Shipbuilding Trends

Posted on by

For those that might like some illustrations to clarify the the acronyms that are being used to describe various ways ships are being powered now, I found a pdf “Naval Shipbuilding, Current Developmental Trends with Combatants and Combat Support Ships,” that shows layouts for six of them:

• CODAD (Combined Diesel and Diesel)
• CODOG (Combined Diesel or Gas Turbine)
• CODAG (Combined Diesel and Gas Turbine)
• CODAG-WARP (Combined Diesel and Gas
Turbine — Waterjet and Refined Propeller)
• CODELAG (Combined Diesel Electric and
Gas Turbine)
• AE (All Electric).

It goes on to talk about hull forms, alternatives to conventional propellers, construction materials and modularity.

Beginning on the about fourth page (of nine, marked as page 29) it becomes a sales pitch for two concepts that were being promoted by Blohm and Voss. One of them, the MEKO CSL (combat ship, littoral). might be of some interest in that it is not too far from the specs for the Offshore Patrol Cutter, except that it appears too compromised toward higher speed and does not look like it has either the endurance or the seakeeping that would make a good cutter.

34 thoughts on “Shipbuilding Trends”

  2. Don’t get me wrong, Blohm & Voss can build good Naval ships, especially Frigates, OPC and Corvettes. I would not be surprise if Blohm & Voss pitches to the US Coast Guard either a MEKO CLS, MEKO® 100 Patrol Corvette or the MEKO® D Corvette. Either one of them could be a good fit.

    Reply ↓

    • Except that you can’t keep up with the times and Technology into Naval shipbuilding. Blohm & Voss can build naval ships that can survive the North Sea and even the harshest of the North Atlantic.Some of Blohm & Voss’s products have tagged along with the US Carrier battle group.

      I still think Blohm & Voss can build a good Cast Guard Cutter that has the speed to keep up with a Carrier battle group or Amphibious Ready group, If need be. Their designs are cutting edge, state of the Art, which says alot about German engineering. They built Corvettes, Frigates and Off shore patrol craft for a lot of countries and the US Market would be Blohm & Voss’s first chance. I think Blohm & Voss can compete with Damen Group for the Future OPC

      If you look at the MEKO CLS, MEKO® 100 Patrol Corvette or the MEKO® D Corvette, both can be optimized as a Cutter, you just take the hull and propulsion, minus any naval weapons the US Coast Guard wants or expects in the near or distant future. The MEKO CLS, MEKO® 100 Patrol Corvette or the MEKO® D Corvette can be turned into a US Coast Guard Cutter If you look at it from a stand point of advances in Technology and use of automation to reduce the numbers of people required to crew a cutter.

      Reply ↓

    • The speed at which range is calculated can have a very significant effect, since horsepower requirements and consequently fuel consumption approximately double when the speed goes up 4 knots.

      For instance my 82-83 Jane’s indicates that the the 210s have a range of 6,100 miles at 14 knots, but only 2,700 miles at 16 knots. (That doesn’t sound right, 14 may require only one diesel while 16 requires both, but still the range at 16 should be higher.)

      Some other examples from the same source:

      327 8,000 miles at 10.5 knots, 4,000 at 19
      311 (a good example since it had four engines) I recall their best range was enough to theoretically circle the earth (presumably running only one engine), but at 18 knots max range was 8,000 miles. using calculations like the ones below I would calculate that the ranges would be 12,444@14 and 17,778@10.

      Since the OPC is expected to have a range of approximately 7,500 miles at 14 knots (536 hours), if we assume our OPC has four engines and that 14 knots is achieved on only one engine, then using two engines to go 18, doubling the hourly fuel consumption, we could reasonably expect that the same ship would have a range of about 4,800 miles at 18 knots.

      There are some cases where this sort of thing does not work, specifically in the case of the FFGs, they really did not have an economical slow cruise mode because they had only two turbines and no cruise diesels. The turbines had high fuel consumption even at idle and could not operate economically at the low power outputs that were all that is necessary to cruise in the low teens.

      So a ship that appears to have an inadequate range quoted at 18-20 knots, may (or may not) have an adequate range at 14.

      Reply ↓

    • @Nicky, “Also Chuck, have you factored how many times the Future OPC may have to RAS in it’s lifetime”

      What do you think RAS has to do with this discussion? When we are working as a CG unit, ships virtually never RAS because there are no replenishment ships around.

      Reply ↓

    • @Nicky, “Chuck, I was just asking because I wanted to know if the Future OPC is ever going to RAS or RAS with smaller patrol boats.”

      A requirement for these capabilities is included in the spec as currently written.

      Reply ↓

      • Okay, just wondering because maybe in the future, our OPC is going to be far away from port and maybe that capability should included.

  3. Since when was the Last time the US Coast Guard cutter has ever Deployed as part of a Carrier Battle Group or an Amphibious ready group.

    The only reason why I look at that as a capability the US Coast Guard should have is because who knows what could happen in the next 20 to 50 yrs down the road. Will our cutters in the next 20 to 50 yrs down the road have that kind of capability, should we ever need it. What kind of Enemies the US could be facing or the prospect of going into a global conflict with maybe China. It’s those capabilities that the US Coast Guard could have in case we ever need them when the US Coast Guard is pulled into the US Navy in times of war. It’s like knowing that the US Coast Guard dose have the capability to launch Harpoons off a 378, but we don’t use it, though we know that a 378 is capable of it and should we EVER use it, we know it could be done.

    Reply ↓

      • You have to remember who will be driving and riding our cutters the future, not us but our kids who are in elementary school right now. They are the ones who will one day run the US Coast Guard in the future. You have to look out for them and build a cutter that can be around for them.

        Also You have to build an OPC for every possibility and every contingency including the prospect of global war with nations such as China or even Iran. Who knows what our future will be in 50 yrs, but at least have an OPC that can be prepared for such future conflicts, if that ever happens within the next 50 yrs.

        Also look how long the 378’s lasted. That should tell you how long our future OPC should last as well. It should have room for future growth in naval technology including the capability of operating UAV’s like the Scan Eagle. Need an OPC that can grow with the times and be ahead of the curve as well.

  4. It may be wiser to look at the questions brought up in the 1992 Coast Guard study of roles and missions. The questions then were, “What specialized service could the CG perform for DOD in the next century, and is there a gap in DOD capabilities that die Coast Guard could fill?”

    Have the questions been answered? If not, then some time should be spent in looking into that next century, or at least into the last, to see if the questions remain valid. I believe they are, but still unanswered. I would also make the word “service” plural.

    The matter of relevance to the Coast Guard crosses many lines both military and civil. The next question should be, Is the Coast Guard relevant?

    Reply ↓

  5. The speed at which range is calculated can have a very significant effect.
    For instance the 210s have a range of 6,100 miles at 14 knots, but only 2,700 miles at 16 knots, so a ship that appears to have an inadequate range quoted at 20 knots, may (or may not) have an adequate range at 14.

    Reply ↓

  6. While reading real history at the regional archives, it occurred to me that just what makes a good cutter in size, cost, and efficiency has been plaguing the Coast Guard since 1791. Hamilton insisted upon, but did not receive, a close watch on costs. He wanted cutters that would be effective in the waters and weather of their respective districts, but he did not want to pay too much for them.

    Hamilton’s letters of 1791-1794 showed the frustration of people not doing what he asked, which was simply, to built a good and tight cutter. He become so frustrated that he ordered the collectors of customs to have their surveyors measure each of the cutters, in the same way they did commercial vessels, and have these dimensions put, not in a normal certificate, but in a registry. Although unstated, he wanted a file of proof to see if what he ordered in vessels was being done. He became his own inspector general. This did not work either, because, nearly fifty years later there were still discussions about what type of vessel, Baltimore or normal schooner, would make the best cutter for the then purposes.

    Not much has changed, but instead of being discussed over decades, the argument is quadrennial. So, here we are again, making the same arguments that Hamilton’s collectors did in 1790.

    Reply ↓

    • as i recall, hamilton was quite at odds with his collectors of customs concerning the original 10 cutters and their immediate follow ons. the local builders were asking for more money then authorized because of conditions in their aors. the authorized amounts were also low, typical even today, especially when considering the fitting out equipment.

      Reply ↓

      • Why was Hamilton at odds with his collectors and why is it that what Hamilton did back then is still being applied to Shipbuilding today

      • A few of the original ten came in on contract terms. Others did not. I suspect there were some kickback to the collectors. Benjamin Lincoln in Boston was notorious for his use of office to make money for himself. It was the cutter he had built that ran over the budget of $1000 by $440. Not a small sum. In addition, the cutter was found to be a “dull sailor” less than a year and another cutter was built to take its place.

        So, counting the additional vessel, it was a huge cost overrun. Hamilton was ticked, but remember Lincoln and he were heroes of the Revolution.
        Hamilton was on the line with the Congress. The appropriation of for only $1000 each for building the ten cutters. In some contracts this included everything, completely ready to go to sea, but this rarely happened. The issue remains alive today because people claim a ship will cost X dollars and they run over the budget, plus there is the issue of vessel purpose. There was not a consistent idea what that was.

  7. Chuck, that paper is focused on surface combatants and therefore doesn’t discuss the cheapest, most obvious solution: twin diesels, with or without a PTI/PTO (power take-in/out – a small, 200-400kw electric motor) for loitering below 8-10kts.

    That’s the solution found on most OPVs. You simply don’t need the added complexity of combined propulsion to reach *only* 22kts!

    Reply ↓

    • The top speed of 22-25 knots suggest that the ships will need something beside the simple two diesel approach that was used in the 270s and 210s, not because you could not get that much speed from two engines, but because it would probably require engines of over 7,000 each (probably much more) and they would not be economical to run at the specified 14 knot cruise, even running only one engine. So I would expect either four engines (four of the same size, or two pairs of the same type but different numbers of cylinders) or two main propulsion diesels and electric propulsion for cruise and loiter.

      The BAM (http://www.naval-technology.com/projects/maritimeactionship/) looks closer to what the Coast Guard seems to have in mind, just a little slow. Reportedly “The ship is equipped by a CODOE propulsion system. The system integrates two 4,500kW diesel engines (just over 12,000 HP total-Chuck) and two 750kW electric engines (just over 2,000 HP total–Chuck) driving two controllable pitch propellers. Onboard power is generated by four 660kW main diesel gensets (just over 3.500 HP total–Chuck) and an emergency generator rated at 260kW. The propulsion system provides a maximum speed of 20.5kt.”

      The OPC is going to need about 3,000-3,500 HP to cruise at the 14 knots included in the specifications. That suggest to me that the ships will have four engines of the same size only if the top speed us at the lower end (22 knots).

      Note that a BAM is now being used to counter piracy of Somalia: http://www.eaglespeak.us/2012/09/somali-pirates-what-spain-is-sending-as.html

      Reply ↓

      • Chuck,
        Don’t get me wrong, the Spanish Navy’s BAM ship would be perfect though I would swap out propulsion for a CODOG, CODLAG or CODAG system. I would think you get more horsepower out of the CODOG, CODLAG or CODAG system than just to diesel engines.

      • Chuck, diesels don’t lose much efficiency even at low loads.

        At 25% load, the fuel consumption penalty will be ~10%. At 40% load, ~5%. Even less with sequential turbocharging. So two large diesels of 7,000-10,000hp each can still give you good efficiency at cruise speeds of 12-14kts, and will be much cheaper over time than 4 diesels when you factor in acquisition costs (incl. smaller hull size) and maintenance.

        (There’s a nice curve for an MTU engine here: http://www.mandieselturbo.com/files/news/filesof15324/TP_V28_33D.pdf)

        Even the 3,700t Holland OPVs only have 2 diesels and can do 21.5kts. The only rationale for 4 diesels would be to get to 25kts. More cost for what benefit exactly? Be careful for what we wish for…

        CODOE is another name for what I was talking about: PTI/PTO (power take-in/take-out). One benefit of PTO is that the electrical motor doesn’t just work for you at slow loitering speeds. You can “reverse” it and use it to generate electricity in cruise, adding load to the diesel engines and thereby pushing them closer to a more efficient part of the SFC curve.

    • H K, thanks, good info. With these engines it does appear that two engines direct drive is a reasonable solution for speeds up to 22 knots, even two 12 cylinders like the Holland class appears, while four 12 cylinder engines would appear a reasonable way to provide around 25 knots and have an economical 14 knot mode.

      The Holland, like the BAM uses hybrid propulsion too. I have found reference to the motors describing them as 400 KW each or a little over 1,000 HP total so probably no more than 10knots on electric power.

      I’m still leaning toward a hybrid system as a way to get both around 25 knots max speed and great range using only two main prop diesels.

      Reply ↓

  8. Since we’re talking about foreign designs, IMHO the proper benchmarks for OPC should be New Zealand’s Protector class and the French Adroit (1,500-2,000 tons, 280-300ft). They are by all accounts extremely seaworthy and versatile despite their small size.

    Most importantly, they meet the spirit of the requirement as stated in the CONOPS, if not every single detail of the spec.

    I’ve harped on this before, but I’m worried that USCG deep-down is going to buy a mini-Bertholf… But that’s simply not affordable. If the spec leads to a 3,000t hull loaded with expensive options, then that’s not the right spec (or ship) for the job.

    Reply ↓

  9. An interesting post here:
    http://navaltoday.com/2012/09/07/indonesia-north-sea-boats-launched-innovative-warships/?utm_source=Naval+Today.com&utm_campaign=cbe6fa25a7-RSS_EMAIL_CAMPAIGN&utm_medium=email

    The vessel in question is only a little larger than a Webber class Fast Response Cutter.

    Both the hull form and construction method are unusual. It looks a bit like an Independence class LCS, but unlike those this vessel is build of a carbon fiber sandwich material.

    Reply ↓

    • Chuck it maybe time for you to step in and read Nicky the riot act about his comments. I am getting a little tired of him throwing down the race card, every time somebody disagrees with him. He doesn’t play nice with other children.

      Reply ↓

  10. There has been some unproductive, off topic conversation here. and perhaps I have been remiss in not stepping in earlier.

    I understand the frustration of some of more knowledgeable readers, because Nicky does not seem to listen or learn, but on the other hand, his opinions may be shared by others who share his questions and opinions, so for their sake I will continue to address his concerns in the hope it will be useful to others. I also ask everyone to be patient and avoid personal attacks.

    And Nicky, I saw nothing racial in the disagreement expressed, please don’t bring this up again.

    Now I am going to delete those comments, because they have no place here.

    Reply ↓

Leave a reply to H_K Cancel reply