Turbo electric engines - Use for....?

[vanDyck]

I mostly ignored turbo electric engines. Is there any sweet spot, where they have advantage over Diesels or geared turbines, and if yes for what types of ships?

[Rear]

Steam Turbines give you more HP per engine ton, but they don't have the best funnel capacity or fuel efficiency, so they're quite good for saving weight but ships might not have the best operational range unless you add a bit of fuel. They also suffer slightly from smoke interference which could decrease base accuracy depending on the ship design.

Turbo-Electric has a range of really nice bonuses at the cost of a much lower HP per engine ton than Steam Turbines. Using this will probably completely eliminate smoke interference and engine vibrations, so it's possibly the best type of engine for gun accuracy outside of cruising speed. As Yaivenov says it does provide a nice cruising speed but I typically try not to lower my ship speed during battles because high speeds give enemy ships a debuff to their accuracy (~16% for every 3knots).

Diesels are really cheap and fuel efficient, providing the highest operational ranges. They save a bit of weight by cutting out the boilers completely. They don't have good HP per engine ton but this is offset by their other bonuses. Probably their only downside is that you start to get a bit of engine vibration again which will slightly decrease gun accuracy, but on the other hand you don't have to slow a ship down much to reach their max accuracy bonus from cruising speed.

Gas Turbines are the most efficient in terms of weight, but also the most expensive by far. They don't provide good cruising speeds, and a lack of funnel capacity gives them significantly lower operational range than diesels.

Comparing costs & maintenance for the same 1940 Light Cruiser, only changing the engines:

Steam Turbines: Cost $1,045,089,000 Maintenance $36,682,620
Geared S.T. : Cost $1,144,195,000 Maintenance $42,220,800
Turbo-Electric: Cost $1,711,157,000 Maintenance $41,581,120
D. Geared S.T. : Cost $1,405,633,000 Maintenance $46,807,570
Diesel 1: Cost $1,547,043,000 Maintenance $34,808,480
Diesel 2: Cost $1,725,286,000 Maintenance $35,713,420
Gas Turbines: Cost $2,238,080,000 Maintenance $60,428,160

This ship with Turbo-Electric instead of Double-geared Steam Turbines will make up the difference in cost ($305,524,000) within 59 months, so as long as you keep the ship in service for at least 5 years it's still worth the cost imo.

Ships with high hull form will have reduced engine weight. This means that engines with low HP ratios become much more viable because engine cost is linked to engine weight, while none of their other bonuses are (especially Maintenance Cost reductions). You can stack high hull form with reduced beam & draught to get free engines that weigh practically nothing and can reach top speeds without breaking a sweat.

In campaign, probably stick to fast designs that have high operational range because the devs have stated that this will help power projection/army logistics. At high Hull Forms this will probably mean Diesel>Gas>T.E. but at low hull forms it's probably gonna be Diesel then T.E. depending on funnels/tech etc.

In custom battles, generally if you don't care about cruise speed use Gas Turbines & if you do care about cruise speed use Diesels.

[vanDyck]

Ok, wow, thanks so far.

[gigamelon1981]

I generally use steam derivatives. like the D. Geared has reasonable stat and engine vibration. But late into a campaign i usually switch to Diesel as it matures, since Diesel at campaign recieves a lot of buff. Diesel however doesn't bring a good engine vibration into table. It brings good cruise speed, efficient fuel, reasonable shaft HP/ton.

Then, I''m using T.E. for a sniper ship. It has the lowest engine vibration of all.
I also use it for some academy missions where technology given is usually spotty.
Like, hey, it didn't give me radar. Oh fine, it give me Turbo Electric, so i will use it.

[hurepoix]

Anecdote ; during WWII the jadgpanzers Ferdinand/Elefant used a comparable engine system. It had no gearbox, and in theory forward and backward maximun speed was the same.

[jfoytek]

Nothing wrong with Turbo electric...

Its got great Range and range matters....
Its maintenance cost is good...
It has a good cruising speed....

In a ship where you have extra weight to play with its definitely a great option...

[lllib]

Originally posted by jfoytek:

Nothing wrong with Turbo electric...

Its got great Range and range matters....
Its maintenance cost is good...
It has a good cruising speed....

In a ship where you have extra weight to play with its definitely a great option...

I was wondering what happened that my ship costs skyrocketed on my latest battleship design... Yep, Turbo-electric.
Cost with Turbo-Electric Drive: 3,489 billion, maintenance 61 million
Cost with Geared Steam Turbines:1,695 billion, maintenance 41 million
Plus switching to Geared freed (on my 48K N3 hull) extra 2172 tons to play with.
I'll check on other hulls but for this one the features don't seem to justify the costs.