Volvo IPS - CMD Zeus

That sounds a bit like you may be trying to wag the dog. The only thing I hear is excitement over IPS. I don't think orders for IPS are slowing down so much as orders for boats and subsequently IPS and everything else.

Maybe there is more than one dog! ;-)

Not wanting to upset the forums non commercialism, but we will get a one sided view, as builders who come to us are looking for alternatives. I'm more likely to hear the problems than the praises of other systems. But that's what is great about forums you'll hear from a range of people with a range of knowledge or industry experience.

Things will get more interesting when the higher powered versions are commercially available. The smaller boat sector can be argued to be suffering most from the current financial climate, yet the current crop of engine and drive packages suit the smaller boats best. Unless you have a hull form that allows multiple engines abreast (either a totally new hull design developed around the drive system and all its hydrodynamic quirks, or an existing one that can be modified to a point where the drive system can work with the hull design and not against it) then the overall size / construction / fit-out will be limited.
As always, power to weight is paramount...some builders will struggle to balance what has become their accepted fit-out and construction standards and materials with the overall weight restrictions dictated by current drive packages, and yet still be as attractive and acceptable a package to their established customer base...come the larger powered engine and drive packages, the market will shift quicker.
There is a strong argument for brand new hull designs that are tailored specifically to get the most out of these drive systems....the offset to this is that these new hull designs will no longer have the optimised form to suit other drive systems such as stern drive, shaft or surface drives. This will need a lot of thought from series production builders as to which way their resources and ultimately volume of product should be directed.
Zeus and IPS work in different ways, each putting different steering / directional and heeling stability / longitudinal trim demands through a given hull design to be able to make the most of their respective handling / efficiency promises. A universal hull design that works fairly well with all of these new and more established drive systems will compromise the running and handling for each to some degree.
As such, a builders decision to go with one or the other of these new systems is rather involved. Once the higher powered options are available, larger market sectors open up and for those builders that produce a wider range of sizes and types, that decision may be easier.

That's a very interesting point. I see no problem for the coustom sector, but what of the Sea Rays, etc. Will they start setting up 2 or 3 molds for each model or throw all their chips in on one or the other? On top of this financial crisis this sounds like a lot of risk. These drive systems could end up like jets and surface-piercing; decades later still trying to find a way into the mass market.

I know that Searay offers the 48' Searay with Zues drives and Cabo has a 40' Zues drives. Both have great fuel economy in comparison to traditional diesels. Check out this test on the 40' Cabo with Mans, Cat, and Zues including speed, fuel burn etc. Although the CATS with traditional drives have a better range at near cruise speed (1800rpm's), they seem to be better then the MANS across the board
http://www.caboyachts.com/yachts/40X/INDEX.ASP

What I have heard is that Brunswick is offering/ or let's say venturing in to create one hull size in each brand that they feel is BEST suited for the zues drives. Yet, with the economy and so forth they will not take any deeper plunge then that at this time. This is only what I heard through the grape vine. Which makes sense, they may be underkill or overkill for other hull types or sizes and not perform as well.

I personally at this time would be leary of convincing an owner to buy a boat with them. They have a lot of pluses and no negatives that I really know of. However, I feel the current buyers are going to be the long term gunea pigs of them. They have a lot of electronics and components, and I would like to see the longterm durability and maintanence costs of those components because they're not cheap.

An improvement in propulsive efficiency has to be a good thing, gains in fuel economy, same speed for less power etc. Trouble is, these gains are subject to a suitable hull form, suitable running trim, suitable heeling characteristics in a turn etc. IPS and Zeus differ in what they want a hull design to do. One of them is easier to get to work well in a typical deep-v hull designed originally for higher speeds, both can work well with flatter, shallower deadrise and less inherent high speed stability. Taking composite hulls from out of a mould...Both can be incorporated into existing hull designs by implanting the mould accordingly and shifting the final build LCG. This is the rub...existing hull designs / moulds were not designed for these drive systems. Whilst there are several successful boats running around with these drives now, the best must be boats developed around the drive system rather than a happy out-come to a 'fit it and see what happens' experiment...the science is relatively new, with very small numbers of case histories (and hence real-world design experience). As mentioned before, once larger powered versions are available, the impetus may accelerate.
If only stern-drives were available that could throw larger props and take bigger power and torque...similar increase in propulsive efficiency, but with the added bonus of trimmable thrust...they would take some of the compromise out of the equation when trying to make existing hull designs and LCG layouts work well.
I still advocate a hull design and package displacement specific to the new-age drive system and associated hydrodynamics is the best way to market boats with these sytems. Some builders can and will, some cant and wont.
Ironic that a system to improve the efficiency and economy of pleasure boats may prove to be uneconomic to develop and incorporate in todays market. Increasing the range of sizes and hence the range of suitable installations will obviously spread the bets and reduce the risk commercially. Big question short term is will the market still be there when the product hits the shelves.

Did anyone notice that Viking announced a 42' convertible and express with IPS drives? They say that it is a boat for "hazy economic times."

http://www.****************/models/pages/overview.asp?numIdVal=42C

I am in the middle of this now, started to develop a 54´hull for the IPS II (pictured), but found out that the added size and weight of the IPS/900 will be negative for the outcome and I am now back to using the IPS/600 as double or triple installations.

This hull will be purpose built for the smaller IPS and since none of the IPS drives have props for more than 45 knots, this will be the top speed anyway.

I agree that more power to stern-drives would be better, but the joy of joystick handling is not there yet and I don´t think they will work as smooth as with IPS.

I can envisage a purpose designed hull with triple IPS set up being rather amazing Lars. Puts a different slant on things power to weight wise.

Yes, it will be a 25% weight saving and the flexibility of using two or three. Plus the hull can be with more bouyancy with smaller drives. We are building very light and today many of our competitors are using 50 % more fuel, going 10 knots slower. Hoping to achieve similar results with this one..

I'm not asking the question, but I'd be very interested in seeing your take on the centreline engine / keel treatment one day. There's a few reasons why I shouldn't, but the interest is there.

Absolutely, as soon as it is launched!

The fact is, I have several ideas but nothing is in my computer yet. I think this must be tank tested, even if I have no idea what I will look for...

My main concern is not to achieve the speed, but building a light boat that also has a smooth ride in rather heavy sea. It must also be as silent as possible, which always is a problem with a light and covered boat where the noise from hitting the water at high speed can be pretty annoying...

Interesting thread we have here...

This thread has gone on a long time now. Very interesting indeed.
AMG, your point over triple 600 vs twin of the new IPS 2 is interesting. But I am so curious about the need for a "tank test". It is my understanding that Volvo Penta has been very open in support for designers/builders through the BEIC (Boat Engine Integration Center) and with the relationship with Donald Blount that many questions have already been answered regarding triple and quad installations. Certainly information on the new higher horsepower like in the Lazzara 92 is harder to come by so far.
Another item of note is the power options offered in a new boat. I was there to witness the shock when members of the press asked Dick Lazzara what other power options were offered in the LSX 75 besides quad IPS. The answer was none. If the system is truly superior to traditional shafts, then why continue to offer the option? This is an old thing with boat building that I am so tired of. Having been on the customer service side of things for many years, boats with less than optimum power options should simply not be built. We would all be better off in the industry. With POD drives, the new engine room arrangements and added staterooms in many cases make it clear that you need to dedicate the design to take every advantage possible and forget the old way.
This is what is selling POD boats, added live-ability, using less fuel, less smoke, quieter operation and joystick. Now Yanmar announced a joystick for their new sterndrive (in about a year) to follow CMD and Volvo Penta.

Sorry, I got carried away. I have extensive experience with the old and the new. I think we are going in the right direction.

The need for tank testing is more to find out the hull resistance with different loads as I intend to make something very different and special for this power option. As you say, it will be only IPS since all is built around them.

Personally I like sterndrives better, for many reasons, but except for a small power increase I don´t expect them to compete with the POD drives when it comes to boats above 50 feet.

Tank testing

AMG, certainly a valid point. The arrangement can make significant changes in the LCG and other important matters. It deserves the proper investigation.

The POD drive is not really designed as an alternative to stern drive, but really to bring stern drive efficiency to the inboard boat market. Stern drive already has directional thrust and underwater exhaust that the inboard has not had. But it also has not had independent steering for example that led to the joystick option. It also has severe limitations regarding exhaust flow and the ability to handle higher torque loads. The joystick application is simply being adopted from the pod drives to the stern drive market to help overcome issues related to docking. But engine center-lines are typically narrower as well which may complicate matters.

I also must note that those outside of North America will deal with Volvo Penta through their Market Regions, not the US branch. So the BEIC I mentioned is mainly for those in North America. Just to clarify the point.

Hi everyone, please allow me to butt in with a question that has concerned me since these drives first came out. Are they built to break away from the hull clean leaving it still watertight incase of an underwater collision or are they going to rip a chunk off your hull? Sorry if this has already been brought up.

Dan

Supposedly, they are supposed to break away and leave the hull intact. I have never seen one that ran across a reef, so I couldn't say for sure.

"Are they built to break away from the hull clean leaving it still watertight"

They are made to break off clean and leave the hull sealed. It's ironic that that seems to be most people's first reaction (myself included). Meanwhile most of us know what happens when you rip the shafts or rudders out of a hull.

Thanks CaptJ and NYCAP123. The drives breaking off was my only concern about them. Hopefully this will never happen to anyone on yachtforums but maybe if it does they will let us know what happens.

Dan

Hi,

Go back to Page 1 of this post and read a few posts from No 5 onwards.

There are two stores of broken drives and a link to another YF Article