Monk 36 Rudder - Page 2

Capuchin · 12-21-2010, 07:44 PM

Hi Woodsong
Ours is a 1991 model hull number 191. On Yacht World, there are two Monk 36's. One a 2001 and the other is a 2007. Both make comment to having an oversized rudder. Not sure if the newer boats were fitted with the larger rudders or not. The auto pilot will not keep the boat tracking all that straight and hand steering is constant.
Thanks for your input.

Woodsong · 12-21-2010, 08:02 PM

Hm. My 1983 Monk tracks pretty straight though the wheel is relatively responsive.

FF · 12-22-2010, 04:31 AM

Actually what I'd REALLY like is power steering like in a car. And about 2 to 2.25 turns lock to lock..

No problem its just money , and you can have the hyd windlass and no time limits bow thruster as well. 6K of smooth AC .

Best bet is to toss in enough spare change for a hyd starter for the main engine and a hand pump.

You will never suffer from a dead batt again.

sunchaser · 12-22-2010, 06:27 AM

It would be interesting to see if the Monk 36 oversized rudder includes oversize block, shaft, control arms*and other associated gear.

Phil Fill · 12-22-2010, 08:51 AM

The Eagle track straight and the auto pilot has no problem even in 3 to 4 ft seas.* But its *40+ tons and a rounded stern so it does not get push around much.* I talk to the shop and the are going to make me a 1 to 2 inch link between the actuator and the rudder to increase the angle.*

The biggest thing I would like to compensate for is the reverse prop walk.* I would take that over tighter turns any day.*

-- Edited by Phil Fill on Wednesday 22nd of December 2010 12:47:26 PM

Egregious · 12-22-2010, 05:29 PM

My Monk is an '84.* I'd consider the rudders pretty normal sized.

Oh yeah, I know the bottom is pretty foul looking.* We're on the hill now to get a much needed bottom job!

-- Edited by Egregious on Wednesday 22nd of December 2010 06:30:19 PM

Woodsong · 12-22-2010, 05:52 PM

Woody- you have twin screws! That is CHEATING!!

**koliver** · 12-22-2010, 06:07 PM

Is there anyone who can explain whether twins require the same or less rudder area as a single?
I would expect them to require less, as the full amount of rudder required should be related to the speed and hull configuration of the boat, rather than the number of pieces it is divided into. So maybe not a linear relationship, but if a single requires for example, 6 sq ft of rudder to achieve performance at hull speed, twins may also require 2 @ 3 sq ft, and if you were to put in a third engine, 3 @ 2 sq ft.
so Woody's rudders should be a lot smaller than Tony's.
sorry Woody.

Egregious · 12-22-2010, 07:28 PM

Quote:

Woodsong wrote:

Woody- you have twin screws! That is CHEATING!!

They didn't make many with twins, but I found one.* I feel both sides of the argument, literally.* I love the maneuverability, and the spare engine saved our butts on our first long trip.* But doing everything X2 is a pain, and more expensive.* Same old arguments, and I still like having twins.

BTW, once they sanded it the bottom looks great, only a few small (size of a fingernail) blisters, and some evidence of galvanic corrosion.* Don't know yet whether it is coming from inside the boat or from a nearby slip.* So I have that to look at...

As far as the size of the rudders, maybe they need to be half the size since I have two...* But she drives straight and similar or better than other similar boats that I've driven, mostly Grand Banks.* Since mine is one of only a few that were built with twins, perhaps they just strapped on the same rudder X2*as they used with the singles?* Two rudders is more drag and all that running gear is why I don't get quite the fuel economy as a single, but I can get up and crank out nearly 10 knots when I have to, although inefficiently.

*

Nomad Willy · 12-22-2010, 11:52 PM

Woody,
Since you have twins I hope you have two 70hp engines instead of two 140hp engines.
When GB made twins they used the same engine as the single so they made two boats, both w the same hull but one w twice as much power and one w half as much power as the other. I hope Monk wasn't that stupid. But I'm afraid you're going to tell me it is so.
I compared you're stern pics and see that your about 1.5" lower in the water. One could assume it is from the weight of the extra engine but that weight would be far enough fwd so it should'nt show to that degree at the stern. Do you suppose it could be that your'e keel is full of water? Do you know if it is or isn't?
About the rudders. I suspect Monk probably decided you had so much extra power that a tiny loss in efficiency was worth loosing for the somewhat large increase in maneuverability and control. Also It's obvious they probably made the twin w the same engines as the single to minimize inventory complications and expense so they would do likewise w the rudders. Just because a boat was designed and built by "professionals" dosn't mean it was done correctly. If Edwin Monk designed the boat for 150hp no builder has any business putting 300 in it and the reverse is also true. Also in this Monk example the single engine boat has a certain weight capacity and the twin engine has a weight capacity that is a full ton less. And the single engined boat has a noticeably higher CG. I'm not saying they did or didn't know what they were doing or that I know what I'm talking about but they probably did it because GB was doing it and GB was selling more boats. I do take back most of the above if Woody's boat has two 75hp engines.

RickB · 12-23-2010, 04:50 AM

Quote:

nomadwilly wrote:And the single engined boat has a noticeably higher CG.

How do you do that?

I have crawled all over lots of boats looking for a CG but haven't ever been able to see one.

-- Edited by RickB on Thursday 23rd of December 2010 05:53:07 AM

Nomad Willy · 12-23-2010, 11:44 AM

CG's have red stripes on their boats and give free inspections. The red stripes are so you can see them easily** ...opposite of navy grey.
Actually I'm assuming the engines are lower than boat CG and any weight added to, around, on or in the engine/s would lower the CG. On an OB boat this would not be the case.

markpierce · 12-23-2010, 11:59 AM

How many 200-pound people on the flying bridge*are needed to offset the presumed lower CofG of a two-engined boat over a single?

sunchaser · 12-23-2010, 12:46 PM

The 200 lbers*won't be on the FB very long when big waves come along.

Marin · 12-23-2010, 01:12 PM

Quote:

nomadwilly wrote:

When GB made twins they used the same engine as the single so they made two boats, both w the same hull but one w twice as much power and one w half as much power as the other. I hope Monk wasn't that stupid.

If you were talking about a displacement boat you'd be right.* But GBs (and other similar boats) are semi-planing boats and so can put the extra power to good use if the owner wants to go faster and is willing to cough up the*money for*the extra fuel.* So "overpowering" a semi-planing boat makes sense if buyers want to go faster, which in the case of GBs, particularly starting in the late '80s, early 90s, was the case.* The typical buyer of a GB42 in the late 1990s, for example, wanted to be able to get to his destination at 15 knots, then cruise the area leisurely at 8 knots, and then make the long run home at 15 knots.* By putting what you would consider way-overpowered engines in the GB42--- a pair of 450 hp Cats (IIRC) in the case of later GB42s--- the owner was able to do this.

So it wasn't stupid design, it was smart marketing.

*

RickB · 12-23-2010, 01:49 PM

Quote:

nomadwilly wrote:Actually I'm assuming the engines are lower than boat CG

They might be smaller engines mounted higher in the hull than a centerline single. Maybe the VCG is higher than the single.

*

markpierce · 12-23-2010, 01:50 PM

Quote:

RickB wrote:

nomadwilly wrote:Actually I'm assuming the engines are lower than boat CG

They might be smaller engines mounted higher in the hull than a centerline single. Maybe the VCG is higher than the single.

But then probably not.

*

RickB · 12-23-2010, 01:52 PM

Quote:

markpierce wrote:But then probably not.

In any event, it's impossible to determine the VCG by looking at a picture of a boat.

Egregious · 12-23-2010, 11:29 PM

Quote:

nomadwilly wrote:

Woody,
Since you have twins I hope you have two 70hp engines instead of two 140hp engines.
When GB made twins they used the same engine as the single so they made two boats, both w the same hull but one w twice as much power and one w half as much power as the other. I hope Monk wasn't that stupid. But I'm afraid you're going to tell me it is so.
I compared you're stern pics and see that your about 1.5" lower in the water. One could assume it is from the weight of the extra engine but that weight would be far enough fwd so it should'nt show to that degree at the stern. Do you suppose it could be that your'e keel is full of water? Do you know if it is or isn't?
About the rudders. I suspect Monk probably decided you had so much extra power that a tiny loss in efficiency was worth loosing for the somewhat large increase in maneuverability and control. Also It's obvious they probably made the twin w the same engines as the single to minimize inventory complications and expense so they would do likewise w the rudders. Just because a boat was designed and built by "professionals" dosn't mean it was done correctly. If Edwin Monk designed the boat for 150hp no builder has any business putting 300 in it and the reverse is also true. Also in this Monk example the single engine boat has a certain weight capacity and the twin engine has a weight capacity that is a full ton less. And the single engined boat has a noticeably higher CG. I'm not saying they did or didn't know what they were doing or that I know what I'm talking about but they probably did it because GB was doing it and GB was selling more boats. I do take back most of the above if Woody's boat has two 75hp engines.

I see your point.* Maybe* I made a mistake.* But the trips I've taken so far and the knowledge I've gained about boats cannot be taken back.

To be clear, yes they just doubled the 135 Perkins.* Yes the outboard side of the Port side engine is a Bitch to get at.*

My next boat will be a single, perhaps with a bow thruster, but I may not need it.