One or Two engines??

[JCW]

Daniel, I disagree with you about an aux engine.

If are able to mount it so it can be easily used, serviced at regular intervals and run from time to time, it should be ok.

Thankfully I have never been forced to use an aux engine, but it certainly gives you a piece of mind if you get a problem with your main engine.

[Manos]

Is a MUST to have an aux engine even if you motor close to shore.
As tango said is a law in Greece to have one if you go out over 3 miles from the closest shore and I fully agree with that one.
In my opinion it should be a law for ALL EU countries!

[Richard B]

Bit daft to enforce on boats cruising in company!

[Manos]

Richard are you serious???

[Richard B]

'course I am.

I never take the aux. when there's lots of other company all the way - no point. Better to have a spare boat or two than just a spare engine.

[simmons0]

I agree wiht Richard, why do you need another engine when your cruising in company with another boat?

[Manos]

Guys with all due respect you always need to have an aux engine if you respect the lives of the people you have on your boat.

The reasons are many but will mention a small example (this is the worst case scenario I can think of) to illustrate it as best as possible:

Say that you are out with company (2-3 RIBs) in the channel going to France or near Lands End or in the Irish Sea, weather calm and suddenly it changes (as it happens) and wind picks up to force 6-7. You have wind against tide too (worst case scenario), waves will be huge, it will be cold, the wind and the sea will hit your face and you will be feeling the stress, you passengers will be afraid and you will have to slow down to 10 knots max to be able to make any head way.

As you make your way, your main engine breaks down, your companions in the other RIBs do not see that you are in trouble (very easy if they are concentrating to sail through rough sea and keep their crew and boat safe), you try to call them on VHF but they cannot hear you (wind and waves make a hell of a noise, plus the banging) or your VHF breaks down, the current takes you away from them and suddenly you lose site of them (all these events will happen in about 5-10 minutes the very max).

......and you do not have a spare engine!!

What do you do?

How do you save the people you have with you? REMEMBER you are responsible for all on board your boat (as a skipper ).

How would you power your boat (even at very slow speed) to safety?

If you cannot steer the boat with or against the waves chances are that you will flood the boat with water from the waves, or (the worst case scenario) turn over.

I am firm that on a boat that does any type of cruising you need to have (apart from life vests for all and flares) a sea anchor and a spare engine at all times.

[Richard B]

Manos, I think that your argument is well reasoned, but I think that in the scenario that you've described, an aux engine would be about as much use as a chocolate teapot, and would be very difficult to rig up.

Also, you're in danger of either broaching or swamping, but I doubt both... being swamped is actually a reasonably safe position to be in (in a RIB).

It would take some time to get the engine on the transon, connect the fuel, and start it up. I think that the boat would already be in trouble. I think that a sea anchor would be a better bet... but can't claim to have practised using one.

Communication is the key - I like cruising in company of people who keep a keen lookout. If you're in a flotilla, there should be a back marker with eagle eyes - a role that I always happy to take, 'specially if we're the biggest boat in the fleet.

[Manos]

Richard what you say is also correct if you did not have the engine mounted on the transom at all time.
I have an 8bhp Mariner, mounted on a small braket and lashed on the A-frame.
In case of emmergency, you just have to cut off the strap and the engine fllas in the wayter and you just pull the cord.
The idea of the aux engine is to have it ready availiable not to try and rig it when you need it.
Have attached a photo to show you what I mean.
This little thing is doing no work what so ever, however I start it every other day during the summer and is serviced like it had been working normally every year.

[Richard B]

Manos, so you've got your aux well rigged.

But here's a couple of questions I would like to know the answers to...

1) Have you ever tried to make way under auxiliary power in that F6 head sea you mentioned?
2) What's your range on auxiliary power? (real, not estimated!)

Has anyone got any real experience of these that they could share?

[Manos]

Hi Richard,

I use the aux 8 bhp engine to go fishing and have used it to run it in for about 15-20 hours in total doing various distances. I have it from brand new.
In calm seas it gives me between 10-11 knots on the GPS flat out and 4 people onboard.
In bad weather force 5-6 high waves, travelling against wind and current the boat does about 4-5 knots flat out depnding sea conditions same load.
With a 30 ltr tank and full throttle it does about 20 miles distance (and probably a bit more) as the tank was not empty at the end. The distance I did this was from Kea to Cape Sounion in moderate (force 4-5 winds) and a speed of 6-8 knots on the GPS. The wind was on our back at first henmce speed 7-8 knots and on our side after we passed Makronisos to Cape Sounion hence 6-6.5 knots.
IT TOOK US HOURS!!!
Bare in mind that my boat with 4 people onboard and full gear weighs about 1000 kgs.
Hope this helps.

[Richard B]

Manos, thanks for that - interesting figures!

Is your Mariner auxiliary engine a 2-stroke?

[Manos]

No probs Richard. Yes the Mariner is 2-strokes.
I have a thing about not using 4-strokes at the moment. I do not entirely trust them yet.
The reason, a car engine in a sea environment doesn't sound safe to me. In the US and in other areas they use them mainly in lakes which is OK. But in salt and if you leave your boat in the water for 4 months at a time the computer and the electronics will suffer quite a bit.
In time and when is proved that people do not have problems with the 4-strokes I will change. But for now will stick with 2-strokes to be on the safe side

PS: On the 640SRs that I am hiring out I have a 4bhp aux engine (instead of 5bhp). I have not done any testing yet but I am told from others who have same aux it gives them a speed in rough weather about 3-5 knots (which is OK)

[Richard B]

Yes, but...

With a 2-stroke, you need a tank of pre-mix. And once that's gone, it's gone.

And, do you dispose of the premix from time to time (don't say that you wash the landrover with it )

[Alex Brown]

All my setup is 4-stroke, which is great in the fact that there is no mix anywhere, and just straight petrol

My aux engine is a 4hp Suzuki - as said before it's permanently fixed, and bolted to the transom to prevent it falling off in extreme conditions.
The built in fuel tank is only 1.5 litres, which is fine, because I always carry a separate 25 litre reserve tank, plus the syphon incase I ever need to pull fuel from the main tank.

It's not fast - 4.5knots in moderate force 4 conditions, but I don't care.... If I break down in the river with a tanker moving and bearing down on me, all I need is to get to the back of the boat, pull start it, and get out the way, drop anchor and get help.
Of course, I could always motor all the way home - at around 3 knots speed on the aux, I have had 45mins, and that seems to have used just over half a tank.

I towed a rib back from half way out to Skomer last year, and the GPS had the return journey down as 9 miles, which was going to take between 2 and 2 and a half hrs, that was running at around 4 knots. I'm sure the aux engine would have done that in around the same time, but just to check, I will have a slow bimble back this summer to see just how far I can get on 1.5 litres of petrol

At the end of the day, from my point of view, the aux is there to get me out of immediate trouble - it's also great for crawling around up river when there are depths of less than half a metre in places

[Daniel]

What i can't understand, Alex and Manos is how you have not broken your aux's. The only explanation i can think of is that you don't drive your boat as hard as I do because there is no way whatsoever a small engine would survive on the transom of my boat - i proved this with grayswish...numerous problems.

I like to jump waves, i like to drive fast in the rough and i like to hear the prop (but don't tell the Mercury warrenty department) - it's fun and that's why i have a RIB.

I'm not 'having a go' i'm just wondering if i'm more enthustaic with my throttle. I'd appreciate some unbiased views from those who have seen my boat and the way i drive it.

I made a decision not to have an aux for this reason, and becasue i know if i had one and kept it anywhere but on the transom it would be very, very, unlikely to be of any use to me or imposiable to mount. I agree i'm putting a lot of faith in my main engine (it is brand new) and possibly needing to ask for the help of others (RNLI included) if there was a problem, but that is the way it is and i accept that as an acceptable risk.

[Manos]

Originally posted by Richard B
Yes, but... With a 2-stroke, you need a tank of pre-mix. And once that's gone, it's gone. And, do you dispose of the premix from time to time (don't say that you wash the landrover with it )

I always have 1 ltr bottle of 2-stroke oil in the boat (in all boats). Also there is a system where by you can take fuel out of the main tank and put in the aux engine tank. So is OK...ish I think.

No I don't use petrol for washing my jeep only diesel Petrol is too expenssive in Greece Cents 78/ltrs, Diesel Cents 30/ltr

[Richard B]

i'm just wondering if i'm more enthustaic with my throttle. I'd appreciate some unbiased views from those who have seen my boat and the way i drive it.

Nah, you drive like a girlie!!

[Manos]

Originally posted by Daniel
What i can't understand, Alex and Manos is how you have not broken your aux's. The only explanation i can think of is that you don't drive your boat as hard as I do because there is no way whatsoever a small engine would survive on the transom of my boat - i proved this with grayswish...numerous problems.

Daniel I do not try to break my boat although I jump waves and go fast even with family on it. However, the trick is to lash the aux engine leg on to the A-frame. The engine does not move neither breaks whatever you do. Try it, it works quite well

PS Forgot to mention that is mounted on a SS bracket too, but this wouldn't work if it was not lashed on to the A-frame, VERY TIGHT

[Alex Brown]

To that question Daniel, I am unsure - I had only thought a bit about the possibility of breaking the aux when I ordered the rib from Humber a year last October.

At the time, I had ordered a stainless bracked to be mounted on the transom for the aux, but when I got to Hull, Humber had had a better idea, to cut the transom away at exactly the right place for the aux engine which is what was done. When I got the aux engine, it went on the back of the boat, and then I placed two bolts through the transom which hold the aux engine tight onto the boat. This keeps things nice and rigid, and as far as I can tell, the only thing that'd be likely to break is the clip that holds the aux engine up. Saying that, when the engine is up, in my case, it wedges up tight against the engine security lock, which stops the thing from bouncing up and down, and also turning too much - this may contribute to the survival of the engine I guess.

I've not been able to get a serious amount of air time on the rib really - when in the river, the hull tends to slice through waves rather than bounce off them (unless I'm at lower speeds 20 knots or less), and when I'm on a swell at sea, although we'll clear the prop of the water, the landings aren't neck breaking either.

I don't hammer my rib to the limit, but I don't faff around either (without crash helmets, it's not worth the risk!!) - wake jumping is great fun, but make sure the person sat on the bow locker is holding on tight though

-Alex