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Old 08 October 2005, 08:22   #31
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Go Teach!!!

missus
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Old 08 October 2005, 13:34   #32
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Originally Posted by jwalker
So, you're out in a F4-5, 10 miles from shore your motor stops and wont restart. You wont be able to make way against the sea and wind with 5hp. Your only options are a following sea or a beam sea. At one end of the beam sea is the shore and rocks, at the other end you are driving offshore. It's gotta be a following sea but you've only got 5hp flat out and each wave is going to try to broach you. Given that you are going to have to drive diagonally to get back to safety you're likely to have a journey of around 15mls. Even if you had the motor flat out and managed your 5knots for the whole return journey, that's going to be around three hours fighting the following sea.

Rather you than me. Be realistic about the possible senario.
Sure, I'm only too well aware of the dangers of a lee shore and the challenge of powering a boat through big waves. Indeed, a purist would argue that I should have specified the RIB with twin engine, twin everything, just in case. However, my budget does not run to this . I've scanned the advice so far ... I'd be happy to receive your opinion on what size engine to mount as an aux ... 6, 8, 9.9, 15, etc.

Rich
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Old 08 October 2005, 14:05   #33
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As big as your boat and pocket can stand. Also, rig a tie bar from the auxiliary motor to the centre of the transom which can be removed from its fixing and connected to the steering arm on the main motor. You can then steer from your normal seating position even if you have to slightly raise the main engine to decrease the drag from the prop. It also serves to fix the aux. and prevent it swinging when not in use.

I reckon you'll need as much power as possible for good steerage if the going gets tough.
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Old 08 October 2005, 14:13   #34
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Originally Posted by The Jackeens
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missus
Yeh, I know. It felt like it as I was typing.
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Old 08 October 2005, 14:46   #35
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but in reality do you go out when it is rough and noone else is around, you have a radio and mobile i suspect so if you were in dia circumstances you could radio for help, but in most scenarios or less extreme scenarios you could plod back with a 5 i would suspect

for me i would be very happy with a 5 as is much better than nothing, and i s light etc and can double up as an engine for a little sib for kids etc to get some use from it

but the ultimate question is ......what price safety and piece of mind...
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Old 08 October 2005, 15:39   #36
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I have a 6hp 4 stoke Suzuki on my 6.5M Solent. Quite usable - yes, Jackeen are right, 6 knots is about the WOT speed. Use the big engine as a rudder and keep the aux locked in centre. Have not had to use her in anger, but have pootled round dock and river and had no problems mooring etc. Anything uder 6 would scare me - and I do not look forward to having to use the 6 for real. But better than nothing. If my big engine did pack up in anything but really good conditions or I was any distance from harbour, I would advise the Coastguard of the problem as a matter of course. Suppose I expect any problems on my big beast to occur somewhere from Berthon to the mouth of the Lymington River, and the aux would allow me to limp back....
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Old 08 October 2005, 16:40   #37
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Hi Bruce,

From memory I think you keep your aux reversed on the bracket?
If that is so, have you ever attempted to get it going it at sea just to see what it would be like if needed in an emergency?

(vg advice as usual JW. Have an apple Have to say tho' I'm a big fan of Seastart.)

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Old 09 October 2005, 03:02   #38
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Quote:
Originally Posted by jwalker
Also, rig a tie bar from the auxiliary motor to the centre of the transom which can be removed from its fixing and connected to the steering arm on the main motor. You can then steer from your normal seating position even if you have to slightly raise the main engine to decrease the drag from the prop. It also serves to fix the aux. and prevent it swinging when not in use.
This sounds like great advice. I like this idea a lot. Have you any pictures &/or diagrams?

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Originally Posted by Chris Hartley
but in reality do you go out when it is rough and noone else is around, you have a radio and mobile i suspect so if you were in dia circumstances you could radio for help, but in most scenarios or less extreme scenarios you could plod back with a 5 i would suspect
I have DSC VHF, mobile and flares as my principle ways of sending a distress signal.

If a 6 hp will achieve my hull speed of 6 knots. I know that additional speed comes with disproportionately more power as the boat transitions onto the plane. What speed might I expect with a 9.9 hp?

I would not go out in bad conditions, however, a few years ago sailed from Cowes to Keyhaven in my 19' sailing yacht. We left Cowes in a F5. Within an hour it was a F8 (confirmed by Coastguard). The wind against tide conditions made it challenging at the least. Therefore, while I don't intend to go out in bad conditions, it is easy to be caught out .
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Old 09 October 2005, 09:23   #39
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Originally Posted by rbw156
....This sounds like great advice. I like this idea a lot. Have you any pictures &/or diagrams?....
Nah, I've no pictures but I can explain it.

I used 3 rose joints of the type used as a standard steering fitment on an outboard. The steering arm on the main motor had a spare threaded hole and one rose joint was greased well and bolted onto it. If there is only one hole in the steering arm, you could easily use a long bolt and fit the new joint on top of the original steering draglink. This joint is to be left here and, hopefully, never used so it can be pivoted out of the way.

If your auxiliary doesn't have one, you'll need to get/make a bracket to work as a steering arm on it.

You'll also need a bracket to mount near the centre of the transom to which one of the other rose joints is bolted. I had used a length if angle across the transom to spread the load of the outboard and to prevent theft using a chainsaw. I bolted the rosejoint to this.

I made a tie bar from a length of 20 aluminium alloy with a stub of M10 thread screwed firmly into each end. The rose joints used an M10 thread.

The third rose joint was screwed onto one end of this tie bar and a locknut was used to allow some adjustment in length at that end.

The other thread of the tie bar was greased and screwed into the joint on the central bracket but it was not completely tightened up so it would allow a bit of rotation of the bar.

A bolt and wingnut then connected the tiebar to the auxiliary motor.

The auxiliary can now be tilted and lowered whilst attached to the bar. I do remember having to put a slight bend into the bar to clear an obstruction. I think it was if the main motor was tilted and also over on full lock it contacted the tie bar. It was an easy fix.

How to use: Spin off the wingnut and remove the bolt. Spin out the tie bar from the joint on the central bracket. Remember it wasn't tightened up so no tools are necessary. Spin the tiebar into the joint on the main motor's steering arm and then reconnect the bolt and wingnut. Voila.

As always, it sounds a bit complicated when written but it's a straightforward job.

The auxiliary engine was not allowed to be supported on the tilt pin when underway. There was a pivoting bracket on the outside of the transom to support it in the tilted position. I've no pics of that either. The engine clipped to the support using the its normal catch so it was only necessary to press the release lever and the bracket fell into the down position and the engine was then lowered. So no mucking about required.

----------------------------------------------


I only once had to use the auxiliary and I was pleased it was 30hp. I suppose it was a bit unusual in that one bank of cylinders on a Merc 200 stopped firing and the engine didn't have enough power to get the boat planing. I was faced with a 20 mile trip home at a few knots, it would be dark in a short while and I'd also miss the tide on the slip by a long way when I got there. Bummer. However, the auxiliary was connected as described above and both engines were used. The boat easily planed and we travelled at close to 30mph for the whole journey. Still missed the slip though and it was just dark as we arrived back at the harbour but a success, none the less.
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Old 09 October 2005, 15:38   #40
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Fantastic, thanks for this detailed description. The only bit I'm like to clarify is this section:

Quote:
Originally Posted by jwalker
The auxiliary engine was not allowed to be supported on the tilt pin when underway.
I assume that you fixed the aux to a pivoted drop plate and that while the aux was in the up position that you also had the o/b tilted up. Is this the case?

Thanks, once again for your advice.
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