Shafts v Drives

[Coupe]

Ok guys, it's time someone injected a decent debate into this forum to liven things up a little /forums/images/graemlins/shocked.gif

Some of you know that I have changed boat from Sports Cruiser Hard Top on drives to a Flybridge on shafts.

I am going to keep this subject to close quarter manouvering. We can talk about seakeeping later.

Now, we have all read the opinions on this forum regarding the manouverability of both sytems and I have alway been advised, by peeps in the know, that shafts are the better option.

My opinion?
drives are far better for manouvering into a tight spot. Using a system which I was taught by a well respected instructer - "steer then gear" and "use the thruster" (sorry Haydn) always worked for me. I could reverse into some very tight spots.

I have spent two days on the new boat practicing in the marina and it is hard work. OK I can berth the thing OK and manouver around OK but I have lots of space to play with.

Don't get me wrong - I can manage the new boat OK but I think she will be difficult in tight marinas like Arklow / Carlingford / Douglas etc.

A couple of points which should be considered...
It could be me - I have much more experience on drives,
It could be that size matters (40ft v 50ft) so I should stay away from tight spots,
I should get out on the boat more often /forums/images/graemlins/grin.gif

It could be something else...
Ok guy, it's over to you - please be gentle /forums/images/graemlins/grin.gif

Now that should liven things up a bit - Haydn in the shafts corner (no bowthruster) and Nautical in the drives corner (IPS not available yet) /forums/images/graemlins/grin.gif

 

[mainshiptom]

Son


It is a much bigger boat now? so it is going to feel harder ?

Tom

 

[Divemaster1]

Answer could be all of the above ... but guess that it is a combination of what you are used to and slighly bigger boat ..

We have twin shafts, 45 ft and no thruster and have had no problem as yet ... even daughter at 14 years of age berth her stern to in relatively tight space.

Not a question of "better" in my mind... just familiarity and getting used to qlose quarter manouvering with the boat and her behaviour in different situations.

Now if you said shafts vs waterjets .. that would be a different discussion.. /forums/images/graemlins/grin.gif

 

[adrianb]

Ok - I'll contribute !!

I've just sold my V42, on sterndrives. ( Yes, it had a Bow thruster)

Now I have a Portofino 46 on shafts.( with thruster too)

I hated the sterndrives at first !!, but soon "mastered" them - I did find reversing into/out of a berth was "slightly" easier.

Previously I had a flybridge, on shafts, in fact 3 of them, and somehow they just seem more "steady" . Not that the sterndrive were "unsteady" just the feel, all the weight at the aft end.

Now, with a sports cruiser on shafts I'm expecting a different "feel" again ! Only moved her from lift in, to berth, and that was in a F6 on Saturday, so can't really comment fully yet on her "feel".

There, the debate rages on !



www.cleanandshiny.co.uk

 

[compie1]

Mick,
Practice,Practice,Practice
thats the only way, size is a big diff. from 40 to 50ft also you had sportscruiser so visibility at the back is not so good anymore so you feel less safe in the new one
and because its new your could be to carefull as with your boat before,
is the speed at iddle higher of the new one compared to your old one?

 

[jfm]

shafts better

I think it's cos you are not yet used to the shafts and 50footer. Takes a while. After you have used it some more, you will see that shafts allow much more trickery. Much quicker to nudge the stern sideways with shafts than drives, because shafts allow sideways movement of the stern without turning the helm, so much quicker to do tricks than "steer and gear" with drives. And by using both engines and the thruster simultaneously, you can move the boat perfectly sideways, even against a wind, with rudder amidships the whole time, just as if you had bow and stern thrusters

I guess you can do most tricks with both. But drives require you to flip the helm full lock to full lock (the "steer then gear" thing) whereas with shafts it's all done rudders amidships, hence quicker and easier to do tricks

 

[Nick_H]

Do you know that when manouvering with twin shafts you don't need to touch the wheel, you do it all with the engines?

 

[KevB]

Of course outdrives are much better. Harder but better.

With oudrives you can vector the direction of the thrust from the props, shafts you have to live with just push and pull coz you cant change the direction of the props (the rudders do <span style="color:black"> b</span>ugger all unless you are moving)

If you are talking about leaving the helm in a centre position and just using the throttles then shaft drive is better because the boat rotates around a more central position.

If it's down to which boat can be manouvered better using all options available then outdrives win hands down.

All inho of course /forums/images/graemlins/laugh.gif

 

[thefatlady]

Shafts with a bow thruster enable the boat to be put anywhere or driven sideways. They give that initial reaction nudge when the gears are engaged. Mush better for getting INTO a tight space.
Outdrives with single props can give a reaction nudge similar to that of a shaft drive, but you lose the uni-directional rudder effect of shafts with one engine forward and one astern.
Outdrives with dual props lose that reaction effect and make close quarters manouvering more difficult.
However, outdrives make warping OUT of very tight spaces a doddle.

I would recommend a few hours with a good instructor. He (or she) will show you the little wrinkles which make it soooo much easier.

 

[hlb]

Half the problem folk have, is not knowing what is achievable and whats just near on imposible. Ferinstance I nearly never back my boat into it's mooring cos it is very difficult to get it out. Only do it when I want to wash the other side. But not sure I'll do it again.

Having said that. Shafts are very easy, cos no faffing about with wheel. But 50ft. I think you need a bow thruster.!!

 

[terryw]

For me it is Drives anytime. Went from Drives to Shafts and never really got the hang of it. I used to dread returning to the marina because I never felt in control. This year I went back to Drives (on a bigger boat) and the feel immediately came back, and the dread vanished.

There is also the performance boost with Drives, but that is another debate.

 

[Nautical]

Oh oh here we go! /forums/images/graemlins/grin.gif

No honestly, most of it is just practice and getting out of the habit from one system to the other.

One thing you will notice is that you have a lot more freeboard and upper works on the P50 than the previous boat so although she sits firmer in the water with any wind around it kinda counter acts the advantage of the shafty feeling, Peeps think that just because you have shafts you are going to be planted in the water come what may and while this is true of say a Tyne Class lifeboat or big Pilot boat we are still in a planning hull with a relatively shallow draft to freeboard so windage is going to be a big factor.

Your best bet is get out to a fairly large mark say a channel bouy or something and practice doing circles around it and I dont mean just going round and round I mean put your nose up close then ahead on one astern the other and balance the power so that you get the stern moving left or right but no forward or rearward movement then dab the truster in the direction the stern is going. With practise you can do the equivilant of a sideways doughnut around a fixed point but you are not going to ding anything if it goes pear shaped.

The easiest way to get alongside the pontoon if you are just getting the feel for things is pull up alongside a few feet off then as above get the stern moving in towards the pontoon don't worry about the bow let it do what ever as soon as Mrs SV is off get a line from the quarter straight onto the toon and then just give it dixie on the thruster. Handy if you have your for'd line rigged so that it runs along the deck to midships and a tail left over the rail (make sure of course that you have fastened the bow end over the rail not under) then Mrs SV only has walk along as the bow comes in and pick the bow rope up and walk to the ford toon cleat you can the faff around with springs etc after.

Now of course if we were talking IPS here a whole different ball game!, imagine having the planted feeling of shafts but the sporty drive of outdrives plus the ability to vector the thrust as you want so close too stuff is a doddle and joy of joys do it all for a third less fuel while travelling 3-4knts faster! /forums/images/graemlins/grin.gif

Oh yes my freinds I am definitely back!, ha ha /forums/images/graemlins/smirk.gif

 

[hlb]

No one leaves my boat until it is tied up. It's dead easy. Just take the bow to a cleat. Straight on to it if you like, dependant on wind. Crew makes a big loop in rope and throws it over the cleat, or dangles it over cleat, is more like it. Keeping hold of rope for a second try if necesary. On the rare occasions that they have missed a few times and you canot hold the bows there anylonger because of wind. Back out and come in again, before you get in trouble. Might only happen once a year in a F8!!

So, in practice, bow to cleat, chuck rope over cleat, tie off, use engines to bring arse end in, engines hold boat tight to pontoon whilst crew leisurely walks off and ties back up.

Also excelent way of getting into very tight spaces. Put the nose in as before, crew needs to be good at getting right length of rope, so bow is held say 6in from boat in front. Push on rope with inside engine and reverse the other. If boat dont fit the gap, reverse process, or adust the rope to 2inch clearance!! Gulp.

 

[Nauti Fox]

Your a lucky git, I normally have to get off and take the rope from Mrs unit 18 as she feebly flaps at the cleat. She won the award last year for worst crew and richly deserves this coveted prize.

 

[hlb]

Well, I suppose some mothers do have em!!

Ey, I told one bloke to throw the rope over the cleat, and he did. All of it. He then looked blank at me and said, what next.

Get another bloody rope!!! /forums/images/graemlins/crazy.gif

 

[duncan]

god job you hadn't asked him to assist with anchoring earlier then /forums/images/graemlins/frown.gif..............

 

[Nautical]

Ah, but thats the point, you have been with your boat for quite a while and your crew are well used to your particular methods. What we are talking here is gaining experience and getting everyone comfortable enough with a new (very big) boat to then start fine tuning the art of close quarter handling.

What one has also to consider is that this boat is a big'un with over 1400hp on tap, to try and loop a rope over a cleat on the toon then use the engines to pull the rest of her in has the potential to have half the pontoon pulled out from its fixings /forums/images/graemlins/confused.gif, better to get her bum in get a line on and use the thruster to get the pointy bit in, thruster is never going to produce enough force to do any damage.

Think I am right in saying that just with engines in gear on tickover this baby is pulling eight knots!, so you can imagine the forces involved if a bit of ummmph is entered into the mix, toon cleats going like an exocet!

 

[Divemaster1]

With all respect I have to disagree....

Go in with bow first, loop around cleat and pull stern in is the best and most reliable way to do the job when alongside... thruster is an aid, and most of them too weak to handle anything that is stronger than a breeze .. tide and a F4 they'll staft to struggle (the avereage ones that is). Besides that, one need to learn to manouver without .. in case of failure, and the bow is the easiest thing to point in, but is als the first to "float" away.. (even for us pulling 1.5M + on a deep V). Use engines controlled to pull her in and be patient...

A bit more difficult when all the way in on a pontoon, ... then I'd change my ways, accept that things are different and go bow in and use same methode as above. Thruster I'd use as an aid, not as primary, or as a "get out of jail card" if something goes wrong... all IMHO of course...

 

[david_bagshaw]

[ QUOTE ]
Do you know that when manoeuvring with twin shafts you don't need to touch the wheel, you do it all with the engines?

[/ QUOTE ]

perhaps with planing / semidisplacement craft, but



at 54 ft & displacement Hull with deep rudders behind the prop, helm position really does count when manoeuvring.

 

[Nautical]

A matter of each to his own I suppose, but having tried every method when switching from one form of drive to another I have always found that once the stern is alongside with a line attached it is much easier to control the whole jobbie. With the stern 'on' first it is alot easier to man handle the bow into position with just the ropes if needed, to haul the stern around of a 20 odd ton boat takes alot more grunt and with any kind of reasonable wind will probably have you in the drink!

Not suggesting that one should rely on thrusters alone but as a method to get used to your new boat and until you and the crew become more confident there is no harm in making life easier for yourself, the skill bits can come later.