CPV Replacement

[ancientmariner]

My last handling of a twin screwed ship , without Bow Thruster, was many years ago. Turning 180 in narrow rivers required some heavy manoeuvring . I noticed in the Manufacturers specifications for the ZF 7640 gearboxes that 4 types are on offer depending on speed of hull, vessel types, all specifications had limits of hours usage except the gearbox for continuous operations but in that case it implied that heavy manoeuvring was outside guarantee. If all these types of matters have been ironed out or limits do not exist for the NR version gearbox then maybe solid choices could be made.

[Anzac]

My last handling of a twin screwed ship , without Bow Thruster, was many years ago. Turning 180 in narrow rivers required some heavy manoeuvring . I noticed in the Manufacturers specifications for the ZF 7640 gearboxes that 4 types are on offer depending on speed of hull, vessel types, all specifications had limits of hours usage except the gearbox for continuous operations but in that case it implied that heavy manoeuvring was outside guarantee. If all these types of matters have been ironed out or limits do not exist for the NR version gearbox then maybe solid choices could be made.

I have to ask. What what be the operational rationale in attempting to take a 55m 340 tonne Naval vessel up a narrow river? If these vessels are to conduct patrols principally on the east coast would only Haulbowline and Dublin be the necessary places to worry about?

[DeV]

I have to ask. What what be the operational rationale in attempting to take a 55m 340 tonne Naval vessel up a narrow river? If these vessels are to conduct patrols principally on the east coast would only Haulbowline and Dublin be the necessary places to worry about?

At a guess, 7 day endurance, need to go into smaller ports for resupply/enforcement action, unpredictable Sea States on Irish Sea… maximum possible flexibility

[Laners]

I have to ask. What what be the operational rationale in attempting to take a 55m 340 tonne Naval vessel up a narrow river? If these vessels are to conduct patrols principally on the east coast would only Haulbowline and Dublin be the necessary places to worry about?

Dublin Port is located on a river .

[ancientmariner]

At a guess, 7 day endurance, need to go into smaller ports for resupply/enforcement action, unpredictable Sea States on Irish Sea… maximum possible flexibility

Indeed as you say. Also outside of Haulbowline our access to berths is determined by harbour authorities. In the case of Dublin you are sent through the east Link Bridge to the South Wall with the width of river wall to wall about 100m diminishing westwards to O'Connell Bridge. You have to crab to the centre of the river and turn your 85m ship on the spot, then line up for the exit span and wait for it to open. If all the bits are reliable then no problem.

[na grohmiti]

Indeed as you say. Also outside of Haulbowline our access to berths is determined by harbour authorities. In the case of Dublin you are sent through the east Link Bridge to the South Wall with the width of river wall to wall about 100m diminishing westwards to O'Connell Bridge. You have to crab to the centre of the river and turn your 85m ship on the spot, then line up for the exit span and wait for it to open. If all the bits are reliable then no problem.

More than one Irish Naval vessel has come foul of the East Link in the past, if I recall correctly. How did P31 fare in that situation? Were her rudders independant? Could she swing unassisted?
I know it has become common practice to get assistance from tugs or rope boats when coming alongside in the Basin lately, even with those ships fitted with bow thruster or loiter drive.

[Anzac]

At a guess, 7 day endurance, need to go into smaller ports for resupply/enforcement action, unpredictable Sea States on Irish Sea… maximum possible flexibility

The Lake Class on an east coast New Zealand patrol at 16kts takes 2 days and 13 hours to conduct a 960nm patrol from the Marsden Point Oil Refinery the most northern port to Bluff the most southern port and the Tiwai Aluminium smelter (Both places of strategic interest and vessel traffic). Another example from Devonport NB it takes 3 days to travel the 1140nm to Port Suva in Fiji, which they have done from time to time. Note both return trips are within the 7 day 3000 nm endurance period.

In the context of 163nm in sailing distance between Dublin and Haulbowline at its patrol speed of 16 kts it is just 10 hours. It is just 6 hours sailing the 90nm from Haulbowline to Rossclare and 7 hours to get across the 109nm to Liverpool if one wanted to pay your neighbours a visit.

Thus you can probably guess my complete scepticism about any need to duck into a small tidal river port or two just a few miles up the coast unless their was no mission planning conducted prior to getting underway - which would not happen in the first case.

Start and finish at Haulbowline!

[na grohmiti]

The Lake Class on an east coast New Zealand patrol at 16kts takes 2 days and 13 hours to conduct a 960nm patrol from the Marsden Point Oil Refinery the most northern port to Bluff the most southern port and the Tiwai Aluminium smelter (Both places of strategic interest and vessel traffic). Another example from Devonport NB it takes 3 days to travel the 1140nm to Port Suva in Fiji, which they have done from time to time. Note both return trips are within the 7 day 3000 nm endurance period.

In the context of 163nm in sailing distance between Dublin and Haulbowline at its patrol speed of 16 kts it is just 10 hours. It is just 6 hours sailing the 90nm from Haulbowline to Rossclare and 7 hours to get across the 109nm to Liverpool if one wanted to pay your neighbours a visit.

Thus you can probably guess my complete scepticism about any need to duck into a small tidal river port or two just a few miles up the coast unless their was no mission planning conducted prior to getting underway - which would not happen in the first case.

Start and finish at Haulbowline!

The vessels they replace spent much of their service life "showing the flag" at our smaller harbours. Harbours that usually would only be frequented by 15m fishing vessels, and smaller leisure craft, with maybe the occasional 2000T coaster.
Part of their role involved visibility, as a deterrent both at sea and ashore. Consider also if a FV is arrested, it could be escorted to the nearest port, where the skipper would face the local judge pending bail etc. Many of the fishing ports are located in one horse towns, far from civilisation...well far from normal infrastructure at least. Anchoring off is of course an option, but not always a practical one.
Prime example here in Wicklow.

[ancientmariner]

The stated need for a continuing Naval presence in the Irish Sea is Brexit related. The Government want two CPV types based on the East coast in Dublin or Dunlaoghaire. A 10 hour trip to an intervention is a bridge too far. It's up to the Navy to make the right choices. The P31 had two synchronised rudders set inside the propellers by a couple of feet 600mm say. The screws as far as I remember turned outward on it's own side. Planned manoeuvres usually worked, Best ship ever.

[Anzac]

Look if you guys are going to buy the Lake Class of the RNZN you may as well (actually should) acquire this maritime domain intelligence system from us at the same time as it expands the operational capability and vessel productivity by a significant quantum across the whole EEZ.

https://starboard.nz/

Starboard MDIS helps nations tackle complex maritime challenges, ranging from risk assessing arriving vessels to detecting illegal fishing and uncovering non-reporting dark vessels.

I have had a look at the berthing facilities up the East and South Coast of Ireland and the VIIA and VIIG areas as published on the Irish Marine Institutes Atlas. There are a couple of minor ports where the IPV's can berth going on where they have visited down here (though very occasionally and not for years). If a Peacock can get into Kinsale or Castletown Bere (Both nice places BTW) then a Lake Class will certainly have no issues. What does strikes me is that we are talking about very small distances and that the VIIA and VIIG zones are not exactly large.

In fact the ability to berth at Haulbowline and Rossclare for replenishment or embark/disembark, if based in Dublin/DunLoaghaire as proposed, needs to only be the principal operational consideration if focused on post Brexit FFV's/Dark Vessel tasking as there are often sensitive and sensible OpSec protocols at play. Ocassional places like Kinsale or Castletown Bere for a bit of 24 hour shore leave and replenishment mid-point on 14-28 day tasking fine.

[ancientmariner]

Our monitoring capability is augmented by the monitoring centre based at Naval Base . They spotted a contact down off the NW African coast that had been off screen for a couple of years, after some surveillance an EU intervention was made and 250,000,000 Euro of solid cannabis was found. The MC is part of a European effort at improving overall surveillance.

[Sluggie]

Dingle was always a great run ashore in a Peacock.

[Graylion]

What about Damen Stanpatrol 5009? Axe bow fof improved seakeeping. Stick a SeaSnake 30mm on it and call it good.

[na grohmiti]

What about Damen Stanpatrol 5009? Axe bow fof improved seakeeping. Stick a SeaSnake 30mm on it and call it good.

Looking at a 3 year lead time at best there, given its not a standard design and would require fitout & layout internally to customer needs.
Other options are available ready to sail tomorrow if necessary.

[Graylion]

Looking at a 3 year lead time at best there, given its not a standard design and would require fitout & layout internally to customer needs.
Other options are available ready to sail tomorrow if necessary.

Which ones apart from the RNzN boats?