[NYCAP123]

Originally Posted by K1W1

Hi,

Take a look here to see what a real pod system looks like.

http://lmgtfy.com/?q=pod+propulsion+system

I know what a "real" pod system looks like. Now you just have to convince Volvo, Cummins, Caterpillar, ZF and a few boat manufacturers. Let me know how that works out.

[Marmot]

Originally Posted by NYCAP123

I know what a "real" pod system looks like.

Sure you do, but like most other people, you don't know what one is.

The marketing folks at the companies jumping on the bandwagon are counting on people like you to think the same way. They use the term because it makes uniformed buyers think it is the same system introduced to provide great benefits (after a few years of costly screwups) to cruise ships and now ice-breaking tankers among other applications.

It just wouldn't attract as much attention if they called it a non-tilting-through-the-bottom-inboard-outboard would it? Or like the workboat crowd call them, Z-drives or tractor drives. The folks they are aiming at want to pretend they are buying into a more technologically sophisticated class of shipowners.

It appears that in this case marketing has once again trumped engineering and will probably continue to do so until enough of the things fall off or sink boats that would have been cheaper and just as effective with transom mounted outdrives. The only thing they offer is a control system that lets prop drivers almost match the maneuverability of jet boats without having to know how to drive ... until the things break off.

[NYCAP123]

Originally Posted by Marmot

Sure you do, but like most other people, you don't know what one is.

The marketing folks at the companies jumping on the bandwagon are counting on people like you to think the same way. They use the term because it makes uniformed buyers think it is the same system introduced to provide great benefits (after a few years of costly screwups) to cruise ships and now ice-breaking tankers among other applications.

It just wouldn't attract as much attention if they called it a non-tilting-through-the-bottom-inboard-outboard would it? Or like the workboat crowd call them, Z-drives or tractor drives. The folks they are aiming at want to pretend they are buying into a more technologically sophisticated class of shipowners.

It appears that in this case marketing has once again trumped engineering and will probably continue to do so until enough of the things fall off or sink boats that would have been cheaper and just as effective with transom mounted outdrives. The only thing they offer is a control system that lets prop drivers almost match the maneuverability of jet boats without having to know how to drive ... until the things break off.

Let us know how your campaign works out. BTW, don't ever presume to know what anyone else does or doesn't know. It makes you look more foolish. I've been on a few tugs with it. I'm no expert and don't profess to be one, but YES I do know what one is.

[K1W1]

Originally Posted by NYCAP123

I've been on a few tugs with it.

Hi,

What have you been on a few Tugs with NYCAP?

I seriously doubt you would find a tug sporting full pods, they tend to use these:

http://en.wikipedia.org/wiki/Voith-Schneider

[Marmot]

Sorry Cap, I don't have a "campaign." I could care less who buys the stuff, I just pointed out that marketing has more power over people in the boat business than engineering and this is a great example.

And if you knew what a pod was, where they came from, and how they worked, you wouldn't call an outdrive a pod, that's not an assumption, that's a fact. I also doubt if you have ever been on a tug with a pod drive. A Z-drive or a tractor maybe, but not a pod drive. But, who knows, I haven't seen everything, maybe your sportsfish has a couple too.

[NYCAP123]

Originally Posted by K1W1

Hi,

What have you been on a few Tugs with NYCAP?

I seriously doubt you would find a tug sporting full pods, they tend to use these:

http://en.wikipedia.org/wiki/Voith-Schneider

Now that's something new to me. Thanks for the education K1W1.

[brian eiland]

Originally Posted by NYCAP123

Now that's something new to me. Thanks for the education K1W1.

Those Voith-Schneider cycloidal drives are quite successful as I understand it.

As far as damage to ANY propulsion system other than jets....DON"T HIT THE BOTTOM...it can be expensive

[AMG]

Originally Posted by brian eiland

As far as damage to ANY propulsion system other than jets....DON"T HIT THE BOTTOM...it can be expensive

You are right, and with jets you should not even be near the bottom...

[rip728]

Well K1W1, I have to say that link was clever.
But I am afraid you still don't really win the argument in the long run (with me you do), as Mercury, CMD and the press are not about to stop calling them POD DRIVES. Volvo Penta went with Inboard Performance System (the IPS thing), maybe they are not the best at marketing? But again, you have my respect on this issue. You and Marmot can hail a victory I suppose. At least I won't call them POD drives in this forum.
The sterndrive comparison Marmot I would not agree with at all. There are no U-joints surrounded by rubber bellows, no aluminum, no rubber hubs and now plenty of torque and horsepower can be applied. The underwater exhaust, low noise and low vibration characteristics however are similar. I know I never had to scrub the transom anymore after a long days run on an IPS powered vessel, so I was pleased.

This is what we need folks, better yachts with better performance, better fuel economy, lower noise, less emissions and easier handling/docking. Can we agree on that?

[rip728]

Originally Posted by Marmot

It appears that in this case marketing has once again trumped engineering and will probably continue to do so until enough of the things fall off or sink boats that would have been cheaper and just as effective with transom mounted outdrives. The only thing they offer is a control system that lets prop drivers almost match the maneuverability of jet boats without having to know how to drive ... until the things break off.

I feel you need to rethink this Marmot. There are some really talented people working on these new propulsion systems. If you look at some efficiency gains and improvements the IPS (with countless magazine reviews and sea trial statistics) and the what they say about ZEUS so far, that this is in fact an improvement over traditional inboard shaft propulsion in planning yachts in the range of 35-75 feet. If you want some pictures of inboard boats with struts pulled out, washed up on shore in pieces or whatever, I think we can find more than a few to send you. Give this stuff a chance will you?

[Marmot]

Originally Posted by rip728

I feel you need to rethink this Marmot. ... Give this stuff a chance will you?

I never said it was useless or didn't work, but I strongly suggest that the marketing hype far exceeds the real performance gains and costs above that of a conventional outdrive. The risk of hull damage and increased drive damage beyond that of an outboard or I/O in a similar grounding outweighs any slight performance increase in my opinion. The marketing department doesn't talk about cost/benefit ratios for these things does it?

Sure you can provide thousands of bent shaft pics, there have been millions upon millions of them running around over the past century or more so the opportunity to acquire a damage history is rather large.

I say marketing trumped engineering because they have usurped a term that describes a particular form of propulsor in order to form a public image that distances these drives from what they really are, an I/O that drives through a hole in the bottom and doesn't offer the hope of salvation in a hard grounding the same way a transom mounted I/O does. They are only sold in pairs because they are trying to sell a control system.

Given the location and operating environment of the type of boats in which these drives are installed, I predict many more horror stories related to what otherwise would have been far less damaging groundings or encounters with crab pots and such. As an engineer I look at cost vs benefit vs risk. I don't see any good numbers in this application.

[AMG]

Marmot, the IPS is for boats that otherwise have shafts and rudders. They are not competing with outdrives, which by the way can also have joystick steering.

The range of engines provided are mainly too powerful for any of the Aquamatic drives and the IPS II and coming IPS III will be sold for yachts up to about 100 feet. They are sold in twin, triple or quadruple configurations, but you can probably have just one as well, but then there is not much advantage over a center mounted shaft and rudder.

[Pascal]

Originally Posted by rip728

This is what we need folks, better yachts with better performance, better fuel economy, lower noise, less emissions and easier handling/docking. Can we agree on that?

I agree... the question is whether or not IPS/Zeus is better enough to offset the cost and justify the risks. Risk maybe too strong a word but straight shafts have been around forever and proven. Mainstream steering system, things like Hynautic, also have a proven track record compared to exotic fly by wire steering systems.

When IPS was first launched, Volvo's marketing campaign claimed 30% better fuel efficiency, mauvrability, speed, etc... it was the magic bullet. when the first real world tests came out, back then mostly in 40/50 footers, it turned out that the fuel efficiency improvement was closer to 15%. Back then, costs of IPS equipped boats were significantly higher meaning that there was no way to recoup the higher initial costs in fuel saving.

As to high speed maneuvrability, who really wants to throw a 50 or 60' MY in a ultra tight turn?

I dont' get the easier docking part either... it's hard to beat a twin inboard for ease of docking, even without grinders.

Now that IPS is making its way in larger boats, i'd like to see real world comparison of fuel saving and performance improvement. Also seems that cramming 3 or 4 engines will raise a lot of serviceability questions as well as costs... twice as long, twice as much to service 4 diesels than 2...

Seems to me that there is macho factor that buidlers may be exploiting... do some owners want to be the first one on the pier with quad diesel setups? or get bragging rights with a 35kts cruise?

I wonder.

but id' love to see real world fuel burn comparison in similar boats.

[Marmot]

Originally Posted by AMG

Marmot, the IPS is for boats that otherwise have shafts and rudders. They are not competing with outdrives, which by the way can also have joystick steering.

Fair enough regarding the use on larger planing boats. But, in that application they are competing with surface piercing drives and jets, either of which offer outstanding high speed performance with far less risk of hull or drive damage.

In the context of 100 foot planing hulls, efficiency is a non-sequitur so claiming higher efficiency in that application is kind of amusing.

[AMG]

Originally Posted by Marmot

In the context of 100 foot planing hulls, efficiency is a non-sequitur so claiming higher efficiency in that application is kind of amusing.

Not when you translate it into range.