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  • Originally posted by ropebag View Post
    Wasn't there a problem with the fresh water and fuel systems polluting each other? (Or something like that..?)
    Don't think it was as bad as that, but I understood due to the Aviation fuel tank location, it was prone to condensation, and consequently, the aviation fuel was prone to water contamination. A problem not unique to ships though.

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    • Originally posted by na grohmitÃ* View Post
      Don't think it was as bad as that, but I understood due to the Aviation fuel tank location, it was prone to condensation, and consequently, the aviation fuel was prone to water contamination. A problem not unique to ships though.
      Sorry for the dislike, fat fingers syndrome. Cheers.

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      • Originally posted by na grohmitÃ* View Post
        Don't think it was as bad as that, but I understood due to the Aviation fuel tank location, it was prone to condensation, and consequently, the aviation fuel was prone to water contamination. A problem not unique to ships though.
        as you point out the JP5 fuel is inherently prone to condensation. The on board procedure was to put the fuel through a daily cycle to remove hydration and after a laid down time , do an on board laboratory test to a clear and bright standard. The fuel also had FS 11 added to minimise icing . Ships with aviation fuel, and no aircraft, were able to keep their fuel healthy for years for visiting aircraft.

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        • The only way to prevent condensation in fuel tanks is to keep them full and away from ambient heat. Given fuel vaporises in most temps above 15 degrees celcius, this isn't always practical. Even fuel tanks on aircraft operating in warm climates are prone to condensation.
          A practical solution in future is instead of having integrated aviation fuel tanks aboard ship, instead deploy an ISO aviation fuel bowser when required. That way all your fuel stays fresh.
          Last edited by na grohmiti; 16 February 2019, 18:39.

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          • Originally posted by EUFighter View Post
            Buying a one-off design will mean a large percentage of the budget will get taken up with engineering and project managements costs. Taking the Spanish LPD program as an example the first vessel L51 Galicia cost around €140m, while her sister ship L52 Castilia cost €67m. Although not all the difference can be put down to the Galicia taking all the project costs and that GFE was not accounted for in Castilia it can be taken that between 25% and 35% of a one off design is just for the engineering/management cost. Therefore any vessels should be based upon an existing design or design series to minimize these costs and get the most ship for each €.
            We didn’t get any discount for P61 onwards. Would we have been better shopping elsewhere. Surely what with brexit, purchasing from the uk will be unlikely

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            • Originally posted by ibenji View Post
              We didn’t get any discount for P61 onwards. Would we have been better shopping elsewhere. Surely what with brexit, purchasing from the uk will be unlikely
              P64 was less than her sisters. Appledore needed the build to keep the shipyard open.

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              • We extended the payment period of the P60 class in other to save money ..... it cost us more in the longer run

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                • Originally posted by ibenji View Post
                  We didn’t get any discount for P61 onwards. Would we have been better shopping elsewhere. ...
                  I doubt it - the price from any other yard would have been similar, and the tender and contract process would have involved more cost. You'd also then have additional through life costs in running, manning, maintaining and supplying 4 ships in two classes rather than 4 ships in one class.

                  Having half the fleet made up of one class of ship is one of the brightest things the NS could have done. Over the 30 year life of the class it will save a fortune.

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                  • Originally posted by DeV View Post
                    We extended the payment period of the P60 class in other to save money ..... it cost us more in the longer run
                    We're not the first that have ended up in such a situation though.

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                    • Originally posted by ancientmariner View Post
                      Just as a matter of information I would like to know what problems hampered P31 over its lifetime other than Service choices.
                      Absolutely none... any of the choices made at dock yard level that proved to be erronous were rectified within the first few years.....Some of the percieved issues were around issues that couldn't have been foreseen at design stage ..and even then the technology didn't exist to rectify them. The Sonar was always problematic but not being an expert I don't know was it the equipment or the fit was the issue but it certainly was a ship stopper.

                      Don't think it was as bad as that, but I understood due to the Aviation fuel tank location, it was prone to condensation, and consequently, the aviation fuel was prone to water contamination. A problem not unique to ships though
                      certainly was a issue but again not a ship stopper

                      do an on board laboratory test to a clear and bright standard.
                      far simpler in that there were filter tests available to highlight water held in suspension by drawing daily samples from the main tanks. I often wondered afterward if there had been an agitator in the tank would it have reduced the likeliehood of suspended water?

                      Certainly she wasn't flawless... had there been a second one it would have been closer to perfection but such is the nature of evoloution. Deirdre through to Aisling..look similar but actually poles apart ....
                      Covid 19 is not over ....it's still very real..Hand Hygiene, Social Distancing and Masks.. keep safe

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                      • Originally posted by ibenji View Post
                        We didn’t get any discount for P61 onwards. Would we have been better shopping elsewhere. Surely what with brexit, purchasing from the uk will be unlikely
                        We did a deal for 3 ships, this spread out the costs over all vessels. It is normal to do this, but the Spanish published the costs per ship and that they put all the costs on the first ship.

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                        • I’d think that the running costs associated with crewing (nos.) of the proposed MRV/EPV would be almost as important, if not as important, as the capital cost of purchasing it, never mind the running costs of fuel, etc. of pushing at ‘fat’ ship around the seas on more mundane patrols. Agree with another poster, that only a sub-100 crew i.e. similar to existing circa 60 crews, to no more than 100 basic crew, would be allowed for.

                          That would seem to narrow the selection to only the Damen Crossover commercial/ amphib’ versions (not ‘defence’ versions) in the c.55-c.85 crew range, and the Asian, Endurance Class (c.65), or something along the Canterbury lines (c.65 crew), and would seem to rule out most of the other contenders mentioned with c.126-160 plus crews (so circa 3 x ships worth of current crew sizes).

                          Also, agree with sentiments of other posters, that Extended (size and range) OPV - ‘EPV’ may not really bring in any new capabilities – and sending crews (work/ life balance etc.!) on longer uninterrupted patrols and cruises is not an issue i think.

                          Whereas, a transport style MRV could anyway make every other ship an EPV (in range), by been able to re-supply them at sea, besides them carrying freight/ pers’ to areas of need when required, or patrolling themselves.

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                          • Also, if an MRV is selected, it should be fairly modest in size i’d think, for this country’s more modest missions, size and means.

                            Further to above, seeing as various countries around the world are planning to replace their minus/ plus 1,000 ton minesweepers, and small patrol vessels and OPVs, with larger circa 2,000 ton ships, maybe replacing the two CPVs - with helicopter-carrying, extended Samuel Beckett class, of the also Vard designed, US Coast Guard, ‘Heritage Class Cutter’ ilk (subject to having a smaller crew), would be better for commonality, and could serve as EPVs of a sort as well, could complement any modest MRV in terms of freight/ pers’ capacity, and shared helicopters, and be used for escorting/ minesweep ahead of them....

                            Or at least a replacement of the CPV’s that are larger, and can carry at least a current Air Corp AW139 sized helicopter (or slightly larger/ heavier follow-on AW149), that could better work in tandem with any MRV.

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                            • Regarding helicopters, it might be more understandable and acceptable to the public, to say that any such new MRV ship, should be capable of carrying not just the Air Corp size helicopters, but larger, Coast Guard and similar size helicopters as well (Merlins/ Commorants , M-17s etc. will mean nothing to them).

                              According to below articles, the Endurance Class are to be replaced (by a more fashionable and bigger thru' deck helicopter carrier – JMMS – Joint Multi-mission ship) after 2020 (soon after?), at approx. 20 plus years old, so possibly a contender as a ‘starter’ at least, for an MRV for the Naval Service, for a few years? Maybe around that time some 2nd hand Coast Guard (CHC owned) helicopters might also become available for purchase...

                              https://www.janes.com/article/81429/...hip-after-2020

                              https://www.youtube.com/watch?v=vCAJC3LZ6-M (re: Endurance replacement with pics' of proposed.)

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                              • Originally posted by WhingeNot View Post
                                Regarding helicopters, it might be more understandable and acceptable to the public, to say that any such new MRV ship, should be capable of carrying not just the Air Corp size helicopters, but larger, Coast Guard and similar size helicopters as well (Merlins/ Commorants , M-17s etc. will mean nothing to them).

                                According to below articles, the Endurance Class are to be replaced (by a more fashionable and bigger thru' deck helicopter carrier – JMMS – Joint Multi-mission ship) after 2020 (soon after?), at approx. 20 plus years old, so possibly a contender as a ‘starter’ at least, for an MRV for the Naval Service, for a few years? Maybe around that time some 2nd hand Coast Guard (CHC owned) helicopters might also become available for purchase...

                                https://www.janes.com/article/81429/...hip-after-2020

                                https://www.youtube.com/watch?v=vCAJC3LZ6-M (re: Endurance replacement with pics' of proposed.)
                                The organic decision/requirement within the NS is for a ship described as an MRV , on dimensions 130 meters x 20 meters x 5.2 meters, with helicopter deck facility. Helicopter decks, big enough, can land any size of helicopter compatible with those dimensions, provided the deck is also strong enough for a collapsed undercarriage landing. Any in service use of Helos, must be by the NS itself, after the P31 experience. Crewing is down to manning the ships Equipments especially in a man all stations situation. Automation of Defence CIWS systems is a help but in certain situations where stand to lasts beyond a rotation of watches," spares " may be needed to meet operational demands.

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