Ballast at the bow of the rib

[two stroke mick]

Hello

I am wondering how many of you out there uses ballast on the front of the rib to help keep the bow down in a head sea. This allows for the bow to cut through the top of the approching wave rather than just riding over it.

I am still experinmenting with by DR 490 and it would appear to like a lot of weight in the bow circa 20-25 kg.

TSM

[K&S]

When using a searider 5.4 i frequently get people to slide fore and aft to suit the conditions.
I would not deliberately move too much static weight there as in a following sea or miss judgment of an oncoming wave could lead to a stuffing that could have been avoided.

[K&S]

Perhaps locate the fuel tank there if not already would give you that sort of weight for at least part of the time ??

In our searider we have the reverse problem and now looking at siting the fuel tanks at the stern.

[Nasher]

Some of us in the solent have had access to the ultimate mobile flexible Ballast system which can be moved fore and aft at request.

Its called the:-

'Oi Hightower, run up to the Bow mate' system.

Nasher.

[jambo]

Hi like K&S I tend to load the front depending on the sea state and the number of passengers and also how my fuel tank is as I have a 40 gall mid tank on my Ribcraft.
Hope it helps
J

[chewy]

One the 75's we use the ballast loads, its good to get you where you want to be but not as much fun as running with no ballast.

I personally think the 21 was the best inshore boat, you only need to look at how long it was in production for compared to the 75.

You fly higher without ballast too.........

[Apherel]

My old boat was much more settled with around 20-30 kg of fixed weight in the bow. I used sand in a soft bag so it could be dumped if ever needed.

Someone on here suggested using sand in old inner tubes tied off with cable ties.

[two stroke mick]

I generally have 4 or 5 1 gallon cans of petrol in the bow to settle the rib

[Stoo]

My dive tanks pretty much live up there... one or two sets of doubles... and they make great ballast. I can't actually lift them out of the boat, so they just stay there~

[Simon B]

Likewise;

30l fuel container or a divers twinset or everyones weightbelts.

[Cookee]

Originally Posted by Apherel

Someone on here suggested using sand in old inner tubes tied off with cable ties.

They work very well as they tend to stay where they are put.

This boat has a 150 litre bow tank that can be filled with the correct amount of water and emptied on the run for perfect balance.

[Hightower]

Originally Posted by Nasher

Some of us in the solent have had access to the ultimate mobile flexible Ballast system which can be moved fore and aft at request.

Its called the:-

'Oi Hightower, run up to the Bow mate' system.

Nasher.

Yeh, Pete7 used to use that system on Old Spice. It's the only way we could get the thing to plane with 4 peeps on board

[Hightower]

I've never needed to move ballast around on mine. If I'm traveling by myself then I can sometimes land Starboard (helm) side down, but I fitted her out to be a very neutral if a little bow heavy which becomes more balanced as the fuel level goes down.

I like the Idea of putting fuel tanks in the bow to level the ride, I'd hate to carry "dead" weight

[9D280]

My old SR4 had 2x 30L tanks - one at the bow & one at the stern - bow tank had a dedicated hose so I didn't need to manhandle them to swap tanks in a lumpy sea. Suz 25 (no PT) so I usually went for emptying the front tank first and the handling & speed improved slowly as the day ticked by.......

[mr_sav]

Hi, my SR6 rides better with a bit of weight up the bow end. I have a bowsprit set-up and locker, however it tipped better with an extremely decent weight thick Tow Rope. I tucked it up the bow, with the expectation that I will never need but it is there if I do. Better than sitting in the shed doing nothing.

However, You may also want to consider the type of prop you are using as well. Different props will either lift or push your bow down, and assist in providing the range of useable tilt.

I always knew this to be the case, however, in recent prop testing (3 styles) I was amazed at the signicant variances the Props showed.

Good Luck

[two stroke mick]

Mr Sav

Interesting comment on the prop. I originally had a 17" * 13 dia prop and moved to a 19"* 13 and now have changed to a 21*13. I have yet to check out the new 21*13. But It may improve matters. The engine was overreving with the lower pitch props (approx 6400-6500 with the 19" and approx 7000 rpm with the 17")

Maybe the new prop will improve the handling of the DR490 in a head sea

TSM

[mr_sav]

Originally Posted by two stroke mick

Mr Sav

Interesting comment on the prop. I originally had a 17" * 13 dia prop and moved to a 19"* 13 and now have changed to a 21*13. I have yet to check out the new 21*13. But It may improve matters. The engine was overreving with the lower pitch props (approx 6400-6500 with the 19" and approx 7000 rpm with the 17")

Maybe the new prop will improve the handling of the DR490 in a head sea

TSM

I suspect the pitch change may not actually help that much with the bow. You could expect to come down a couple of hundred revs, however, It sounds to me you a prop that is not buest suited for your boat.

I just realised you are running an ETEC.

Are you running Vipers out of interest. They have quite a sweep on the blades, and causes bow lift. Go the SST (Traditional Props) and give them a go if your dealer is assisting you.

This is info from my Link the other week. It may be of interest or use to you. Note I am running twin Donks on an SR6, however, the principals are there.


http://rib.net/forum/showthread.php?t=27364

Regards.

[two stroke mick]

The props are just the standard ali types

[mr_sav]

Originally Posted by two stroke mick

The props are just the standard ali types

OK, I think you will find that is your problem. I don't know if this is a new motor or not, assuming you are trying different pitches is leaning me towards it may-be.

If the Ali's are standard with the 60hp range then it may be worth you seeing what an upgrade cost would be to the traditonal non-swept SST Blades.

You would not be disapointed.

I would recommend you try the 17" non swept SST Blade, and then determine whether you need to go up or down pitch to get the recommended Rev Range at WOT.

Best Of Luck.

[two stroke mick]

I have managed o get 2 10 lt fuel tanks these will fit into the bow locker of my Rib. I intend to plumb them up so that they can be connected to the engine with a snap type connection. Before this I used to have to pull in and top up of 4 no 5lt cans which is a pain in the ar**