Calling all Oliver Hazard Perry-class FFG fans

[Dave from Downunder]

Thanks guys - i went back and have read the whole thread

Fletcher - Those decals from Darren are yet to be printed - I emailed him las week and he has suggested Fall (so i am hoping available by the end of teh year.

Willie - Your skills and patience are amazing!!! Any further photos. I noticed the template you used for the helo deck markings was a HMAS PArramatta tittled sheet. One of our ANZAC class ships. (note i live about 10 minute from parramatta the city)

Dave

[el Cid]

Anyone know why the rudder is offset? Is it due to the torque of having only one screw?

Yes, exactly. To counter the "prop walk" of the single screw.

Cheers,

Keith

[matrose73]

Anyone know why the rudder is offset? Is it due to the torque of having only one screw?

Yes, exactly. To counter the "prop walk" of the single screw.

Cheers,

Keith

Actually, nothing to do with the "prop walk", which remains present. It is so the shaft can be pulled if it should have to be replaced without having to also remove the rudder (which would have to be done if the rudder was directly behind the shaft and screw.)

[el Cid]

"Steering Gear - The steering gear is a simple ram unit with two electric steering gear pumps. The single rudder is offset 18 inches to starboard to give the ship an even turning radius, regardless of direction of turn."

[Guest]

"Steering Gear - The steering gear is a simple ram unit with two electric steering gear pumps. The single rudder is offset 18 inches to starboard to give the ship an even turning radius, regardless of direction of turn."

Interesting. This is not what they were teaching when I went through the FFG Basic Engineering Course a dozen years ago. Of course, the instructor was an ENC, not someone from the design yard, so it may have been whatever he had been taught way back when and been repeating ever since...

[el Cid]

During ESWS quals many moons ago I seem to remember someone mentioning the shaft removal/rudder interference issue, but I think it was considered a side benefit of the rudder placement.

Lots of ship classes have rudders that interfere with shaft removal. Is pulling a prop shaft a common job?

Cheers,

Keith
FFG-8 (1982-1987)

[Neptune]

I doubt it is. On merchant ships the arrangement is nearly always a single prop with nearly immediately behind it a rudder. To remove the shaft they first remove the rudder. Doesn't happen much though, could be different with warships.
I think the placement is perhaps due to the characteristics of that propellor. It's fairly common that ships with single props (again merchant experience, not sure wether it's the same for military, but educated guess tells me it is) turn shorter in one direction than in the other. That is mainly caused by the single left or right turning propellor. If going astern the ship will also swing to one side due to the propellor. Putting the rudder offset might counter this tendency of turning shorter in one direction and/or astern.
I heard the Perries have two small auxiliary thrusters to "get home", perhaps the placement of these thrusters influences rudder placement? I don't know where they are located, so I can't make any guess on that...

[el Cid]

"I heard the Perries have two small auxiliary thrusters to "get home", perhaps the placement of these thrusters influences rudder placement? I don't know where they are located, so I can't make any guess on that..."

The Auxiliary Power Units (APUs), which pivot 360 degrees, are located below the bridge (approximate ship's pivot point) and are retracted up into the hull except during slow-speed precision maneuvering (eg. mooring) or as you mentioned, for emergency "get home" propulsion. I can't imagine any relation to the rudder offset.

Cheers,

Keith
FFG-8 (1982-1987)

[Unicorn]

Hi Guys, I've just posted a series of photos of HMAS Sydney that I took yesterday here in Melbourne.

http://davidgatt.id.au/

David Gatt

Many thanks David, an excellent resource.

Your images will be of great interest to Task Force 72 members, especially given the number of 1:72 Adelaide class FFGs currently being built.

There are at least five that I am directly aware of, Adelaide, Canberra, Sydney, Darwin and Melbourne. That is in addition to the various models that have already been completed.

Thanks again

Unicorn

[Unicorn]

In the spirit of giving back, here are some images of a RAN FFG model modified to the proposal offered to the RAN for the FFG upgrade program by Tenix Shipbuilding of Australia.

Tenix contacted a member of Task Force 72 with a requirement to have a model of the proposed mods available at short notice. To complete it in time he modified his own model of HMAS Adelaide to the new design and at Tenix's request re-badged it as HMAS Newcastle. 06.

You can see the changes to radars, directors, the reshaped funnel, filled in bridge wings, new decks and other, less obvious changes.

In the end the RAN chose to go with another suppliers proposal, leaving the modeller with his model which he kept in this configuration, changing it back to HMAS Adelaide's hull number, 01.

Sporting HMAS Newcastle's 06 hull number


Back to carrying Adelaide's number.






Unicorn

[Willie]

Willie - Your skills and patience are amazing!!! Any further photos. I noticed the template you used for the helo deck markings was a HMAS Parramatta tittled sheet. One of our ANZAC class ships. (note i live about 10 minute from parramatta the city)

Hi there Dave and all,

Thanks for your kind remarks, but honestly, if I can do it, it means anybody can...

As for new pics I have a couple of them more. I have already closed the structure. All the bulkheads are badly bent in length, and displaced almost 2 mm. outwards, so firstable it was necessary to correct all fixing lines with stretched sprue, and then instead of glueing, I had to stitch the bulkheads to the main deck with blocks of Evergreen.

The lines are perfectly flat on deck, and I needed only an extra drop of poly to seal the beams off completely.

Very best regards,

Willie.[/size]

[Willie]

Hi all again,

To close the upper deck was an interesting affair as well, because the deck was so bent when set in place that it was making something like waves in many places, and was sunk in almost 1 mm. in some other points. Really, nothing in this kit seems to be OK.
My solution was to set some stretched sprue in lines again, pressing them to place with the deck piece while the glue was still fresh, without allowing it to stick or dry, something quite delicate, because otherwise all tall elements on deck would be falling to either side, and to reverse the fall with plastic and sandpaper would be quite exasperating as well. But I think I could make it to set even in all the length. Then I had to add some more sprue to all the seams, sand them, then add some putty and sand again. Now, at last, there are no cracks or seams to see anymore.

The hangar bulkhead is perfectly closed as well, and I think the effect is quite good.

The fire test is naturally to set all the elements on deck, and check wether they are vertical or not...

...And they are.

Very best regards,

Willie.[/size]

[Willie]

Hi again,

As the main deck is already closed, it is possible to start drilling the holes for setting the parts in their places. The original drills were not correct, and had to be closed in the most part. All the pieces have now to be presented to find out the relative distances between them. As this is the first time I do this I have taken a couple of pics so that you can see the overall appearance at the moment :

And some more details :

And now this starts to look like F81 Santa Maria in the fall 2006.

I hope you like it, and very best regards from this side of the North Atlantic,

Willie.[/size]

[orb]

Fantastic work Willie. Keep it going!

[Dave from Downunder]

I can only find one fault with it Willie.
The screw (Prop) seems to be in the wrong place.
I think it should be below the water line as it may interfer with helo op's

Seriously - looking great
Dave

[Guest]

Lots of ship classes have rudders that interfere with shaft removal. Is pulling a prop shaft a common job?

I'm not sure that I would call it a "common" job, as it's very infrequently done, but having to remove a rudder does make the job significantly more expensive than not having to do it. I've not served on an FFG that had to replace the shaft or screw, but I did take the USS JOHN PAUL JONES (DDG 53) through her 10-year drydocking as Chief Engineer, and we had scheduled both CPP hubs for refurbishment, and ended up replacing both shafts due to some issues with corrosion. (DDG51 class rudders, BTW are offset inboard of the screws, allowing the shafts to be pulled without having to remove the rudders -- I've seen pictures that show this well, but couldn't find one in my quick google image search.)

Days in drydock, independent of any other work, are hugely expensive -- so saving 3-5 days (or more) by not having to pull and replace the rudder if the shaft needs to be pulled is a significant chunk of money.

I do, BTW, also find the reason of the rudder being offset to allow for turns to port/stbd to be the same diameter, as least somewhat persuasive -- although I would bet that it is only true for a certain range of speed and rudder angle combinations. I can tell you for a fact that the amount of TIME that it took to do a complete 360 degree turn at high speeds and rudder angles (for instance, when executing an Anderson turn for a man overboard, or during torpedo evasion drills), was different depending on whether the ship was turning to port or starboard.

Cheers,
Joel

USS STEPHEN W. GROVES (FFG 29), 1997-1999
USS VANDEGRIFT (FFG 48), 2000-2002

[navydavesof]

are the FFG's getting RAM's to replace thier forward missle launchers?

It has not come to being yet so it might not at all. The USN has instead been putting Mk38 Mod2 guns up there instead

[Brett Morrow]

Anybody have any pics of the APU`s, manouvering trusters, which I assume are fitted to both short and long hull versions, and also a good shot of the elongated sonar of the extended hull unit, which is very different to the early version dome sonar.
Cheers, Brett M.

[Guest]

Anybody have any pics of the APU`s, manouvering trusters, which I assume are fitted to both short and long hull versions, and also a good shot of the elongated sonar of the extended hull unit, which is very different to the early version dome sonar.
Cheers, Brett M.

Brett,

As far as I am aware, there is no difference to the actual hull-mounted sonar between the short-hull and long-hull FFG's (US version). Both have the SQS-56. The long-hull FFG also has the SQR-19 towed array (TACTAS - Tactical Towed Array SONAR). The TACTAS handling room is located on the port side of the ship all the way aft on the DC deck, immediately below the flight deck. The array itself is made up of 20 40-foot modules, each approximately 4-inches in diameter. The array is deployed from a hole that is located on the port side on the stern transom.

The image of USS RENTZ (below), although a long-deck, lacks the hole for the towed-array. (It also lacks the RAST tracks that would indicate that it was a LAMPS III capable ship.)
http://www.navsource.org/archives/07/im ... 074604.jpg

The image of USS DOYLE (below) clearly shows the hole port-side on the stern transom, through which the SQR-19 is deployed.
http://www.navsource.org/archives/07/im ... 073933.jpg

The attached link below is to a couple of pages of a book on shiphandling that has a picture of an FFG APU. The picture is a bit disorienting, as it appears to be the starboard APU, but the picture is framed upside-down.
http://books.google.com/books?id=zehsDH ... &q&f=false

Cheers,
Joel

[Brett Morrow]

Thanks Joel for the link to the APU , obviously the only bloke who knew where to look.
I was already aware about the towed array, my question on the Sonar was in relation to the Hull capsule, pics of the early version capsule show it a different shape to the `Teardrop`
I was curious as to, looking at the Teardrop capsule front on , if the port/starboard sides which meet the hull are sloped inwards, somewhat like a bulb, or angle outwards following the curve, or are vertical.
Can`t find any good clear shots of the capsule anywhere.
Cheers, Brett M.