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Two motors or One?

Posted: Fri Mar 14, 2014 8:07 am
by Hugz
I'm thinking two long shaft motors as she has a fairly deep transom. The second motor mainly for reliability and at the times when there is a bit of a windage problem.

QM2 Stern.JPG


Going to have to raise the bridge a tad if going upstream.

QM2 harbour bridge.JPG


Taken from the Opera house. She is rather large. Apparently contains a shopping centre!

QM2 Opera House.JPG

Re: Two motors or One?

Posted: Fri Mar 14, 2014 8:20 am
by THCL500J8
Mate i had a look at her when she was in Brisbane, your going to need a couple of 102plus long shafts, and a couple of extra long range tanks.
Yes there is a shopping center, and yes the Misses did buy something.

Re: Two motors or One?

Posted: Fri Mar 14, 2014 8:58 am
by Hugz
She is leaving Sydney at 9pm tonight heading for Brisso. Probably best to keep the Missus at home this weekend..... What did she buy? I'm guessing they don't have a Seagull spares shop onboard. :D

Re: Two motors or One?

Posted: Fri Mar 14, 2014 9:32 am
by skyetoyman
Bit of a bugger to change a prop shaft spring though.

Re: Two motors or One?

Posted: Sun Mar 16, 2014 3:21 am
by Hugz
Yep, that it would be, probably get a sore back starting them too.

She is in Brisbane now and then at Yorkey's Knob. Thats got be in Queensland :?

Re: Two motors or One?

Posted: Sun Mar 16, 2014 8:00 am
by THCL500J8
Yep, its a suburb just north of Cairns. its were the P&O terminal is. 10 or 15 km North.

Re: Two motors or One?

Posted: Thu Mar 20, 2014 12:22 am
by Robin Anderson
Two engines definitely the way to go for reliability but I would recommend just one longshaft centrally mounted with the other engine being a short shaft mounted slightly off the centre line on a swing down bracket. The fact is that you would not need to run both engines at the same time - ample thrust from just one, providing it has the large 5 bladed 11""diameter Hydrofan. Running both engines at the same time would just cause too much noise (passengers may complain) and double running costs. The swing down bracket is the one to use when operating the craft in shallow water because it will lift up should you hit the bottom with the skeg, thus avoiding potentially expensive damage to a fixed transom mount. Should be able to reach hull speed in a few years, given a fair wind and tide :x
Robin.

Re: Two motors or One?

Posted: Thu Mar 20, 2014 12:45 am
by Hugz
Indeed! Some care might be needed with some rubber dampening on the swing down bracket. I would have no wish to subject the passengers to any vibrational discomfort. Stirred but not shaken should be the motto here.

Re: Two motors or One?

Posted: Thu Mar 20, 2014 10:15 pm
by 1650bullet
Don't forget the 10-1 fuel--oil ratio. I would go for a F N R as well for something that big

Re: Two motors or One?

Posted: Thu Mar 20, 2014 11:40 pm
by Hugz
Yep, 10 to 1 it is, bio-degradable of course. I note there are a lot of ports either side so plenty of room for pairs of sweeps for stopping and reverse. They do have a galley class I presume?

Re: Two motors or One?

Posted: Sat Mar 22, 2014 11:01 am
by Rob Ripley
I was fascinated watching a cruise liner spin (bow and stern thrusters and twin drive pods) in its own length in Milford Sound, all the while showing the forward view on the wide screen.

Re: Two motors or One?

Posted: Sun Apr 13, 2014 12:30 pm
by CatiGull
1650bullet wrote:Don't forget the 10-1 fuel--oil ratio. I would go for a F N R as well for something that big



R is made redundant by efficient boat handling, surely.

Re: Two motors or One?

Posted: Sun Apr 13, 2014 10:04 pm
by Robin Anderson
CatiGull wrote:
1650bullet wrote:Don't forget the 10-1 fuel--oil ratio. I would go for a F N R as well for something that big



R is made redundant by efficient boat handling, surely.


Exactly Catigull, it would also confuse the passengers if the vessel started going astern, they would all be facing the wrong way, some of em might be quite elderly and the scenery rushing past backwards could unsettle them.
Robin

Re: Two motors or One?

Posted: Mon Apr 14, 2014 12:41 am
by Rob Ripley
I suppose it was a bit confusing for a few, but after a PiƱa Colada (or two) who could tell where anything was going !

Re: Two motors or One?

Posted: Mon Apr 14, 2014 12:46 am
by Rob Ripley
One plus of putting a Seagull together from a box of parts is that the tiller can now turn almost 90 degrees to the transom - my boat can now spin in her own length .... works well with a 40+, the C100 just cavitates !