Pod drives for large yachts

2682 hp. 2000 kw.

RR has Mermaid up to 11,000 kw and beyond and HICE up to 18,000 kw. So, no question they could do something nice for recreational vessels.

We looked at a manufacturer of normal tunnel thrusters who had through collaboration with another company developed a range of rim drive thrusters.
At the time we were looking I became aware of a recent delivery that was changing from rim drive to conventional thrusters. I made some enquiries and found it was because of some cracks and system failures.
The company we were looking at assured us they had solved all their problems and as such fully expected to be able to charge an eye watering price. Needless to say we did not accept their offer and I have not seen in the press that they are selling thousands of units.

Every model ever shown by anyone at any show has been "well received." I always use to tell the sales guys not to tell me how well the line was received, show me the orders.

Sunseeker is pushing pods. Many of their boats are available with IPS.

As to the larger boats, in many cases they have proven designs that work well for them. Why spend the money to try something different and far more expensive for them? You've also mentioned some that exceed the capabilities of IPS and Zeus and challenge the speed capabilities of some of the other pod systems.

One reason for the slow uptake could be the need to redesign the stern section to enable the use of them and the high level of complication for the operators.

For a fiberglass builder, it's designing and building an entirely new mold. It's more a new model than it is a modification of an existing model. Every design factor changes.

You got me there. I have no experience in building of fiberglass boats, steel and aluminium are what I have spent my career involved with.

We used to moor next to 'Brittania' that had these fwd drives, she went well for a mid 80's yacht.

I was actually referring to the engineering dept. DE is a much more complex arrgt than a traditional drive line.

K1W1 is referring now to the larger pods. The discussion took a twist. We've gone from Volvo to Rolls Royce and they type pods you'd use on a 164' MY.

How a commercial application is working for IPS.

Also do not forget few things about IPS : 1) they are very sensitive, in case of fouling on propellers they can lose more than 5 knots, and even more if the fouling is also on the hull. In the same conditions with shaft you will lose no more than 2 knots. It means they work well only if the hull and the propellers are perfectly clean. 2) if you need to install 3 IPS, it means that the deadrise at stern is basically flat, aka slamming in rough sea.
IPS and POD are basically stern drive. Stern drive can be in general used only until 40 feet since maximum power available is around 400 HP. Over 40 feet POD or IPS.
About consumption, I will say not a big difference with shaft, since you burn 10% less (more or less) with clean hull and prop, but this condition does not last long, unless you use your boat every day or unless every week you jump in the water cleaning your propellers. About maintenance, much more expensive IPS and POD than shaft. About safe navigation.....I let you judge, in my opinion shaft is safer, but someone can have a different opinion. About manouvring , if on shaft you have stern and bow trust there is zero difference.
The only real advantages of POD and IPS are noise reduction and basically no vibration. But you can get the same advantages with waterjets. Waterjets are in my opinion better than ips and pod, also because with waterjets you have nothing under the hull and you can use your boat with no problems also in shallow water. But waterjets are much more expensive than IPS or POD, so rarely a yard is using them ( small medium boats : Hinckley, bigger boats AB yachts and Mangusta ).

If the IPS boat will lose 3 more knots than a shaft boat, it is still faster and using less fuel. About the slamming of a triple IPS, it has to be very rough sea to get the whole boat airborne..? On what boat have you had this experience..?

Not essentially megayacht size but Volvo has introduced the IPS 1350 which is its first foray into the 1,000HP market. I am more surprised that the ZF pods haven't taken off more. They can be coupled up to 1,200HP MANs which is probably good performance for that category size.

I have two questions. First is has Brunswick/Mercury ever done business with MAN? Second is do you really think Cummins would allow that?

It's my understanding that Zeus was owned, not by Mercury alone, but by CMD, Cummins MerCruiser Diesel, which was 50/50 owned. I'm not sure that entity still exists but I'm not aware of anything that has changed the effective ownership of Zeus.