Volvo IPS - CMD Zeus

The Salthouse Marine Group website has some informative stuff and links to articles on their first quad IPS driven 65 footer - and another one is in build. It seems that when trolling at least the craft works well with two of the 4 engines going. Another NZ builder, Genesis Marine is heavily into IPS options and their market seems to be convinced about the advantages.

There's quite a bit of reference being made to joy stick control and that is a great advantage available for most steerable drive systems I understand. Jet boats have used this for many years now, after original development was done for Hinkley's I think, but it has now extended into much more varied military, commercial and now other recreational applications overall and not just with jets. Nothing new or exceptional about such controllers being now adapted for drive systems IPS/Zeus therefore or at least not as much as marketing people would like us to think. These days such steerage innovation is often also coupled with dynamic positioning capability using GPS input, particularly useful for military and commercial users. Just observe the huge cruise ships with their steerable pod drives and thrusters manouvering in close quarters or just staying put in one spot without anchoring under 'hands free' control. It's just money afterall as is probably most evident when you see the high end superyacht tenders being built recently that dance in every direction or stay put under a 'sky hook'. Become a good boat handler after 2 minutes tuition? It ain't natural but eminently safer!

"Become a good boat handler after 2 minutes tuition?"
That's what the sales staffs want people to think, but that's also what's holding up the "dynamic positioning capability" for recreational craft. When you dumb it down far enough it's hard to then say you have to think enough to maintain a watch and manual control. (While we wait for the bridge let's go below for lunch. ) I expect that the joy stick will catch on more and more, but I kind of hope that automatic station keeping doesn't (except on professionally manned vessels).

I actually fully agree with you - just like the a...holes who set an autopilot in busy waterways whilst doing 20+ knots and then pour themselves another gin.

Oh, you've met him too.

Volvo offer IPS with 2 options for the EVC-C2.

One is slow speed throttle control, just click into gear and the hydraulic clutch slips at just the right speed. The other is a traditional trolling option.

These programs are an aftersales option but I think most builders should fit them as standard. The Vodia programs also activate a joystick control anywhere you wish to put one. I'm starting to like them (that from an old-school boat handler like me is saying something).

One further issue is that IPS has an active corrosion device, like the Mercathode system, that uses Aluminum anodes. They are designed to fizz in the water, builders are still fitting Zinc ones right next to them and wondering why the Ally ones don't last? DOH!!!

Hi,

I was recently introduced to a prospective large yacht Owner who wants to have his boat with DP, he was convinced that he needed to be DP 2 or higher.

He was under the impression that the boat could be setup in a position and that was it just like anchoring. The cost and complexity of DP 2and above has put him to now just want DP 1 capability and function but no class notation for such. This also helps with manning as you don't require DP Certified Officers onboard.

"He was under the impression that the boat could be setup in a position and that was it just like anchoring."

Don't you just know that some fool is going to have 10 people swimming with the drives holding position and sucking legs in.

Hi,

This is one of the reasons I feel that Pump Jets make for a good alternative on non DP classed Yachts that want to have this feature.

The actual amount of Power required to hold in most conditions when guests will be swimming around boat is very little and could in most cases be handled by one or two Pump Jets.

Before anyone goes off that I am posting in the wrong forum I will declare that I am talking about bigger yachts here (over 50 m)

If someone is that stupid they would do that with conventional drives as well I believe. But stranger things have happened........ There is a picture in Marlin magazine of a guy out in Kona in a 15' Boston whaler that hooked a decent sized marlin. He hooked the flying gaff to the stern clean (rather then at least the bow) and proceeded to gaff this marlin. The Marlin then proceeded to pull the stern underwater when it got pissed off and capsized the boat. LOL

Brunswick is very very good at putting ALL of those ugly stickers all over the helm telling the owners what not to do.......like shut off all engines before swimming and nonsense like that. Last time I saw a new Seagay it must've had about a dozen warning stickers plastered all over the helm......I really think we need some sort of licensing that is mandatory for all recreational owner/operators in the US. The stuff I see go on in South Florida is beyond dangerous a lot of times.

Hi,

After re reading some of the above posts I see that an important component of DP seems to have been forgotten.

If you are going to have a vessel running in DP Mode then if you have purely mechanical drives ( Engine/ Gearbox to Drive or Prop) you will need to have that engine running all the time you want the DP Capability to be active. This would be the way that most if not all of the boats using these IPS Drives would be arranged.

Pump Jets which are mostly electrically driven are a great thing and quite efficient at what they do.

I know of a 70 m yacht that can do 4.5 kts on it's Stern Thruster alone.

The Thruster is rated at 250 Kw , this is less than 10% of the combined Main Engine power.

IPS/Zeus Pods for Full Displacement Yachts

I am not sure if this question has been asked before:

How feasable or possible at all to install IPS/Zeus pod drives to full displacement expedition boats (60-80 ft and 150K-250K lbs.)? Would it make any sense? Do you think any modification will be required to the props or to the engine itself, besides to the hull of course?

Obviously the max desired speed is around 13 knots and long range (3K+ nm) cruising speed is around 9 knots. Most of the existing shaft drive trawler/expedition boats require single or dual 300 - 500 hp engines which are already produced by Volvo Penta and CMD. Any thoughts?

Thanks,

Denizci.

The short answer is that it would make no sense although you might look into the rotating pods such as you'll find on some harbor tugs. I think bow & stern thrusters would make more sense.

Pods in full displacement yachts

Denizci,

The efficiency gains with these pod systems do not start to show up until you get to maybe 20 knots and beyond. The faster the speeds the greater the gain after that. The low speed maneuverability improvements alone do not really make this a good solution. I am familiar with the gear ratios and props for the Volvo Penta systems, and they really do not offer anything that is designed for less than about 20 knots. This will likely change in the future, but for now they are designed for planning hulls with two to four engines.
Low RPM, high torque diesels require a really substantial transmission to survive. The pod is a transmission after all and a final drive line.

I hope this helps explain things.
Rick

Thanks rick, this was very helpful.

Denizci.

Hi,

As stated elsewhere these type drives are not true Pod Drives.

True Pods can be and are installed on full displacement yachts and ships from about 60m upwards.

pod drives

Hello K1W1,

You are right about the existing application of pod drives on ships and large yachts (or even tug boats). Since my previous post, I got some more information on this subject from the manufacturers.

There is more than one resason why IPS/Zeus type of drives are not suitable for full displacemnt yachts. By the way, Lazzara has come up with triple Zeus config for its cruiser called LMC 76. This boat is semi-displacement; however, it will be interesting to see how it will perform on long range trips...

Back to the main subject. The basic reasons for un-suitability of IPS/Zeus for full-displacements are:
- these drives cannot provide required torque due to the smaller prop diameter
- gear reduction ratio is not appropriate
- gearbox is not designed to handle heavy load

I am optimistic that companies like ZF, Schottel, Jastram or ABB will address my original question and come up with a product (a true pod drive system) which is designed for mid size (60-80 feet) FRP long-range trawler boat. So the advanteges of these systems (like efficiency, higher speed, maneuverability and space saving features) can be realized by these kind of boats as well.

Cheers,

Denizci

I wouldn't hold my breath waiting for this myself.

You might want to read up some more on the true Pod systems.

Space Saving is one of the not attributes I am familiar with being associated with these units. The drive gear switchboards, frequency converters ,transformers and gensets (which in reality are your manin engines) all require space

Weight is another thing to consider and it's location onboard.

My view is that with a full displacement boat that has a fuller shape underwater as opposed to a planing design can see engine placement better optimised (deeper) to offer minimal shaft angle plus larger props and deliver high efficiency out of a conventional shaft-mounted set up. Well proven and much cheaper of course so why bother with anything else? Pods in displacement vessels offer lower speed manouverability advantages but not necessarily great gains in efficiency e.g a harbour vehicular ferry may have a couple of ducted pod units on oposing 'corners' but the reason for that is not propulsion efficiency but manouverability. Much like a cruise ship's requirements but forget it being so likely in a highly efficient international container vessel.

A big reason for outdrives and IPS/Zeus thru-hull type systems offering better efficiency in planing hulls is that the alignment is at least parallel to the hull but even if the gurus do invent an affordable pod drive for slower speed designs, any propulsion efficiency benefit will be much less than the the case apparently is for planing boats. Perhaps the only advantage may be the better manouverability at low speed - and engine location perhaps freeing up some internal room. Displacement craft efficiency is a whole package - hull design, weight and optimised propulsion and few igains can be achieved beyond a well set up conventional shaft-mounted prop.

Other Propulsion Configurations/Options

Something like these?? (not exactly of the same sophistication of the IPS & Zeus 'systems', but more along the KISS principle)

Rim Driven Propellers
http://www.yachtforums.com/forums/te...ropellers.html

Retractable Rim Drive
http://www.runningtideyachts.com/dyn...Rim_Drives.php

Pulling Prop Drive (Chain or Belt)
http://www.yachtforums.com/forums/7567-post9.html

Chain Drive
http://www.yachtforums.com/forums/15453-post14.html

Brian,

Thank you for providing such thorough information on alternative propolsion systems. It was mind blowing. I wasn't even aware of the existence of them. It was a good learning session while I was going through all those links (and side links) you have posted.

What I see so far is, even though there are few examples of successful application of these systems, they seem like they are somehow still in their experimenting or proving themselves stage and couldn't make it out to the mainstream market yet. Maybe just because of financial or marketing reasons, but for some reason they are not there yet.

This brings me to Blair's point where he mentions a well designed conventional shaft propolsion is still the most accepted system in place.

I am still optimistic though. There will be well accepted alternative (to shaft drive) systems for trawler boats in the future..

Thanks ya'll...