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  • Royal Navy can't handle heat?

    Britain's Royal Navy warships are breaking down because sea is too hot

    http://www.cnn.com/2016/06/09/europe...ips/index.html
    (CNN)Britain's £1bn ($1.4bn) warships are losing power in the Persian Gulf because they cannot cope with the warm waters, MPs have been told.

    Six Type 45 destroyers have repeatedly experienced power outages because of the temperatures, leaving servicemen in complete darkness.
    During the Defence Committee hearing on Tuesday, MPs questioned company executives about the warship failures.
    "The equipment is having to operate in far more arduous conditions that were initially required," Rolls-Royce director Tomas Leahy said.
    Managing director of BAE Systems Maritime, John Hudson, supported Leahy's comments, adding: "The operating profile at the time was that there would not be repeated or continuous operations in the Gulf."
    The Royal Navy's Type 45 Destroyer, HMS Defender sails into the HM Naval Base Portsmouth for the first time on July 25, 2012.




    Leahy told MPs that turbines do not generate as much power when they run in a hot environment, which is not recognized by the system.
    "This is when you get your total electrical failure," Leahy explained.
    "Suddenly, you have lost your main generator on your system and you are plunged into darkness."
    However, a spokesperson from Britain's Ministry of Defence (MoD) denied this, telling CNN: "The Type 45 was designed for world-wide operations, from sub-Arctic to extreme tropical environments, and continues to operate effectively in the Gulf and the South Atlantic all year round."
    MPs were shocked when they heard about the failures.
    "I'm just absolutely stunned," said Douglas Chapman from the Scottish National Party.
    "It's a £1 billion asset that you're putting into a war zone, and we don't know if these people will go in there and come back out alive because there might be a problem with the power system on the ship. I'm just astounded."
    Crew aboard HMS Daring, the largest and most powerful destroyer warship ever built for the Royal Navy, leaves Portsmouth Harbour on January 11, 2012 in Portsmouth, England.




    The British MoD says Type 45 destroyers are the most advanced warships ever built by Britain and are the backbone of the Royal Navy's air defense capability. They first went into service in 2006, and are due to last 30 years.
    The committee also raised fears about the cost of repairing the ships and whether it would delay the release of Type 26 frigates which are to replace older vessels.
    "If this were a major war, our 19 destroyers and frigates are effectively 13," Former First Sea Lord Alan West explained in the meeting.
    "I think that our nation is making a terrible error in allowing this to happen ... I understand they have a program for resolving it, but it should be being done much more quickly."
    West warned further delays would leave the UK "grossly inadequate" for required tasks.
    "There is almost no extra money available this year, and we are really strapped next year. The Government aren't coming clean about that," West said.
    "We have run out of money, effectively. Therefore, they [MoD] have pushed this program to the right and that is bloody dangerous."
    Read this and it made me think of desertswo...

  • #2
    Same here regarding Desertswo.

    I saw that story on-line a couple of days ago, and began reading that first link (MPs have been told). It is a little lengthy, and seems to cover a lot. Did not yet see where this issue was discussed, so I downloaded it for later. Still haven't gotten back to it.

    For anyone who may not be familiar, it is true with all steam systems that raising the condensing temperature of the steam condensate (such as with higher temperature sea water) will lower the energy output of the turbine being driven, whether the turbine is driving a generator or main propulsion. It is effectively the same as lowering the steam pressure. It is the differential pressure (between the supplied steam on the inlet of the turbine and the condenser on the outlet of the turbine) that determines power output. In short, lower steam pressure or higher condensing pressure equals less power out.

    What I find incredible about this report is that this difference results in a shutdown on those ships. I suspect a ploy to increase funding. That, or a software issue. Such as computer thinking "Unexplained power reduction? Must be a problem. Better shut down before damage occurs." In which case a software change to allow the computer to recognize why the reduction is occurring. This could be "...the program for resolving it..." the above article mentions. Of course, this is speculation on my part... .

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    • #3
      Originally posted by Cruiser View Post
      Same here regarding Desertswo.

      I saw that story on-line a couple of days ago, and began reading that first link (MPs have been told). It is a little lengthy, and seems to cover a lot. Did not yet see where this issue was discussed, so I downloaded it for later. Still haven't gotten back to it.

      For anyone who may not be familiar, it is true with all steam systems that raising the condensing temperature of the steam condensate (such as with higher temperature sea water) will lower the energy output of the turbine being driven, whether the turbine is driving a generator or main propulsion. It is effectively the same as lowering the steam pressure. It is the differential pressure (between the supplied steam on the inlet of the turbine and the condenser on the outlet of the turbine) that determines power output. In short, lower steam pressure or higher condensing pressure equals less power out.

      What I find incredible about this report is that this difference results in a shutdown on those ships. I suspect a ploy to increase funding. That, or a software issue. Such as computer thinking "Unexplained power reduction? Must be a problem. Better shut down before damage occurs." In which case a software change to allow the computer to recognize why the reduction is occurring. This could be "...the program for resolving it..." the above article mentions. Of course, this is speculation on my part... .
      Well, crud. Just plain crud. Getting so long in the tooth, and so long-removed from my Navy days that I completely forgot hardly anything uses steam any more.
      So, even though what I wrote about steam is correct, it does not apply here. The HMS Defender, like most of today's ships (if not all- which I think is the case) uses gas turbines.

      I'll try to keep that in mind, so as not to waste everybody's time.

      Still, waste heat must be rejected. And the sea is a good heat sink, into which to reject that heat. And when it comes to rejecting heat, the same principles that apply to pressure apply to heat. The greater the difference in temperature between where the heat is, and where you want it to go, the more heat will be transferred. So, a warmer sea means slower, or less, heat transfer. And the warmer any piece of equipment that is being cooled will run. To compensate for a warmer sea, there are a number things that can be done. The simplest of which is larger heat exchangers. The most obvious example of this can be seen by anybody who has recently replaced their home air conditioner. The government-mandated increase in energy efficiency is most easily achieved by increasing the size of the outside heat exchanger. The new unit is likely either taller, or now has a 4-sided coil vs a 3-sided coil. Of course, there are more severe space limitations on a ship than there is on the side of a house. But there are other options still available. And it's not like there isn't a precedent for operating in warm waters.

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      • #4
        Originally posted by Cruiser View Post
        What I find incredible about this report is that this difference results in a shutdown on those ships.
        This is what causes the shutdown (omitted by most newspapers reporting on it), from the first linked one:

        "In an integrated electric propulsion system, the electrical system loads the WR-21 up to its 21 MW power rating, and that is what it is expecting to see. If you then operate in a hot environment, the WR-21 cannot deliver 21 MW any more, but the electrical propulsion system does not know that and still demands it. It continues to load it, saying, “Where’s my 21 MW?” The net result is that the engine cannot deliver any more fuel or power, so the speed of the generator starts to drop off. We then have under-frequency protection as part of the system design and eventually the breaker will open because of the low frequency of the gas turbine. That is when you get your total electrical failure. Suddenly, you have lost your main generator on your system and you are plunged into darkness. It is not a fault of the WR-21; even if it were a single-cycle gas turbine it would still suffer the same fate in those circumstances. It is a law of physics."

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        • #5
          Originally posted by kato View Post
          This is what causes the shutdown (omitted by most newspapers reporting on it), from the first linked one:

          "In an integrated electric propulsion system, the electrical system loads the WR-21 up to its 21 MW power rating, and that is what it is expecting to see. If you then operate in a hot environment, the WR-21 cannot deliver 21 MW any more, but the electrical propulsion system does not know that and still demands it. It continues to load it, saying, “Where’s my 21 MW?” The net result is that the engine cannot deliver any more fuel or power, so the speed of the generator starts to drop off. We then have under-frequency protection as part of the system design and eventually the breaker will open because of the low frequency of the gas turbine. That is when you get your total electrical failure. Suddenly, you have lost your main generator on your system and you are plunged into darkness. It is not a fault of the WR-21; even if it were a single-cycle gas turbine it would still suffer the same fate in those circumstances. It is a law of physics."
          Thanks for posting that.
          I finally got around to reading to that point in the article.

          Seems they should be able to shed some non-critical loads to maintain engine/generator speed.
          Perhaps at 21 MW, in full battle readiness, all non-critical loads have already been shed.

          Auto and motorcycle racing people are quite familiar with reduced power output in hot environments. As the witness stated, "It is a law of physics".

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          • #6
            Originally posted by Cruiser View Post
            Perhaps at 21 MW, in full battle readiness, all non-critical loads have already been shed.
            No, that can't be right. At full battle readiness you're not actually firing weapons. So there must be electrical capacity held in reserve to fire them.

            And "... the electrical system loads the WR-21 up to its 21 MW power rating...". So what does this mean, I wonder. That all electrical loads are not only on-line, but operating at full load? Each drawing maximum amperage? Meaning that all motors are operating at full speed (actually, greatest amp draw is when starting a motor from an at rest condition)? I have a decent electrical background, but this statement has me a bit bewildered. Because it gives me a visual image of a ship with everything operating simultaneously. As in guns and missile launchers wildly aiming here and there, things raising and lowering, other things going back and forth, up and down... . A ship possessed.

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            • #7
              I saw comments I other sites which stated the ambient temp in the Gulf is 91 degrees F

              And tap water in Kuwait was at 108

              No wonder it's an issue!
              “Loyalty to country ALWAYS. Loyalty to government, when it deserves it.”
              Mark Twain

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              • #8
                No doubt the Cameron government will solve this by reducing UK green house emissions, which will serve as a moral beacon to encourage everyone else like the Russians and Chinese to reduce their emissions, which (along with generous payments to 3rd world countries actually harmed by global warming) will eventually arrest and reverse global anthropogenic temperature rise, which will eventually allow the type 45s to operate in the Gulf during the cooler periods of the year.

                Meanwhile the down times will serve as helpful quiet periods for sailors to reflect on the shames of Britain 's imperial past.

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                • #9
                  Surely something as critical as the power supply for a command and control system should be independent and separate from the main generator, Can't believe there isn't an auxiliary supply either.

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