[Public-List] Reversing the A-30

[Gordon Laco]

Well I guess I asked for it.... Sorry this is so long but it's not easy to
describe briefly without access to diagrams

When backing up, the key is to only engage the transmission in short bursts.
Remember that the boat will always try to weathercock her head down wind and
make a plan that accommodates this.   If you have to make a turn while
reversing, don't rely on the rudder to be effective;  instead, use 'burps'
of power ahead (with lots of rudder) to shove the stern in the direction you
need it to go.  Be aggressive with the throttle and picture a blast or jet
of water being directed by the rudder when doing this, but not so aggressive
that you stop movement astern.

Where we keep SURPRISE a south wind, luckily rare here, can make getting out
of our slip complicated because the usual backing out and turning involves
turning the stern away from the wind, the opposite to what the boat wants to
do.  Since I know SURPRISE just won't want to turn her stern away from the
wind while backing out, I don't ask it of her.  We either turn the 'wrong'
way until she's done a 180 in reverse ( a complete U), then apply full
opposite rudder with full throttle to shove her head up so we can turn again
and get out.... Or just back out.   The A30 will quite happily track
straight in reverse if she's backing upwind.  The natural tendency for the
bow to fall off helps in this case.   Once can avoid prop walk being a
problem by keeping the engine in neutral or just idling in reverse with
burps of reverse power keeping her moving.  If a sharper course adjustment
is needed, one can put the transmission in forward and give it a hard bash
instantly followed by going back into neutral before sternway is lost.  At
the first opportunity, we spin the boat in her length so that we can more
elegantly leave in forward.

To spin the boat in her length, a useful thing in tight quarters, one can
use the A30's weight and overhangs to help.  If at rest, get her moving
astern, but before she gets much way on, put the helm hard over and burp
sharply in reverse.  She'll stop, stunned, but her head will begin swinging.
Get her moving astern again, but before much speed gets on her, do it again.
The A30, like most traditional vessels, can use the heavy ends' tremendous
momentum which is developed once she starts a swinging motion.

This is easier if the boat has forward way on, such as for example coming up
to a wharf that has a space between boats made fast alongside.  (in a car
we'd call it parallel parking)  Say we want to spin to port so as to slide
into the space, ending up with the bow facing the way back out...  approach
slowly... Start a turn in as if aiming for the centre of the space with full
rudder then as the bow begins to spin to port put the transmission in
reverse and burp up to full power for a second.  The boat will stop (stunned
is how I visualize it) but keep swinging to port... Let her start backing
then give her a burp ahead - remember the helm is still hard over causeing
the prop wash to shove the bow to port again.  She'll start moving forward
but before she gets much way on, go into reverse and stun her again.  She'll
swing faster.  Do this a couple or a few times and the boat will be halted
with regard to way through the water, but will be swinging.  Once she has
nearly done her 180, give her a little reverse helm and slow ahead... She'll
gently stop swinging and slowly slide forward into the space.

I appreciate this may be unclear when one is not watching it being done...
But I recommend people try it out in open water on a quiet day.

The reason we can do this better than most fin keeled yachts is because the
prop wash plays directly upon the rudder.  The cut out and the rudder
position in our boats is about perfect to direct the prop wash as a jet of
water shoving the stern forward or aft.  The A30's relatively great weight
imparts great momentum.... The prop wash will tend to spin the boat before
it starts it moving ahead or astern.

Back to reversing.... Imagine the boat doing 1.5 or 2 knots astern backing
down a channel.  The prop walk, the wind or whatever starts her tending off
course.  You know the rudder won't do anything so you krank the helm over to
full in the direction you want the bow to swing... And burp a lot of power
just for a second, in forward.  The boat will slow... But so long as you
judge the amount of power correctly she won't stop, and you'll have shoved
the stern back into line and you can burp in reverse to keep her moving.
Obviously one can't do this too many times in a row or she will stop... But
that's good, because now you can spin her and finish the passage out in
forward.

In a cross wind, you'd be better off spinning as described above and then
motoring out normally because nothing will prevent the bow from falling away
from the wind.  

Sorry this is so Long and I hope it makes sense.

Gord #426 SURPRISE


On 03/04/11 8:18 AM, "Greg Bover" <gregbover at cbfisk.com> wrote:

> <<<<<<I've heard of that sort of thing.  My feeling is that full keeled
> yachts are
> 'less maneauvreable' than fin keeled yachts only when they are handled by
> sailors who aren't used to them.   Any full keeled yacht with a prop in an
> aperture can be made to spin in its own length by use of rudder and engine.
> Fin keeled yachts have made people lazy and forget how to handle their
> boats.
> Do I sound like I'm getting on a high horse?  I guess so! Sorry.
> Gord<<<<<<
> 
> All right, Gord, I'll admit it. I can't back up Linnet worth a damn. Care to
> expand on your comment with some instruction?
> 
> Greg
> 
> Greg Bover
> Frances Fitch
> Linnet #114
> Gloucester
> 
> 
> Gregory R. Bover
> VP Operations, Project Manager
> C. B. Fisk, Inc
> 978 283 1909
> www.cbfisk.com
> 
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