Announcement

Collapse
No announcement yet.

EPV for naval service

Collapse
This is a sticky topic.
X
X
 
  • Filter
  • Time
  • Show
Clear All
new posts

  • Originally posted by ropebag View Post
    If you want to do HADR you need to be able to put JCB's ashore without the use of port facilities, that means an LCU. That also means you can bring in lorries with PSP and matting, and water purification plants, power generation systems...

    HADR needs helicopters, LCU, Engineers, loggies, and lots of satellite phones. If you're not bringing that stuff, you're getting in the way,and it would be better if you just donated to charity.
    And then you need a well deck and probably another few thousand tonnes displacement

    Comment


    • In terms of landing craft they usually start with LCVP, then go up to LCM and finally LCU. After that it is a landing ship.

      LCVP
      most common design used by Dutch and RN
      https://products.damen.com/en/ranges...personnel-1604

      LCM
      (similar to that mounted on HMNZS Canterbury, no well deck!
      https://military.wikia.org/wiki/LCM-1E
      Italian LCM
      https://www.vittoria.biz/en/c-828-landing-craft-mtm/

      LCU
      Damen version for the Dutch but RN Mk10 is very similar.
      https://products.damen.com/en/ranges...t-utility-3607

      Comment


      • Originally posted by DeV View Post
        And then you need a well deck and probably another few thousand tonnes displacement
        If you want to lug bricks, you buy a van, not a CBR 600.

        Comment


        • Originally posted by DeV View Post
          And then you need a well deck and probably another few thousand tonnes displacement
          My view of the MRV is that multi role is predominant-can be command platform-can move troops and equipment-can accept interaction with helicopters-can supply to own ships/others-can tow to her tonnage standards-can be a HADR assist vessel including evac/medical when equipped-can deliver/manufacture FW- can take/deliver shore power-can support/defend in its location.
          Hadr equipment wouldn't be a part of her everyday pay load, although she should have mobile equipment to move on board weights. Cranes would have the SWL capacity to 20 tonnes at least. The LCVP type should if possible dry load and be lowered to launch. The equipped Hadr role should include portable equipments useful in disaster areas and include JCB or CAT equipment to about 9/10 Tonnes to be discharged by Crane/Quay wall ramp from ship. Any other increase in capability in a particular role removes flexibility and is a different ship. All capabilities must be clearly seen and designed in.

          Comment


          • Originally posted by ancientmariner View Post
            My view of the MRV is that multi role is predominant-can be command platform-can move troops and equipment-can accept interaction with helicopters-can supply to own ships/others-can tow to her tonnage standards-can be a HADR assist vessel including evac/medical when equipped-can deliver/manufacture FW- can take/deliver shore power-can support/defend in its location.
            Hadr equipment wouldn't be a part of her everyday pay load, although she should have mobile equipment to move on board weights. Cranes would have the SWL capacity to 20 tonnes at least. The LCVP type should if possible dry load and be lowered to launch. The equipped Hadr role should include portable equipments useful in disaster areas and include JCB or CAT equipment to about 9/10 Tonnes to be discharged by Crane/Quay wall ramp from ship. Any other increase in capability in a particular role removes flexibility and is a different ship. All capabilities must be clearly seen and designed in.
            But isn’t necessarily the NS, DF or DoD view

            Comment


            • Originally posted by DeV View Post
              But isn’t necessarily the NS, DF or DoD view
              Like everyone else, expressing views from experience , and many ship types, in the global environment. Sailed in 24 vessels . it's also free advice for anyone interested.

              Comment


              • Originally posted by EUFighter View Post
                Why did the USN have such ships in the first place? Well they had plenty of destroyer escorts and not a lot for them to do in the Pacific. While we all focus on the big actions like Tarawa, Makin, Iwo Jima there were many much smaller islands that had to be attached and did not need a full on assault. But this was a time of learning in amphibious warfare and many of the ships types from that time are no longer to be found in service.

                Some comments brought up the Absolon class, it is close to what the APD's had with the exception it primary assault means would be via helicopter as it does not carry landing craft like a LCVP or LCM. But it weapons fit make it much better suited to the proposed mission than that in the article (SPY radar, SM missiles etc). It is likely that we could get 2x MRV's and 2x Absolon class vessels for the price of one of the proposed LRPV's.
                My reaction when I read that article was in inquiriy as to what exactly this guy was on.

                Comment


                • Originally posted by ancientmariner View Post
                  My view of the MRV is that multi role is predominant-can be command platform-can move troops and equipment-can accept interaction with helicopters-can supply to own ships/others-can tow to her tonnage standards-can be a HADR assist vessel including evac/medical when equipped-can deliver/manufacture FW- can take/deliver shore power-can support/defend in its location.
                  Hadr equipment wouldn't be a part of her everyday pay load, although she should have mobile equipment to move on board weights. Cranes would have the SWL capacity to 20 tonnes at least. The LCVP type should if possible dry load and be lowered to launch. The equipped Hadr role should include portable equipments useful in disaster areas and include JCB or CAT equipment to about 9/10 Tonnes to be discharged by Crane/Quay wall ramp from ship. Any other increase in capability in a particular role removes flexibility and is a different ship. All capabilities must be clearly seen and designed in.
                  An important point for me here is that I want the vessel to be fully diesel-electric, so it can supply a maximum of power to shore in HADR situations. Like USS Lexington did for Tacoma in 1924.

                  Comment


                  • This is already the case, Naval vessels have enough generating capacity onboard to power a small town.
                    For now, everything hangs on implementation of the CoDF report.

                    Comment


                    • Originally posted by na grohmiti View Post
                      This is already the case, Naval vessels have enough generating capacity onboard to power a small town.
                      Massive difference between your auxiliary power (maybe 2 MW if you're lucky) or your main power (maybe 10 MW) is used. USS Lexington was of the generation of US warships that had turbine electric propulsion and 130 MW available. There is a massive difference between your prime movers and your generating capacity for hotel load.

                      Comment


                      • I'm no marine engineer, but it's a figure that is frequently quoted.
                        I dont understand what you mean by turbine electric propulsion.
                        Do you mean that a steam turbine is driving a generator, which propels the ship using motors instead of a standard shaft from the engine gearbox?
                        Another option is an industrial standard generator, usually the same size as a 40 foot container. It provides all the power heavy industry needs when they go off grid during peak loads.
                        But the standard genny set up on most OPV does the same thing.
                        For now, everything hangs on implementation of the CoDF report.

                        Comment


                        • Originally posted by na grohmiti View Post
                          I'm no marine engineer, but it's a figure that is frequently quoted.
                          I dont understand what you mean by turbine electric propulsion.
                          Do you mean that a steam turbine is driving a generator, which propels the ship using motors instead of a standard shaft from the engine gearbox?
                          Another option is an industrial standard generator, usually the same size as a 40 foot container. It provides all the power heavy industry needs when they go off grid during peak loads.
                          But the standard genny set up on most OPV does the same thing.
                          Yeah that was the system the USN used back in that time period, think there were issues with them due to shock damage.

                          Comment


                          • Originally posted by na grohmiti View Post
                            I'm no marine engineer, but it's a figure that is frequently quoted.
                            I dont understand what you mean by turbine electric propulsion.
                            Do you mean that a steam turbine is driving a generator, which propels the ship using motors instead of a standard shaft from the engine gearbox?
                            Another option is an industrial standard generator, usually the same size as a 40 foot container. It provides all the power heavy industry needs when they go off grid during peak loads.
                            But the standard genny set up on most OPV does the same thing.
                            Steam turbines driving generators, driving electric motors, driving the shaft. so 130 MW electric power..

                            I am not talking about your basic genny. I am talking about the prime mover, the thing moving the ship through the water being electric,. This is _not_ your bulk standard genny.

                            Look at HMS Queen Elizabeth (the curent one) several diesels and 2 GTs providing electricity to drive the electric motors that drive the 2 shafts. Queen Mary has a similar propulsion, as does Juan Carlos. Your gennies do not nearly have the same amount of power as the engines actually propelling the ship. So I am suggesting that the ship be diesel electric driven so that she has something like 10 MW generating capacity instead of maybe 2MW.

                            So while every waship has a certain amount of generating power it is only a small amount compared to the power of the propulsion diesels. In a diesel electric drive all the power of the prime movers is available for providing electricity. In my example USS Lexington (CV-2) provided the City of Tacoma not with power from her gennies, but from her main propulsion.
                            Last edited by Graylion; 6 June 2020, 02:44.

                            Comment


                            • Originally posted by Sparky42 View Post
                              Yeah that was the system the USN used back in that time period, think there were issues with them due to shock damage.
                              Hadn't heard that. They went out of use due to weight and the restrictions of the naval treaties.

                              Comment


                              • The TE system did not go out of use due to naval treaty restrictions, many vessels had this type of propulsion installed that were built during WW2. Most famous would be the Buckley class destroyer escorts (the one from the film The Enemy Below). The main reason the USN switched to steam turbine power for their first new build battleship since they stopped build at the end of WW1 (Carolina class) was the advances in turbine technology. They started to fit high pressure turbine systems (high but not crazy German high). This allowed for a reduction on size for the same power. On the Destroyer Escort side, the challenges of war production eventually saw the replacement of the TE system with the now widely used diesel electric system, even if the former was vastly superior for hunting subs.

                                Comment

                                Working...
                                X