propulsion for trawler

[shoaib_jaff]

everybody,
what type of propeller is suitable for a stern trawler?
how about a ducted propeller?

[RANCHI OTTO]

ducted propeller is a good solution because gives thrust at low speed.
I've designed some ducted propeller with very good results for such type of vessels.

[shoaib_jaff]

ranchi otto,
what type of propulsion would you prefer single/twin screw

[shoaib_jaff]

ranchi otto,
which would be more cost effective diesel engine driven or turbine driven for stern trawler

[RANCHI OTTO]

Stupid answer---less cost with 1 engine, more manoeuvrability and safe in sea with 2 engines.
Standard propulsion plant is 1 engine + ducted propeller (rudder with Costa Bulb)

[StianM]

Originally Posted by shoaib_jaff

ranchi otto,
what type of propulsion would you prefer single/twin screw

Depend's For manovering you are probartly allready well informed about the advantage off two proppelers. Personal I would go for 1 proppeler and add a hydraulic bow thruster for increased manuvering. 2 engines is safer than 1 and the power comsumtion is difernt for diferent aplications. There are manufacturers off 2-1 gearboxes that would allow you to runn 2 engines on 1 proppeler. This would increase safety and allow you to runn 1 engine when the nead for power is low and 2 engines when you nead more power. The 2 engines can have diferent power output.

Originally Posted by shoaib_jaff

ranchi otto,
which would be more cost effective diesel engine driven or turbine driven for stern trawler

Turbine? gas or steam? Steam is no no. Gas turbine is exspensive, but reabilety is high, but the fuel consumption is about the same.
For instalation cost I would go for the diesel.

[Guillermo]

For the 50 m stern trawler you are designing, I recommend the use of a diesel engine (if diesel oil price doesn't go on skyrocketing! ), a variable pitch, slow turning, ducted single screw for propulsion and a bow thruster for manoeuvers.

[StianM]

If you are concerned about the fuel cost you should buy a RRM Bergen K series engine witch is prepared for HFO operation.

You have to be efficient and fish 26 hours a day if it's going to justefy the extra cost off sutch instalation

[Guillermo]

Originally Posted by StianM

If you are concerned about the fuel cost you should buy a RRM Bergen K series engine witch is prepared for HFO operation.

You have to be efficient and fish 26 hours a day if it's going to justefy the extra cost off sutch instalation

HFO doesn't seem an alternative in my opinion. Expensive installation and too dirty, bad enviromental reputation.

Alternative fishing vessels propulsion systems are nowadays being seriously considered, as the fuel costs have risen so much. More efficient propellers and hulls, diesel-electric systems, natural gas fuel, and even auxiliary wind (sails and kites) propulsion systems are being considered, among others.

Interesting this kites thing. I'm not sure they are really feasible for fishing vessels, except, maybe, for long range ones going to far away fishing grounds. Big stern trawlers and tuna vessels, probably. There is a concern for the use of kites also when trawling, as it's thought it would be difficult to handle them in a hurry when manoeuvering with the fishing tackle. But SkySails proclames their control system allows the kite to be brought to a zhenital position (so only vertical pushing) within 30 seconds, so.... See http://www.skysails.info/index.php?L=1

As the chairman of the NA & ME Association in Galicia, I've organized a conference on fishing vessels propulsion to be held in Vigo on May the 25th. SkySails CEO is coming to lecture. I'll let you know when I learn more.

Cheers.

[StianM]

Originally Posted by Guillermo

HFO doesn't seem an alternative in my opinion. Expensive installation and too dirty, bad enviromental reputation.

It's allready hapening in Norway. Diesel cost become so high that old Fish boat's are doing instalation off HFO modules and new ones are build with HFO modules. The instalation cost will increase yes, but you can get fuel that is half the price.
Make up a opinion on how manny years the boat will runn and find out what is the extra instalation costs and maintinance cost and how mutch fuel you will use a year.
If you can save money on it befour the boat is retired you should consider it since the oil price could go more up if Bush decide to go to war against Iran.
I ben service engeneer for a company selling HFO modules and seperators and I also know it's a horible fuel to work with. Stay away unless you make money on it.
What is your nead for propulsion? how manny kW do you nead? do you want a configuration with 2 engines and 2 proppelers? 2 engines and 1 proppeler? 1 engine and 1 proppeler? Shaft generator or only generators? fixed pitch or cp? What about engine rom space?