Downeasters "Backing under power " General Forum Forums

I found a fairly long and interesting thread on the old forums on backing under power and thought it worth moving a few of the posts over here.. pitch in if you have something to add.

1.
This bit of boat fun is called the "paddle wheel effect". Most boats have right handed propellors (ie they rotate clockwise when going ahead). This has no affect on the sideways motion when the boat has built up forward speed but at very slow ahead speed and more importantly when going astern the "paddle wheel" bit takes over. (i.e. when going astern it claws the stern to port, with a right handed prop). To add to the fun any cross wind will either cancel or increase the effect depending on this pivot point of the boat (this depends on the layout of the superstructure, bicycles, laundry etc on the upper deck.).

The solution – find a nice secluded bay, away from prying
eyes. Send the wife, partner , dog etc. below to read a book and drive around astern for a few hours. Ideally a few mooring buoys for targets will help lining up etc. You will eventually get to know the boat. If your prop is left handed it would explain why she claws to stbd when astern , but that would be unusual. It may have been a current and/or wind effect. The full keel of the DE make them track better when ahead but difficult to steer in a straight line astern. As stated previously try slowing down the astern revs, and reducing the angle of the rudder, sometimes this helps. Once you know the characteristics of the boat and what she likes, plan your docking accordingly – don't be embarrased to go alongside a dock in a direction you know the boat likes and then warp her around using lines and a little engine etc..

If you ever charter one of the new Tupperware production boats, ONLY drive them astern when entering a marina etc. NEVER ahead. I deliver these things and I have learned this trick from the docking kids. The boats have no tracking ability in slow forward speed, but zip around like witches when going astern. Try this sometime, especially if its a charter boat.

I was captain of a single screw 1,000 tonne Irish Navy ship for three years. She wouldnt turn to stbd. at slow speed on Tuesdays, Fridays and Sundays and would crab viciously to port when going astern, except when I stood on one leg. She also had tendency to roll more when we switched on the
stabilizers. That must be why we call ships/boats "SHE". I suspect that some aircraft have similar design features.

Practice, Practice, Practice and have fun

Gerry

2.

Here's a couple of "exercises" to practice when you are where you can't hit anything. They really helped me get my DE38 figured out. Once you have mastered them you can really dazzle the "docking watchers" at the marina. (When I was a flight instructor, we called those folks "porch monkeys".
1. Make the boat "pivot" with no forward (or aft) motion. (if you have a left hand prop, do all this backwards). With the boat at a dead stop, throw the wheel full to starboard. With the engine at idle (800 to 1000 rpm) engage fwd gear. The boat will begin to turn to the right. Just as it begins to move foreward, move the gear selector to reverse. The stern will continue to walk to port and your forward motion will stop. When she just starts to back up, go back to foreward gear. Keep repeating this, and the boat will just spin in a circle as if the mast went all the way to the mud below. Note that this ONLY works to the right.
2. Slow backing into a slip. This one is really impressive, but only works in calm winds (at least for me). Throw the wheel hard to PORT. With the engine at idle, engage reverse. The stern will begin to walk to port and the boat will begin to move aft. Without touching the helm, briefly engage foreward gear (just enough to kick the stern to starboard, but not enough to arrest your aft progress) then engage reverse again. Repeat the gear shifting as needed. Don't move the helm. With a little practice you can back your way through some pretty complex passages.
Good Luck.

3.
If you can't get good speed then I usually use forward to point the bow where I want it, I've been in many tight marinas and use a blast of forward to handle the bow then back in reverse. Using this technique I can turn the boat in just about its own length, I've been in a 40ft wide river and turned the boat around on the mississipp. Backing into a slip using the prop walk is also a handy trick that works real good if there is no current, if there is a current just remember there is no keel in the front just the back so……….the current affects the stern way more than the bow, I also use this when docking as sometimes this will lay you right on the dock where you want to go and you'll look good doing it !!!!!