engine electronic controls = bad?

[Portage_Bay]

A bit more modern than WWII boats. Chinese fisheries patrol boat with 2 engines turning one prop launched in 2011. https://www.cummins.com/case-studies/two-engines-one-propeller

 

[FF]

Either or both engines can operate the prop shaft.

Disconnect either with with a lever , only hassle was dog gears required package to be stopped to re engage the off engine.

I would envision a pair of 3-71 , so cruising on one would be efficient.

If rated under 100HP each , it might get by the Air Police.

Both would have a hyd pump so either could power a hyd cruise gen set, windlass , and other big loads. Scuba compressor or eutetic refrigeration.

A single engine on the shaft with the other simply running the hyd. would allow a great (75 ? HP) , and not time limited bow or stern thruster.

 

[Hippocampus]

Wonder if another way to achieve this would be to have prop(s) turned by electric motors. The props could even alias. The electric motors wouldn’t care where the power came from. One, two or three gensets or alt. energy or batteries or like boomers nuc. piles. Believe some current “hybrid” boats are already set up with something similar avoiding the mechanical complexity diesel or battery. Single failure point would be the electric motor but given light weight of a electric motor v diesel going to two props wouldn’t add much weight.

 

[backinblue]

Kind of like this

https://www.greenlinehybrid.com/en/propulsion

 

[twistedtree]

Either or both engines can operate the prop shaft.

Disconnect either with with a lever , only hassle was dog gears required package to be stopped to re engage the off engine.

I would envision a pair of 3-71 , so cruising on one would be efficient.

If rated under 100HP each , it might get by the Air Police.

Both would have a hyd pump so either could power a hyd cruise gen set, windlass , and other big loads. Scuba compressor or eutetic refrigeration.

A single engine on the shaft with the other simply running the hyd. would allow a great (75 ? HP) , and not time limited bow or stern thruster.

This is what leads builders to diesel electric power plants. The only difference is the energy coupling, combining, and transmission is electric rather than gears and hydraulic.

 

[Hippocampus]

My very limited understanding is there’s two ways to do this.
One, through a clutch like Greenline. The other like I described above and alluded to by TT.
Think a pure electric power train avoids much of the inefficiencies of mechanical transmissions while also decreasing service requirements. Drop to actual shaft HP in a mechanical set up is impressive.

 

[OldDan1943]

Electronic steering and engine control is very common on ships and planes.
Do you think the nuclear subs have wire cables running back to the rudder and dive planes? The days of wire cables running to the various control surfaces of an airplane are long gone.

 

[ghost]

I entirely trust electronic controls. I installed mine just last year and love them. I did keep one set of transmission controls with the final cable attachments sitting zip tied next to the transmission control horn, just in case. I mean, no reason not to…

 

[Portage_Bay]

The sky is the limit as long as money is no object and engine room space is not limited. I have some limited experience with diesel electric drive where multiple gen sets power multiple propulsion and thruster systems plus the house loads. For maximum flexibility the entire system can get very complicated very fast.

If the system is kept relatively simple it may be doable on a modestly sized recreational boat.

If the gens are making AC power and feeding the drive motor(s) direclty the gens can be perfectly syncronized and paralleled and load sharing using off the shelf components. This would allow a system to be designed that is powered by one or more generators and driving one or more drive motor/shaft/prop and one or more thrusters. All motors would draw off the AC bus. Fairly simple concpet unless a high degree of automation of the generators and bus is desired.

But... there is nothing simplier than a diesel coupled to a transmission driving a shaft.

Wonder if another way to achieve this would be to have prop(s) turned by electric motors. The props could even alias. The electric motors wouldn’t care where the power came from. One, two or three gensets or alt. energy or batteries or like boomers nuc. piles. Believe some current “hybrid” boats are already set up with something similar avoiding the mechanical complexity diesel or battery. Single failure point would be the electric motor but given light weight of a electric motor v diesel going to two props wouldn’t add much weight.

 

[diver dave]

One of my favorite wreck dives is the HydroAtlantic. It sank in 170’ of seawater off of Boca Raton. 1905 ocean dredge.
Imagine my surprise when i entered the ER for the first time. 5 large, identical looking diesels. Two pairs driving two shafts thru two combiner gearboxes. I think the center was driving a generator, not positive.
Diving air at that time, not sure of a lot of things i saw in those days…

 

[diver dave]

One of my favorite wreck dives is the HydroAtlantic. It sank in 170’ of seawater off of Boca Raton. 1905 ocean dredge.
Imagine my surprise when i entered the ER for the first time. 5 large, identical looking diesels. Two pairs driving two shafts thru two combiner gearboxes. I think the center was driving a generator, not positive.
Diving air at that time, not sure of a lot of things i saw in those days…

Just one generation before, they invented lead acid batteries.