Handling Question:moving sideways w/twins

[markpierce]

To me "idle" refers to to the minimum throttle setting, whether the transmission is engaged or not.

There is a big difference on the engine's load at idle between neutral gear and "engaged." "Idle" to me means minimum RPM and out of gear. Minimum throttle while transmission is engaged: we're talking no-wake speed.

 

[BruceK]

To me "idle" refers to to the minimum throttle setting, whether the transmission is engaged or not.

. But I need a higher idle speed in neutral for satisfactory lowest rpm in gear, so there are 2 idle speeds, one in neutral, one in gear.

 

[markpierce]

. But I need a higher idle speed in neutral for satisfactory lowest rpm in gear, so there are 2 idle speeds, one in neutral, one in gear.

Shouldn't be an issue with diesel engines because they are governor-controlled to maintain specified RPM as opposed to a throttle used for gasoline engines. Putting my diesel engine in gear does not alter RPM.

 

[skipperdude]

Yes that's why A diesel is either idel or underload.

 

[Tony B]

We always referred to "idle" as "Out of Gear". A few extra words, but what the heck.
When you hit the first detent position in gear, we referred to that idle speed as "Clutch".
So when you were teaching someone how to handle the boat, the usual terminology was either " Put it in Clutch" or "Take it out of gear". This of course is assuming that additional power was not required.
When docking, speed or actually lack of, is critical. This is where the single lever is king. You shift and power up with the same handle. Imagine the nightmare with 4 throttle levers and 4 shifter levers. Or, sometimes even 6 engines.

 

[BruceK]

Shouldn't be an issue with diesel engines because they are governor-controlled to maintain specified RPM as opposed to a throttle used for gasoline engines. Putting my diesel engine in gear does not alter RPM.

Definitely happens with my old Lehman 120s. Your engine(John Deere?) and its controls are almost certainly more sophisticated. One rpm for no load, a lower rpm when loaded(in gear). For tight maneuvering I set throttle/rpm in gear, leaving throttle untouched while shifting in/out of gear.

 

[cappy208]

On engines with strictly mechanical governors they are set to low speed idle. (what ever the mechanic feels the set up requires). It depends upon the physical dynamics of the engine, gear, shaft, wheel. The newer electronic controls are customizable to have both high idle, low idle and an 'engage bump' so there is no staggering of rpm as it is engaged. I suspect most (if not all) the denizens here on TF have the ancient variety mechanical governors though!

 

[jagr19]

i managed to get my boat walking sideways. i have a twin engine with counter rotating prob. how do i get it to slow down and drift sideways? i approached the dock sideways with the method and it was pretty fast, is it good enough to idle both engines and keep the wheel turned away from the dock or do i have to straighten the wheel.

 

[skipperdude]

Rudder to midships the rudder is pretty useless until you gain enough headway. throttle would depend on what the setting is. What is the lowest rpm in gear? it may just be that the RPM is set to high to go any slower. The engine should have low and high idle. It can be adjusted.

 

[koliver]

i managed to get my boat walking sideways. i have a twin engine with counter rotating prob. how do i get it to slow down and drift sideways? i approached the dock sideways with the method and it was pretty fast, is it good enough to idle both engines and keep the wheel turned away from the dock or do i have to straighten the wheel.

If I understand your situation correctly, you are concerned that your "walking sideways" happens too fast and you want to do the same manoevre more slowly.
If you staighten the wheel, your boat will pivot. It is the prop wash from the engine in forward that is keeping you from pivoting. That is couneracted by the prop walk of the engine in reverse, trying to move the stern away from the dock and holding the boat from moving forward. To Walk towards the dock, the prop wash must contribute a little more sideways motion than the walk of the other engine. Keeping things in balance requires a delicate hand on the throttles. If you can't slow it down, your engines may be idling too fast. You can try shifting into neutral, but not spinning the wheel.

 

[FlyWright]

I do it like you described. Mine doesn't 'drift sideways' as much as it walks bow then stern like a falling leaf toward the dock. The net result is a drift toward the dock. Very tough to do into a moderate wind with my boat.

 

[waddenkruiser]

Regardless what we try, our boat doesn't move laterally (= moving purely sideways without moving for / aft while keeping the boat parallel to the dock) by using the twin engines only (props outward turning in forward gear).
Either we have to use the thruster or we approach the dock under a certain angle and pivot in the spot (by engines only or supported by a spring line).
What we can do is to move diagonal forward keeping the boat parallel to the dock. E.g. if we want to leave a port side dock having enough space in front of us we put the port engine in forward (starboard out of gear) and rudder hard to port - and the boat moves forward and parallel from the dock.

 

[Tony B]

Turn wheel in opposite direction that you want to walk. F'rinstance, If you are docking and the dock is to your port side, turn your wheel to starboard, then cross your shifters in the opposite direction, like if you were turning toward the dock. The boat will make some noise and vibrate some. If boat dont move much, just turn your wheel toward the dock very little and very slowly. Once the boat starts to move very slowly return the wheel to the stbd direction.

Keep in mind that this usually only works with relatively flat bottom boats like in semi-displacement hulls. It generally wont work with any kind of a keel.

Also note that sometimes you may have to work the throttle also. This works best if your shifter an throttle control were all in the same lever.

 

[psneeld]

Lots of boats won't move perfectly sideways with just using engines and rudders...and any wind or current will affect even those that will in still air and current.

Try all the techniques...but don't get frustrated if your boat doesn't do it.

 

[KalaKai]

I really enjoyed reading this thread! I'm in the process of moving from sail to power and pick up my boat Monday. I've spend 30 years on sailboats and have to learn how to handle twin screws, so this thread was very interesting for me.

Thanks to everyone for the tips.

I found an online simulator and tried the various tactics mentioned in this thread. The simulator, of course, isn't real life accurate, but sliding to starboard did work with rudder hard over to port, port engine forward, std reverse. She slid to port, but only for a second.

Regardless, the simulator is fun to play around with...

The Boat Docker

 

[TDunn]

Well you could just switch into docking mode then tilt the joystick to the side you want to move to. It worked perfectly for me the last time I drove a Hinckley jetboat

 

[Gdavid]

It worked perfectly for me the last time I drove a Hinckley jetboat

Me too, until I woke up.

 

[Panacea123]

Several years ago I watched a good friend move his 48' trawler perfectly sideways along a dock a bunch of us were side tied and backed into. He explained the maneuver at the time but, years later, I tried it with no wind or current, and failed. The way my head thinks: when backed against a dock to move perfectly sideways to port, for example, helm hard to starboard, starboard engine in reverse (to get "portward" thrust off that rudder, I'm thinking), port engine in forward (to offset any starboard rearward movement?) Maybe you have to bump the port engine in and out of gear to control the sideways movement? Anybody out there a proven expert at this? My boat shown in photo, 3208s (not that it should matter.)
Ted

Have done this many times.
My old boat had no keel and it was a snap
Current boat has large keel still works but not as well.
As to you gear positions you hav it backwards, with your helm hard to starboard stb gear in reverse port in forward you will turn in a circle to stbd.

Should be to walk to port=
Helm hard stbd
Stbd gear forward
Port gear reverse

I use this routinely to get off a dock
Cheers

 

[waddenkruiser]

Turn wheel in opposite direction that you want to walk. F'rinstance, If you are docking and the dock is to your port side, turn your wheel to starboard, then cross your shifters in the opposite direction, like if you were turning toward the dock. The boat will make some noise and vibrate some. If boat dont move much, just turn your wheel toward the dock very little and very slowly. Once the boat starts to move very slowly return the wheel to the stbd direction.

Keep in mind that this usually only works with relatively flat bottom boats like in semi-displacement hulls. It generally wont work with any kind of a keel.

Also note that sometimes you may have to work the throttle also. This works best if your shifter an throttle control were all in the same lever.

THX, We will try so next spring when back to the wet elements ...