Shipbucket

these new dimensions result in your CoG being close to 9 meters above the keel. that is about main deck level. seems doable!

that bow still has way too much overhang, making it an structural weak point.

engines are mostly half above the waterline, because they are kind of huge
your aux generators are quite oversized too, I would go for an real auxilary enerator for port use etc, and keep the gas turbines as the main electricity suppliers.

keep in mind that the batteries will be heavy, they are filled with fluids and are compact and metal covered, so they might need to be placed near the center of the ship.

and for the bow mount. the bows on those ships are twice as high, the ships going half as fast, and the mount is 'just' an phalanx, not an multimillion dollar weapon. the arc of fire is indeed very good, but the problems you run into are these:
- waves are not good for electronics. waves crash over that bow at least in storms, in which a ship as this is at least once a year. you don't want your mount damaged or even lost because of that.
- when you hit another ship, and that is likely to happen once in each ships lifetime, you will immidiately destroy this weapon, even with the slightest bumb
- crew is not allowed that far in the front of the ship belowdecks when the ship is at sea, due to that space being the fore peak(tank).

my idea for the propulsion would be to have the gas turbines amidships and the electrical engine aft of that. the ship has less beam there, so less chance on getting damaged, the prop axis will be shorter, and you still have your 3 separated engine rooms.

acelanceloet wrote:these new dimensions result in your CoG being close to 9 meters above the keel. that is about main deck level. seems doable!

that bow still has way too much overhang, making it an structural weak point.

engines are mostly half above the waterline, because they are kind of huge
your aux generators are quite oversized too, I would go for an real auxilary enerator for port use etc, and keep the gas turbines as the main electricity suppliers.

The two diesels only supply enough power to run propulsion at 1/3 power right now, you think I should downgrade them further? That sort of makes them useless because if you take a hit and lose the turbines you can only go about 10kts without any weapons.

keep in mind that the batteries will be heavy, they are filled with fluids and are compact and metal covered, so they might need to be placed near the center of the ship.

Good point, I will look into that. The CIWS batteries were already planned to be dead amidships, but the forward weapon designated spaces, while low, are still forward of the hull. I will have to look into this.

and for the bow mount. the bows on those ships are twice as high, the ships going half as fast, and the mount is 'just' an phalanx, not an multimillion dollar weapon. the arc of fire is indeed very good, but the problems you run into are these:

True, exactly twice actually. As for "just a phalanx" you need to rememeber that weapon is the most finicky thing in the USN aresenal. You look at it wrong and its breaks. Sometimes it just breaks without even looking at it. Inherent fragility of the weapon system is not really an issue, any weapon on the forward part of the ship will take the same sea spray regardless of location and if a Phalanx can take it near anything can.

- waves are not good for electronics. waves crash over that bow at least in storms, in which a ship as this is at least once a year. you don't want your mount damaged or even lost because of that.

Not so much. I have never seen blue water over the point of the bow (I am sure its possible), what I have seen is it coming over the rails around the tip of the bow and drowning out the gun and VLS. I have seen waves bash in the bow break doors at the superstructure of a Perry too, so again the focsle is just a risky place. Even so I don't think its more than can be handled.

- when you hit another ship, and that is likely to happen once in each ships lifetime, you will immidiately destroy this weapon, even with the slightest bumb

Bow on collisions are EXTREMELY uncommon, and when they do occur they are generally with small vessels at the waterline that nobody saw a night. This would not be a concern any more than say a sonar dome that is far more expensive and more in danger from a bow collision.

- crew is not allowed that far in the front of the ship belowdecks when the ship is at sea, due to that space being the fore peak(tank).

Thats not actually true, people work in the forward part of the ship all the time. Granted in storms it is only essential watch standers but 99% of the time bosun mates are working in their spaces at the tip of the bow in a DDG for instance, as are the sonar tecks at the botton of the bow.

That being said there are no manned spaces for the bow weapon forward of the internal future weapons block.

In any case I am looking into all of this so your comments are not falling on deaf ears. I put this graphic together for comparison:



Top graphic (FFLX):

1. Internal Seamanship Deck
2. Possible anchor location (chain locker below)
3. Spaces to house forward weapon machinery, I may move this up a deck but I still want separation from the gun so it doesn't shake the electronics apart.
4. Sonar spaces

Bottom Graphic (DDG51 Flight I):
1. CPO Berthing
2. Ship Store
3. Crew Berthing
4. Crew Berthing
5. Weapons Office
6. Storeroom
7. Bosun Locker
8. Chain Locker
9. Sonar Spaces

Bow Outlines (Left to Right)

- FFLX
- DDG51
- FFG7
- Sovremenny

The first graphics show a comparison of bow utilization. Note the FFLX is far more forgiving than the Burke regarding locating crew in the bow! Honestly neither would be bad, I lived in that berthing space on my first cruise.

The second graphic shows the comparison of bow overhangs as a ratio of distance over water to height. The FFLX has five meters more overhang than the Burke, but honestly nothing that is so far out of the envelope to be outside the realm of possibility. Also note that the Burke keeps all its six tons of anchor right at the tip of the bow (6.5 tons worth plus chain), something the FFLX will not do. Assuming the forward weapon mount is around the size of a Phalanx at seven tons and some purpose built reinforcement I see no reason the weapon can't be supported.

The real issue I have with the bow mount is stability. There is a lot of movement on the bow and a direct fire laser weapon needs accuracy for seconds worth of firing. If you do the math for an aircraft sized target 50nm away that leaves very little room for excess movement. A Phalanx mount has a very robust stabalization system already but more will be needed for this weapon (why I bulged the bow out at the tip for accomodation) which could add tons of weight.

Some things I know I can do is perhaps extend the waterline hull out two or three meters to reduce the over hang of the bow and increas structural load bearing, as well as move the mount back two meters to further get it closer to the keel.

I originally thought your bow critisisms was do to wave piercing issues not structural loading, sorry for the confusion.

my idea for the propulsion would be to have the gas turbines amidships and the electrical engine aft of that. the ship has less beam there, so less chance on getting damaged, the prop axis will be shorter, and you still have your 3 separated engine rooms.

I thought about that too but if you take a hit in the middle engine space you may very well not just lose the gas turbines, but also lose the power connections from the deisels to the AIMs.

from lloyds rules and regulations 2012, Volume 1, Part 3, Chapter 2, section 4: wrote:
4.1.8 Partial or main bulkheads are to be located beneath
the ends of superstructures and deckhouses and masts and
heavy items of equipment such as weapon systems to
support and transmit the static and dynamic forces into the
hull structure. They are to be of sufficient strength and
rigidity to carry the concentrated loads imposed on them and
maintain alignment where necessary.

4.1.3 No accesses are to be fitted in collision bulkheads.
In particular designs where it would be impracticable to
arrange access to the fore peak other than through the
collision bulkhead, access may be permitted if acceptable to
the Naval Authority. Where accesses are provided, the
openings are to be as small as practicable and positioned as
far above the design waterline as possible. In such cases
access is to be by manholes with closely spaced bolts
situated as high as possible above the design waterline and,
in any event, no lower than the damage control deck.

both of these rules give problems with the arrangement of the weapon forward.

I refered to the phalanx as just an phalanx as it is an modular system, relatively easy to bolt on and relatively cheap to replace and repair. an laser weapon would not benefit from this..... also, an phalanx is quite light and does not need the structural support an heavier mount would need. and yes, I think this mount will be a lot heavier.

for the rake of the bow, I would, keeping the strength deck in mind, actually judge the l*h to be closer to 2:1. and keep in mind that the only bow that comes close to yours, that of the burke, is much bigger then your ship, near 2 times the displacement.
but! if you take off that small extension for that bow weapon, your bow comes quite close to how I would imagine it, the thing that makes it bad is that extension at the end.

collisions are uncommon in general, but all rules set up, such as the above, are based on the damage that comes from them. but, fine, I will bring my previous statement on that back to bow damage instead of collision damage, which can appear due to storms, enemies or failure of .... well anything.

if your gas turbines are taken out, you should no longer think about fighting. you must think about getting home safely.
in other words, if you carry engines around just for the sake 'if the other engines fail' you are doing something wrong already.

water loses power due to resistance if it flows, all the more if gravity is trying to get it back to the sea from the deck of an ship. due to this, the forwardmost will get the most water 'force' while the bridge gets a lot less.

and one big problem with that forward mount: it's deck penetration. you have no space for any construction below it, meaning that you will struggle with even getting the power line to it. (as that will be huge) let alone cooling. and let alone someone to build, connect, and maintain those connections in that very cramped space (I myself have been in the outher bow sections of some ships, it is quite tight in there, welders take turns in working in that kind of spaces.

ow, and also, keep in mind that your fore peak must be between 5,7m and 9,12m from your fore perpendicular. your long bow makes that that is quite an huge part of your vessel, and I think that at least your forward reserved weapon bay penetrates in the space that should be fore peak.

about not getting water over the bow. That is fully possible but that is called the: "Norwegian way of washing!"


this picture was taken when she was alongside an american tanker for fueling. Later that day there was taken a second picture of her on the way home to the base, where the only ting you could see of here was the mast every thing else was under water. but then she was traveling close to here top speed of 31 knots in bad weather. (Crazy Norwegians)


Because of this, The forward gun had to be rebuild almost every single time they was used or have been in bad weather. In the en those old 3" guns could only fire maximum 15 to 20 shots before they had to be rebuild. and all this because of water over the bow. So the last thing you need is something at the bow. And this is a Norwegian dud saying that, not a man from Holland that have education in ship design.... So if ace... say that is a No no than it's perhaps not so smart idea. But then I have seen crazy things that works nice.


BTW. When Oslo class was build they had cabins in the bow. and those that had place there was almost 80% more often to sickbay because they broke something than anywhere else in the ship. But today you can't be there anymore. "Loyd's" say so!

From when HNoMS Oslo sank:

@ acelanceloet

Very little of that Lloyd reference applies to this design question other than the part about locating weapons in the superstructure. While a agree this is generally a good idea there are plenty of examples of where this is not used (the main gun on most vessels, the VLS on most vessels, the periphery CIWIS defenses on carriers, etc.) They seem mostly concerned with weapons empacements penetrating the transverse DC bulkheads in regards to flooding. As this is as above the waterline as you can get on a hull mounted weapon that isn't an issue.

This is the THEL which is what the new weapon is inspired by:



And this is HELLADS





As you can see the THEL is actually smaller than the CIWIS in some respects (a little wider, much shorter) and far less bulky. No ammo, radar, barrels or gatling machinery. I estimate the mount itself to be no more than three tons. I will add a steath covering similar to theat for the Mk 110. From what I can tell there is no required deck penetration, the actual mount being mostly the aiming and stabilization gear vice the weapon itself. This weapon was designed to be land mobile so it has two trailors of equipment that goes with it which was to go in the designated space further into the bow.

As for the HELLADS it would have a larger mount but all its internal components fit in a B1-B weapons bay. If an aircraft can carry it there is no way it is too heavy for a frigate with the gear spread out through 1/3 of the hull. They are talking about getting this small enough to go into fighter jets. Which is good because while I want much more power out of the weapon, I don't need it to fit into or not weigh down a fighter jet.

As to the engines I don't want to power weapons for offensive actions but rather for survival. The Diesels only provide enough power to maybe get to 1/3 speed IF all their power is applied there. Thats not going to happen though because there would still be some ship services and while I don't think the concern would be getting the energy weapons or air search radars up if you already took a hit (I doubt they would work even if you had power), I would like to at least get the SeaRAM up to hopefully let you avoid another hit. I see what you are saying though. The fact is that the FFG7 is a one hit ship and I am not trying gold plate my design so perhaps the FFLX will be a one hit ship too.

I don't quite understand what you are saying concering fore peak measurements? Can you elaborate?

@huehen

That is some crazy stuff, but it is again from driving 30+ in heavy North Sea swells. You mentioned those waves routinely damaged the ships main gun and I see no reason why it wouldn't do the same to a DDG51, yet no DDG51 (nore FFG one armed bandit type) I know of has ever had its main gun damaged by weather like that so it must not be a particularly common phenomena for most ships.

So based on your two posts I spent my lunch parked at a peir with a good view of a DDG51 and FFG7 berthed bow in side by side. While eating my sandwich I noted that the the FFG bow really is a fragile thing, tapering to an actual point with little in the way of structural load bearing from what I could see. The DDG, OTOH, has a much more robust bow with a rounded point that was obviously designed to carry the weight of two anchors up there. My design has bow dimensions between the two, so with some work I still think I can get to something with a degree of the DDGs strength with the smaller profilr of the FFG. There will be a new drawing shortly.

Also, I think its become obvious discussing how to mount these weapons is not productive when we don't know what they look like or their size (including me), so since the point is to design this thing around its components I need to at least get an initial drawing out. I will work on that and post it before the next hull redraw.

Again, thanks for the comments guys!

EDIT: Couldn't help myself!



This is the THEL, a canceled project from the 90's/00's by the army to provided area defense against incoming rockets and mortors. It was successful in true to life scenarios, shooting down several projectiles in quick seccession.

If you're interested in shipboard lasers, I encourage you to read this publicly available document (PDF warning) prepared by the Congressional Research Service, last updated 22 Jan 2013. It's insightful.

Erik, thanks for the info that was a great document!

So my hull redraws are taking a bit longer than I thought but while working on them I decided I should get the weapons profile worked out as that will affect the engine spaces and thus the hull. Below are the weapons envelopes based on the current armament proposal for the FFLX.

Take a look and let me know if I missed any bases! LWS = Laser Weapons System.

Orange = Guns/Torpedo
Purpoe = Missile
Gold = Laser

Weapons are listed inside to outside. The profile is to port, all envelopes have bilateral symetry to the hull.



AAW weapons

1.) Zues LWS (5km)
2.) RIM-116/SeaRAM (10km)
3.) RIM-162 ESSM (50km)
4.) Lancer LWS AKA "Evil Eye" (60km)

NOTES:
- The Lancer LWS looses effectivness against small targets at 30km, and is only effective against large aircraft targets at the max range of 60km. Adverse weather can also greatly reduce effectivness at range.



ASuW Weapons:

1.) Zues LWS 9 (5km)
2.) Lancer LWS (11km)
3.) Mk 110 NGS (17km)

NOTES:
- The Lancer is limited in range to the horizon for surface targets. If a target is large with a high freeboard or super structure that extends above the horizon it may be able to be engaged at a greater range.
- The mk 110 can use optical fire control from the top of the mast or use OTH targeting via embarked Scan Eagle or other UAV.
- The FFLX has ten CSW stations that can mount a mix of M2 machine guns, M240G machine guns, GAU-17A, Mk 19 grenade launchers (only supported on two aft flight deck mounts) or GAU-19 (only supported on bridge wing mounts). Range envelopes for CSW are not shown.



1.) Mk-46 SVTT (11km)
2.) RUM 139 VL-ASROC (22km)

NOTES:
- The range envelope shown is for the rocket range of the VL-ASROC only, the follow on range of the activated Mk-46 is not shown.

It just occurred to me, unless this was already covered in Erik's link, that you'd want the lasers to be mounted as high up as possible, not necessarily on the bow - where it would still be damaged by a lot of wave action especially.

There are two competing interests regarding its placement, keeping in mind the this frigate is only large enough to support one large scale laser system.

1.) Range
2.) Firing arc

Since this is the primary air defense weapon the only advantage a higher placement would provide is extending the observable area inside the horizon. Right now it is 12m which gives it a roughly 11km range to the horizon against surface targets, and maybe 12km range against sea skiming air targets while only masking 20 odd degrees aft.

The only higher places to mount this weapon is either on top of the refuling stations (thats what those hatches in the protrusion from the forward face are hiding) where the forward SeaRAM is or somewhere above the flight deck. That first option would severly limit firing arc, basically to 100 degrees off the bow to either side. The second option would give you much more arc, masking only 60 degrees forward if placed in the aft SeaRAM position (30 degrees each port and starboard), but it would also have to contend with firing through exhaust gas. The thing is both these higher mounts are only about .5m to 1m higher than the bow mount, so we are talking about trading 200 degrees of firing arc for maybe 2kms im horizon range.

I am using this for horizons btw:

http://totally-cuckoo.com/distance_visi ... orizon.htm

For stability I am still contemplating replacing the Mk 110 with the laser system, but this has its own problems the most important being the absense of any major ASuW weapon. The others are that while still well forward of the forward SeaRAM mount it will still suffer a large arc reduction as well as being exposed to VLS exhaust gases when using the weapons simulaneously which for all intents and purposes makes the weopon unusable if you are launching missiles.

I am running with the bow mount for now. The next drawing will have it at least three meters back from the pointy end, and it will be inside a sealth enclosure (positive pressurised to keep water vapor off the lense when firing), I don't think the wave action will be a big concern.

I stay with the fact that it is an VERY bad idea to fit the weapon on that point on the bow.
other then that, I wait for seeing your completed hull design