navydavesof wrote:So, Mr. Freeland, what do you have in mind? Are you going to go with a shortened Nimitz-class model? Are you going to use a Kirov and build a hangar and flight deck on it to make a Western modified Kiev-class? Are you going to go as small as modifying a Slava CG with a hangar and flight deck? That might work, too!
I think I would get a Nimitz model and cut a plug out of it the length of an aircraft elevator + 1/2". That should shorten your flight deck and hull up to meet the requirements you're talking about. Then, you could literally use the kit parts to build up the CVV you're talking about.
I accidentally placed an order for all the parts I need to make my own version of a modern "reduced cost CV" in 1/350 as well the other night. Damn you, Mikes Harder Lemonade!!!
I'm starting with that 1/800 CV-63 I bought and going from there. First is figure out island placement and then see what that does to the elevators. After that, use existing deck or scratch build? I'll use phalanx and RAM as usual, but am thinking of a Mk-56 array instead of Mk-29 launcher for the ESSM. I'll have to study up a bit before I start any cutting.
I'm designing my island and have a question for the group. Assuming a similar power plant to the Queen Elizabeth class, how large should the turbine exhausts be? I can't seem to get a good view of them from all the images of the QE that I've been searching. I'm trying to keep it in roughly the same place as the original but a little wider and maybe 20% longer since I'm working in the DBR panels.
Edit: Now this is funny, I google earthed the berth she is building in and got a great topside view. A rough estimate shows two meters in diameter. God I love overheads
jasonfreeland wrote:I'm designing my island and have a question for the group. Assuming a similar power plant to the Queen Elizabeth class, how large should the turbine exhausts be?
Too many options here.
The QE-class uses CODELAG (Combined Diesel Electric and Gas Turbine).
Do you desire a top speed of 25kts+, or 30kts+?
If you want 30kts+ you need to double the propulsion plant size of the QE Class.
CV-63 was ~210MW which works out to roughly six MT30s (You could scale up from the LCS stack area).
You might also consider multiple stacks, or even outboard stacks.
Are you using direct drive turbines with reduction gears on your CVV, or electric motors and with turbine alternators and diesel alternators? Using the electric motors eliminates the need for reduction gears and potentially makes your ship more fuel efficient. The electric motors allow the gas turbines and diesels to run at their most efficient rpm constantly. If so the exhaust funnels and be dispersed to different locations and can in some cases not require tall funnels. Gas turbines, diesels, and electric motors all have lower manning requirements than oil fired boilers, steam turbines, and reduction gears. Electric motors require less maintenance and in general have a higher availability. For a modern CVV I'd expect that you would have enough diesel alternators to drive the ship up to its cruising speed and the gas turbines to provide the additional power for higher speeds.
I'm thinking integrated electric (alternators with electric motors) are the way to go. I ordered a 1/800 Ford island structure from a shapeways vendor so I will need to route the exhaust separate from the island. The outboard stacks sound interesting, any suggested design reading?
jasonfreeland wrote:I'm thinking integrated electric (alternators with electric motors) are the way to go. I ordered a 1/800 Ford island structure from a shapeways vendor so I will need to route the exhaust separate from the island. The outboard stacks sound interesting, any suggested design reading?
1. U.S. Aircraft Carriers: An Illustrated Design History by Norman Friedman
2. USS United States (CVA-58) flush deck design - the stack configuration issues are relevant
3. Look at foreign CV designs that use gas turbines as prime movers: e.g. Italian aircraft carrier Giuseppe Garibaldi (551)
jasonfreeland wrote:I'm thinking integrated electric (alternators with electric motors) are the way to go. I ordered a 1/800 Ford island structure from a shapeways vendor so I will need to route the exhaust separate from the island. The outboard stacks sound interesting, any suggested design reading?
1. U.S. Aircraft Carriers: An Illustrated Design History by Norman Friedman
2. USS United States (CVA-58) flush deck design - the stack configuration issues are relevant
3. Look at foreign CV designs that use gas turbines as prime movers: e.g. Italian aircraft carrier Giuseppe Garibaldi (551)
I've been doing some digging and noticed the IJN Soryu's stacks are outboard and angle downward. How well did that work and what kind of draft issues did it have (anyone know)? I'm guessing the exhaust below the waterline system that some smaller ships are using, won't work with something as large as a carrier?
jasonfreeland wrote:
I've been doing some digging and noticed the IJN Soryu's stacks are outboard and angle downward. How well did that work and what kind of draft issues did it have (anyone know)?
I cannot comment on the Soryu directly, but exhaust has to be routed as far away from the ship as possible.
Any design that does not have exhaust separation in the vertical plane will have stack gases blowing across the deck under some conditions and that is unacceptable.
jasonfreeland wrote: I'm guessing the exhaust below the waterline system that some smaller ships are using, won't work with something as large as a carrier?
Absolutely not, and certainly not with gas turbines.
The more I look at this, the more I think a second island is in order. If I put the Ford island forward, the angle of the DBR antennas will let me put a aft island for the stacks.
I haven't done a great deal of work yet, but here is the island I ordered. The designer did a nice job, most of the stuff he sells is a lot smaller scale. The big question is placement, is it to close to the elevators? I could put it where the original island was, but then I have to change the exhaust placement.
Nice job with the island! That rapid prototype is really cool. I may be totally missing the context of the placement, but why do you seem to have the island facing backward on the deck?
jasonfreeland wrote:The big question is placement, is it to close to the elevators?
Unless you don't want anything around the island itself (which is fine), I would say yes. However, if you would like the island to be by itself, then it works out just fine.
jasonfreeland wrote:I could put it where the original island was, but then I have to change the exhaust placement.
You could also test your modeling skills and move the elevators to accommodate your vision better
Nice job with the island! That rapid prototype is really cool. I may be totally missing the context of the placement, but why do you seem to have the island facing backward on the deck?
Your not missing context, I was in a hurry and missed it until you said anything. Nothing is glued down yet so no harm.
You could also test your modeling skills and move the elevators to accommodate your vision better
I really need to do something different with the turbine exhausts, but haven't come up with anything yet. I even picked up Friedman's carrier book via intralibrary loan, but still haven't come up with anything. I really need something like the Izumo class Island, but my wife would kill me if I ordered another one.
Damn you, Mikes Harder Lemonade!!!
