I wonder what the top speed of the NSC will be during sea trials? Of course if the top speed is classified then we should leave it at that.
According to publicly available information the NSC’s CODAG propulsion system uses two MTU 20V 1163 TB93 diesels and one GE LM2500 gas turbine engine.
These are the same engines used in the currently “in-service for several years” F124 Sachsen class frigates. Both the F124 and NSC ships are twin screw and use controllable pitch propellers.
The F124 Sachsen class has a top speed of 29 knots.
The NSC has an advertised speed of 28 knots. (Is that really the top speed?)
However, the F124 Sachsen class frigates are 51 feet longer than the NSC: (469’ versus 418’).
The F124 Sachsen class frigate's displacement is 1,300 Long Tons more than the NSC: (5,600 LT versus 4,300 LT).
I couldn’t find info to compare the NSC and F124 reduction gear ratios but they are likely similar.
Ed, generally they will only publicly advertise the "top" speed of a combatant as: 32+, 28+, etc.
Destroyer I served on had an "advertised" speed of 32+ kts, but conducting a Full Power Trial running back to Pearl from Barking Sands missile range off of Kauai one Friday afternoon with no following current, we were doing a few over the "advertised" speed (do the math there) and that was with no liberty turns from the Engineers or tweaking any of the safetys in the LM2500s.
USN battlegroups most often transit at an SOA of around 18 or so knots. My opinion and others is that the key is for the ship to be able to sustain that on diesels in order to avoid bringing up a turbine and playing "catch up" every few hours or so (as happened when the CG experimented with deploying the Hamilton class with USN battlegroups in the late '90s).
Yes, and as maximum hull speed is approached efficiency goes straight down while the power curve goes straight up... there was something else about structural rigidity in there too... I don't remember. I don't think it affected speed but hull stress became an issue.
1973, USS MIDWAY (CVA-41) yes 1110, it was a CVA back then, not a CV. Returning from Viet Nam, approaching the out-chop line...(closer to home then RVN). Message at around 2139 to DE (KNOX CLASS) escorting - Arriving OUTCHOP at 0000 local time, intend to run at 35 knots; request you maintain 10,000 yard astern position...until relieved. All engines all boilers brought on line (all 12), speed increasing, stern vibrating, vibration felt on the hanger deck 1/3 of the way forward; usually only felt on the aft 1/5 of ship. Approximately 2300, message from DE - unable to maintain your speed and distance; have a save trip home...Actual speed? Well over 40+ knots...not bad for a ship whose keel was laid down shortly after 12/7/1941...
Nobodyaskedmebut, I was at Puget Sound Naval Shipyard a few years back and went aboard MIDWAY (a company that I have done some work with over the years was using it for AT/FP training for SSBN sailors). RDML Prueler's (who later made it all the way to a 4th star and retired as CINCPAC) name was still listed on the CARGRU staff dowger in the hanger.
You'd be pleased to know that she still looked great inside given the meticulous care that was put in mothballing her, which is more than can be said for the CONSTELLATION which was moored one pier over and was in disgraceful condition IMO for a ship that hadn't been struck from the Naval Register yet.
I haven't been aboard her since they've moved her to the Broadway pier in San Diego though. Although there appears to be a nice restaurant on the fantail.
Jonesy, are you reading the forum? I do believe your post is a bit of deja vu...1110 asked the question. Who knows how fast a ship will go until the order is given, the turns are put on, and the results are calculated? I know on VENTUROUS during high speed trials near LA, we exceeded the "estimated" (on paper) speed by more then just a few 10ths of a knot; it was a significantly higher number (I forget how much higher) that caused the CO, XO, and EO to say WOW!
Tim, the NSC's speed calculations based on the lastest engineering changes will be able to predict if the NSC can make the 28 knots threshold. My sources tell me the NSC has used up the design and service life margins so it may not be able to make that threshold.
Originally posted by 1110: KeepingUpWithJones, do you mean the service life margins as specified in the contract of 230 days underway per year for 30 years?
Excellent observation 1110 But 230 days underway endurance, and 30 years service life are irrelevant according to the Lockheed requirements 'tailor'. Now, were these values irrelevant in Lockheed's operational effectiveness calculations that were part of the proposal? I would imagine that Lockheed used these values to "convince" the Coast Guard it needed less replacement cutters if they were heavily equipped with Lockheed-equipped C4I$R systems
Yes indeed. Surface Force has sources too who are indicating that instead of holding the LM accountable to the contract requirements, the USCG is sliding to a 180 days underway standard for 8 NSC ships (vs. the 12 WHEC-715 Hamilton class they will replace). How the USCG intends to make up this loss in operational capablity is anyone's guess.
Originally posted by 1110: Yes indeed. Some of Surface Force's sources are also indicating that instead of holding the LM accountable to the contract requirements, the USCG is sliding to a 180 days underway standard for 8 NSC ships (vs. the 12 WHEC-715 Hamilton class they will replace). How the USCG tends to make up this loss in operational capablity is anyone's guess.
"Yes Indeed" 1110. My sources tell me that Lockheed sold the Coast Guard on 8 NSC's replacing 12 378 ft cutters by marketing that the NSC can be underway 230 days, instead of 180 days. So now the NSC is designed for 180 days. So will the Coast Guard get 12 NSC's? That is what happens when the Coast Guard hires an "integrator" like Lockheed. The way I see it the Coast Guard ends up getting less surface assets they need in order to pay for Lockheed equiped C$I$R.
