On Wed, 21 Nov 2007 15:35:14 -0500, Wayne.B
wrote:

On Wed, 21 Nov 2007 05:21:29 GMT, "Glenn \(s/v Seawing\)"
wrote:

This has got Dad and I talking about possibilities. He cruises on a GB42 &
I on my Gulfstar 41 Sloop. We've been trying to slow his boat down enough
so I can keep up on a regular basis. I was thinking of buying a small fleet
of large dingies to tow behind him to slow him down, but that's an expensive
option. Sounds like your idea may be well worth experimenting with. The


primary concern for me, would be damage to the transmission....those puppies
are expensive.

Tell me about it. Four man days to get one out, two to rebuild it,
three to put it back in, and about two Boat Units worth of parts.

Maybe this'll help Dad cut down on his fuel bill. I
constantly tease him 'bout it...he normally burns 4.5gph while I about
2/3gph....when I'm motoring. I sure like his GB though...maybe when I get
tired of sailing (whenever that could be). :-)

What if he towed your Gulfstar? That would slow him down! :-)


Basically diesel fuel consumption is a factor of horsepower produced.
There are formula all over the Net.

The Grand Banks hulls are semi-displacement hulls and probably produce
an optimum distance/fuel consumption at higher speeds so just puling
the throttles back will probably not accomplish a really major
increase in fuel economy.

If you really want to get the best fuel/hour figure do what the
trawler yachts do and stick in a couple of 50 HP engines, run them at
about 35 HP which will be at a high enough power setting to keep the
engines from carboning up and be pretty economical.

Or you can get what I have in my 40 ft. boat - a 40 HP engine. Of
course I've got sails too.....=:-)


Bruce-in-Bangkok
(Note:remove underscores
from address for reply)

On Thu, 22 Nov 2007 08:55:50 +0700, Bruce in Bangkok
wrote:

The Grand Banks hulls are semi-displacement hulls and probably produce
an optimum distance/fuel consumption at higher speeds so just puling
the throttles back will probably not accomplish a really major
increase in fuel economy.

Depends on what you call major.

By cutting back 15 % from maximum cruising speed to "normal", fuel
economy doubles as horsepower is cut in half.

Reducing speed another 20% below normal gives an additional 50%
improvement in NMPG.

GB42s can be made to plane if sufficient power is applied but that is
nearly impossible with our GB49, even with close to 600 hp available.

"Wayne.B" wrote in message
...
On Wed, 21 Nov 2007 05:21:29 GMT, "Glenn \(s/v Seawing\)"
wrote:

This has got Dad and I talking about possibilities. He cruises on a GB42
&
I on my Gulfstar 41 Sloop. We've been trying to slow his boat down enough
so I can keep up on a regular basis. I was thinking of buying a small
fleet
of large dingies to tow behind him to slow him down, but that's an
expensive
option. Sounds like your idea may be well worth experimenting with. The


primary concern for me, would be damage to the transmission....those
puppies
are expensive.

Tell me about it. Four man days to get one out, two to rebuild it,
three to put it back in, and about two Boat Units worth of parts.

Maybe this'll help Dad cut down on his fuel bill. I
constantly tease him 'bout it...he normally burns 4.5gph while I about
2/3gph....when I'm motoring. I sure like his GB though...maybe when I get
tired of sailing (whenever that could be). :-)

What if he towed your Gulfstar? That would slow him down! :-)

Right, don't think this thought has not crossed my mind. It would sure
improve my fuel economy too...as well as the relaxation hours. :-)

Back to the transmissions; it seems that you've satisfied yourself that you
are not significantly risking damage to them...yes?

Thanks for being so helpful Wayne.

Glenn.
s/v Seawing.

On Wed, 21 Nov 2007 21:27:16 -0500, Wayne.B
wrote:

On Thu, 22 Nov 2007 08:55:50 +0700, Bruce in Bangkok
wrote:

The Grand Banks hulls are semi-displacement hulls and probably produce
an optimum distance/fuel consumption at higher speeds so just puling
the throttles back will probably not accomplish a really major
increase in fuel economy.

Depends on what you call major.

By cutting back 15 % from maximum cruising speed to "normal", fuel
economy doubles as horsepower is cut in half.

Reducing speed another 20% below normal gives an additional 50%
improvement in NMPG.

GB42s can be made to plane if sufficient power is applied but that is
nearly impossible with our GB49, even with close to 600 hp available.


A Sea Horse built steel hull 49 ft. trawler yacht would probably have
a John Deere 100 HP engine installed and cruise at about 7 K using a
ridiculously low amount of fuel.


Bruce-in-Bangkok
(Note:remove underscores
from address for reply)

On Thu, 22 Nov 2007 05:57:18 GMT, "Glenn \(s/v Seawing\)"
wrote:

Back to the transmissions; it seems that you've satisfied yourself that you
are not significantly risking damage to them...yes?

According to the manufacturer and all of the so called experts, we
should be OK. I like Jere Lull's sugggestion regarding feathering
props but I suspect there is a considerable expense to doing that,
plus some increased complexity risk.

Since the GB42 probably has smaller props, it might also be easier to
implement one of the jerry rigged solutions for preventing shaft
rotation.

CalifBill wrote:
"Dan" wrote in message
...
HK wrote:


We've got some guests coming north from Florida this week for the
holiday. Two hours in the plane and they're here.
Like magic! Wow!

-dk

And 3 hours in airports!



That, too.

-dk

"Wayne.B" wrote in message
...
On Thu, 22 Nov 2007 05:57:18 GMT, "Glenn \(s/v Seawing\)"
wrote:

Back to the transmissions; it seems that you've satisfied
yourself that you
are not significantly risking damage to them...yes?

According to the manufacturer and all of the so called
experts, we
should be OK. I like Jere Lull's sugggestion regarding
feathering
props but I suspect there is a considerable expense to
doing that,
plus some increased complexity risk.

Since the GB42 probably has smaller props, it might also
be easier to
implement one of the jerry rigged solutions for preventing
shaft

rotation.

Do you have room to install a collar, with a small disc for
a cable actuated caliper of some sort. Like a bicycle
brake, only larger.


SBV

"Bruce in Bangkok" wrote in message
...

If you really want to get the best fuel/hour figure do
what the
trawler yachts do and stick in a couple of 50 HP engines,
run them at
about 35 HP which will be at a high enough power setting
to keep the
engines from carboning up and be pretty economical.


That wouldn't produce a big enough wake to satisfy Wayne.

SBV

On Thu, 22 Nov 2007 21:34:48 -0500, "Scotty" wrote:

Do you have room to install a collar, with a small disc for
a cable actuated caliper of some sort. Like a bicycle
brake, only larger.

The collar would probably be easy although there is nothing available
off the shelf that I'm aware of. The difficult part would be creating
a secure attachment point for the caliper. Given the forces involved,
the caliper itself would need to be hydraulically actuated like a disc
brake.

"Wayne.B" wrote in message
...
On Thu, 22 Nov 2007 21:34:48 -0500, "Scotty"
wrote:

Do you have room to install a collar, with a small disc
for
a cable actuated caliper of some sort. Like a bicycle
brake, only larger.

The collar would probably be easy although there is
nothing available
off the shelf that I'm aware of. The difficult part would
be creating
a secure attachment point for the caliper. Given the
forces involved,
the caliper itself would need to be hydraulically actuated
like a disc
brake.

Something like a handbrake on a forktruck would work.