Shipbucket

Although I do not have much time (i'm building my house), i keep on working on several of my AU designs.

The main of it is my Cretan Republic.
This navy is not signatory of Naval Treaties so it has no legal weight limits for its ships. It has to use as few as possible crew, have great range to reach its distant trading posts. The cretan engineers are quite obsessed with fire arc and quick target change.

I wish to use a diesel electric power plant, i consider it has the following advantage:

Diesel engine:
- operating simplicity (less crew),
- robustness (less maintenance>less crew) ,
- fuel economy (greater range).

Electric transmission:
- no need for heavy and complex gearbox,
- more electrical power available in the ship to run assistance systems (less crew),
- flexibility of implementation (Engine and transmission can be split).
Admitting that those advantages are for real (?), are they already in the 30's/40's?

It appears also that diesel engine needs smaller exhaust (?).

I'd like to use the same configuration Gollevainen choose on his finnish Kullervo (her smokestack his hidden in the tube mast). admitting it is functional for a vessel this size (?), is it to for a capital ship ?

Should i post it in the "GENERAL DISCUSSION"?

_________________
"You can rape history, if you give her a child"
Alexandre Dumas

JE SUIS CHARLIE

Hi

Diesel eletrics were chosen for the OTL Finnish armoured ships mostly becouse they were designed by Germans, who wanted to experiment with such propulsion onboard for evaluating its purposefullness in possible future german ships. In theory it appeared practical and attractive solution mostly becouse of the size and weigth issues, and economicality, which specially attracted Germans. The actuall solution was not that succesfull, the entire construction was crumbesome and the transmission weigthed lot more than the actual powerplant, and together it didn't offer any practical advance over simple and more common steam engines or even turbines, I don't know how it would have worked on larger ships, with larger marginals, but in small coastal defence ships, every ton and centimeter in draugth had to be carefully studied.
I choose Diesel eletrics in my AU becouse of attaining much of plausability and IMO AUs with wrong decissions, miss-investments and general failurers analog to real life are lot more intresting than ones with superships designed with deep hindsight considering practical proplems.

_________________
Shipbucket mainsite, aka "The Archive"
New AU project "Aravala"

My main question would be why does the Cretan Republic (I assume its based in OTL island of Crete ?) need range ? (especially for Capital ships who have more range than small ships anyway) Where are your trading posts and how far are they away ? (and can you really send Capital ships to help them past Gibraltar/Italy/Malta and Suez in war time ?)

IMO you would want a fleet like Italy and France with very fast short range ship ? (none of that helps having Diesels, apart from for your fast small MTBs)

I also don't think that 1930s Diesels (or DE) had robustness (less maintenance>less crew) so will still need lots of maintenance.

Re - more electrical power available in the ship to run assistance systems (less crew),
I don't think you have much need for electric power in 30s ships (no radar/computers/etc)and I don't think assistance systems will work with 1930 control tech.

Re - less crew without lots of computers/control technology don't you need lots of men to move switches/reset fuses so not sure the saving are really very great.

Hi waritem,

In addition to the other stuff, I really would emphasise the size - while diesel of the era were relatively efficient, to get a lot of power required large - unfeasibly large - diesels - if you compare the Deustchland class to, say, the Town-class, the Town class is physically smaller, but not by much, yet manages to fit in a 82,500 shp plant on the later models of Town-class compared to only about 52,000 shp on the Deutschland-class. Adding in electric drive, for all that I've gone and done it on the AU I've got, adds even more space requirements.

That said, there are some other advantages that you've touched on - I'm not sure from the navweaps article whether this is due to using electric training and elevation motors or some other side-effect of electric transmission (in which case I'm unsure if it would carry over from TE to DE transmission), but it seems to make more power available for those training and elevation systems. Also, physically de-coupling the diesels would let you isolate them acoustically (which you probably don't care all that much about) and also mean that you can just run the diesel at it's single most efficient (or powerful, depending on your requirements) speed, whatever speed the propellers are turning - this is where TE used to score, particularly over direct drive, letting the turbine spin up to more-efficient rpms without affecting the screws in the slightest. Electric drive, again according to the navweaps article, is reputed to be easier to fix and gives you more scope with arrangements - turning corners on a drive shaft could be challenging, electric drive doesn't care nearly as much about that - but I suspect that the separate generator and motor will be more complex than the comparable gearbox rather than the simpler, more robust system you've described.

Hope that helps (and I hope it makes sense!),
Adam

_________________
Public Service Announcement: This is the preferred SB / FD font.

NSWE: viewtopic.php?f=14&t=5695

I think exactly the same.
AS i've said in my "IMPERIAL IRANIAN NAVY 1937 PROGRAM":
"in my AU i don't look for the best but for something realistic (almost......
So if a ship is not more silly than something that existed, it's ok."

So i understand that, in your opinion, chose diesel electric drive is (maybe) a failure (small, big, or huge.....) but a realistic one.

One question:
What to you mean exactly by "larger marginals"?

_________________
"You can rape history, if you give her a child"
Alexandre Dumas

JE SUIS CHARLIE

I think what Golly means by that is that large ships tend to have some more 'expendable' weight than smaller ships, where every pound counts. Therefore the large ships can get away with having diesel-electrics and the extra weight the system adds overall.

_________________
Salide - Denton - The Interrealms

I am not very active on the forums anymore, but work is still being done on my AUs. Visit the Salidan Altiverse Page on the SB Wiki for more information. All current work is being done on Google Docs.
If anyone wishes for their nations to interact with the countries of the Salidan Altiverse, please send me a PM, after which we can further discuss through email.

yea pretty much what ezgo said.

_________________
Shipbucket mainsite, aka "The Archive"
New AU project "Aravala"