Another pod drive system

Nautical

Nautical

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www.outerreefyachts.com
So it seems the cat is out of the bag and Yanmar have entered the pod revolution. So that's the three majors now at it so to speak.

Fairly obvious that pods are here to stay and increasing at a greater rate than ever before.

So who is going to be overall winner or is it a three way split you just choose your preferred manufacturer and takes your choice or is it one will have the 'legs' to out run the other two and become the mass market's propulsion system of choice.

Personally I think each will run alongside each other and you make your choice so I guess the argument beta max V's VHS doesn't stack up.

And where are the old guard in all this, with ever more and more pressure on green issues, fuel efficiency and the rising cost of fuel, are they still the choice of many in years to come or is the writing on the wall, perhaps for lower volume product like expedition or semi D stuff will still use the older technology for the foreseeable future but are the days of the old guard numbered ??

Yeah I know I am biased but interested to see on a personal level whether the very strong 'anti' feeling from say three seasons ago is still simmering under the surface or is there a change in sentiment towards pod drive.
 
I think that article should have read ZF does another Pod drive for another manufectere
arent they also building the Zeus and Volvo IPS....

for 40 - 50 sports cruiser they are surely here to stay, taking place of shaft and stern drives in this size
for the others...
there is still a big question mark with Flybridges, Cranchi is doing a new 43 with IPS so may be that might move something,
the rest is still a big question mark and seems to be moving a bit slow
I think for big opens it is all about waiting for the bigger IPS 750 and 850 to be produced and then the benchmark with go up to 20 metres for opens or hardtop boats,
any idea when this will be launched as Volvo seems to be 15 months in delay here
still the big question mark remains with the flybridge boats, where there is a big market and so far we are seeing still few boats equipped with it
 
Well yes ZF are a major developer of pod systems but of course each is marketed under their own brand.

I believe the Azimut 50 fly that was a prototype for the bigger IPS system was very well received by jurnos that tested it but as you say VP have been slow in bringing it to market, either through technical problems (which I can't see as they have already the technology out in the field and operating in 000's of vessels) or it is a problem with capacity to build it as the D4/D6 units are selling so well.

Although against our product I have to say the Zeus system seems a better product, better packaged, cheaper and if anything slightly more suited to open's. The downside is the availability of dealer locations and trained engineers, VP have a huge lead on the ground and a bigger infrastructure to support it which is a major factor in choosing which manufacturer.
 
Maybe there are parrallels with sail boat propulsion where the saildrive still has less than 50% of the market after over 20 years, even though the two big players offer both systems to the same customers.
 
[ QUOTE ]
So it seems the cat is out of the bag....

[/ QUOTE ]

Interesting choice of words, CAT will be using said ZF drive an all!!!
 
I think I may be a bit of a luddite in these matters but it seems to me that I have two unstressed engines with mechanical controls which are inside the boat and the only bits that dangle in the water all of the time are the screws and part of the shafts. These enable the boat to be moved pretty much where I want. The only downside that I can see is that the system has various inefficiencies in it. First, it lacks an engine management system so it is a bit wasteful in terms of fuel burn. Second the bits that dangle in the water create quite a bit of drag. However for a leisure user I would guess that the extra fuel-burn is more than made up for against lower maintenance costs and the thought that quite a lot of problems can be fixed with a spanner rather than a computer is also worth something.

I think the pod concept is attractive especially the independent vectoring and the fact that they are all coupled with efficient modern engines. I would like to see some stats on maintenance costs and on the durability of the computerised systems which they rely on, though. My guess is that in a commercial environment where routine maintenance is factored into the running costs they would be financially worthwhile but maybe less so for the leisure user.
 
Maybe its getting less publicity, but we are seeing more and more builders looking at enclosed shafts as a drive improvement option.
From fancy craig loomes designed syuperyachts to commercial workboats the benefits have now been proven in some documented tests.

I think the pods will end up like Tranoma has suggested, much like the saildrives in numbers.

Pods don't suit all builders or all owners but they have their place and we will see more.
 
Do you know what it is that stops an out-drive taking more than 370HP? Is it that the drive can't handle the torque, the propeller can't operate efficiently or is it simply marketing policy to avoid hitting other sectors (such as IPS/Zeus)?

I've often wondered, seeing as Volvo have a 435 HP version they could simply bolt on presumably?
 
The problem is that with big diesel engines the torque can be a drive killer as Yanmar found out with Bravo 3's.
But there are drives that can handle more than 370hp, they are called Dry Sump 6, NXT1, SSM 6 & 7 and are made by Mercruiser for petrol engines.
We have 2 Nortech 36's one has 2 x 700hp V8's and the other2x 1000hp V8's and I can assure you that they deliver the power no problem, having driven them at over 100 kts! /forums/images/graemlins/grin.gif
 
I dont think its the power, but the torque of big diesel engines. While there are drives for 600Hp petrols, these engines will be designed to produce peak power not peak torque.

a 370Hp diesel could easily have in excess of 600nm of torque, about the same or a bit more than the 600Hp petrol
 
For new build and the implied resources to get regular servicing they are a nice technological solution. I would be less certain about being a subsequent owner and know for a fact that I could not afford the servicing costs so reduced fuel consumption would be at the risk of nasty graunching sounds after a year or so. As a river based boat the prospect of dinging one on a shallow bit, or wrapping a rope round one in the Tideway fills me with horror.

One might argue about the relative fragility of outdrives coupled with the relative inaccessibility of shafts being a bit of a risk for the less well-heeled.
 
That's a fine point, a little reminiscent of the servicing and maintenance issues of cars once they're a few years old. A 5 year old car can be just about written off now if it has a major electronics failure. So in boat terms, the new builds will last longer than cars because the relative investment the owners have put in means they will get main agent servicing for longer, but once these boats are on their 3rd and 4th owners, maintenance budgets will start to get tight.
 
That was one of the arguments against saildrives, but the designs are largely unchanged and have proved very reliable - even if expensive if they do go wrong compared with failures on shaft drives.

From what I have seen of pods, it is probably not the basic engineering (gears, bearings, seals etc) that will be the problem but the control systems that make them do such clever things. The car analogy is good here. Engine and transmission failures are rare, it is the electronics that are the problem. Very reliable to the point that they go wrong!
 
What is interesting though is that an IPS drive is built on exactly the same principle as a sterndrive, two 90 degree gear boxes connected together, so technically speaking a sterndrive if built to the same design as an IPS should handle the torque, but perhaps its size/weight would be a limiting factor.
Discuss...
 
As you say, unless someone can invent new designs for small bearings / gears that can support high loads, then you end up with something big. A DP-H drive isn't exactly light, as it is.

dv.
 
I would be most interested to know just how deeply ZF have been involved in IPS - if at all. AFAIK, Volvo are claiming in-house design of that.

When Zeus first surfaced I was told by CMD USA that it was originally a Cummins design from some years ago that had been put on the backburner as being before its time. Which is why they were able to respond so rapidly to IPS. Now it appears that it was a ZF design all along, but CMD had an agreement for a limited period of exclusivity which has now expired. Zeus is a CMD trademark but I'm told the drives supplied direct from ZF will also carry the Zeus badge!

Bearing in mind CMD's insistence that Zeus required close cooperation with the boat builder on hull design for it to work properly, it will be interesting whether Caterpillar, Yanmar and VW adopt the same principle. Or will they be happy simply to deliver engine/drive packages to boat builders and leave them to get on with it?

Best wishes
Tony Jones (Tech Talk)
 
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