LE Roisin performance

[Orang]

Hello all,

I'm interested in hearing any comments that you might have, positive or negative, on the performance of the Roisin or Niamh vessels as they relate to the design of the ships. Have any of you been on board the vessels? Were there complaints, or positive remarks? Are they generally capable of performing their intended missions? That sort of thing.

I'm a naval architect and I am presently curious about the design philosophy behind the Vigilant, Roisin, Niamh, and NZ project protector OPVs (all relatively similar designs).

Any insight you might have would be appreciated.

[GoneToTheCanner]

hi Orang
Can you nip over to the "Eithne Upgrades" thread next door and make an input about recoil forces? I doubt the figure of 7 tonnes per sq.ft myself.
regards
GttC

[Orang]

Done and done. I think your doubt has more to do with the confusing units used rather than the legitimacy of the number. Unfortunately, I don't have much experience with weapons systems and thus can't comment on whether or not the number is legitimate.

With 100 views and no responses to the topic, I'm starting to hear the crickets chirping, so maybe I'll try to open it up a bit.

This is the design philosophy used for the Roisin and Niamh:

http://www.akeryardsmarine.com/ship_patrol.html

In a nutshell, designing an OPV to commercial rather than naval surface combattant standards to bring the capital cost down to levels that are accessible to the small to average navy.

Do you think this is a good idea?

[Goldie fish]

As an outsider, though not unfamiliar with ships the first thing that strikes you about the P50 class is the space.
They are quite broad beamed, and consequently have lots of deck space, both internally and externally. Crew accomodation is also quite spacious, and this helps considerably making long patrols more bearable when you do not have to share an 18foot by 12 foot cabin with 20 other people(possibly an exaggeration, just to make a point). The RN are also coming around to this way of thinking in their newest class of patrol vessel, the River. Passageways below decks are also considerably wider. You can even pass someone in the passageway, without becoming intimate with them while doing so...
The Changing room for Boat crews, while a simple addition has also been the subject of great praise. Its great to be able to Dry the wets, without wetting the drys at the same time.

Outside of accomodation, compared to the earlier vessels, the wheelhouse is also very roomy. On the short trip, as a "guest" that i spent aboard, I found it was possible, as a non crewmember to remain in the bridge, yet not be in anyones way.

Structurally, though I'm no expert, there was some comment about minor flaws with L.E Roisin. She lost a Bilge Keel early in her service (replaced under warranty), and was also damaged while proceeding to the rescue of the Canadian Sub that got into difficulties of the Northwest coast. However the flaws were rectified in L.E.Niamh, and its fair to say the damage was caused by the strength of the seas rather than the weakness of the design.

The Caley Davits (Combined with the Delta RIB)were also a fantastic addition to the Naval service, first seen on this design. It makes the practice of small boat handling at sea far safer for the crew,though effer cranes are still carried for the smaller Sea Rider.

I think the real key in discussion of the type though is the crews opinions. I have yet to hear crew complain about the ships. They complain about being away from their families for prolongued periods on the ships, but not of the ships themselves.

[Orang]

Thanks for the input GF.
I know in the new New Zealand vessels crew comfort was a concern as they wanted to keep personnel happy and interested.

I have a feeling the LE Roisin crew just got lucky that the design philosophy of a commercial-oriented vessel provides far more space for quarters than a naval vessel.

[Farel']

One shortcoming in design I have heard is the shortage in bunkspace. There is no real capacity for Special Forces, accomodation for trainees is also very limited, accomodation for other service providers Coastguard, police, fisheries officers is virtually non existant. There is no flexible carrying space for a few containers - the deck space I understand is suited for one 20ft TEU.

In terms of stabilisation they are fitted with active stabilisers - however increasingly work in rough weather means slow speed so the idea of some for of tank stabilisation might be better for very slow or stop operations.

It is being suggested that larger seariders with diesel and waterjet might be advantageous.

[Aidan]

Again, as an 'outsider', but one with a quasi professional interest in the NS, the size and crewing of the OPVs was the one thing that stood out the most.

I was on board both at the same time as Naval Officers from a number of countries, and they, to a man, commented that the design philosophy was unusual and unlikely to ever work for them. They were generally very impressed by the ships (and the beer) but were less certain about their use in other services. In their cases (other EU Navies) the investment and shiny toys went into new frigates or LPV types, while Fisheries Protection and Patrol craft were very much second tier vessels. The size, fit (in terms of bridge equipment in particular) and relative comfort that the crew lived in on the P51 and 52 were all beyond the 'requirements' of their services. In each of their case, patrols tended to be much shorter and the sea conditions better, and there was much less emphasis on putting boarding parties on board vessels. And questions were asked about the need for a 76mm Oto on a ship that spent most of its time on fisheries patrol ...

On the flip side, they also pointed out that the vessels had little in the way of real military capacity, and couldn't really be used asuch in a deployed situation, apart from blockade or general sea control duties (not surprising given that they were never designed for it).

One particular individual, from a medium sized and very flat Northern European country, would have taken the Niamh home though, if he thought he couldv'e gotten away with it.

[af22]

i have served on both & yes to the space & comfort being a blessing on long patrols usually 23 days which is the norm for the LPV's, alot of the early problems found on the roisin were indeed sorted on the niamh like the positioning of the junior rates mess on roisin it is just forward of the steering flat & the seating area with tv & dvd system are up against this bulkhead it is not uncommon to see the sky viewing card fly across the mess if she is doing any bit of speed & turning . it is also very noisy in there i think the last noise level survey that was carried out was borderline & that was not done with the ship doing any serious manouvring its like sitting in engine bay of a tractor when she is doing above 15kts & turns . on the niamh it was moved futher forward to where the galley is on roisin & the dry goods stores & fridges moved to where mess was. but as for stablilty go there are very comfortable in bad weather alot more that the older ship & my stomach will second that lol . as for mantinance i can mainly only speak for the seamans side of it & they are very easy to keep painted clean etc.yes there is very little area for extra personel its can take 45 thats with one full time in the sick bay. you colud set up bunks in areas like the gym but would not be very comfortable there on long journey to deploy troops etc. overall a great addition to the ageing fleet lets hope the next few are at least just as good

[hptmurphy]

Okay lets look back to the Deirdre then.as an OPV she was leagues ahead of any other type of vessel in her class at the time. A survey carried out in about 1979 by the RN concluded that to maintain the type of duties required for FPVS...the comfort level would have to be of the type offered by the Deirdre type of vessel.

I accept the submissions by those who have served on her..but bear in mind..again..she was a class leader..and will always be subject to critiscism. To be improved on in follow on vessels.

Lets face it ..It was only when Aoife was comissioned had the P20s been perfected.Aisling was the best ship in the navy for a long time

No doubt .. a second module in the P30 class would have moved on from Eithnes failings..and lets face it.some of those are still only being sorted.

If and when..the blue green machine arrives..it will be subjected to the same scrutiny.

Always to be aware..these are not pure warships...P20s were based on a trawler hull

P31 was mostly drawings and models

and the P50s were bought off the shelf..without too much development..

Its not an eternity ago when guys were still living in mess decks...and there was a lot of dead trees in the building of ships...

be a little greatful please..

[Goldie fish]

It would be worthwhile for the NS to send some of their younger crews on exchange with other navies, if just to see how good they have it at home.

[af22]

Its not an eternity ago when guys were still living in mess decks...and there was a lot of dead trees in the building of ships...

be a little greatful please



i am not saying we are not greatful as i said p51&p52 are great additions and sorry if my problems with them seem trivial to you but it those TRIVIAL things that cause tension among crew & the way the crews are being caught for extra patrols & time in shortened people are going to sea stressed & slightest things can cause a blow out believe me not uncommon to see someone lose the plot over noise & vibration in mess on P51 , basically all im saying is current crews are great ful & the man asked for peoples opinions on the ships i was giving mine having served on both & said overall great addition so is that not greatful enough !!!!!! would a personal letter to the flag be better lol

[Goldie fish]

Dear frankie...

(Older members will get it)

[Orang]

and the P50s were bought off the shelf..without too much development..

Can you elaborate on this statement?
As far as I know, they were based on the Mauritian MCGS Vigilant.

[Dogwatch]

hpt never did 220+ days at sea either. As orang says ships weren't bought off the shelf, they were designed specifically for the NS, using a Vigilant hull as a basis with specific NS requirements... far from off the shelf

[Goldie fish]

Ah he did....the David F is at sea isnt it?