EPV for naval service

[ancientmariner]

you just calculated the volume of a block. For a ship you'll need the block coefficient, for simplicity's sake assume .5 so we are talking ~6.3 Gg displacement

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Block Coefficient Cb is likely, I hope, closer to .75, especially if the stern is near full width and immersed at operational drafts. the tonnage may be approaching 9000 tonnes. I should have included Cb. The volume given was not of the block but of the amount of water displaced by the ship immersed to 5 meters.It's the volume of water adjusted by the SG of water in which it floats to give displacement.

[Graylion]

Endurance Class: 141 * 21 * 5m, 7.6 Gg. This gives a Cb of .513, So I'd say .5 is a decent approximation.

https://en.wikipedia.org/wiki/Endura..._platform_dock

[ancientmariner]

The vessels has a standard displacement of 6,500 tonnes at a lesser draft than that at loaded displacement which is stated to be 8,500 tonnes. Allowing for salt water I would put her Cb at .58.

[Graylion]

anyway. my point is that this is not a 12 Gg ship, but a 6.5 Gg ship ... Can we stop buying toys please? KTHXBAI

[ancientmariner]

anyway. my point is that this is not a 12 Gg ship, but a 6.5 Gg ship ... Can we stop buying toys please? KTHXBAI

I concede your principal point. The ship in loaded terms would be close to 8000 tonnes. However the requests for expressions of interest will be around a ship 130 X 20 X 5 meters approx. If the ship has a chance of Home maintenance then it must be no bigger than 140 X 21 X 5.5 as the drydock locally is constrained in beam width of ship. A ship with uplift of 2000 tonnes, properly outfitted for role, and with topline defensive equipments should be more than a toy.

[Graylion]

I concede your principal point. The ship in loaded terms would be close to 8000 tonnes. However the requests for expressions of interest will be around a ship 130 X 20 X 5 meters approx. If the ship has a chance of Home maintenance then it must be no bigger than 140 X 21 X 5.5 as the drydock locally is constrained in beam width of ship. A ship with uplift of 2000 tonnes, properly outfitted for role, and with topline defensive equipments should be more than a toy.

There is always H&W

[na grohmití]

There is always H&W

Not in the shipbuilding business any more. Just repairs and conversions.

[Graylion]

Not in the shipbuilding business any more. Just repairs and conversions.

I thought we were talking about repairs just now? ie the ability to drydock NS vessels?

[na grohmití]

Inconceivable sending a ship overseas to a foreign country for regular refits. Particularly when there is a functioning dockyard less than a km from the Naval base.

[Laners]

Inconceivable sending a ship overseas to a foreign country for regular refits. Particularly when there is a functioning dockyard less than a km from the Naval base.

Well the ships are built abroad , so what's the difference .

[na grohmití]

Well the ships are built abroad , so what's the difference .

Where do you put the crew when the ship is gutted. This is a constant problem the NS never addressed, even in Haulbowline. One wonders if the fact the Flag is an ingineer he may come up with a workable solution.

[DeV]

Inconceivable sending a ship overseas to a foreign country for regular refits. Particularly when there is a functioning dockyard less than a km from the Naval base.

Well if it was so big it didn’t fit in it’s drydock...

[hptmurphy]

Well if it was so big it didn’t fit in it’s drydock...

then the country needs a new dry dock!

[Laners]

Where do you put the crew when the ship is gutted. This is a constant problem the NS never addressed, even in Haulbowline. One wonders if the fact the Flag is an ingineer he may come up with a workable solution.

Leave period and dry docking go hand in hand , a visit to a UK yard would be a day trip with a delivery / skeleton crew .

[DeV]

Leave period and dry docking go hand in hand , a visit to a UK yard would be a day trip with a delivery / skeleton crew .

So no NS personnel undertake an maintenance or other activities during drydocking?

[na grohmití]

That's the dockyards job. In many cases there is nothing to maintain anyway as the ship can be a bare metal shell.

[DeV]

That's the dockyards job. In many cases there is nothing to maintain anyway as the ship can be a bare metal shell.

In 2009 the contractor was NS personnel (probably on other taskings). Have things changed?

[na grohmití]

It depends on the work being done.

[ancientmariner]

In 2009 the contractor was NS personnel (probably on other taskings). Have things changed?

When a ship is to enter a Drydock, a Specification of work to be done is previously drawn up, and submitted to the contractor for bid cost. In our case while the Dock is unitary, there may be more than one contractor capable of doing the job. Drydocking is done on a time basis, for hull painting , but may also occur due to a ship/sea interface problem, such as a build up of growth slowing the ship or inlet/outlet malfunctions. While in drydock crew may be involved in maintenance work that does not create civilian/ union unrest.
When a ship enters the naval dockyard for a maintenance period it can be carried out by Naval personnel only, or Dockyard and naval personnel working on separate systems, or Dockyard personnel only. In the last two cases work specifications are drawn up and costed as if for a civilian yard.

[DeV]

Typo on my part - during drydocking ship’s crew do undertake maintenance work to supplement the civvy contractor (I assume different tasks (eg there isn’t a NS/civvy mix of people working on the hulk)) at least that was the case in 2009

[na grohmití]

Typo on my part - during drydocking ship’s crew do undertake maintenance work to supplement the civvy contractor (I assume different tasks (eg there isn’t a NS/civvy mix of people working on the hulk)) at least that was the case in 2009

As I said, it depends what work is being done. Naval crews are skilled workers, but there are some jobs that are best left to contractors. Not all occasions the ship is in drydock are for pure "drydocking". Mid life refits are also done here. I think it was 2007 when every inch of paint was removed from Eithne's upper decks by abrasion blasting. This involved erecting a scaffolding "tent" around the areas being worked on to prevent harmful dust getting into the armosphere. This is a very hazardous task that must be carried out by people who do it regularly. On the same occasion the ship was completely rewired, and the ECDIS upgraded. Yes the Naval crew could do it, but it would be more efficient to get a crew of civvy contractors in.

[Tempest]

https://m.facebook.com/story.php?sto...00001411435392

I hope the new EPV will cope with these conditions?!?

[Anzac]

https://m.facebook.com/story.php?sto...00001411435392

I hope the new EPV will cope with these conditions?!?

This footage is actually of the MV Suilvan then operated by Strait Ferries in New Zealand between 1995-2004 leaving Wellington harbour for Picton on February 6 2002. It sunk off Suva Harbour Fiji in 2015.

The EPV will no doubt be substantially larger. The Suilvan built in 1974 had just 250 lane metres was only 3636 GT and 86m.

[na grohmití]

Did that used to work the Scottish Isles for Calmac? Quite small for a ferry. About the same dimensions as an OPV. Close coastal waters in shallows like that are not a good environment for ships like that in a storm.

[Pegasus]

Yes it did - https://en.wikipedia.org/wiki/MV_Suilven