Boat Builders view on POD's

http://www.sail-world.com/index.cfm?Nid=105195&refre=y&ntid=80&rid=2
quote

In 2013, Maritimo will be focusing on 'building the most fuel efficient and lowest running costs luxury cruisers', through investment in its personnel, R&D, after sales service and 'customer connectivity'.

Despite the hype associated with pod drive propulsion, Barry Cotter acknowledged a widespread customer disillusion with the technology that was costing them many thousands of dollars in repairs.

'It’s a classic case of not believing everything a sales man tells you,' explained Barry-Cotter. 'We have observed with the pods, by three to five years, customers are finding bills of $40,000 coming in. Even Cummins Zeus, the second largest manufacturers of pod drives in the world is exploring other options, like a single computer for the engine, with joystick control and shaft drive inboard engine, which saves costs all round.'

The problems lie with the shape of the pods, Barry-Cotter stated. 'You can’t trim fore and aft. In the M43, at seven and a half knots we have found shaft drive is nearly 50% more efficient – it’s bizarre the difference. Shaft drive are eons ahead. Going forward, we won’t even bother with the pods because of the service issues.'

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Ah ha trimable PODs coming, look mum we invented the sterndrive

 

They also present a huge mass of metal under the water. Difficult to keep this metal antifouled and everytime I see one hauled its anodes are 100 percent wasted.

In ten years when the legs must be removed for maintenance you will have a huge shipyard bill.

One obvious advantage is that the entire power package is compact and doesn't hang off the transom like out drives.

 

yep
so they are easy to remove??
Corrosion on a sterndrive is a problem, I cant see these being different?
You dont want to own a moored sterndrive boat after a few years and low and behold these now seem to have the same reputation
Imagine a 10 year old pod boat left in a marina with a bad earth and no maintenance....I wonder if it would stay afloat that long?

Reading the about comment from BBCotter I wonder as is usually the case that the boats need to designed to suit the power train you just cant put new drive train in a hull that has spent years being optimised for another kind of power ( Grand Banks found that one out)
I always remember US small production boats that came in outboard and sterndrive, they look the same but there was always more beam at the waterline on the sterndrive so it would carry the weight

 

A Stern drive is a pretty simple, cheap fitting that can be serviced by normal shipyard staff. Not so with a POD.

Personally I would go conventional shaft or sterndrive.

 

http://www.gizmag.com/azimut-grande-140/25366/

Larger "pod" drives on the way. 2,000 kW at 600 propeller rpm

 

I do like the idea but on a rack stored boat as per a sterndrive

 

I can't speak for the Zeus Drive, but the Volvo unit has integral trim tab and when the units are installed they are trimmed fore / aft to the most efficient drive angle. They are also cast bronze as opposed to aluminum typically found in an outdrive.

Another item to note is that counterrotating props are typically "matched pairs" and if damaged must be reconditioned to the highest standard, another cost factor to consider.

Steve

 

A stern drive compared to a shaft drive surely is not simple. all those mechanical parts (and different materials) soaking in an electrolyte and mechanical wind up.A bit of a nightmare really.

A simple trim able shaft drive gives many advantages other drives do not have like running surface or subsurface props and all stainless steel.

 

Sterndrives are no simpler than pods, both require the same amount of gears, bearings, steering rams and direction control. Pods do have the advantage of keeping the steering mechanism protected inside the hull.

The simplicity of a shaft is gone when you make the shaftline "trim able"

 

Please explain !!

The simplicity of a shaft is gone when you make the shaftline "trim able"
Why ??? why does making it trimable make it complicated ??

if the way its trimmed is simple its adding to its efficency and making it a much better unit ,!!shallower draught ,efficent drive and trimable !!
I fully support Tom Kane on this one thats for sure !!

 

show me a shaft drive that was made more simple by making it trimmable
in fact can you show me an under hull trimmable shaft in any production boat, once its invented I'm sure it will be a winner

 

The reason for pods is that it eliminates the skills needed for engine installation and any issues with alignment during shipping/use/storage, ie the engine supplier owns the whole system....it also increases the engine suppliers sales (single source supplier and service...) boat builders lie, all of it except for the higher prices.....

 

This is true...similar to a saildrive.

Im not convinced that this benefits the end user.

Time will tell.

 

I agree with the above. It is the only way it makes sense to me too.

These things are really going to rear their ugly heads in the resale market. They are just fine for the guy who likes the performance, extra space they give and has ownership during the term the factory is financially responsible for them. Think along the lines of composite stern-drive. The expense of replacing them may exceed the value of the whole boat. In the current situation how would you rid yourself of a pod problem. Only answer is the same thing again since the configuration is not changeable without significant hull remodeling.

 

Riveria yachts have already had customer feed back from long term testing and I think will no longer install them
Quote from BBCotter
http://www.sail-world.com/news_printerfriendly.cfm?Nid=105195

"In 2013, Maritimo will be focusing on 'building the most fuel efficient and lowest running costs luxury cruisers', through investment in its personnel, R&D, after sales service and 'customer connectivity'.

Despite the hype associated with pod drive propulsion, Barry Cotter acknowledged a widespread customer disillusion with the technology that was costing them many thousands of dollars in repairs.

'It’s a classic case of not believing everything a sales man tells you,' explained Barry-Cotter. 'We have observed with the pods, by three to five years, customers are finding bills of $40,000 coming in. Even Cummins Zeus, the second largest manufacturers of pod drives in the world is exploring other options, like a single computer for the engine, with joystick control and shaft drive inboard engine, which saves costs all round.'

The problems lie with the shape of the pods, Barry-Cotter stated. 'You can’t trim fore and aft. In the M43, at seven and a half knots we have found shaft drive is nearly 50% more efficient – it’s bizarre the difference. Shaft drive are eons ahead. Going forward, we won’t even bother with the pods because of the service issues.'