Jump to content

Hydraulic system pros and cons


OCM

Featured Posts

7 minutes ago, ditchcrawler said:

I met a butty in Birmingham with a hydraulic drive and I could hear in whining for ages after it had gone by. Mine doesnt whine at all

Depends on what kind of pump/motor is used. IIRC the cheap ones (vane pumps/motors) are noisier/whinier and less efficient and robust, the expensive ones (bent axis pump/motor) are quieter and more efficient and robust.

Link to comment
Share on other sites

33 minutes ago, ditchcrawler said:

I met a butty in Birmingham with a hydraulic drive and I could hear in whining for ages after it had gone by. Mine doesnt whine at all

I will resist the temptation ūüėĀūüėĪūüė∑ūüėéūü§≠¬†

Edited by Loddon
Link to comment
Share on other sites

2 hours ago, cuthound said:

That said it does come in very useful for long reverses.

 

That, in my opinion, is a first class reason to have one. 

 

 

They do seem to be a maintenance headache though. 

Link to comment
Share on other sites

5 minutes ago, MtB said:

 

That, in my opinion, is a first class reason to have one. 

 

 

They do seem to be a maintenance headache though. 

A bucket or a weight on a bit of rope works as well and no maintenance.

Link to comment
Share on other sites

7 minutes ago, Loddon said:

A bucket or a weight on a bit of rope works as well and no maintenance.

 

 

Sounds an attractive idea but I tried that, and found it less than useless. 

Link to comment
Share on other sites

16 minutes ago, MtB said:

 

That, in my opinion, is a first class reason to have one. 

 

 

They do seem to be a maintenance headache though. 

 

I agree, mine stopped working about a year after I bought the boat. I checked the easy things like battery voltage, fuse integrity and for prop fouling but it was more serious than those. 3 years later when I was having the boat docked I asked the boatyard to have a quick look and give me a quote to repair it.

 

"Motor seized, needs a new one at £1200" was there reply.

 

"Leave it" I said. Later I took the motor to Cox's Auto Electrics at Atherstone who unsiezed the motor and replaced the brushes and contactors for £400. When I put the motor back in the contactors chattered but it still wouldn't work. Turned out the battery isolater had gone HR.

 

All of the above resulted from condensation in the BT compartment collecting over winter, so I now leave the locker (which is under the cratch) open, which has eliminated the condensation issue 

 

Edited by cuthound
Clarification
Link to comment
Share on other sites

23 minutes ago, MtB said:

 

That, in my opinion, is a first class reason to have one. 

 

 

They do seem to be a maintenance headache though. 

 

My only experience with bowthrusters was having to replace one on the Sea Otter I used to own.  I tried to live without it but it's almost impossible to handle an Otter without a thruster.  

 

It was an electric "Max Power" and though the motor could be heard whizzing away there was no drive to the propeller.  I hoped it was the shear pin that had broken but it wasn't so the thing had to come out and as I only had limited time on the lift out it was a case of replacing it with a new unit.  

 

I got the old one back home and dismantled it, now I'm no engineer but it was very obvious the drive mechanism was very poorly made.  There's a shear pin to protect the transmission, but it was obvious that this pin was far too strong and in my case I guess at some point a foreign object had got caught in the tunnel but instead of the shear pin breaking, the transmission itself had disintegrated.  

 

I guess the bigger heavy duty thrusters are more durable, but I was very surprised at how fragile this thing was considering the environment they operate in. 

Edited by Neil2
Link to comment
Share on other sites

1 hour ago, MtB said:

 

 

Sounds an attractive idea but I tried that, and found it less than useless. 

Done it several times on various barges dragging a 25kg weight,  however my NB goes well in reverse so have never needed to use it.

Link to comment
Share on other sites

3 hours ago, MtB said:

 

 

Sounds an attractive idea but I tried that, and found it less than useless. 

You have to put the weight, tyre or bucket in the water.

3 hours ago, cuthound said:

 

I agree, mine stopped working about a year after I bought the boat. I checked the easy things like battery voltage, fuse integrity and for prop fouling but it was more serious than those. 3 years later when I was having the boat docked I asked the boatyard to have a quick look and give me a quote to repair it.

 

"Motor seized, needs a new one at £1200" was there reply.

 

"Leave it" I said. Later I took the motor to Cox's Auto Electrics at Atherstone who unsiezed the motor and replaced the brushes and contactors for £400. When I put the motor back in the contactors chattered but it still wouldn't work. Turned out the battery isolater had gone HR.

 

All of the above resulted from condensation in the BT compartment collecting over winter, so I now leave the locker (which is under the cratch) open, which has eliminated the condensation issue 

 

All comes back the boating rule, -----KISS-----

Link to comment
Share on other sites

6 hours ago, cuthound said:

 

But your steering won't improve if you keep using the BT.

 

I had been boating 41 years before I got a boat with a BT.

 

It is currently not working again, and unless it is a cheap fix will stay that way.

 

That said it does come in very useful for long reverses.

Also for when the boss wants to pick, plumbs, blackberries, soles or apples on the offside bushes and trees

  • Haha 1
Link to comment
Share on other sites

To keep everything in proportion on Oates which has a relatively shallow hull and correspondingly shallow cabin, it was fitted with a hydraulic drive c.1999. It was a high quality installation, done by some very reputable people on a Kelvin J2 (22hp but they're big horses!). It's a 38' boat with a very efficient hull (round bottomed, long swim etc). This means it has plenty of power and does not whine. The main advantage is that you can walk straight through the back cabin without stooping and the prop is mounted at the ideal height. The system is pretty simple and probably heavily over-engineered (like most of the engine and boat). I am aware that a major failure would be more expensive than a simple shaft failure and I will gradually piece together the bits to reinstate the gearbox internals if they turn up (anyone got any spare bits of Kelvin J type gearbox?) but for the time being, the conclusion appears to be that well designed, well installed, high quality hydraulic drives do not present an issue as a long-term solution.

 

Alec

Edited by agg221
Link to comment
Share on other sites

Classic yacht Waitangi has a hydraulic drive which means the engine can be located under the cockpit floor which is directly over the top of the propeller.

Works well, no whining but the prop still turns slowly when in neutral so is a rope magnet to some degree whenever the engine is running. 

"No lines over the side" is a standard call prior to any engine start. 

Edited by DandV
Link to comment
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
  • Recently Browsing   0 members

    No registered users viewing this page.

√ó
√ó
  • 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.