For anyone wondering, the problem was too little engine power. I updated the recommended horsepower for each prop

Should not be required. If you can't fix your problem you could send me a blueprint and I can have a look

Should I have a catch block to support the weight of it? I just had it placed on a steel tube directly in line with the engine. Blueprinted ships I see in workshop have pulley+catch block systems. I was just worried about doing that because I haven't tested catch blocks much since the CE update

Make sure the prop is not colliding with something. That is definitely not normal. I can run it perfectly fine myself

maybe 1 rpm

It should work with a large prop. How much rpm are you getting?

I have a huge engine sunk below the water line (with an air-compressor) and water/oil inputs, but I cant seem to turn a large propeller with it? Medium propeller works fine but looks really wonkey on a ~200 foot boat. The huge engine says it makes 2680 horse power, and the large propeller says it needs 50-300 horsepower? It feels like there should be something in-between 250kg and 3000kg. Unless I'm doing something wrong? I've tried steel tube and round timber for connection, don't want to mess around with catch blocks on DS

I have attempted to attach huge propeller to 2x2 size axle. But it can't be attached to center, because it was made before pulley and more catch block mod is made.

It looks slightly odd for huge propeller to attach on 1x size axle, but it works. It would be nice to have pulley that can be attached to 2x2 size axle and propellers too, though.

Ship example with huge propeller: https://steamhost.cn/steamcommunity_com/sharedfiles/filedetails/?id=2373845027

Not quite aestetic ship, but it is usable and can be easy reconfigured. I think that I have near limit how fast ship can be with single propeller ~120 km/h . Additional engine seems that does not help much, just make things even more unstable.

the loss is probably countered by the power increase by having a much smaller shaft. The length does not only cause big rotation loss but also its diameter

that is if you set them up perfectly so that the grids are orientated exactly the same

i always thought the rope connection was almost lossless, how much energy are we talking about? they always seemed extremely smooth to me, when the ropes did not break on me ofc

it would :D
But that is fine because you could place the other prop on the side and using a rope will always give you a lot of energy loss anyway

what if the props are connected via ropes instead of via a shaft? would that "cheat" the system?

every prop gets 10% less thrust for every other prop. So your total thrust will be: 1: 100%, 2: 180%, 3: 240%, 4: 280%
So at 4 props you gain very little. Remember it also takes energy to spin the props so at 3 you might already have trouble spinning them at max speed.

by 10 percent do you mean of the total power so 100% -10 -10 -10 etc, or do you mean out of total so 0.1^n ?

air props follow same rules. I also checked the code and you lose 10% power for every prop

reason i keep asking all these questions is because i am attempting to push ship building in this game to its limits, the last ship of mine was 3/4 the length with a smaller beam and a lower draft and that was already by your own words the largest ship you have seen. I keep trying to slap on more armour, more engines, more turrets, larger turrets etc. and for this i need every piece of data that would allow me to go even larger. so if i am able to put more power into the ship it can only mean good things

brings up the question, is the same restriction in place for the air props?

ok, thanks for the info

I think the propeller description talks about this?
Every prop you add you lose efficiency on all props by I think 20%. If you have more engine power than your prop can use it is better to use 2 or 3 props but once you have 4+ you lose power.
I only suggest doing this on medium or small props. The huge prop its weight alone will make it not worth it and you likely can never spin it fast enough to require a second prop

thx for the tip, i got the vessel going at 4m/s+ thanks to that change. Does stacking several props on the same shaft work? i did do some tests in the past but they where inconclusive.

i will try that, thanks for your help

There is some sort of bug in the game where the longer you make the shaft the less speed it will have. So because you likely have a very long shaft even with that many engines your not getting a lot of rotation speed. a fix would be to connect the shaft with a rope connection but this can be quite complicated. You can also just not use a long shaft. I think even one or two huge engines is all you need for a huge prop if you use a very short shaft

Long way of saying perhaps you could up the power/ rpm of those props? maybe add even bigger props, but right now idk how to make my ships faster. Should i maybe focus on reducing draft making them wider, should i make them narrower increasing the draft? I am kinda lost for ideas at this point.

i have just made my ship undergo speed trials and i cant seem to get it going faster then 2m/s. The propellers in my opinion are quite under powered as for the same engine power i have been able to get some quite high speeds with the air propellers sequenced up. My ship has 4 shafts each with a huge propeller and 21 huge engines powering it for a total of 84 engines. This takes up majority of my internal volume on the lower levels and is quite hard to control as if i start by taking control of the engines at one end i get the disconnect warning by the time i get to the last few engines. i have not yet started adding things like armour and steel cladding to the weaker parts of the ship, though the conning tower is in place and so is 1/2 turrets. this means that these engines cant get the ship going at a lower displacement then the one the final version is going to have.

Following your advice i have laid down a new ship,. it will take a month or 2 before it is finished as i do have uni to attend to. but here is a picture of the power plant and bottom hull, lets see if this can get me to like 10 knots https://steamhost.cn/steamcommunity_com/sharedfiles/filedetails/?id=1876477183

The major problem with not achieving high speeds is that the rudder just hangs there and does not do much and thus the ship is almost impossible to turn. Differential thrust does not also turn it. But I guess I will have to sort that out through more trial and error, but thank you for the tips and for taking time out of your day to asses that hunk of junk. I hope you did not pay too much attention to that turret as I have not worked out all the kinks in the traverse mechanism.

In that case i will make the required modifications, however it would be nice to propel that sort of ship. my main(kinda) issue is that drag irl a function of the draft(duh) and the square of the velocity(duh.). My draft is fucking enormous however 3.5knots is not a very high speed especially for a warship and thus the square is not all that high. I was hoping to get it going at 20 knots when I started building... but 10knots would have been fine however due to the thiccness of that craft I did not even achieve that(with the air props it is doable).

Your ship is enormous haha. Its 2 million kg! Heaviest ship I have seen by far.
But I have no real issues with the propellers. They spin really fast and I got this extremely heavy ship up to 1.8 m/s which is not that bad.
But I don't think you get much performance boost from that many engines. There is something weird with the physics and a very long shaft like that will greatly reduce the rotation speed. You might get the same speed with just 4 engines. Probably better to just use less engines and more propellers if possible.

also i have experimented with reduction gears on ships in the past and they 1, cant take the torque and 2 when they do the game does not register that the prop is connected to an engine and thus you get zero propulsive power at all. i have experimented with various gear ratios but none of them work

i know that my friends often had trouble viewing the ships as they are quite large so the game often likes to give up, but lets hope that if it is in the form of a world you will be able to view it

this is the world instead https://steamhost.cn/steamcommunity_com/sharedfiles/filedetails/?id=1854374977

You said to use steam engines or "clang" to power them what exactly is clang?

it does require the steel blocks mod, and a few others, but since you have created about half of them i do not think it will be a problem for you

https://steamhost.cn/steamcommunity_com/sharedfiles/filedetails/?id=1853278827

do you have a blueprint of your ship? I can take a look at it

i do not think the huge propeller is tweaked correctly, i'v got 2 of them each on a separate shaft with 15 huge steam engines powering it each which takes up 2/3 of a ships length and i can barely do 1m/s. i have checked that they are both are spinning correctly, i have made sure all the engines are spinning in the right direction and the propeller is submerged (up to just above its center point) i have made sure all the engines are connected(which btw the game sometimes struggles with and does not connect blocks to engine outputs) and i am a bit lost for what can be done at this point. it is not an efficient method of propelling a ship seeing that if i where to take a quarter of the engines and a a stack of huge air propellers it would make this ship go at over 10m/s which is a bit high but acceptable. tldr: props are not a worth while use of space for the power they provide

Thank you for not stopping working on mods

Updated

Noobs hes working on the water mod it has some bugs

Hello, please update your mods to the new version.

combine engines. The engines with double output can be attached to eachother

how do you get 400 hp for gaint propellers??!!?!?!?!

@peaceman, if you have seen those old trailers (or what ever they are) on the ME's store page, you can see some old mechanical blocks in some of the videos. You could remake them to the newest version of ME :)

Only issue is the dependency in the files. If we use a mod like Water with Layers/Coal mining then this mod causes a crash due to repeat calls for /tide. That is one of the issues with the auto dependency thing

what I did is exactly how a mirrored version would work, except visualy the model is not mirrored

what im doing is placing 2 side by side to propel the ship forwards
the idea for a mirrored version is to have them spin opposite directions and still look uniform

flipping one would cause one to thrust forwards and the other backwards, and thus just rotate the ship

anyways it is just an idea, and its your mod so you do you

I have made it so when you flip the propeller it will produce thrust in the other direction

is there a chance to get mirrored versions added?

I added it. I planned to do this but forgot, thanks for reminding me :D