auxilliary engine

[Frank mellin]

I have a 26ft colvic northener and also an inflatable honda dinghy as a tender.
The dinghy has a 2hp yamaha engine which is fine for the dinghy.
Perhaps a stupid question but if I had an engine failure on the Colvic would the 2hp auxilliary get me out of trouble,.
I appreciate that it would not provide steering but the colvic has a manual overide on the rudder.
Speed would obviously be irrelevant but getting into a secure position would not.

 

[BruceK]

A 2hp will move you but so slowly it would be completely smothered by the gentlest of wind, current or wave action. So no.

 

[colhel]

This question comes up quite a lot, I wonder if there's some sort of calculator that can be used. ie. A boat with a length of ** a beam of ** and a weight of ** would need x amount of hp to push along at, say, 6 knots in calm conditions.
Over to the mathematicians ?

 

[BruceK]

Well 3/4 throttle on a 8hp 2 stroke pushed a 17 foot cuddy speedboat 3.5 knts against an F2 wind but with a 1 knt current. Make of it what you will.

 

[ontheplane]

Nope, to make any kind of headway something between 5 and 10hp might be ok.

The rudder only works if you are making headway so perhaps mount the ob on a bracket and tiller steer her?agreed, even then 4kts would be approx speed give or take 1 or 2....

 

[C08]

My Tohatsu 3.5 2 stroke will push my 3.5T cat at 2/3 knots in flat water but not anywhere against a headwind or tidal flow.

 

[ontheplane]

Yep - they used to pull 600 tonne barges along canals with just one horsepower.... however they only got 1-2 knots, no current, and often not really much wind either....

 

[Caraway]

Yep - they used to pull 600 tonne barges along canals with just one horsepower.... however they only got 1-2 knots, no current, and often not really much wind either....

Unless they had eaten too many oats.

 

[Davy_S]

I had a Seagull Silver Century with clutch mounted on the swim platform of a Cranchi weekender (around 22ft) the main engine was a Volvo 138hp petrol, in Greece, no tide, flat water, the seagull flat out would do 3 knots, would not have done it in a swell or tide.

 

[Seastoke]

I had a Seagull Silver Century with clutch mounted on the swim platform of a Cranchi weekender (around 22ft) the main engine was a Volvo 138hp petrol, in Greece, no tide, flat water, the seagull flat out would do 3 knots, would not have done it in a swell or tide.

In Wales we shoot seagulls on our boat.

 

[Flyingspanner]

Then eat them - with a nice bottle of Chianti ?

 

[ontheplane]

Then eat them - with a nice bottle of Chianti ?

And some Falfa beans......