Use pressurized water as manuevering thruster?

Willdo does produce large jets for barges

I personally think that jet thrusters are worth considering. Willdo is producing jet thrusters for tug boats, I believe that this size of boat need a lot of side thrust. If tug boats are using Willdo thrusters, then they are powerfull and reliable enought for a pleasure boat as well

You can talk to them directly and they can pretty much make ANY size thruster, directly coupled to an engine, hydraulic powered, electric powered or by V-belt.

I am quite sure that they can design a suitable jet thruster for a barge since this company comes from the land of barges (Holland).

By the way, they have a 250 KgF unit as well.....!!
Single prop

 

Sternweel rat...in view of the size boat you are planning and your preference for diesel/electric propulsion, have you looked at splitting the sternwheel into two independently controlled halves? If so, I would be interested in your rationale for not going that route. Incidentally, I just bought a piece of property down in Mobile County with a 700'x50' canal off of Fowl River and am trying to decide what to put on it. I missed a heck of a deal on the 87' Jean Mary, if you are familiar with her. Would value any insights/suggestions

 

Sternwheel,

Have you got any further with your thruster project. I just had my unfinished 46' sailboat hull delivered. The bow is really not designed to handle a propeller driven thruster. By the time I move back to the point where I have enough depth to cover the tunnel, I've lost a great deal of leverage, and therefore the unit gets larger and I move aft a bit more...and I guess you can see where this leads.

I think the better solution is to put some small water jets right up front. The WillDo units fit the bill, but I wouldn't be suprised if the total bill added up to $10k. I'd like to see what could be built from standard components and use the system for multiple uses as mentioned before. I don't think building it would be that hard, but I have no idea how to size it. I read somewhere that if 4 hp was required for a standard thruster, then 4 + 1hp (for hoses) at the pump would provide the necessary thrust. Anyone care to comment?

Regards,

SeaJay

 

Anyone care to comment?

A few hours of practice will allow 95% or better of the manuverability of the bow thruster boat/

Save the complexity , save the hassles , space loss and $$$ and finish the boat as simply as can be done.

BESTITIS is a disease that grabs builders , and wastes years and buckets of ca$h.

For 1/1000 the cost of a thruster you can get a boat manuvering lesson.

There are no "nice to have" on a cruiser only MUST haves.

FF

 

Fred.

I agree with your general idea that simple is better, and many of the ideas I am incorporating in this boat follow that philosophy. However, I sail on SF Bay and much of our limited dockage is subject to high winds and currents. As I will single-hand this boat much of the time, a little assist from a thruster on occassion doesn't seem to be out of line.

However, if you really want to get to the heart of the matter, if I wanted simple, I'd just go out and buy a boat. Building does not equal cost effective or simple! The truth of the matter that it is the totality of the engineering solution required to design a boat that I love. We all noodle about in our own ways.

Fred, I've read a lot of your posts, you're a creative guy, so help me figure this out...what size pump do you think I'd need, and what off-the-shelf technology might be using similar valves?

Best Regards,

SeaJay

 

"help me figure this out...what size pump do you think I'd need"

The "pump" will suffer as all pumps will from the skin friction of the delivery pipe , and the power required to get good thrust will go up about 50% with every slow bend in the delivery and about 90% for any 90deg changes.UGH!

Frankly if you want the least hassle and best most useful cruising boat , I would install a complete hyd system in the boat.

Then USED a windlass, used hyd bow thruster , huge hyd bilge pump and even powered sheet winches could help on the boat.

Tailing is EZ , sheet cranking is hard so if the hyd accumulator was hand pumped while sailing , tacking would be a snooze.

There are even hyd start setups for most diesels , so dead batteries might be a hassle for the entertainment system , but not a threat to the vessel.Same hand pump and accumulator as for sheet winches.

The best way to create a GREAT boat is to see what the big $$$ folks do on big boats , and scale the great reliable stuff down for use on your project.

A boat with keel cooling , a dry stack and full hyd is really hard to kill, and fantastically EZ to maintain.

And should you ever overload any system , no electric white smoke pours out , and NO REPLACEMENTS are needed.

FF

 

If you are willing to give up the space for the equipment and large pipes, you might consider getting an old Ski Doo drive package and installing that.

The pipes would be the same diameter as the jet skis output and a valve like a carburetor plate could be cable operated to open on the side you need the thrust.

Since it would only operate a few min at a time fuel costs would be minor.

Perhaps it could fit under a forward bunk to save room, at docking speeds it would not have to have the water inlet facing forward.

FF

 

Fred,

Excellent points. If you check out the Willdo system, it features hydraulic power. Here is the result of 20 hours of thinking while driving back and forth to Portland.

1. My original thought was a jet ski pump and it is still under consideration (without gas motor)

2. Is there such a thing as a reversible pump? Visualize a short length of 2" pipe in place of a standard bow thruster tunnel. Now plumb in this "two way" pump in the middle where the thruster prop/motor normally sits. Now there is virtually no friction losses due to long runs of pipe, and one less thru-hull. Suck water in one side and shoot it out the other. Even if such a pump doesn't exist, the thing can be configured with valves just like the Willdo. The point is that instead of running two rather large water pipes through the middle of the boat with all of the associated losses, you are running two smaller hydraulic lines ( with all of their associate losses). Absolute power effieciency is low priority. I've got lots of power and the thruster only runs for very short periods. My real problems is that a 6" tunnel just isn't going to work.

3.There are many things I like about hydraulics but I kept coming back to the fact that I wanted the windlass(s) to be indepentent of the engine, ie battery operated. It seemed logical to run an electrical foward thruster motor since I figured I'd put a couple of batteries up front to handle the windlass anyway. I thought about an accumulator, but don't know much about them, and how much capacity they have. If I had enough to haul the anchor without the engine (or could get it with a manual pump) we could be talking turkey.

4. I'm with you on the keel cooling. I have also given some thought to a dry exhaust, but I can't figure out where to locate it so that a) it doesn't interfer with the rig b) doesn't foul the sails, and c) where I don't have to breath the stuff while I'm in the cockpit.

Anyway Fred, thanks for the suggestions...we're thinking along the same lines.

Best Regards,

Sea Jay

 

3.There are many things I like about hydraulics but I kept coming back to the fact that I wanted the windlass(s) to be indepentent of the engine, ie battery operated.

A windlass when working hard will require 100 to 200A for 10 or 15 min to be usefull. That would require about 1000 lbs of batteries if you do not wish to harm them in use. And don't forget the last 15% of recharge may take hours and hours!

4. I'm with you on the keel cooling. I have also given some thought to a dry exhaust, but I can't figure out where to locate it

The ones I have seen that worked well ran the exhaust up the mizzen mast.

If you have only one mast a standpipe about 6 or 8 ft tall must bring the hot gas past the halyard wincg working area.

The diesel smell will be 35 to 50 ft up.

FF

 

For modestly sized work boats hydraulics are the only way to go, power, power power! Ships with large AC generating capacity can use electrical power much as we would on land to great benefit. But in a battery/dc situation hydraulics are my choice.

 

But in a battery/dc situation hydraulics are my choice.

Surely the answer today, BUT,

The modern aircraft hates the weight of a fixed hyd system , and the ease of battle damage rendering it ALL disabled.

Modern A/C practice is a power pack that runs on electric (with multiple paths for power and control) and powers the use item in place.

The load on the electric motor is fixed , so if the hyd stalls , there is no damage to the electric side.

AS surplus mfg capacity always drives prices down I would look for hyd/electric packages on better items like windlasses.

Advantage no fixed piping and pump/resevoir system , no hyd cooling required , and yet the delightful ability of Hyd to be overloaded with ZERO damage is kept.

The use of a 240 to 440V power supply would get rid of the huge heavy , costly DC cable requirement.

FF

 

Doesn't it take more electrical power to drive an electrohydraulic winch then it would to drive the winch by electrical power alone?

 

Aowwwwww, this thread is annoying me, as FF suggests get the training and FORGET lateral thrusters.... Best option, stand at the stern and urinate, else get trained to use your existing power systems.... bloody shiver me timbers (I was going to use other adjectives, but remembered it is Sunday) you are supposed to be learning and becoming a responsible boatie, Go practice...

 

Masalai - you must have been feeling liverish. All the training in the world won't prevent damage from gusting winds, adverse currents while manouvering a boat with a stern leveraged power source about 2 miles from the uncontrollable bow.

I feel the solution for this design dillema is a high powered water pump with its own small petrol motor, pushing sea water along galvanised steel pipes. The controls would be the equivalent of taps (one for port, one for starboard) that control the water jets exiting the hull close to the bow. Instinct tells me 1 inch pipe with a fire-hose nozzle would do the trick.

In my minds eye, I see a system where the pumps are running at full capacity , and the pumped sea water being squirted harmlessly straight down. When the helmsman wants to turn the bow, the water 'tap', closes the 'escape pipe' as it opens the port or bow jet.

It would be reletively easy to jury-rig a test setup to verify the efficiency of the setup before bulding it into the boat.

I have vivid recollection of seeing a documentary with a long 30ft hull being slowly turned with no more than the equivalent of a garden hose outlet.

The pump motor could be the same one for the onboard generator, to justify its purpose a bit more.

 

Well WTF did the likes of Chris Columbus, James Cook Willhelm Dampier and the myriad others who did not have even that much "reliable power"??? do you really NEED such? - - I have seen local trawler and other boat drivers do very well with a single prop....