Portofino
Well-Known Member
That’s because your water pick up @ speed is starting to become dependent on fwd motion ,kinda ram effect .
The pump can,t suck enough in at the dock and cool everything over a certain rpm
Motorboat Newbie's Change Of Direction
- Thread starter londonrascal
- Start date
That’s because your water pick up @ speed is starting to become dependent on fwd motion ,kinda ram effect .
The pump can,t suck enough in at the dock and cool everything over a certain rpm
Piers
Well-Known Member
The Cummins in our Fleming 55 are 450HP each, but idle quite low at 650rpm. At WOT, they can push Play d'eau at 17kts but the consumption is horrendous.
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The comparison between electronic and hydraulic systems is not really a valid one for boats in my size range. Builders could use hydraulic systems, but they are more work to install, and fixing problems afterwards in enclosed spaces is harder.
An electronic system is a small cable from the throttle to a helm control box, then a small cable to the other end of the boat that can be routed anywhere. For smaller boats, the most common alternative is a mechanical cable system: this is also cheap to install, but it was not such a great helming experience for Mrs FP, who does not have big biceps.
As to reliability, given the numbers of engines sold with EDC, you’d have heard about any endemic problems by now. There is the option to send a child into the engine room with an adjustable spanner and a screwdriver to operate the gear shift manually as a backup. Throttle is all fly by wire.
I would accept that a hydraulic system might be the connoisseur’s choice, but there’s a reason that there aren’t so many of these around, probably similar to why you won’t find the racks in Tesco bulging with Penfolds Grange Hermitage.
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petem
Well-Known Member
I stand corrected.
MapisM
Well-Known Member
Doh! So much for having based my previous comments on a totally different boat...
Ok, I'll update a couple of points as appropriate.
Electronic throttles: are you sure to have the option of controlling manually the engine and gearbox, should the ZF system go nuts? Afaik, the actuator boxes inside the e/r (as opposed to the Kobelt boxes, which are unique in this respect) neither allow the disengagement of mechanical cables, nor have any manual levers to move the cables, once detached from the actuators.
Imho, whoever replaced cables-only controls in a boat whose engines and gearboxes are both mechanical made an expensive mistake.
Though maybe he just liked the feel of electronic single levers, and if so, who am I to argue...?
Boat model/stabilizers: Fwiw, the T575 which I previously mentioned as much more prone to rolling than I expected was a Sundeck.
Her owner was on his third Trader, and both the choice of electric rather than hydraulic thrusters and of Sundeck rather than Sunliner version were based on his previous experience, which included a 535 Sunliner.
According to him, the much heavier superstructure+crane makes her even worse in terms of rolling, to the point of being, in his wording, "scary" without stabs.
That said, of course this can't be an issue on flat waters. And I have zero interest in raising this matter time and again - the last sentence in my previous post wasn't "each to their own" for nothing...
But just to explain you where I'm coming from, I changed my boat this year, and the T575 is one of the boats I considered as a replacement (I actually went as far as buying her, but eventually the deal aborted for reasons that had nothing to see with the boat per se). My previous boat was a 53' full D trawler with Naiad stabs, which I owned since 2000. Eventually, I bought a planing boat without any stabs, so it's not like I believe you can't live without stabs. At the end of the day, compromises is what boating is all about.
Otoh, 'fiuaskme in what sort of sea conditions (assuming stabs missing or not working) I would have rather came back to port with my previous boat and with a T575, my very personal answer would be somewhere between F5 and 6 vs. F3 to F4 respectively.
YMMV of course, but imho that's something worth considering, whenever you would wish to cruise in open sea.
petem
Well-Known Member
I'm not convinced by that one Porto.
MapisM
Well-Known Member
Why quite rightly?
Aside from when cold, afaik there's no reason to prevent running a diesel engine at WOT regardless of whether it's under load or not.
MapisM
Well-Known Member
Neither am I.
Never heard of that being an issue, and btw the cooling needs at say 2200rpm with no load are nowhere near the cooling needs when running at the same rpm with 100%load.
If I should bet why VP restricted from running at max rpm when not in gear, my money would be on them simply seeing no reason to allow that.
Piers
Well-Known Member
I'd make two comments to your post. First, why not make better cables so you don't need big biceps. Must be less expensive that creating electronic systems. Second, reliability is not just down to having a bug free software (is there such a thing?) but a system which is panic-proof when the user is suddenly under considerable pressure.
Bouba
Well-Known Member
My boat has a docking mode which prevents panic movements
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If for no other reason, to prevent numpty owners from trying to rev their engines to 3500rpm when cold.
I suppose they could have added a "higher permitted when warmed up" mode, but this isn't something that many people would need.
I also don't know long a gearbox would be happy with it's input shaft running at 3500rpm and output shaft at zero - maybe someone else could comment.
londonrascal
Well-Known Member
Thanks for the message, when was she last used - don't ask me sensible questions like that lol but I would guess August, this was when she was taken from her berth to the marina where she was lifted and had a lot of works undertaken and brought back September. Put it like this, as the Engineer said the previous owner did not go out much on her but would want her ready to just in case, so we needed to look after her as if she was being used regularly. Judging from the amount of glassware on board I would say she spent more time in port as a floating bar for the consumption of fine wines.
This weekend has been one of just getting to know her, cleaning and cleaning going through things, chucking away things, keeping things and you know stopping every few minutes and smiling thinking 'she is mine' and then feeling really happy when you change a bulb or get the manual off the net for the hob. I have therefore not had much chance to do a proper video, I will before I leave try and do something and then it is back to London - stop off at home - then back off to Norfolk to fit our new solar panels, stereo and Dek King to river boat so it never stops..
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londonrascal
Well-Known Member
London, you might also want to think about changing your anodes. Magnesium might be better if she has zincs on her. Nice boat
Yep I already have thought of this, going to keep what is on now as only put on in August. Then then she is in the fresh water come her next lift will switch over to Magnesium which is what we have on Broad Ambition, also I am impressed with the Anti-Foul we have on her which works well so will use on Independence in due course and got from a light blue bottom to either a deep navy or red.
Piers
Well-Known Member
If only that system was on the Prestige mobo that came close to ramming Play d'eau in Port La Foret this year. New owner on board couldn't take the boat out of gear or reduce engine revs. First he rammed the pontoon before slewing to ram Play d'eau. Thankfully, we'd seen this about to happen and managed to lasso a cleat for him leaving his anchor inches from our stern whilst he jumped off his boat leaving it in gear and blaming the boat. Boat eventually secured and engines killed, before engineers arrived and showed him how to press various buttons - the rest is history.
Almost pulled my arms out of their sockets. Bring back cables....Shall we end our discussion at this point?
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The cables did work well when new, but degraded gradually over time. It's possible that some future design of mechanical cable will be self lubricating and not gradually seize up in a salty atmosphere, but this wasn't what was fitted to my boat. The electronic system on the current boat has required zero maintenance so far, and still works just as well as it did as when it was new.
As to electronic systems ... bear in mind that a diesel such as D4 or D6 is has a fuel delivery system that is electronically controlled anyway. There is no lever on the side of the high pressure pump! The electronic controls are just extending those control signals over a longer cable run.
As to panic free, I'm not sure how it's any different. There is an obvious mechanical detent at the neutral position, backed up by a beep, plus you can adjust the friction of the shifters. Your Prestige disaster owner sounds like he might have run upstairs (or downstairs) to the other helm station without actually activating that helm ... basic stuff that the owner should have known before going to sea. Seeing a skipper run away from an active helm station whilst still in gear (also known as "abandoning the bridge") would certainly induce a sense of panic in me if I was a passenger or the owner of a nearby boat.
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Piers
Well-Known Member
Even if obvious after training, when the pressures on, you never know what will be done. Having seen some crazy actions when examining commercial pilots after placing them under pressure, I still prefer 'simple.'
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If I was a passenger on a plane, and I saw both the pilot and co-pilot rapidly leave the cockpit at the same time, I don't think my primary concern would be whether the control systems were hydraulic or mechanical
Piers
Well-Known Member
If I was a passenger on a plane, and I saw both the pilot and co-pilot rapidly leave the cockpit at the same time, I don't think my primary concern would be whether the control systems were hydraulic or mechanical
Like it!
jrudge
Well-Known Member
I don't know where you get some of this stuff from!
The S65 has hydraulic bow and stern thrusters and they work fine.
If on low idle you use both you hear to bow thruster ( you cant hear the stern at all) reduce in rpm SLIGHTLY.
It still works absolutely fine. If you use hi idle ( electric switch on the helm that increases ideal fro i think 600 to circa 750 or 800) then the drop is less - however under either setting the thrusters are more than adequate for just about any wind conditions.
As they were hydraulic and could run forever and the berth we were in in Cala Dor was tight I used to habitually turn the boat using the thrusters - one port and one stbd. Other than this ( which was just my preferred way and the engines could easily do it for me ) other than coming out of a fuel berth sideways you did not need to use them together.
Even if you did they were very powerful so you could not have them on for long or you would shoot across the marina and you are only trying to come out a boat width.
MapisM
Well-Known Member
Interestingly, that matches nicely what Piers was told about engines being possibly not man enough for hydraulic thrusters, as per his post #215. In fact, the displacement of his boat is similar to the Sq65, and her hull shape is, if anything, more demanding in terms of thrusters power.
Otoh, his engines are less than half the displacement and the power, compared to the Sq65.
Therefore, it's reasonable to guess that the same hydraulic pumps that the Sq65 was capable to handle might have been too much for the Fl55 - not to mention the Fl58, which is much heavier than the Sq65 but still has the same engines as the Fl55...
