engines/motors

[frickenbarrett]

we should be able to run diesel or motor at a time, to save fuel/power at the cost of speed, also on this note I think we should the hit points on the motors and diesels to 8 each and make it to where if the hitpoints go to 4 only one diesel/motor would be disabled. This would be differnt for water damage however as I think the hit points should go donw by 2 instead of one at a time.

Just and idea

[Formous]

Being permanently stranded is not what I'd call a fun situation.

[frickenbarrett]

Originally posted by Formous:

Being permanently stranded is not what I'd call a fun situation.

well duh, thats why you save fuel by running on 1 diesel engine and have a chance to live, by having at least one diesel engine running and not having both of them get destoryed

[Formous]

Diesel in 1 engine will not work. Just having a engine run does not make it vulnerable to damage. More so, you can't run a boat on a single engine most of the time. Any boat in fact of the size of a destroyer or Uboat or larger running on a single engine is what you would call crippled and in need of immediate retreat from the theater of war. No. Turning off a engine does not suddenly make you more effective. It just forces your rudder to over steer and call a emergency situation with the captain and crew and radio report.

More so, aside from the added strain and drastically lowered thrust power, you would force the remaining engine to increase the mechanical stress on the equipment drastically. Both engines running is far less expensive then only putting one on. This is how naval engineering works. Larger ships require more engines to run. And with how Uboats are designed and function even today, you wouldn't want one engine to run. Each propeller is connected to a drive shaft, which is operated by a single engine. One off would force the boat into a huge circular drift.

[Vanguard(Aqua)]

pretty sure germans couuld slave both screws to one sides powerplant if they needed to and the diesel dosent turn the sfaft it runs a moter/generator that runs the shaft kinda like a modern day diesel electric locomotive

[Formous]

Originally posted by Vanguard(Aqua):

pretty sure germans couuld slave both screws to one sides powerplant if they needed to and the diesel dosent turn the sfaft it runs a moter/generator that runs the shaft kinda like a modern day diesel electric locomotive

True, but it still involves a fair bit of stress to the engine and a loss of power to both shafts. Not to mention what you discuss is far from simple mechanical work you could do from the interior of the sub. Sure the sub could take a engine and turn it off to repair the engine itself out at sea, most of the time, but a complete overhaul change to the mechanisms under and around the boat, regularly, is very difficult. Not to mention the speed loss, and the higher fuel burn you need to maintain even 3/4ths the original speed. The truth is 2 engines provides far more power then 1 can, and is generally a far more efficient method.

[Vanguard(Aqua)]

Originally posted by Formous:

Originally posted by Vanguard(Aqua):

pretty sure germans couuld slave both screws to one sides powerplant if they needed to and the diesel dosent turn the sfaft it runs a moter/generator that runs the shaft kinda like a modern day diesel electric locomotive

True, but it still involves a fair bit of stress to the engine and a loss of power to both shafts. Not to mention what you discuss is far from simple mechanical work you could do from the interior of the sub. Sure the sub could take a engine and turn it off to repair the engine itself out at sea, most of the time, but a complete overhaul change to the mechanisms under and around the boat, regularly, is very difficult. Not to mention the speed loss, and the higher fuel burn you need to maintain even 3/4ths the original speed. The truth is 2 engines provides far more power then 1 can, and is generally a far more efficient method.

oh i know what the germans did gave them a huuuuuge advantage so much so that everybody else copyed the designs but that dosent mean im not gonna bother explaining it to folks(if i can as best i can) the secret to there boats was the way they could clutch the shafts into the powerplant they could even if needed run the diesels AND e moters at the same time if they really had to get up and go"

[wolf310ii]

Originally posted by Formous:

Diesel in 1 engine will not work.
...

Its not that horrible.
Its true, running only one propeller is less efficient, because the standing still propeller and the countersteering produce drag, but...

The Typ VII can run one side with the diesel and generator and the other side only with the E-motor. On slower speeds thats more fuel efficient, on travel they dont run always on full speed (most time only with 4-8kt, to save fuel), so the "speed loss" is no problem.
To prevent that on diesel wears out more than the other, they just switched the side from time to time. This was a regular procedure, not an emergency.
Only a total loss of one diesel would end a patrol

[frickenbarrett]

just a simple search

https://books.google.com/books?id=9vwlAwAAQBAJ&pg=PT13&lpg=PT13&dq=would+u+boats+run+off+one+diesel+to+save+fuel?&source=bl&ots=4PXJCmkLoq&sig=ACfU3U1x17chxKIFi5MuqmbU919HsqZL1A&hl=en&sa=X&ved=2ahUKEwieoN7Jio_kAhX6IDQIHZbqDEsQ6AEwFHoECAYQAQ#v=onepage&q=would%20u%20boats%20run%20off%20one%20diesel%20to%20save%20fuel%3F&f=false

[r4y30n]

Originally posted by wolf310ii:

The Typ VII can run one side with the diesel and generator and the other side only with the E-motor. On slower speeds thats more fuel efficient, on travel they dont run always on full speed (most time only with 4-8kt, to save fuel), so the "speed loss" is no problem.

There’s still a conversion loss. If I remember right, the electric shaft ran at roughly half the speed of the diesel shaft. (All this is in the giant Type VII manual)

Plus the running engine is under higher load at lower speed. This increases efficiency up to a point but if there’s too much load you start using excess fuel to keep temps down. Not to mention the additional wear and tear.

But all this is academic, the developers are a small team spending all their time and effort fixing bugs, a feature request like this would require a serious rework of the propulsion code as well as some kind of UI to let you select these new modes. I don’t see any of that happening. Not this year, anyway.

[wolf310ii]

Originally posted by r4y30n:

There’s still a conversion loss. If I remember right, the electric shaft ran at roughly half the speed of the diesel shaft. (All this is in the giant Type VII manual)

No, diesel, E-motor/generator and propeller sitting on the same shaft, separated by clutches and run with the same speed. There is no gear between diesel and E-motor.
The diesel can make 470rpm at full load, 480rpm at overload and 490rpm at max load.
The E-motor (without diesel) can make 280/295rpm (AEG or BBC Motor) and as generator 450rpm

Plus the running engine is under higher load at lower speed. This increases efficiency up to a point but if there’s too much load you start using excess fuel to keep temps down. Not to mention the additional wear and tear.

It should be obvious that they use the diesel electric configuration only at speeds when its efficient and not at all speeds. If they have to go faster, they switch back to both diesel.
Except if they lost one diesel, but in this case, noone cares about more wear and tear

[r4y30n]

I know how the engines and motors are installed, you’re misinterpreting what I said.

From the aforementioned manual, page 141: “Diesel-electric drive allows driving both propellers even if one diesel engine has failed. The operational diesel engine works directly driving the propeller on its side. The E motor whose armature would normally run idle, works as a generator delivering power to the other ship side. The E motor on the other side drives the propeller; the diesel engine clutch is disengaged. The current from the primary E motor can either be switched in such a way that it only drives the secondary E motor or an additional light charge of the batteries takes place.”

When you run the motors that way the electric-only shaft is gonna turn slower than the diesel-driven shaft because the motor is rated for max continuous power of 238 kW vs the engines 1000+ kW, not to mention the redlines you listed.

http://www.uboatarchive.net/Manual/Manual.htm

[wolf310ii]

Originally posted by r4y30n:

I know how the engines and motors are installed, you’re misinterpreting what I said.

From the aforementioned manual, page 141: “Diesel-electric drive allows driving both propellers even if one diesel engine has failed. The operational diesel engine works directly driving the propeller on its side. The E motor whose armature would normally run idle, works as a generator delivering power to the other ship side. The E motor on the other side drives the propeller; the diesel engine clutch is disengaged. The current from the primary E motor can either be switched in such a way that it only drives the secondary E motor or an additional light charge of the batteries takes place.”

When you run the motors that way the electric-only shaft is gonna turn slower than the diesel-driven shaft because the motor is rated for max continuous power of 238 kW vs the engines 1000+ kW, not to mention the redlines you listed.

http://www.uboatarchive.net/Manual/Manual.htm

You know that the diesel dont have only on and off? They can change the rpm free from idle to max rpm.
So the diesel side and the E-motor side run with the same rpm.