Propulsion suggestions

Your are always welcome ;-)

Glad you like the idea, and i find your D.I.Y solution, excellent.
An end, is always the beginning of something else ;-)

 

Thank you for all your replies. I did pick up schedule 80 pipe, 3 inch for the down shaft and 5 inch for the lower unit. I was going to put the hydraulic motor in the lower unit and attach the prop directly to it. Someone mentioned that with that set up there might be damage to the motor from the forward and reverse thrust with out an additional thrust bearing installed.

In the past day I have come across a pair of twin 50 hp out boards, one with a blown power head. I have an appointment to look at them tomorrow. If they are any thing like the photo I will pick them up and remove the power heads and install the hydraulic motors in their place. With this set up I will not have to be concerned about the water pick up and cooling.

As far as the motor to power the pump it will either be two 18 hp Briggs & Stratton power packs, or twin 18 hp continuous EV motors with about 42 HP peak. Either of those would be mounted below deck.

Thanks again,
Mark

 

Irony is not within your very limited part of knowledge and understanding?

To use the new SI unit: ---80 dK---- for this one.

Sasha

 

Sasha, Mako2 needed help.
Sasha : your name means : Defender or Helper of mankind

I much prefer the second option as it seems you are often misunderstanding, doing the first.
I guess Mako 2.

80 ! Thanks, Be my guest.
But do not forget to recall all the story.

http://www.boatdesign.net/forums/hy...c-generator-create-jobs-31205.html#post338887

Thanks again for your help about this, my friend.


Mako2, happy to know you are on the way for a solution. Good luck !

 

Thank you, will keep the post upto date as progress is made

 

I like the hydraulic unit on the excavator bit, good idea.
You could even mount it on the boom so the crane will lower the prop into the water and also steer it.

Just depends on installing and removing the motor with prop on the end of the boom every time you move becomes a problem to not.

Plus's
no fouling as out of the water when not used.
easy maintainence
easy to mod
can use all around the barge so get thruster like operation

We had a similar project in the marina where I used to work and we went with the walking spud system as you needed the spuds to hold yourself still while operating so mod them to tilt. Ok if you need to move a long way, tow it?

 

An update on our progress:

We picked up a pair of hydraulic power packs each is a 16HP Briggs & Stratton vtwin attached directly to a 10 GPM, 2000 PSI pump. We also have a pair of 22" 4 blade propellers.

We are looking at purchasing a pair of hydraulic motors to be mounted in the outboard pods. The motor we are looking at are Charlyn 2000 series because of the axial load. These are low speed high torque motors, The 8ci motor is rated at approximately 500 RPM at 20 gpm, at the 10 gpm the rpm will be approximately 350. We would be direct coupling the propeller to the motor so the prop RPM will be the same.

The 350 prop RPM should be about the same as an engine idling at 700 RPM with a 2 to 1 gear.

I would be interested in any thoughts on the combination of the motor with the parts we already have.

Thanks,
Mark

 

You will be able to swing a big prop at that rpm that will give impressive bollard pull compared with what you have now.

At this stage to do any reasonable design you need an estimate of the boat drag at the target speed.

The most reliable way to get an indication on the barge drag is to tow it with another boat at the speed you would like to achieve. Need some sort of force measurement. If you are handy with hydrauliocs you can make a load cell with a hydraulic cyclinder and pressure guage.

I expect you will use a directional valve to get forward and reverse on each drive. I also expect you will also need pressure relief for the reversal and the event you drive the prop into something.

Rick W