's berth. Hope this helps some?
LNG
@@keithsimon8980 the diesel engine was invented in 1899, no way it was already in ships lmao
@@VoltageLP LNG or Heavy Fuel Oil
Power to weight and way less maintenance (Beleive it or not). I worked with Gas Turbine for over 20 years in the NAVY. And a considerable chunk of those 20 years were on ships that also had diesel engines (used for electrical power). Gas turbines are more responsive, have a significant power to weight ratio are MUCH MORE reliable, they will burn just about anything (adjustments required to fuel controls) and are so much less maintenance intensive. I've seen both sides and the differences are considerable.
Yes. The lower maintenance required by the gas turbines compared to reciprocating diesels is so extreme that it dramatically effects the engineering manpower required onboard. For civilian ships, that's a big cost savings. For military ships, it's fewer lives at risk. Also, gas turbines burn much more cleanly (much lower emissions of particulates and oxides of sulfur and nitrogen). Where LNG (mainly methane, a much worse greenhouse gas than CO2) is used as the fuel, about 2-3% escapes unburnt through a reciprocating engine while gas turbines consume the fuel much more completely. So gas turbines are a much better choice for the environment.
Edited to add: I would love to see a marine gas turbine derived from the GE T901 now in development.
That's one aspect I've always wondered about. I know most foreign ports don't have JP5 available for bunkering, so can you adjust a turbine to run on MDO or ideally HFO?
@@akimbojimbo3763 a gas turbine will burn pretty much anything. Some adjustments to the fuel controls to compensate for the different specific gravities of the fuels is all that would be needed.
@@jrwhite7916 interesting, I'll have to do some more reading. Thanks for the reply! I suppose I thought they could only run on distillates or LNG since that's what you see manufacturers advertise them for
A nice, purely turbine driven ship was the Destriero, built in Italy to set a transatlantic record. Three LM1600 powering three pump-jets. It crossed the Atlantic in 58 and 1/2 hours.
Right so here is an actual marine engineer's perspective.
Gas turbines are not cost effective for comercial shipping. There are some cruise ships that use them for power generation but these ships call in alaska and were required at one point (not sure if they still are) to shut down thier diesel generator engines while along side because of emissions legislation.
A gas turbines has to have specalists come on board or highly specialised crews through extra training (which the vast majority companies aren't willing to pay for)to under take inspections or repairs to gas turbine engines. They are more difficult also to repair at sea in an emergency due to the incredibly fine tolerances involved.
Gas turbines require complex gearboxes to bring down thier shaft speed to a usable rpm for power generation. Most power generation at sea is done by medium speed diesel engines running direct drive to an alternator at 720 rpm (no need for extra drive line machinery). Most marine propusion is done by slow speed 2 stroke marine diesel engines these run from speeds of 10 too 120 rpm. These engines direct drive the propellor and are reversible. Negating the need for more drive line components and expensive variable pitch propellers. An added benefit to this is there is less power lost in the driveline increasing engine efficency.
Moving on in regards to efficiency a gas turbine currently sits somewhere between 24% and 32% Efficency and burns highly refined high grade fuel, there is a benefit to this in that it dose control and decrease emissions slightly but not significantly. A medium speed or slow speed 2 stroke marine engine can run on heavy fuel oil, the lowest grade of refinery fuel, and only just above tarmac. It had to be heated to 300 degrees C for use. Marine slow speed engines are now pushing over 70% efficency ounce all thier waste heat recovery systems are taken into account and 4 strokes are still only around 30% but are having the same waste heat recovery systems slowly introduced but the costs saved in fuel more than outweighs thier use instead of gas turbines.
There is also the problem of fuel storage for gas turbines at sea we are limited by law to fuels that have a flash point of above 60 degrees c which is to combat the fire risk. Standard jet fuel is banned by law at sea as it dosent meat these requirements. Meaning turbines have to run on less clean, less refined fuel than they would in an aviation setting meaning they require more maintenance and cleaning that a comparative aviation turbine. This can be gotten around in the case of armed forces or for ships that are only using extremely limited quantities but this is an extremely limited quantity and can only sustain the ships electrical power needs excluding propulsion for a few hours.
Marine heavy fuel oil is priced currently at $408 per metric ton, compared to $455 for aviation fuel. Considering that a ship on an average voyage will consume 10000 metric tons of fuel it adds up to a significant saving over time.
Space is not to much of a concern at sea and weight isn't either when you are building ships the size of 4 football (soccer for the yanks) pitches and weigh in at +90000 tons empty.
nice explanation!
Interesting! Curious how long/far is that average ship voyage burning 10000 metric tons of fuel?
@@LeverPhile usually something like the europe China run. Works out at around 150 to 180 tons pre day, some of the older ships are as high as 300 ton per day but usually have bad weather to add to that.
@@robthurlow1347 Aren't modern high pressure ratio gas turbines available for marine use? Or are the maintenance and fuel requirements issues you mention enough to make them unattractive?
32% thermal efficiency is very low for a modern GT. I'm not very familiar with marine applications but I know that the GG cores in modern airliners with pressure ratios > 40 can reach into the 50's %, which is about on parity with large diesels, and their waste heat can also be recuperated.
@@ASJC27 I have to admit I'm not entirely sure id have to look into that. But the maintenance and fuel issues alone are the reason they are only used in very limited applications. Another problem that I forgot to add is that ships of course because they are at sea transmit a lot of vibration through the hulls and bending moments all of which could easily destroy a turbine within seconds. They can be isolated from it of course but it is a costly exercise.
The US Navy switched to GT propulsion for two reasons, primarily. 1st is it is turnkey ready. In less than an hour the mains are at full power readiness from "cold Iron", where as a boiler system takes 24 hrs from cold iron. Power density is always a big plus, along with constant speed screws, and instant reversability allowing for "crash back" demands where the ship can stop in 1.5 lengths of the ship from full speed. Comes in handy.
The fact that a turbine can be repaired on board with spares in supply, much lower heat stress on crew and ship, and a higher safety factor than a 1200# steam system was no doubt an added sales pitch. You can fly a fresh engine to the ship, but not a boiler. They weighed a lot of pro's and cons no doubt.
The power density is indeed the very big plus. One or two gas turbines + reduction gearboxes, et voila, 100,000hp (or whatever) on tap any time you like.
Tolerance to bad fuel quality is another plus point for a gas turbine; diesels can get a bit picky about certain contaminents that GT's don't care about.
I don't know about USN vessels, but RN vessels can replace their engines at sea, craned over from an auxillary.
Super heated steam was really nasty stuff; killed many a sailor. But for all that, steam did work very well. This Wiki page on the RN Leander class (en.wikipedia.org/wiki/Leander-class_frigate) has the speed stated substantially lower than what I know they could do, if the govenors were disabled (as was often done in the Falkands war). Those ships had a lot of speed in reserve.
I once went on the old HMS Ark Royal IV, (1970s), on a Saturday. They were burning oil at full rate, still alongside. They expected to be able to move the ship on the Wednesday...
AgentJayZ, you really are *EXCELLENT* at explaining things that are 'kinda technical' in a very accessible and straightforward manner. This skill is quite rare now. We need more of your kind. It's a pleasure to listen to you.
The type 23 frigate (UK) has a complete array of engines. It's a CODLAG (combined Diesel-Electric and Gas Turbine) arrangement which means the props are driven (through gear boxes) by electric motors. The electricity is generated by a suite of 4 diesel electric generators (900kW each). I believe (but not sure at all) that the turbine has a reduction gear that then drives into the same gearboxes (one for each shaft). There is some clever jiggery pokery in there somewhere as the port and starboard props can be driven at independent RPM settings even on gas turbine (to turn faster when chasing a submarine). I cant remember how fast the turbine is to go from cold and stopped to full power but I can remember being very surprised at how fast when someone told me. The Type 26 (UK) uses a a similar arrangement but instead of a marine Spey (same basic design as used in the RAF Phantom and a few others like the Buck). The Type 26 according to wiki uses the MT30 which also has a Wiki page and states minimum efficient power is 25MW or a bit over 33k BHP (the marine Spey is a tad under 20MW according to Wiki). I would say that needs verifying as the Spey in the Phantom was not double the power of the J79 (which was 10MW). IE the dry thrust of the Spey MK202 was 54kN compared to the J79-GE-17 at about 53kN. Specifically something does not add up here or there is something major missing from my knowledge.
You're more or less right, except type 23s use two gas turbines, one on each shaft. I've just put up a two part presentation that goes into a lot of detail on them. th-cam.com/video/_XQ2bY2hTuA/w-d-xo.html
retired Canadian Navy sailor here, the Canadian patrol frigates use a diesel cruies engine 6000 kw for speeds up to 15 knots and two LM 2500 gas turbines for faster speeds and when quick response is required .
Thx for informative video as usual AgentJayZ I served during Vietnam war on USN Patrol Gunboat which was powered by a Cruise On Diesel or Gas Turbine (CODOG) propulsion. As I was engineman and fuel and water king I had to keep track of fuel usuage and report to the skipper so learned quickly what volume of fuel was consumped at what speed by each. The gas turbine was an LM1500 delivering 13,000 shp to two 6'dia. titanium variable pitch propellers at a maximum of 720 shaft rpm for high speed 40kts+ @ 1000gph of jp5 with this power and drive sys 165' 200t aluminum and fiberglass boat could get to 40kts in 2 lengths and full stop in a length & 1/2 but the cook would be pissed as all his pots and pans would be flying. With 15,000 gal of fuel on board max endurance was about 600miles by comparison the 2 v12 Cummins diesel 875hp engines burned about 1400 gpd with a max cruise speed of 17knots we could transit a maximum of 4k kn miles. The gas turbine was very low maintenance but the diesels were all ways needing preventative maintenance or repairs but We were spinning them at 2100 rpm & 1200 deg f egt when transiting @17 knots so 3k hours was about all they'd due before filling the engine room with shrapnel. I remember seeing a British Destroyer in Hong Kong that had 3 different power plants not sure of type that was early '73 IIRC. Great discussion AgentJayZ thx again for your videos and sharing your vast knowledge.
Absolutely awesome to hear from you!
You are the actual man who knows the most about what we talk about in this video.
...and because the LM1500 is one of our most common engines we work on.
Thank you for the details that are so hard to find.
Another thing worth noting is that boat/ship power requirements increase massively once the ship wants to go beyond "hull speed" - which is based upon its length. That's because it starts having to surf up the bow wave its creating, and ships are heavy so that takes a lot of energy. So typically in the Royal Navy anyway, they'll have a diesel for standard cruising and turbines for short burst of speed. The USN seems to go for all turbine and like you say, just turn them some of them off when they don't need all the power.
I was a gas turbine tech in navy,, instant start, we had 4 @ 20,000 bhp
Hooked to a reduction drive. It was a lambo in the water. Most of the time we only ran one. It was ecconomical
Someone with real experience and knowledge. So much more interesting than all the pie in the sky speculation from guys who claim to know stuff.
Thank you!
Once again another excellent video by AJZ. Prior to gas turbines the Navy had oil fired boilers for steam and it took a minimum of 4 hours to get up steam to get underway. Now they can get underway in 15 minutes. They can also change out a turbine in 24 hours. They all run through a reduction gear
I worked at a company making frigates that had two diesel engines and one gas turbine.
Hi Jay, thanks for all you do. Just for some perspective, a friend of mine who used to be a nuclear tech on one of the big US nuclear carriers shared this; Size wise, the Orenda behind you as compared to the reactors that run carriers are about the same size by length and about half as wide. And they can generate over 2 million peak military horse power. Chew on those numbers for a while. With that kind of energy density, no wonder that they wanted to make reactors go airborne! That would be like a F-1 Apollo rocket engine pushing it through the water!
I'm amazed. I know nothing about mobile nuclear reactors, but I imagined them to be very large. My guess would have been the volume of 27 school buses stacked 3X3X3.
@@AgentJayZ He's definitely leaving out all the associated machinery and piping, the reactor vessel is small but very heavy and comes with a host of associated systems to keep it cooled. Still, it has insane power and energy density, especially when you consider the lack of fuel storage it more than makes up for the total system size/weight on a large platform.
Yes, the core is small but the pressure vessel it is in has steel walls about 8 inches thick, not to mention the radiation shielding. It was the weight of the shielding that doomed airborne reactors. Plus maybe some concerns for what would happen in a crash... But, a large ship (or sub) with unlimited range without having to refuel for 20 years totally makes up for the weight and cost.
Amazing video, really makes you think.
"My" 1.2 MW Diesel (Emergency Power Supply) takes about 5 minutes to come to power. You can feel the vibrations in the whole building.
Let’s talk Diesel engines first. I’m now retired diesel mechanic/ Class A truck driver with a bachelors of Science degree in Auto-Diesel technology from a accredited 4 year engineering college in the USA. One thing I don’t know everything but I know a lot. First the EMD locomotive Diesel engine depending on the cubic inch displacement and number of cylinders ranges from 1K hp to 5K hp and has a rpm range from 250 to about 900 rpm. These engines can come on line fairly fast, most Diesel engines can if you have auxiliary systems that keep the cooling and oil systems warm let’s say at 120 degrees Fahrenheit and have a pre-lube oil system you can be rolling in 1 minute or less it just all depends on the setup. Second is Caterpillar big displacement engines they are 4 stroke engines in the 2,500 to about 5,000 HP range and run a little higher rpm generally about 1,200 rpm max load. And same as the EMD if you have auxiliary systems to keep everything warm they are ready to go. Now let’s talk about MTU Diesel engines . MTU makes a line of V engine configuration that can run up to 2,000 rpm in different HP ranges just depending on the number of cylinders they have. MTU years ago used Detroit Diesel engine electronic fuel injection system hardware that was used on the Detroit Diesel 60 series engines. What they are using today I don’t know. Cat and Cummins are using electronic fuel Managment systems totally ; the one thing I’m not sure of is EMD I do not know if they are using electronic fuel management systems or the old mechanical direct injector system with mechanical governors I don’t know. Once you get over the 10, 000 HP mark you get into the real big Diesel engines and there are so many types out there and most of them are 2 stroke engines. The start up procedures can be lengthy from 30 minutes to 2 hours depending on the situation. These big marine engines run on 2 types of fuel generally. First is ordinarily diesel fuel then the other is in the old days called bunker C oil. There is today I think a replacement for bunker C oil that’s almost liquid Tar like and must be kept heated all the time or it solidifies into a solid. The big ships burn diesel fuel in port to cut down on exhaust emissions while in ports and rivers then switch to the heavier bunker oils out in the oceans. Also a lot of the newer big ships are being fitted with exhaust emissions equipment like on your car but a lot bigger in scale so what’s really going on in the marine propulsion business it can be a lot of options out there.
I served on a Hamilton Class USCG Cutter which had turbines. In a moderate sea state under full turbine power you could surf off the wake. Impressive.
They can also take the hot exhaust from the gas turbine to make steam and run it through a steam turbine. It then takes the left over heat to make hot water. Fascinating system.
"Why Use Turbine Engines in Ships" - because why not?
badum, tssssss
Rode in a Boeing 939 hydrofoil once. Two 5000 hp Rolls Royse Allison 501KF engines. 100 mph in open ocean. Smooth as glass.
Just a fantastic explanation and very enjoyable. Thanks so much!
If you need a lot of HP and have the room burn diesel. If you need a lot of HP and don't have the room burn JP-4 . If you need A LOT of HP and have the space burn Uranium.
hunting down parts for some of these engines must be an absolute mission
It gets harder every year.
Great video, served as an Officer on the USS Abraham Lincoln. There are no backup engines or propulsion on a Nimitz Class Carrier. There are 2 reactors for combined and redundant power and propulsion. There are emergency diesel generators for electrical power.
Thanks. I knew I should really try to avoid discussing the biggest ships, and their nuclear engines, which never really get shut off.
@@AgentJayZ In the 3yrs I was on board, they did a dual reactor scram once. Basically, the ship went dark except for emergency flood lighting. The diesel generators kicked in a few minutes after simulating a dual reactor casualty (I think in combat conditions, they would kick in instantaneously). Both reactors were off-line for about 15 mins until they go critical again. It's one of the most dangerous evolutions for a Navy since the Carrier is completely vulnerable.
love your content! big support from australia jay
Spruance class Destroyers, Ticonderoga class Cruisers, Arleigh Burke class Destroyers all have 4-LM2500’s for Propulsion and 3-Allison (now Rolls Royce) Generators in the 2-4.5 Megawatt range. The US Navy’s design philosophy dictated the propulsion system’s arrangement (redundant Engine Rooms separated by other watertight compartments). Generators Allison/Rolls Royce GT Engines based on the T-56 Aircraft Engines that first flew in the late 50’s. Latest versions are much improved at 4.5 MW. Primary design reason for using Gas Turbines vice Diesel is that Diesel Engines are easily detectable by Submarine Sonar and ASW is a primary mission Area. The Noise signature of the Gas Turbines is high Frequency in Nature, which does not transmit well through water. These ships (all of them) usually run only one LM2500 for propulsion up to about 18 knots with two of the much smaller GT Generators running for Electricity. The smaller Perry Class Frigates had two LM2500 propulsion engines and four 16V149 Detroit Diesel Generators. The Generators were economical to operate but required a lot of Maintenance. Still in service with some Foreign Navies. GT’s are very efficient at rated Power but are not very efficient at low loads. Newer design GT’s are more efficient. The WR-21 Gas Turbine was used on the British Daring class Destroyers and has had reliability issues with the “Recuperator” that has resulted in a Major redesign to add more diesel Generator capacity. The Recuperator does increase thermal efficiency.
Jay thank you for sharing your knowledge these videos are awesome
Another excellent episode. Thanks!
The fuel consumption of a Bristol Proteus? Wikipedia (I have donated) gives a figure of 273 Imperial (bigger than US) gallons per hour, which equals 4.55 gallons per minute. I have a clear memory of standing in the control room of a Proteus test bed, as an apprentice, watching the Avery Hardoll meter (the same as those used at UK petrol stations), with the one gallon per revolution hand going round at almost exactly four times per minute.
I went on to become (as you know, AgentJayZ) a member of the Marine Olympus and Marine Tyne design team at R-R Industrial and Marine. For those who might wonder why a RN Type 42 destroyer could cruise at 18 knots, using two Marine Tynes , producing about 10,000shp, but needed two Marine Olympus, producing about 50,000shp, to achieve 30 knots, the answer is that a cube law, not a square law, applies to a ship's hull resistance.
In the last days of my employment with R-R, I worked for a short time on the MT30 engine, two of which (plus diesel engines for cruise) power HMS Queen Elizabeth and HMS Prince of Wales. I am also quietly proud of the fact that the US Navy's Zumwalt-class destroyers have two MT30s.
PS GE claims 33,600shp for the LM2500.
Not to be picky, but I believe the hulls resistance follows the square law. The cube is the result of multiplying resistance (force) by velocity. (P=FV) Just saying...
Thanks for the info, glad to see you are surviving with us, greetings from Springfield Illinois, Land of Abe Lincoln. Stay safe and well!
Same cube law for cars, going 200 km/h you don't need much more than 100 hp but going 400 km/h requires 1000 hp.
@@fascistpedant758 Yes, you are being picky.
I was trying to apply the KISS principle for the benefit of the majority of AgentJayZ's readers. Perhaps I should have referred to the total force, which is resisting the movement of a ship's hull through the water. Nevertheless, the example that I gave surely makes the point?
I honestly thought that I was a pedant (first class), objecting, as I frequently do, to the use of the term 'centrifugal force' on this channel and elsewhere. But then I have to defer to AgentJayZ objecting to the term 'suction', despite having referred to the "suction (and pressure) surfaces" of compressor and turbine blades, throughout a career of over 40 years in gas turbine design.
@@grahamj9101 I apologize if I offended you. My goal was not to correct or criticize you, but to clarify your statement, to avoid confusion among other viewers. Though I do think the discrepancy is more substantial than the "controversy" around the popular use of the terms "centrifugal" or "suction".
There you go. Awesome Jay!!!
Super @agentjz, awesome vid and love the cap. You almost look English in a small mill town. Keep rocking Jet City.
AVRO Arrow one of the most beautiful aircraft ever conceived
Best part of Wikipedia is the footnotes at the bottom of the page. The articles cover the basics and footnotes marked throughout let you dive deeper or validate things that don't sound right.
Gas turbines are also used on fast high end motor yachts for high speed with a low weight penalty. Also on the jet race boats AgentJayZ has posted about in the past (some _very_ cool videos about them).
Hey, Thanks for the video, perfect explanation, great as always
Diesel plant engines typically have an auxiliary coolant heater that circulates warm coolant through the coolant system to keep the block up to temp in case of need of emergency start and some very small diesel powered standby generators(10-15K?) for things like small radio stations have electric heating elements continuously heating the block as well as a big capacitor bank and possibly a spring wound instead of an electric starter to supply uninterrupted power to sensitive electronics. Was doing some work on a small radio station building and they had a power outage(not my doing) and the generator unit responded so fast the lights didn't even twitch or dim and was told the radio signal also didn't even twitch.
Hi Agent JayZ, loving your channel. Like to tell something about Diesel engines. It is true that they are speeded up slowly. However, the reason is the total drive of the ship including shaft and propeller. A computer controls the acceleration of large ships in order to spare the whole installation. Propeller shafts are sensitive and normally not oversized.
The engine itself is very quick an can be started like a cars engine and can be runned up easily. I have been working for Mitsui in Japan to equip ships diesels with gas supply for running on liquidied gases. You would be astonished how they handle their engines in the shop. Starting without warming up, after a few seconds giving thousands of Kilowatts to the testgenerator or brake. Histrorically the control parameter at voyage is a speed governor for the engine. Keep in mind that on sea you do have waves (sometimes large ones) which request different power more and less more and less more and less 1.000.000 times a year ! It was a chalenge for us to get our gas supplier reacting that fast.
Gas turbines are normally not coupled to the shaft but have electric power transmission. Nowadays the propulsion drives do not speed constantly but vary the speed according to the power. So the turbine can run constantly.
I assume that the turbine ships are built for performance and stability. And only costs are not that important. That is to say for playboys and military :)
It's also worth noting that power requirement of a ship increase dramatically with speed, especially if a ship exceeds hull speed. (the speed where the wavelength of the bow wave created by the ship exceeds the hull length, so that it's effectively traveling up hill)
A 3000t frigate might be able to make 15 knots on only 2000kw of power. But to go 30 knots it'll be in the ballpark of 50,000kw.
So 95% of the time it will just use a small diesel. But in certain tactical situations where it might need the excess speed, it'll fire open the gas turbines.
Uh, yes. I think we covered that.
The principal advantage might be in doing a Brayton / Rankine combined cycle. The Siemens S class turbines achieve 60% efficiency this way. That would certainly help offset the relatively high cost of burning gas.
In an electric utility generator application, a turbine at idle will burn 30% of the fuel at full load. As the gentleman states, the turbine is very efficient at full power. The loss of efficiency at light load is due to the large amount of energy it takes to compress the incoming air enough for the turbine combustor(s) to operate.
good stuff! very informative
Fantastic explanation!
I'm currently sitting here watching this while on a Watson-class MSC ship. These ships are LARGE. Big RORO type cargo vessels, technically called LMSRs... Anyway, just downstairs in the engine room here are dual LM2500s, with MASSIVE reduction gear units, that are basically in a v-drive configuration.
GE now has GTG's which scavenge waste heat for boilers which add their own steam turbines to the power generation chain.
Combined Cycle Power Plants utilize the GT Hot Exhaust to feed a Heat Recovery Steam Generator increasing the efficiency of the Combined Cycle Power Plants to about 60%. The better Simple Cycle Gas Turbine Power Plants are 40-46 and are normally used for Peaking Service. The US Navy used Waste Heat recovery Boilers (HRSG’s) on the GTG’s of the Spruance Class Destroyers & Ticonderoga Cruisers but not the propulsion Gas Turbines. It was not practical to place WHB/HRSG’s on the Exhaust of the propulsion GT’s due to varying speeds and exhaust heat. The Steam was used for hotel services and Flash type Evaporators (biggest user). The Waste Heat Boilers (HRSG) present a lot of Maintenance and operational problems. Advances in Reverse Osmosis Technology have eliminated the need for Steam Flash type Evaporators. The Arleigh Burke Class Destroyers did away with the WHB/HRSG Steam system to improve reliability without a fuel cost penalty. Combined Cycle Power Plants are great for Electrical Production on land but not very practical on Ships. I have worked extensively with both.
@@ultraclassic1550 I was referencing CCPP's. Although both the Navy and civil CCPP's are still GT based systems. It's more form than function which separates them.
I was on a FFG7 class we had 2 lm2500 gas turbine engines, we only had to use 1 at a time unless we intended to reach or exceed our maximum rated speed, we also had variable pitch propellers to take advantage of the GT engine's most efficient speed. And we had 12 cyl diesel engines for electrical bus.
The British type 22 frigates used two Tyne for slow speed and cruise and two olympys for sprint (later ships had speys) and a kind of fluid coupling linking them to the gear box. They had variable pitch props for maneuvering.
Unarguably one of your best vids, ‘zed’...Oh, and I’ve seen’m all.
One gas turbine advantage for ships,especially naval vessels is start up time. A diesel engine needs to be warmed up to operating temperature before being put under high loads. A gas turbine can go to full power almost immediately, as shown with turboprop aircraft. Gas turbines are also a lot lighter. In fact cruise ships use them as well.
Yes. We discussed this in my video called "turbine engines for ships" a little while ago.
cruise ships tend to use gas turbines has generators not powering the propellor mechanically, its basically an hybrid system.
I was an engineer in the Navy, my first ship was the USS Kitty Hawk CV-63. We used to hate the engineers on the small boys. For us deployment basically started a week before everyone else. Doing all boiler pre light off inspections and every other pre inspection, then boiler light off, post inspections myriads of tests and checks then shut down for a few days. Then light off like maybe 1 or two days prior to departure and building up of steam and all engineering had to be back aboard the night prior to departure.
So while we're getting ready to get underway we see the engineers from our escorts roll in looking half asleep and this is like 45 minutes before we were supposed to depart. Minutes after they board we see some white puffs from thier stacks and bamn they were ready to go.
Fucking bastards...... We'd mutter, very jealous of all thier extra free time lol.
@@axel_x8954 Cruise Ships use Diesel-Electric Propulsion, with Diesel Engines driving Generators which then power everything on Board, including the Propeller Motors which are controlled via AC-AC Frequency Converters. There is nothing Hybrid about it, as there are no Batteries involved except for very few Ships with Hybrid Propulsion; usually Antarctic Expediton Cruise Ships. Some large Cruise Ships have a single Gas Turbine as Boosters for very high Demand, but generally, Gas Turbines are too inefficient for Cruise Ships.
The only Cruise Ships that I would consider actual Gas Turbine Ships are the Queen Mary 2, which has two GE LM2500 Gas Turbines additionally to the four Wärtsilä V16 Diesels, to get it to 35 Knots for crossing the Atlantic; and the Celebrity Millenium Class which have two GE LM2500 Gas Turbines in a Combined Gas and Steam Turbine Layout, where Waste Heat is reclaimed via Exhaust Gas Boilers to power a Steam Turbine, which reaches a Combined Efficiency comparable to Diesel Engines.
The Queen Mary 2 ocean liner is a pretty cool ship. It's got a honking great Diesel electic propulsion setup, plus a couple of (I think) LM 2500 up in the funnel. They were added to give a power boost to improve the top speed. The cool bit was that they could be at the top of the ship - handy for inlet and exhaust flow - yet the electrical power generated could be easily conducted down cables to the propulsion pods at the bottom. Those cables are no doubt quite large, but routing those was far easier than trying to up the LM2500s down in the engine room.
It's a High Voltage System, probably 11 kV as that's a standardised Voltage in Shipbuilding. 50 MW at 11 kV would mean around 10 cm (4") Diameter per Cable, and there's four of them (three Phases and Neutral). But I guess that it uses more than one Cable per Phase.
@@Genius_at_Work Not the sparkies' favourite job, laying in cable like that!
I wonder if they would be able to use the ship structure for the return? Probably not, I'd guess that heavy currents running through the ship would be bound to cause undesirable galvanic effects somewhere or other.
I know that trams that use the rail as a return with rail that's set into concrete (instead of conventional track with cover plates, and a lot of continuity cabling) have a lot of trouble with stray current getting into utilities like water, gas pipes, things like that (causes endless trouble apparently).
Does 3 phase delta get away with a smaller neutral? It's been so long since I had to worry about that stuff in my degree course...
@@abarratt8869 I'm no Electrical Engineer, but Electric Installations on Ships usually have three Conductors only, so the Neutral Point between the Phases must be earthed and thus the Steel is sort of the Return, except that in a balanced Three Phase System, the Phases cancel each other out. As literally all Consumers except Lighting and domnestic Outlets (230 V) are Triple Phase, it usually is balanced very well. Hence Three Phase Systems usually have a smaller Neutral, if any. E.g. do High Voltage Transmission Lines (100+ kV) have no Neutral, to answer your last Question.
Stray Currents only occured where one Rail was Positive and the other Negative. These Experiments quickly were abandoned because of said Problems with Stray Currents, and because treading onto the Positive Rail had an imminent Danger of Electric Shock, especially when it was damp. Trams use the earthed Rails as Negative, with the Catenary being Positive. Same as in Metros or "real" Railways with Third Rail Electrification or a DC Catenary. AC Railway is the same too, just with the Catenary as Phase and the Rails as Neutral, but that's basically different Terms for the same Thing. The only Case that I know, where the Rails aren't used as Conductors, are some Lines of the London Underground, that use a Fourth Rail as Negative. Don't know if its earthed. An interesting Oddity are the very few Triple Phase AC Systems found in some Rack Railways (Jungfraubahn and Gornergratbahn in Switzerland, Chemin du Fer de la Rune in the French Pyrenees and another one in Brazil). They have two Catenaries like a Trolleybus, except that they aren't Positive and Negative but two Phases instead. The Third Phase is in the Rails, that are earthed like in any other Railway. Instead, "Neutral" Point is shifted and has a considerable Alternating Voltage on it. Just imagine the Vector Diagram of the three Phases, but it rotates around one of the Phases instead of the Neutral Point.
Ships main engines go from stopped to ready to answer bells in a half hour to more.
You have to turn on all kinds of auxillary equipment before the main engines can start turning over. First, a diesel-powered generator, to power a compressor to get the air enough to start the crank. Also, you need to start electrically driven lubrication pumps and seawater pumps to feed cooling water into the heat exchangers. Just for starters. Before the main engine can be started, though, it needs to be turned over slowly by the auxillary equipment to spread the heated lube to cylinders, crankshaft, valves and gears. That takes from 15 minutes and up to half an hour depending on size of the engine.
Het Jay interessant video! I van tel you that the Dutch navy uses diesel engines (v16, ~10.000 hp) and gasturbines from Rolls-Royce rating at ~35.000 hp as dubbel set so two screws , two gearboxes etc. Screws are pitch controlled. I worked as a ships engineer and a hot stand-by engine with cooling water @90c the start from 0 to 100% is about 1,5 min. These where 9 cilinder diesel engines with a cilinder bore of 49 cm and a power of 9450 kw, ~13.000 hp. From cold start your coolingwater temperature and oil temperature are leading. This can take up to 30 min to heat and reach Max power.
9 cylinder engines - now they're a very rare layout. The only plausible reason I can think of to do this is if the engines are part of a product family where they add more cylinders to get more power (~1000 kW per piston based on the number above) and the power produced by 9 cylinders happened to be what was needed for the application. The crank shaft throws and camshaft layout (If it's a 2 stroke marine diesel the cam shaft isn't an issue) would still need to be specifically spaced for a 9 cylinder unless the crank is cast in 3 cylinder blocks. Very cool to hear about this stuff.
@@peglor it is true that wartsila the engine builder adds cilinders according to the power that is required for the application. I can tell you that with an even as possible firing order split the engines where very prone to vibrating, even breaking the stud bolts that hold on the turbo charger. The engine where 4 stroke by the way and the range goes from i believe inline 6 to 9 and v12 to v18.
This may have already been said but there are a number of cruise ships I was on one the Serenade from Royal Caribbean Cruise Lines and they had to jet engines in the in there. And they were using them as generators only and using isopod propellers two of them to drive the ship. Another addict avenius is there a lot cleaner and maintenance and stuff too. Very clean bilge on that ship.
The gearbox you mention is for the CODAG system, combining diesel and the GT.
You also have ships with the LM2500 hooked up directly to the waterjet system that can go a bit faster because they don´t have the problem of turning a propeller too fast. Basically it´s a huge jetski and it is truly awesome.
I´ve played with many turbines, but nothing beats when you do a fast load step and you can notice the acceleration on a 70,000 ton ship. You can really feel the power of the engine
Excellent. If you have any stories about operating these ships, this is the place to share them.
Really interesting stuff
Every time you mention the Iroquois I wonder when you will find time to work on yours again. It would be so cool to see that running again. Speaking of the Arrow, it was a shame that it was cancelled, but it was a scandal that they then were forced to try and destroy all evidence of it. Not even the TSR-2 suffered that badly.
An interesting aside note about the Orenda Iriquois: my dad had been tasked with returning the b47 that been used as a test bed for that engine to the US.
During pre-flight he noted that the entire tail of the aircraft had been twisted by the large asymmetrical thrust loads to the point where he deemed it unsafe to fly. Told the brass that some high paid Boeing test pilots should be given the job along with a big bonus instead!
Awesome to hear from you. Operational stories from the real world are gold!
@@AgentJayZ Too bad we can't talk to the actual guys who flew it though! It was a different (and rapidly evolving) culture as far as safety goes for sure.
Interesting, as usual ! thanks !
Ok guys, i love this man!
IIRC Smaller Navy vessels use a Diesel for cruising and one or more Gas Turbines for higher speeds. The maim advantage is compact high power at low weight. The Diesels are fuel efficient and turbines are power efficient.
For reference (timestamp 6:01) ↙️:
“Gas turbine” - EN Wikipedia
en.wikipedia.org/wiki/Gas_turbine;
“Marine propulsion” - EN Wikipedia
en.wikipedia.org/wiki/Marine_propulsion;
(PS.: The suggested URLs/links titles are in the description.)
EDIT: Timestamp 20:06 ↙️:
“Cool Your Jets” - title of TH-cam video
th-cam.com/video/O49EwwUaSsk/w-d-xo.html;
The lack of efficiency at anything other than 100% is why some navy ships are now using all of their combustion engines, turbine and piston, as generators feeding an integrated power system (IPS) which provides power to propulsion and all other shipboard systems. They will only turn on the generators they need at the time, so if they are cruising at 16knots they might just use 1 gas turbine and 1 diesel, but if they needed full speed they turn everything on an give it the full beans.
The Royal Navy's Type 45 destroyers were the first (maybe not, but I think they were) warships to use IPS, with 2 Rolls Royce WR21 gas turbines and a pair of smaller Wartsila diesels feeding power to a pair of 25,000hp electric motors. They don't use Azipods, don't think any large navy ships are using them other than fleet replenishment vessels.
Now, there is also the Queen Elizabeth class aircraft carriers using 2x Rolls MT30 (48,000hp) and 4 Wartsila diesels (I think about 14,000hp) feeding 4x 25,000hp electric motors. The US Navy Zumwalt class destroyers use a similar setup.
Military vehicles are often limited by international treaties, restricting the amount of the larger, more powerful categories more than the smaller ones. Using gas turbine instead of just a piston engine allows you to get high peak power, at way less weight. That allows you either use more useful load (armament, weaponry,...) while staying within the weight limit for the category, or allows the vehicle to "fall" within the "less powerful" weapon category, so treaties allow that state to own more such units. Bottom line you get significantly more fighting power while still staying within the limits of the arms reduction treaties.
This was the case for the Abrams tank and I would be surprised the battle ships to be any different story...
Even crazier than ships running on gas turbines is tanks doing it! Same reasons (space/weight), same problems - idle fuel consumption on the Abrams was awful until they added an APU, although cruising was decent.
42 inch diameter? 42 is always the right answer :-)
And if I ever get a boat with a turbine I'll definitely refer to it as "the warp core".
_"DEEP TURBINE."_ 😉
New jersey battleship channel has a recent video comparing a destroyer and battleship engineering. Lots of overlap with this upload. Thanks for your insight
A few years back there was a comment "...yeah but a diesel engine starts faster..." to which J replied "A 20000 HP diesel engine? Right..."
I think properly spelled...riiight.
@@u2mister17 true 🤣
In large cargo ships which use slow speed diesel engines, it takes only a few seconds to change from stop to 30 percent ahead or astern RPM, if the engine is already warmed up, that is called manouvering range, But from 30 to 100 percent MCR power, there is a ramp up program, which takes between 30 minutes to 1 hour,
It's the warm up time required, from stopped and stone cold, to full power, that I am most interested in.
@@AgentJayZ On in service ships the engine is never truly "cold" the oil and water is kept warm with auxiliaries. When the ship gets underway 0% to 30% power is available right away with no warm needed.. When increasing load from say 30% to 90% power the load is slowly increased to let everything come up to full temperature slowly. A similar time is used when slowing down to let everything cool down slowly. The 0% to 30% range are referred to as the "maneuvering speeds" where the range above that is called "sea speed"
I’m a marine engineer, most of the ships I’ve worked on have small (still house sized) slow speed diesels, in the 6,000-10,000hp range. The engine is almost always kept preheated and takes 20-60 minutes to start, much longer on bigger ships. If the engine is allowed to fully cool you could be looking at between 4 and 24 hours to get it warm enough to start.
I was on a ship that used opposed piston 2 stroke diesels. When full speed was needed we would fire up the turbines and the speed difference was... Diesel at full speed = turbine just above idle. As the power on the turbines would come up a device called a "triple S clutch" would disengage the diesels and switch to turbines
perhaps worth noting is that gas generators wouldn't really make any sense outside of military or rescue vessels. Large shipping vessels never exceed their hull speed (a product of length primarily) because doing so tanks their fuel efficiency. Exceeding minimum power requirements just improves acceleration and stopping, so largish understressed diesels make the most sense for civilian applications
An additional consideration is steerage. Most ships do not have effective rudder steering below 6 knots. This is a major reason that ships use harbor tugs. Bow thrusters and other expensive devices can partially remedy this condition. What steerage means is there is a minimum manoeuvring speed which means a floor for power consumption when underway. Also, in the case of main propulsion breakdown, there is sometimes a way to divert auxiliary power to the screws to maintain steerage. Foundering on the rocks is considered very bad form. Limping into port is a much better option. In the case of conventionally powered aircraft carriers. It could take hours to get under way from a cold start. Forrestal class ships had 8 boilers and 4 screws. In port, they always kept 2 boilers in service to be able to get underway in an emergency. Full power took over an hour. This meant that in port, the electrical systems were run off the boilers and the diesel generators were mostly idle.Steam from the boilers was run through a heat exchanger to keep the water jackets up to temperature on the diesel engines and an electric motor slowly turned the diesel through a reduction gear to keep lube oil circulating and the piston rings oiled. With this arrangement, it took only minutes to get the diesels up to full power, assume the electrical load and make steam available for the screws. It was a complex system, and that was not full power to the screws. Now, enter the turboshaft, full power in minutes from a cold start. For the Navy, that was a big advantage!
Here in Finland was built this passenger ship: en.wikipedia.org/wiki/GTS_Finnjet , It had originally had 2X Pratt&Whitney FT 4C-1DLF gas turbines. Later 2x big Diesels were added to save fuel especially for slow winter traffic. Gas Turbines were used on busy summer times when faster speed was paid with tickets.
Great vid thank you
I was thinking of getting the USS High Point PCH-1 it was the Navy's first operational hydrofoil that had two gas turbine engines for foilborne and a 12v71 for hullborne. I subscribed here to learn that I was probably over my head. All of the U.S. Navy's hydrofoils were gas turbine powered. Some used water jets and others were propeller driven.
That IS a very good question..
Some modern ships use electric Azipods for propulsion and a gas generator for power. Amazing how fast/maneuverable Azipods are!
Yeah it's a amazing system. But lacks the speed of a gasturbine system. I have served on both kinds of ships. (The Johan de Witt and Ruyter)
The azipod system has a lot of parts that can fail. Compared to simple prop and diesel setup.
A lot of energy is lost that way
Are they typically coupled to the prop shafts mechanically? Are electrical couplings a thing?
Typically there are gearboxes and other couplings between the engines and the propeller shafts, yes. But fully electrical solutions are a thing and becoming more common as the power conversion and switching technology matures.
"Electrical couplings" are usually referred to as Integrated Electric Propulsion or Full Electric Propulsion (or both - IFEP). In this concept the engines - whether gas turbine or piston - drive alternators which feed an electricity grid, supplying electric propulsion motors as well as all other ship electrical demand. Because there is no physical shafting between the engines and the propellers - and instead just electrical cabling, the engines - and propulsion motors - can be placed far more conveniently for the rest of the ship's design. And there are efficiency gains due to being able to better match the number and type of generators in operation with the total electrical load.
The Royal Navy's Type 45 destroyer's were among the first IFEP designs. They use a pair of Rolls Royce WR21 gas turbines plus a pair of 12 cylinder diesel alternators - with the propellers turned by electric drive motors. Although, due to technical issues with the WR21's (long story) the diesel gensets are about to be swapped for three more powerful ones.
The Queen Elizabeth class carriers are a similar arrangement - four diesel gensets deep in the ship providing over 11 megawatts of power together plus a pair of Rolls' 36MW MT30 gas turbines. Because of the flexibility of the electrical design, the GTs are located in the sponsons immediately underneath the islands (and uptakes/stacks) so they are easy to service and swap out if necessary - and also don't have their uptakes and exhausts eating up valuable space inside the ship.
As per A Barratt's post below, the Queen Mary 2's IFEP solution is also ingenious, as the pair of LM2500+s are sat right on the top deck. So no valuable space at all is wasted within the ship volume on their uptakes or exhausts. And as EE suggests, its propulsion motors are fully steerable azipods connected directly to the propellers - so there are further advantages in terms of manouverability, and the drive motors don't even take up *any* space inside the hull.
The US Navy are utilising this concept too. The three Zumwalt class destroyers are IFEP - and if I remember correctly, one of the Arleigh Burke class destroyers is trialing a version of it.
Exactly, the primary reasons are: 1) power density (power output per unit engine volume), 2) power-to-weight ratio and 3) max power output. Most modern military vessels (including some privately owned vessels, see Larry Ellisson's "Katana") run CODOG systems (Combined Diesel and/or Gas Turbine), most often x2 high efficiency diesels (for low / medium speed operations) and a single x1 gas turbine (for high speed / sprint ops). Power density is important because space on most vessels is at a premium. The power-to-weight and max power output requirements are fairly obvious for medium size / large military vessels which require high speed capabilities and ones in which gas turbines (esp aeroderivatives) are almost impossible to compete with. The reason for the massive advantage of gas turbines in 2) & 3) comes down to the much greater mass flow you get through them compared to other engine configurations - since thermodynamically power output is directly proportional to mass flow. Great vid
Wikipedia also has an article named Integrated electric propulsion (IEP) which is a newer method of ship propulsion. Electrical transmission eliminates gearboxes and clutches. The Smithsonian channel had an interesting miniseries about the HMS Queen Elizabeth that uses this setup. Two Rolls-Royce Marine 36 MW MT30 gas turbine alternators and four 10 MW diesel engines.
As an American, the tragic Avro story is just a shameful part of our history and Canada is owed a great apology for the entire fiasco. The world lost major aviation acheivements the likes of which have never been duplicated. It was nothing short of a crime.
It was a shame, slashing aeronautical engineering to finance agricultural subsidies. But the Avro Arrow had no qualities that separated itself from its contemporaries the North American F-107 or the Vought Vought XF8U-3 Crusader III.
Nice troll, Gil. You really need to do a bit of searchin' and learnin'.
@@AgentJayZ You might like this
The Iriquois would have helped. Arrow's wing loading and weaponry (which is the point of it all, right) (but who knows weaponry-wise since none of them were fully developed.) As for faster, higher, range, there's no breakaway that made any of the systems more effective against Bears than, say, an F-106. As for Canada's decision to purchase the Voodoo, no contest: Arrow.
Your opinion is enough to prompt some comparison work, for your edification - It's not scrambled eggs!
*Arrow* */* *XF8U-3* */* *F-107A*
Crew: 2 */* 1 */* 1
Length: 77 ft 9 in (23.70 m) */* 58 ft 8 in (17.88 m) */* 61 ft 10 in (18.85 m)
Wingspan: 50 ft (15 m) */* 39 ft 11 in (12.16 m) */* 36 ft 7 in (11.15 m)
Height: 21 ft 2 in (6.45 m) */* 16 ft 4 in (4.98 m) */* 19 ft 8 in (5.89 m)
Wing area: 1,225 sq ft (113.8 m2) */* 450 sq ft (41.8 m2) */* 376 sq ft (35 m2)
Empty weight: 49,040 lb (22,244 kg) */* 21,860 lb (9,915 kg) */* 22,696 lb (10,295 kg)
Gross weight: 56,920 lb (25,818 kg) */* 32,320 lb (14,660 kg) */* 39,755 lb (18,033 kg)
Max tkoff wgt: 68,605 lb (31,119 kg) */* 38,770 lb (17,590 kg) */* 41,537 lb (18,841 kg)
Powerplant: 2 × P&W J75-P-3 16,500 lbf */* 1 × P&W J75-P-5A 16,500 lbf dry, */* 1 × P&W YJ75-P-9
Powerplant: each dry, 23,500 afterburner */* 29,500 lbf afterburner */*
Max speed: 1,136 kn (1,307 mph, */* Mach 2.39 50,000 ft (15,000 m) */* 1,295 mph (2,084 km/h, 1,125 kn)
2,104 km*/*h) 50,000 ft */* - */* -
Mach 2+ potential */* - */* -
Max speed: Mach 1.98 */* - */* Mach 2
Cruise speed: 527 kn M0.91 at 36,000 */* 500 kn (575 mph, 925 km*/*h) */* -
Combat range: 360 nmi (410 mi, 670 km) */* 560 nmi (645 mi, 1,040 km) combat */* 2,428 mi (3,885 km, 2,109 nmi)
Service ceiling: 53,000 ft (16,000 m) */* 65,000 ft (19,800 m) */* 53,200 ft (16,220 m)
Wing loading: 46.5 lb/sq ft (227 kg*/*m2) */* 72 lb/sq ft (350 kg*/*m2) */* 106 lb/sq ft (516 kg/m2)
Thrust/weight: 0.825 at loaded weight */* 0.74 at take-off, 0.97 at combat */* 0.62
Missiles: 2× Genie */* 4 × AIM-9 Sidewinder missiles */* Bombs: 10,000 lb
4× Canadair Velvet Glove */* - */* -
8x AIM-4 Falcon */* - */* -
3 AIM-7 Sparrow II */* 3 × AIM-7 Sparrow */* -
Hughes MX-1179 fire
control system */* Raytheon Aero 1B system */* -
- */* Autotechnicas AN/AWG-7 */* -
- */* AN/APQ-50 radar\ */* -
Max speed of the Arrow was over Mach 3. Yes, SR-71 territory.
Bite me.
@@AgentJayZ Maybe you noticed the bulk of the post supported your position, and I wrote "it would have benefitted from the Iroquois." I don't get the "bite me" remark. BTW: Maximum speed reference: _Avro Arrow: The Story of the Avro Arrow from its Evolution to its Extinction_ page 116 - If that's a bite, so be it.
In the biggest diesel engine in cargo ship is 14 cylinder 4 turbocharged at 107,000 brake horsepower at the fly wheel it known as The Wärtsilä RT-flex96C 2 stroke
The answer is actually quite simple. Horse power to weight ratio. There are other things to take into consideration but that's the main reason.
the Canadian Patrol Frigates use LM 2500 gas turbines in a CODOG configuration with a propulsion diesel, the diesel are for cruising the gas turbines for speed
One thousand HP??? currently even a small tugboat would have two of these. I served on a CG Cutter some fifty odd years ago that had a hybrid plant of diesel and turbine engines. the diesels made about 2500 hp each while the turbines made about 16,000 hp each, the diesel could get us up to 22 knots or just under 500 miles per day, with the turbines we could and did do 32 knots. Had we had right sized diesels, say about 6,000 hp each, we probably could have done about 27 knots, damn fast for a little ship (under 400') (length and potential speed on ships is related {economical cruise speed is about the square root of the length in feet}). Diesel engines typically run 25,000 hours between major overhauls, turbines need a hot section at 2500 hours and a major at about 5000 hours. Diesel overhauls are done on the ship while turbines are removed. The big difference is fuel consumption, the turbines burned each hour what the diesels would burn in a day and they burned jet fuel, more expensive than diesel, our range on turbines was about 3000 miles, on diesels 30,000 miles. It takes a LOT of space for all that additional fuel furthermore turbines do not throttle well, they are efficient at high speed but are enormously inefficient at lower speeds.
the Brits just built two aircraft carriers, both use diesel engines as their prime mover (they use electric drives so the engines are running alternators to make electricity for the motors). I believe this allows cruise in the middle 20s with considerable range, it does have a turbine that allows speeds in the mid to high 30s but the fuel consumption is horrible. I don't think a diesel engine of 10k hp is currently available in the US while diesel engines up to 125k HP are available in Europe, Japan, and Korea. this is a major issue for the commercial shipbuilding industry in the US since most all commercial vessels are diesel. The US built steam turbine vessel up to recently but steamers use about three times the fuel of a diesel and need about four times the engineering crew.
Just curious, is there enough heat, typically, post power turbine to produce co-generated steam?
Yes. It's a common practice to use the exhaust heat to generate steam.
A lot of it.
@@AgentJayZ Are you referring to Steam used for Heating? IIRC, the only Ships to ever have used COGAS (Combined Gas and Steam Turbine) Propulsion are the Celebrity Millenium Class Cruise Ships, with two GE LM2500 Gas Turbines at 25 MW each, and a 9 MW Steam Turbine. Plus a V16 Wärtsilä Diesel Engine at some 11 od MW, to counter the terrific low Load Efficiency of Gas Turbines.
What about small quick attack ships? I've seen small fast anti-ship boats (17 man crew) in the Baltic Sea and this boats/ships use gas turbines. Is it the best option for this kinds of ships?
I don't doubt the engineers that is for sure but what would be a disadvantage for a small ship like this when using a turbine engine?
WOW very interesting thank you.
Very good education, I always thought a Diesel is always more efficient than a turbine
and the Turbine had much less maint.
Interesting video, as all your videos are. Something that may be of interest if it hasn't been mentioned in the comments. Modern cruise ships which are diesel electric. And like the turbine engine propelled ships you mention and like you mention at the end of your vid, they have multiple engines (diesel), as many as six, and share the varying load in the same manner, electrically.
My question, how do you think about RR WR-21 gas turbine? It maintains stable efficiency from half to full power.
The WR-21 maintains that efficiency, courtesy of considerable complexity. It has intercooling, with recuperative heat exchange from the power turbine exhaust to HP compressor delivery. It also has a stage of variable nozzle guide vanes at entry to the power turbine.
A problem with the intercooler (or the heat exchanger - I'm not sure) has restricted the power availability, and compromised reliability, at high ambient temperatures. The solution has been to cut a big hole in the side of the ships and shoehorn in a third diesel engine.
@@grahamj9101 Agree, but it’s still simpler than gas-steam combined cycle.Assume we have to add a HRSG and steam turbine onboard.
Back in the 70’s, the largest USCoast Guard Cutters used four gas turbines and 8 Diesel engines for propulsion. Normal cruise was the diesels. The gas turbines were for high speed pursuit only and ran in conjunction with the diesels. I don’t recall what gas turbines were installed, I believe they were Allison, but I’m not sure.
That’s like a Kabillion pounds of engines . Crazy that was considers the “Efficient “ way to use propulsion
The Coast Guard cutters used Pratt & Whitney Engines, I believe.
I saw a vid where these guys were looking for a project car at a junkyard and it had some vehicles packed with Avro Arrow parts in boxes that were bought for scrap years ago. The vid was from 2020.
Thank you for all the work you put into these videos. I am curious who builds the power turbines? Does the gas generator manufacturer make them or is it the manufacturer of the connected equipment or a 3rd party? Are they a standard part or designed specifically to the application? Lastly, I know some ships have counter rotating shafts. Is the change of rotation direction done with different versions of power turbines (clockwise at counter clockwise) or is that likely done in the connected reduction gear? Thanks!
Some engines have an integral power turbine, and some don't. The LM2500 comes in both configurations. Sometimes the engine manufacturer also make the separate PT, like Orenda, and there are also manufacturers who make PTs but not gas generators, like Cooper-Bessemer. I don't work on PTs so we never see them in the shop.
Also, since the output of the PT goes through a reduction gearbox for driving the ships propeller, it is much simpler to change the direction of rotation with gearing. Even more so when you consider that the prop needs to be reversible in operation.
I am not aware of any case where there are two different rotational versions of any turbine, or turbine engine. Many people have made the claim, but none have ever supplied any evidence.
@@AgentJayZ thank you for taking time to answer. Given the size of the gearbox used to combine 2 LM2500's I was wondering where the most cost efficient way to select rotation direction was. A cool side note is that many of these installations do not have to be able to reverse propeller shaft rotation. They can actually reverse the propeller pitch for reverse. Another page taken from aircraft. Thanks again.
The first turbine powered vessel was Turbinia, a steam turbine, built by A Parsons in 1894. The Navy weren't interested so in the 1897 Spithead Review for Queen Victorie Parsons turned up unannounced on Turbinia and rang rings around the Royal Navy who tried to catch him but could not. In 1905 the Admiralty declared that in future all RN ships would be turbine driven
In huge container ships which don't go fast anyway, Diesel is the wau to go especially if they use heavy fuel oil and the shaft alternator.
Using in a co-generation cycle with a steam turbo-generator, or with supercritical CO2 cycle, Brayton Cycle, to generate electric power. In a ship with electric propulsion, like cruise ships, you can optimize the use of the turbines, and improve efficiency thanks to the "free" extra power from the exhaust gas.
Where does the exhaust go?