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My new boat has the Volvo IPS where the props face forward. I also have the joystick and it is a marvel in controlling and docking. I am currently cruising in the Puget Sound, Gulf Islands areas.
In just under 100hours of engine time on the water, there have been eight (8) different encounters with flotsam that has resulted in requiring the boat to be hauled, the props changed and sent out for repairs.
Volvo's response to date has been 1. It is seasonal, more junk in the water Nov.-Feb. 2. Operator error (even though it isn't just me, it happened to a professional driver also), and 3. they know of NO other similar problems anywhere.
Vertical Trim tabs (Volvo QL) are being added for better sight lines and log skeg(s) in front of the props for deflection. Both are only theoretical fixes as there is nothing to compare them to.
Does ANYONE have any information, experience or references for this situation?
Obviously the frequency of incidents is not acceptable and something has to be done in order to keep the boat from being geographically and seasonally challenged. I mean I doubt if anyone with IPS drives in Florida, for example, is having any similar problem at all.
Anything anybody can add would be extremely helpful.
Thanks,
Nick
Boat specs: 48' LOA, Beam: 15', Wt: 35K lbs., Volvo D-6 diesel (425hp).
I really don't know how you blame a drive train manufacturer when you hit stuff in the water.
I mean, what do you expect them to do about it?
Would the incidence of damage been any different if you were using aft facing props on a sterndrive (common in the Pacific Northwest)? I doubt it, but who knows. If so, the answer may simply be that the IPS system is not approporiate to your area, which as you well know, is infamous for floating debris, particularly "deadheads" and other semi-submerged hazards. I know in my area around the rainy season, the yards here are quite busy with prop/shaft damage on conventional inboard boats. This does not stop or deter people from using IPS, which is quite sucessfull here with Tiara for example.
I wonder if the manufacturer could build a shielding housing around the forward facing props on their ips pods. A sort of tunnel drive housing with an open grid front and rear to allow proper flow, so that they could be flotsem proof but still carry out their mission. Sorry to hear about your misfortune.
Interesting.
There's debris, and there's DEBRIS
I just WAG'ing here, but if there's a floating log or lumber of substantial size you're going to do damage to any type of drive. I tend to think that smaller stuff might get deflected by the shaft and strut- at least sometimes. When you've got a prop spinning at something like 3000 rpm it wouldn't take much to damage a prop.
If Volvo did any testing on this- and I'm sure they did- I've never read anything about it. Perhaps it's a downside they don't discuss.
The new pod drives are interesting, but the hype about huge fuel efficiency and performance gains aren't panning out from boat tests I've seen. I have always been concerned about maintenance and repair costs for these systems. Both Volvo and Mercury (Zeus) brag about how the drives are designed to "shear" off in the event of impact- but they don't tell you what it's going to COST to do the repair. How severe does the impact need to be? What about lesser collisions that would only damage it without it shearing off? Running gear- all of it- can be replaced for probably 3 or 4K per side. Can anyone tell me what it costs to replace a IPS drive??
If you guys that are questioning how he could possibly run into all this trash without seeing it and avoiding it, blah, blah, blah had any experience at all on wooded rivers or coastal areas (such as Puget Sound) which have wooded rivers/creeks/streams emptying in to them, you would not ask the question.
Such waters are FULL of tree trash at various times of the year (varies with location/season) and trust me, much of it you cannot see, it will be completely submerged just below the surface, and lots of it. There are ways of trying to detect it (ripples, odd currents, etc.,) but they are of more help in a river itself, with current, than they are in a coastal bay or sound. And you are never able to see it all. And can you slow down, yes, but unless you stop (i.e., don't boat) you can't avoid all collisions.
I thought when I first saw the Volvo system that only a damn fool would design such a system. And to the poster that asked would it be worse than a sterndrive in such waters, I have operated sterndrives extensively in those conditions, and hell yes a forward facing prop would be worse. Sure, the sterndrives take their hits too, as do their props, but a big sterndrive can take a mighty whack on the casing without serious damage.
Rivers in Florida and the northern gulf do not carry the trash load that many northern rivers, especially in areas with winter freeze/snow and then(often) fairly sudden melt with some bank flooding, do. The worst trash "wash out" occurs in the spring in those areas, when areas above the normal water level, with lots of fallen wood on the ground, get flushed out. But it happens to some extent all the time.
About the seasonal pattern in the NW, I don't know, in detail, but I see NO reason not to take what the OP says pretty much at face value. Everybody has to have a first post sometime, and often that gets done when a guy has a problem.
I don't think the question was so much as to how could you run into submerged debris, as to what is the manufacturer is supposed to do about it. Intuitively, it might seem that forward facing props might get hit more than rear facing sterndrive props, but I'm not so sure. It would seem that anything that hits a sterndrive leg head on gets pushed into the props anyway.
Does one get hit more than another? Data to support this?
It's a fair question, and one that the damn fools that design airplanes seemed OK with. They may not have flotsam, but they do have birdstrikes, with the same or worse results. You don't see many pusher props in airplanes, and they have a lot more to lose.
Again, I see a LOT of conventional inboards with prop damage every rainy season.
I agree with much you say, for sure with the idea that in your rainy season (or our springtime) there is plenty of prop damage to go around, both to sterndrives and conventional units. Many in our part of the country think that conventional shaft/prop/rudder assemblies are MORE likely to take serious damage than sterndrive units. (Serious damage to the gear other than the prop.)
And yes, from bitter personal experience, lots of times what you hit with the front of the outdrive will in fact end up in the props.
As far as data comparing forward facing vs. rear facing, the forwards are too new to have much. Remember, though, just like intuitive is often wrong, nevertheless, it is probably more often right than wrong. I'll stick with idea that forward facing is asking for trouble from debris.
And last thing. With most big boat sterndrives, once back in the slip you can (in a skiff or rowboat) pull/swap props fairly easily, without hauling the boat, which of course isn't possible with the IPS. Also, I agree with the poster above who pointed out that with stern, you may only damage the prop, or, if worse, it will still be cheaper to repair/replace than with the IPS.
About airplanes, well, 'whole 'nother subject. Several things: where I learned, we had fair amount of seaplane operations. As you probably know, bird strikes are thought to pose a greater hazard to water and near-water operations. Some of the pusher seaplane guys felt that the pushers actually DID lessen the danger of bird strikes. We may see a whole lot more pushers if Rutan and some of the avantgarde designers have their way (and yes, I know that some of Burt's aircraft have forward-facing props.) And of course you remember the early pushers, some kinda well known. I believe one was called the Wright Flyer (it was even a canard, too.) What did those boys think, intuitively?
OK, sort of kidding, but the flotsam of birds vs. the flotsam in a river/bay in trash season(s) is just not comparable at all. (Comparable frequency, I mean. As far as consequences, yes, birdstrikes can be very very bad.)
I would just make the point on repair costs that many sportfish guys easily spend 3-4k per side- just on props. A catastrophic collison such that might dislodge a IPS unit would likely bend shafts and cause hull damage as well, in fact costing more than a IPS downleg replacement.
To the OP's point though, I cannot imagine having for example a twin diesel express with say, C9 Cats, and complaining to Caterpillar about excessive prop damage in a straight inboard configuration. It may not be the skippers fault, but it sure isn't Cats' fault either. You're right about the IPS being too new for data, but I think that it (IPS) may be criticized just because it is new. If IPS came before aft facing sterndrives, we might all be laughing at the notion of pointing props backwards.
I guess if I had 8 damage based haulouts in 100 hrs, I would sell the boat and buy an aluminum hull-rigged with jet drives. I wish the OP luck and hope he resolves it.
On Saturday, I had the pleasure of sea trialing the Spencer 43 Express with the Volvo IPS drives.
Comments about IPS:
Manueverability is out of this world. The fish have no chance on this boat. The boat completed a 360 in exactly 9 seconds. One of my questions was how would the boat back down. Well, not only was there no water coming in, I had to hold on because the boat was hauling ass. We were sitting at a dead stop and the captain moved the throttles top the pins. The boat jumped on top IMMEDIATELY. We were at 30 knots in seconds. I was so amazed at the torque and acceleration. I would most definately feel confident with these engines. Another very nice thing was the absence of smoke from the exhaust. Even when accelerating hard after backing down did not produce a single puff of smoke.
lcosta01 - Was there any in deck storage (fish boxes) on that Spencer?
The IPS drives are a interesting concept but a person does NOT need to be a scientist to know they are MORE vulnerable than a traditional drive. When I was a kid operating a boat in the bay in shallow water I would be scolded to NOT put the boat in reverse for fear of hitting some debris and damaging the prop. I was taught to stay in forward gear and maneuver the boat out of the shallows and not to back out because if you hit something the prop is first to be damaged instead of hitting the skeg/lower unit first. IPS appears to be a very interesting system and if it is as fuel efficient as they claim this is a great concept but the practical application is to date questionable in my opinion, especially in an area like the OP is operating. I suggest a damn good forward reading sonar for this application.
Although there was no below deck storage in the cockpit, the transom livewell doubles as a fishbox. It can easily hold multiple YFs of 50-60#s. I was interested to see the livewell as a fishbox, and I was very satisfied with it.
Profinity, your assessment of IPS being more vulnerable (to what exactly, btw?) is wrong. Do a cost survey of a hard grounding (snapped/bent shafts, ruined props, struts punching thru the hull, etc) in a traditional boat vs. IPS. The numbers don't lie...
The above was my first blog, ever.
I think I failed in my effort to present a "balanced" view of the situation.
In my recent search for a new boat, the highest criteria was the Volvos IPS. I determined it represented the (partial) future of cruising and my bottom line was always "I do not want yesterdays technology". This was, and is, very difficult as things are evolving at such a rapid pace, especially in marine electronics and propulsion systems. As it turned out, all of the theoretical literature was proved beyond a doubt by the actual performance. I can strongly endorse everything Icosta01 says about the IPS and, as I pointed out in my original, Paragon is a 48' LOA welded aluminum, 35,000lb boat. So I got exactly what I wanted and its superior performance capabilities has made a much more confident skipper out of me. I will be one of the first to sing its praises, and applaud Volvo for having the Corporate will to put such an innovative and breakthrough item on the recreational cruisers market.
As with anything this new, this different, however, there is this prop issue. It probably was thought about but determined to be so minor as to be insignificant. And to Volvo, it probably is. I don't really know what % the N.W. market represents to Volvo, but compared to world wide operations, I would guess pretty small.
The point mainly was to start some discussion about the problem, to see if there were any others with a similar situation, and to find out if there have been any successful fixes or work-arounds. Coastal Craft, the Gibsons, B.C. based builder of my boat, asked Volvo why the props for the stern drives were so much more robust, nearly twice the thickness of the IPS. The response was simply that the props were designed for the drives. We thought that maybe if we used the thicker props, it could help eliminate some of the incidents. Based on some of the damage I have observed, I thought the more robust prop could have eliminated a couple of the haul outs. Even the minor bends cause unacceptable levels of vibration at certain RPM's and we thought a stronger prop wouldn't have bent even slightly if it had more "meat" on it. But this is not going to happen, at least not while it is under warranty.
Volvo has verbally signed off on the idea of skegs, as long as they are a certain minumum distance in front of the props, I think it was 40". However, their engineers must sign off on the drawings before installation and that process is currently underway.
What eventually will be very useful is data on the number of incidents, the amount of damage, the actual hours of operation on the water, the waters operated on, and so on, of the various prop encounters. Admittedly, this will be very difficult, and slow to discover. But since all of these systems are new and as such under warranty, it would seem like there would be some way of pulling those statistics out of all the other reports. I can understand, however, where Volvo would be reluctant to collect, let alone publish, this kind of information.
I have finally reached a point in life where I have the time and the means to cruise full time, and that is what I would rather be doing.
Many thanks for all your time and thoughtful comments.
I think the market in the PNW for Volvo is acutally quite sizeable, Volvo diesels are very popular up there, as they are here.
Keep in mind Volvo invented the sterndrive, the Duoprop system, and now IPS. All of these technologies were initially criticized as being faulty, and all are now being copied by others in the market, with great success.
I think they know exactly the comparable damage effects between sterndrives and IPS, and I believe the numbers are favorable in the direction of IPS, or the developement investment would never have been made.
Is it possible that somehow the shape of your specific hull causes eddy currents or some type of unusual vortices that directs material towards the props? At any rate, it would seem that with an aluminum hull, you have some relatively straightforward options to add deflecting features to protect the drives. I think I might challenge their engineering people to some CFD work on the computer to validate the skeg design and placement before I started welding willy nilly.
I do not think thicker props is the answer, I diasgree with the premise that this is any benefit at all. I've bent props just by leaning on the throttles too hard from a dead stop, and suffered the vibration immediately. You just can't hit props at all with anything and expect them to run true.
Good luck with your boat and keep us posted on the outcome.
CMP- Time will tell. I understand and appreciate the cost of hard grounding and running gear. If you are going to critique my post then compare apples to apples. A hard grounding is one issue, the OP's experience involved flotsam, not hard grounding. With this IPS system the props are the first to make contact. The concept is nonetheless very interesting.
The QEII is probably not the best example of such a system as the scale changes the dynamics. Imagine hitting a log with the QEII (ship)? You probably would not notice the encounter. Hit a log with a boat and likely you will have a story like the OP.
And in his situation, the prop shafts in a traditional install make first contact, then the props and possibly the rudder-there may or may not be major damage in either situation. In NH, I've hit many things from trees to logs, to fish boxes and pallets. My props took a beating and they were traditional. I've bent shafts in semi-hard groundings (sand bars) and have been fortunate not to have had them be so hard as to punch holes in the hull, but we know that happens. If yer not hitting things, yer not using yer boat enough, right?!? Hard groundings is where IPS is head and shoulders over traditional gear. Add in the innate efficiencies and ease of use in mauevering and it's a winner...
Volvo IPS 
Hard groundings is where IPS is head and shoulders over traditional gear. Add in the innate efficiencies and ease of use in mauevering and it's a winner...
