Electric ship research: 20MW frigates?

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perfectgeneral	Electric ship research: 20MW frigates?	Lead	[-]
Posts: 341 (10-May-2008 15:15:51) Reply Quote More My Recent Posts Message Me Connection Blocking Invite Ignore User's Posts	Electric_Warship_III.pdf The transverse flux permanent magnet motor looks particularly promising. The 20MW motors used in Daring weigh 70t each. These promise to weigh about 39t, but the state of research is around 65t. A Frigate powered by a single WR21 and a 1-2MW advanced cycle Gas Turbine Alternator looks likely in our future. You could get down to a hull size of 3000t for an electric ship. Electric Warship VI Anyone in IMAREST? Marine Propulsion - King http://petitions.pm.gov.uk/Want10Destroyers/ http://petitions.pm.gov.uk/4Subs88Months/ Last Edited By: perfectgeneral 11-May-2008 00:26:49. Edited 3 times.
perfectgeneral		#1	[-]
Posts: 343 (10-May-2008 15:34:11) Reply Quote More My Recent Posts Message Me Connection Blocking Invite Ignore User's Posts	I like the quiet operation of a couple of AWJ-21 (10.89MW advanced water jets), but they are more suited to operations over 30knots (30-50knots ?). Perhaps the second batch of Type 45 might manage that with four AWJ-21s? Podded motor(s) seems more likely, especially as this is the way commercial applications of the technology would be heading (COTS). Would the hull be small enough to justify a Trimaran hullform at 3000t? http://petitions.pm.gov.uk/Want10Destroyers/ http://petitions.pm.gov.uk/4Subs88Months/
Zen9		#2	[-]
Posts: 3522 (10-May-2008 19:29:54) Reply Quote More My Recent Posts Message Me Connection Blocking Invite Ignore User's Posts	I see nothing wrong with the idea of a single WR21 and a number of diesel generators, quite why you need two types of gas turbine is beyond me. I must confess a preference for a Trimaran hull, building on the work with Triton from a few years ago. Quite where to put the crane for a UUV or TAS is a curious business. CAAM is a logical self defence missile, likely using the TVC booster from SeaWolf and either the SeaWolf silos or multiple missiles per Sylver silo. Idealy we'd drop seperate launchers for any anti-ship missile and have our ASMs in the same type of VLS silo....perhaps the Kongsberg NSM, SeaSkua II, or a VLS Harpoon. CMS is a big issue, but we have Nautis as a potential basis, but it depends on its interoperability with CAAM. All assuming we're talking about a C3 type here?
perfectgeneral	C3? There abouts, but with C2 potential	#3	[-]
Posts: 344 (10-May-2008 22:30:26) Reply Quote More My Recent Posts Message Me Connection Blocking Invite Ignore User's Posts	Surface-Combatant-C3 The C3 has Diesel power to 25knots and a 30mm or 76mm gun. Could these be capable of uprating to Gas Turbine power to 30+knots and a 114mm gun? http://petitions.pm.gov.uk/Want10Destroyers/ http://petitions.pm.gov.uk/4Subs88Months/
Peter Parkinson		#4	[-]
Posts: 1766 (12-May-2008 11:32:58) Reply Quote More My Recent Posts Message Me Connection Blocking Invite Ignore User's Posts	As I thought Darings machinery is very heavy with its propulsion motors at seventy tons each. What I find amazing though is a return to a DC ring main, the first four Darings of 52 were supposedly the last RN major warships to have what was standard then of 220 DC ring main and 220V DC generation. The last four Darings were 440V 3 phase AC 60 Hertz and were looked upon as simpler, less weight and much less requirement for aux machinery. When I worked on the ex Sluys modernized as the Iranean Artemiz which was still a DC ship with DC ring main we had problems with the static invertors (DTDs) which gave us the AC supplies required by the radar, comms, sonar and weapon systems. The new Daring I think has eight phase AC generators driven by WR21 GTs then the AC is converted to DC to supply a 750V DC ring main. From the ring main there are static invertors to get back to AC to supply AC propulsion motors and all the other stuff on board. We are told that it will require less maintenance and be more reliable than previous designs. My experience with GT drven generators, Allen and Rushton is that they trip off at the slightest whim and that diesel driven generators just cough and keep on running. Since when has added complexity produced more reliability only in the minds of desk bound designers I think.
perfectgeneral		#5	[-]
Posts: 345 (12-May-2008 18:21:26) Reply Quote More My Recent Posts Message Me Connection Blocking Invite Ignore User's Posts	They have a new way of switching high voltage DC so that it doesn't arc across the switch gear. It is a combination of solid state electronic and electromechanical switching. Would this influence your experienced assessment? http://petitions.pm.gov.uk/Want10Destroyers/ http://petitions.pm.gov.uk/4Subs88Months/
emc		#6	[-]
Posts: 3745 (12-May-2008 20:29:40) Reply Quote More My Recent Posts Message Me Connection Blocking Invite Ignore User's Posts	High voltage DC is frequently used for long-distance utility power transmission, using rectifiers and static inverters at either end. HVDC has no inductive losses, which are non-trivial when the transmission lines are a few thousand miles long. Aboard a ship (tiny things that they are...), transmission losses associated with AC vs DC are probably much less than the losses in converting AC -> DC -> AC and the fact that DC generators are probably less efficient than AC generators. DC does have some advantages, especially in regards to motor control (this is one reason why most city subway and trolley lines use 600VDC power), over AC, but they're usually outweighed by the greater convenience of AC. I'm rather surprised that the RN would continue to use DC mains power aboard ship. Do any of the other fleets continue to do so?
Nathan	Reply to emc	#7	[-]
Posts: 2254 (12-May-2008 22:24:29) Reply Quote More My Recent Posts Message Me Connection Blocking Invite Ignore User's Posts	"I'm rather surprised that the RN would continue to use DC mains power aboard ship. Do any of the other fleets continue to do so? " But they aren't continuing are they? Continuing must mean that they had continued to use DC on ships whereas in fact they had changed to AC for general use in the 1940s and have changed to DC for these IEP ships. I'm no expert at all in this but shouldn't we be comparing this with other new integrated electric propulsion ships rather than recent conventionally propelled GT-gearbox or Nuke-steam turbine-gearbox ships?
Razor		#8	[-]
Posts: 405 (12-May-2008 22:26:54) Reply Quote More My Recent Posts Message Me Connection Blocking Invite Ignore User's Posts	"I'm rather surprised that the RN would continue to use DC mains power aboard ship. Do any of the other fleets continue to do so? " I thought they made this change in the 1940s half way through the Daring Class
emc		#9	[-]
Posts: 3746 (13-May-2008 11:47:53) Reply Quote More My Recent Posts Message Me Connection Blocking Invite Ignore User's Posts	Razor wrote: "I'm rather surprised that the RN would continue to use DC mains power aboard ship. Do any of the other fleets continue to do so? " I thought they made this change in the 1940s half way through the Daring Class I'm confusing classes. Not enough caffeine.
perfectgeneral		#10	[-]
Posts: 348 (16-May-2008 08:35:10) Reply Quote More My Recent Posts Message Me Connection Blocking Invite Ignore User's Posts	perfectgeneral wrote: Podded motor(s) seems more likely, especially as this is the way commercial applications of the technology would be heading (COTS). Would the hull be small enough to justify a Trimaran hullform at 3000t? How big a ship could be made from composite materials? Them would have advantages in weight and magnetic signature. Apparently the Formidable endured sea state six plus on it's jouney to Singapore from France: http://www.defense-aerospace.com/formidable In addition, its sea-keeping capabilities have also passed the stern evaluation tests with flying colours, after going through tumultuous sea states during the ship's 39-day voyage from France. The ship experienced conditions of over sea state six, indicating strong winds and high swelling of about four metres in the Indian Ocean. Although a few of the crew were sick, and they could still carry on with the training. That gave the crew a lot of confidence in the sea-keeping capabilities of the ship. I would hope that a similar ShipCo design would be less queasy. Stabilising fins and/or a trimaran hullform might help? The light frigate (3200t full load) has the capacity to operate a single medium size helicopter in the 10t class (S-70B Seahawk). The helicopter deck at the stern, approximately 22m x 16m (360m²), has a single landing spot. The hangar is fully equipped with helicopter support and maintenance systems. The frigate carries an additional 15 aircrew for helicopter flight operations. http://petitions.pm.gov.uk/Want10Destroyers/ http://petitions.pm.gov.uk/4Subs88Months/ Last Edited By: perfectgeneral 17-May-2008 18:41:04. Edited 1 times.
perfectgeneral		#11	[-]
Posts: 351 (17-May-2008 19:12:44) Reply Quote More My Recent Posts Message Me Connection Blocking Invite Ignore User's Posts	The French LaFayette class (3600t full load) carry a 100mm main gun weighing 22tons compared with 22.5 tons for the 4.5 inch Mk 8 Mod 1. Her 15.4MW power plant propels the ship to 25kt. A lighter hull should reach 29-31kt with 20MW of power. C3 is aiming more for the Floreal class (2950 tonnes full load) role (The concept of "sentry frigate" emerged from the will of the French government to protect its Exclusive Economic Zone (12 million km²), as defined in the Montego Bay treaties. Another need was to address matters of humanitarian aid, diplomacy, or naval law enforcement.) This also employs the same 100mm main gun, so the same comparrision applies. http://petitions.pm.gov.uk/Want10Destroyers/ http://petitions.pm.gov.uk/4Subs88Months/ Last Edited By: perfectgeneral 17-May-2008 19:19:24. Edited 1 times.

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