Twin power steering pumps?

[Han_solo]

I was thinking the other day that my boats twin engined with the power steering pump fitted on the starboard unit and there's no means of rigging up an emergency tiller should that engine and steering fail for any reason. So my question is is it possible to have a steering system that would work with a pump on each engine that would work with both pumps running at the same time or with some kind of diverter valve that would allow you to use either one?

Cheers.

 

[[2068]]

On most boats, failure of power steering results in increased steering effort, but not steering failure.
Also, if you have an autopilot, this can be used as a secondary steering control of a sort, but probably not in the marina.
If it’s a hydraulic system, if you’ve lost too much hydraulic fluid for some reason, you are toast, and will require rescuing. Keeping a litre of fluid on board is a good idea.

 

[Lon nan Gruagach]

I was thinking the other day that my boats twin engined with the power steering pump fitted on the starboard unit and there's no means of rigging up an emergency tiller should that engine and steering fail for any reason. So my question is is it possible to have a steering system that would work with a pump on each engine that would work with both pumps running at the same time or with some kind of diverter valve that would allow you to use either one?

Cheers.

If, and I cant see why they wouldnt be, normal gear pumps then there is no reason a simple parallel arrangement wouldnt work, no valves, diverters or anything really... except the non running engine will be pushed backwards (a bit) If that is an issue then a non return valve in the out from each pump will do the trick.

 

[PCUK]

As said, failed power steering doesn't affect the wheel steering operation, just makes it a little heavier. A manual tiller is the only 100% reliable back-up.

 

[Assassin]

You could fit a second pump to your other engine and connect it with changeover valves, simply leave the drive belts off and if you have an emergency situation you simply refit them.

 

[jrudge]

I suppose the question is how many power steering failures are down the to pumps as opposed to fluid leak / ram / other part of system

I don’t know the answer but I don’t recall anyone on here having pump failure

If an engine failed ( more likely ) if would give a backup I suppose

 

[BruceK]

I am presuming the OP wants to stay on the plane otherwise apart from the steering being a bit stiff it's easy enough to maintain a course on a twin engined boat using throttles alone.

 

[julians]

I've posted this before,but now seems an opportune time to post again.

Our old sealine s34 had two VP engines and drives, the power steering was driven off only the starboard engine .

The starboard engine developed a fault, which meant I couldn't run the engine,so I had no power steering. No problems I thought I'll just trundle home on one engine and put up with heavier steering.

A few miles later the steering wheel went suddenly light, like it was not attached to the drives, turning the wheel did nothing.

At this point the drive were pointing left, so the boat would just go round in circles ( remember only one engine working), I could use th bow thruster for a degree of course correction but this wasn't sustainable to get me home.

I flagged down a passing fishing boat and asked them to tow me home.

I got back fine in the end. The steering failed because a sheer pin couldn't take the heavier force required to move the drives without the hydraulic pump.

We briefly looked into what would be required to have power steering run from either engine,but gave up as it looked too complex.

 

[Han_solo]

I've posted this before,but now seems an opportune time to post again.

Our old sealine s34 had two VP engines and drives, the power steering was driven off only the starboard engine .

The starboard engine developed a fault, which meant I couldn't run the engine,so I had no power steering. No problems I thought I'll just trundle home on one engine and put up with heavier steering.

A few miles later the steering wheel went suddenly light, like it was not attached to the drives, turning the wheel did nothing.

At this point the drive were pointing left, so the boat would just go round in circles ( remember only one engine working), I could use th bow thruster for a degree of course correction but this wasn't sustainable to get me home.

I flagged down a passing fishing boat and asked them to tow me home.

I got back fine in the end. The steering failed because a sheer pin couldn't take the heavier force required to move the drives without the hydraulic pump.

We briefly looked into what would be required to have power steering run from either engine,but gave up as it looked too complex.

That's an interesting point about the sheer pin failing because of the extra strain put on it.

 

[Han_solo]

You could fit a second pump to your other engine and connect it with changeover valves, simply leave the drive belts off and if you have an emergency situation you simply refit them.

That sounds the way to go.

 

[Han_solo]

I am presuming the OP wants to stay on the plane otherwise apart from the steering being a bit stiff it's easy enough to maintain a course on a twin engined boat using throttles alone.

It was just me running a few "what if" scenarios through my head regarding my new boat to try to eliminate any weaknesses in it's set up.

 

[jrudge]

It was just me running a few "what if" scenarios through my head regarding my new boat to try to eliminate any weaknesses in it's set up.

My own view is that there are more points of failure in the steering system than the pump so where do you stop? Carrying spares and tools maybe a more realistic option.

 

[Han_solo]

My own view is that there are more points of failure in the steering system than the pump so where do you stop? Carrying spares and tools maybe a more realistic option.

Good point jrudge but I also think knowing you have back up systems in place wherever practical gives you that bit more peace of mind.

 

[jrudge]

It does but only if the relative risk and consequences of failure are worth it. No wc is probably in most cases more likely and more severe than steering given you can steer with a failed pump!

 

[prv]

My own view is that there are more points of failure in the steering system than the pump so where do you stop?

In some cases (Fleming, FPB, etc), only after twin powered systems, twin independent autopilots, a clip-on big wheel to a hidden manual helm pump, direct push-button control of the local hydraulics, and a tiller and set of relieving tackles in the steering flat :biggrin-new:

(Trawler people get a kick out of this kind of thing )

Pete

 

[jrudge]

In some cases (Fleming, FPB, etc), only after twin powered systems, twin independent autopilots, a clip-on big wheel to a hidden manual helm pump, direct push-button control of the local hydraulics, and a tiller and set of relieving tackles in the steering flat :biggrin-new:

(Trawler people get a kick out of this kind of thing )

Pete

Which I suppose comes back to the consequences of failure.

A planning boat by virtue of its range will at a max be some 120 miles from a port - usually I would suggest less than 20.

The flemings of this works as I understand can go for thousands of miles on a tank, so the consequence of failure could b pretty severe - steering issues for 1000 miles at 8 knots - not amusing!

Even then there must be a point where they simply carry spares as opposed to investing in multiple redundant systems. Redundant filtration would be high on my list - keep the engines running.

 

[Assassin]

jrudge makes a good point about failures and where the weakest components in the system are and it would be prudent to keep them up to par, a shear pin or two would be useful to carry and knowing how to change them would be useful, so it really comes down what the Op really wants. It would appear to me that it comes down to an individual system and how good it really is in a specific application, in most cases a warning of impending pump failure is given by a noisy pump and this is audible to most people.

 

[Lon nan Gruagach]

jrudge makes a good point about failures and where the weakest components in the system are and it would be prudent to keep them up to par, a shear pin or two would be useful to carry and knowing how to change them would be useful, so it really comes down what the Op really wants. It would appear to me that it comes down to an individual system and how good it really is in a specific application, in most cases a warning of impending pump failure is given by a noisy pump and this is audible to most people.

I think the point about the shear pin was that with no pump the load on that part of the system can be expected to break it in reasonable use. In other words just push a bit harder, the steering is going to be heavy isnt good enough since pushing a bit harder will break it.
Its common that power steering can be damaged by using it with no pump, certainly on cars at any rate.

 

[SEARANGER ANCASTER]

no reason why you cant have them on a divertor valve but on my last boat , I fitted the hoses with quick release couplings and left the belt off so easy enough to stick on a belt and connect hoses up . Never needed it though.