Jump to content
Strawberry Orange Banana Lime Leaf Slate Sky Blueberry Grape Watermelon Chocolate Marble
Strawberry Orange Banana Lime Leaf Slate Sky Blueberry Grape Watermelon Chocolate Marble
Sign in to follow this  
jockwalt

hydraulic drives

Featured Posts

iam fitting a new 60ft narrowboat out and looking at hydraulic drives has anyone got experience of ars or hercules pros and cons

Share this post


Link to post
Share on other sites

iam fitting a new 60ft narrowboat out and looking at hydraulic drives has anyone got experience of ars or hercules pros and cons

 

Hi, I have had first hand unfortunate experience of one of the companies you mention and to be honest I was glad to see the back end of them!

Cheers

A

Share this post


Link to post
Share on other sites

Hi, I have had first hand unfortunate experience of one of the companies you mention and to be honest I was glad to see the back end of them!

Cheers

A

Mine was supplied by ARS but the company changed hands about 4 years ago so couldn't say what they are like now.

Share this post


Link to post
Share on other sites

iam fitting a new 60ft narrowboat out and looking at hydraulic drives has anyone got experience of ars or hercules pros and cons

 

I forgot to mention that my last dealings with hydraulic drives and bow thrusters was about 3 years ago

Cheers

A

Share this post


Link to post
Share on other sites

iam fitting a new 60ft narrowboat out and looking at hydraulic drives has anyone got experience of ars or hercules pros and cons

Knowing little about hydraulic drives, my gut feeling is why? What advantage does it give? Disadvantages surely include less efficiency (ie more fuel burn), lots of flexible high pressure pipe that will have limited life, lots of oily fluid with the propensity for leaks, and I suspect increased probability of drive failure compared to a 2 clutch gearbox such as PRM etc. But maybe I just don't understand!

Share this post


Link to post
Share on other sites

Knowing little about hydraulic drives, my gut feeling is why? What advantage does it give? Disadvantages surely include less efficiency (ie more fuel burn), lots of flexible high pressure pipe that will have limited life, lots of oily fluid with the propensity for leaks, and I suspect increased probability of drive failure compared to a 2 clutch gearbox such as PRM etc. But maybe I just don't understand!

With a BD3 I was not worried about efficiency,I could afford to lose a bit and I don't use any more diesel than anyone else from what I have read on here. If I get half a tree in the prop the relife valve just lifts, I dont rip the mountings out. I have not repacked the stern gland in 10 years, the adjustment bolts are only finger tight. I can change from forward to reverse at any revs. I have full headroom in the boatmans cabin with easy acces to the rear deck. And that's off the top of my head

 

Jock I cant reply to you, contact me via my web site.

Share this post


Link to post
Share on other sites

With a BD3 I was not worried about efficiency,I could afford to lose a bit and I don't use any more diesel than anyone else from what I have read on here. If I get half a tree in the prop the relife valve just lifts, I dont rip the mountings out. I have not repacked the stern gland in 10 years, the adjustment bolts are only finger tight. I can change from forward to reverse at any revs. I have full headroom in the boatmans cabin with easy acces to the rear deck. And that's off the top of my head

 

Mmmh. So, (in reverse order) no benefit for headroom unless you have a mid engine/boatman's cabin. You can change from forward to reverse at any revs with a PRM type gearbox, though that is only recommended in an emergency. Perhaps the advantage is more relevant with speedwheel rather than morse-type lever?

 

Stern gland life is related to alignment, but surely a python-esque type of propshaft coupling is a simpler solution than hydraulic drive?

 

PRM type gearbox will slip under extreme load such as tree on the prop, though I suspect you should be quick to kill the engine before clutch burns out, whereas with hydraulic it's less of a drama (Speedwheel again?). "Ripping the mountings out" sounds unlikely with steel bearers, perhaps more of a possibility with your wooden bearers?

 

It just seems a lot of extra expense for some pretty minor advantages (and some disadvantages). Do I sound convinced yet?

Share this post


Link to post
Share on other sites

Mmmh. So, (in reverse order) no benefit for headroom unless you have a mid engine/boatman's cabin. You can change from forward to reverse at any revs with a PRM type gearbox, though that is only recommended in an emergency. Perhaps the advantage is more relevant with speedwheel rather than morse-type lever?

 

Stern gland life is related to alignment, but surely a python-esque type of propshaft coupling is a simpler solution than hydraulic drive?

 

PRM type gearbox will slip under extreme load such as tree on the prop, though I suspect you should be quick to kill the engine before clutch burns out, whereas with hydraulic it's less of a drama (Speedwheel again?). "Ripping the mountings out" sounds unlikely with steel bearers, perhaps more of a possibility with your wooden bearers?

 

It just seems a lot of extra expense for some pretty minor advantages (and some disadvantages). Do I sound convinced yet?

 

There is nothing new about hydraulic drive. 40 years ago I had a couple of pals who fitted these to 3 cylinder Perkins engines. Both of them worked in the plant hire business and knew what they were doing + they had access to cheap parts and over-engineered their installations. There are advantages for some people and Ditchcrawler has obviously got a tried and tested set-up which works well. There are/can be advantages.

 

But, there is a modern boat on the visitor moorings just down the canal with hydraulic drive which I won't mention ..............

Share this post


Link to post
Share on other sites

I've had an ARS hydraulic drive fitted to the ellum of our butty for the last fifteen years, with absolutely no problems until last year when an oil seal needed replacing. The drive unit was sent back to ARS, but they weren't able to remove the drive shaft because it had corrorded in. The reason for the corrosion was that no one had realised that the drive needed to be protected with its own small anode. This meant that I had to buy a new unit - not cheap.

 

At the same time I renewed the hydraulic pipes, some of which were showing signs of cracking on their outer covers.

 

I have read that hydraulic drives are more efficient at transmitting power to the prop than conventional systems with gearbox and prop shaft. I can't prove this, but I can tell you that a bog standard BMC 1.8 makes the boat go like the clappers.

 

There are two disadvantages I've found: the egg whisk like prop means that stopping the 25 ton boat takes longer I'd like. Also there was a high pitched whine from tbe drive unit. However, this has largely disapppeared since the new one was fitted.

Edited by koukouvagia

Share this post


Link to post
Share on other sites

I have read that hydraulic drives are more efficient at transmitting power to the prop than conventional systems with gearbox and prop shaft. I can't prove this, but I can tell you that a bog standard BMC 1.8 makes the boat go like the clappers.

 

I wouldn't have thought it would make transmission more efficient per se, just that the engine can run at more efficient revs.

 

There must be losses as well when the PRV operates for whatever reason. Listen to slipping belts on car power assisted steering pumps when on full lock.

Share this post


Link to post
Share on other sites

iam fitting a new 60ft narrowboat out and looking at hydraulic drives has anyone got experience of ars or hercules pros and cons

I wanted hydraulic drive for my motorised horseboat and did talk to various companies who offered them but wasn't really impressed. So; in the end I designed and installed my own system. My engine is a Ruston 3VRO (almost identical to the JP3) and I wanted this drive partially to increase the back cabin headroom and partially to give me improved control of the prop speed through the use of a variable displacement pump. A further benefit is that by being able to achieve a 1:1 drive ratio, once I have built up to cruising speed I can maintain it with the engine almost at idle which is quieter and uses a lot less fuel.

 

One of the things you need to be clear about at the start is what you expect from this drive system. If you want it to merely drive the prop then it is simple in terms of component count and physical installation (a closed loop system), if you want it to power bow thrusters, generators etc etc as well then it becomes more complex (an open loop system).

 

In an closed loop system, the fluid is merely pumped round the motor and then returns to the pump. So the pressure is purely related to the load on the prop and the flow rate to the speed of the engine and pump displacement.

 

In an open loop system, the fluid is pressurised to a predetermined level beyond which a relief valve opens and returns it to the reservoir tank. This pressurised fluid is then diverted to the various motors via control valves and then returns to the tank.

 

If you want to have a look at my installation or chat about it please PM me.

 

Regards

 

Arnot

Share this post


Link to post
Share on other sites

there are two types of hydraulic power transmission systems that are used for marine applications.

the cheapest type is the "gear" pump and motor,the main drawback of using gear/pump systems is that they are only 65% efficient when new,so if a 100 horse power engine is driving the pump,only 65 HP will be transmitted to the propeller.

 

the second type is the multi-piston pump which is usually 90-95% efficient.

these pumps are more complex and so more expensive.

 

another ad vantage of multi-piston installations is that VARIABLE SWASHPLATE can be used,allowing a choice of OUTPUT RATIOS,on boats i have fitted these unit to the engine revs can be kept low for modest speeds(such as canals) and full power availability for river and sea work.

 

ratios can be finely controlled and varied 1 TO 1 THROUGH TO 5 TO 1.

Share this post


Link to post
Share on other sites

:smiley_offtopic: Hiya Brian,

 

The Screwfix item for the magnetic door catch has changed to 82681.

 

Cheers,

Tony

Ta, if I ever update the web site I will change it.

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
Sign in to follow this  

  • Recently Browsing   0 members

    No registered users viewing this page.

×
×
  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue.