Fuel tank(s) question

scousefreddy · 23 February 2007, 01:30

I have a 5m Humber Assault with a standard console/jockey seat and another jockey seat fitted. Engine is a 50 hp 4 stroke and I use two 25L removable tanks which just about squeeze into the space under the console but there's no more room in there when the tanks are in.

I only bought my RIB last year (my first!) and haven't really got around to checking how many miles to the litre I get, but I've been told by a few people that 1 mile per litre is a good average. On that basis I'd be ok for around 50 miles, but today I've seen a couple of interesting cruises in the cruise section (a round Anglesey cruise and another which is 43 miles each way with no place to refuel!) and I'm wondering what I could do fuel storage wise to give me the ability to go more than 50 miles?

I know I could buy 2 or 3 more 25L tanks and store them on deck, but is that the best option? With the 2 jockey seats fitted space is already tight and I'm concerned about losing more space and people tripping over fuel tanks all the time. I'm curious how other RIB owners with RIBs of a similar size manage?

I think my console will take a 70L fixed tank, so should I be thinking of a fixed tank or would buying more 25L tanks be the best option?

Stoo · 23 February 2007, 02:35

I would think that a 50 4 stroke should getter better mileage than that. If I keep my revs down to about 3800, that's what I get with a 150 2 stroke on a heavy 5.9m.

Having said that, you can never have too much fuel for a long cruise, but if all your doing is hauling around a lot of extra weight in fuel you don't use, that's counter productive.

I have a 132l inboard tank, but also 50l in spare cans. I only fill these if I'm going 'someplace' though...

BogMonster · 23 February 2007, 10:03

Mine is 5.8 but I carry 2 x plastic cans (non approved for fuel tut tut) ratchet strapped to the front of the console, never seem to move in any conditions and they are completely out of the way as well as providing a bit of ballast in the nose - hold about 60L total. I carry one of the "shake up and down syphon pumps" on the end of about 4 foot of hose, which is 100% reliable if a little slow for refuelling, takes about 5 min to empty one of the cans I suppose, but a lot less chance of spillage than a funnel which is important to me as the tank is in the console and I wouldn't wish to have lots of fuel sloshing round under my butt!

I always keep my cans full at all times. When my father was learning to fly many years ago, his grizzled old instructor told him 3 things that were useless to you as a pilot:

- Runway behind you
- Height above you
- Fuel in the bowser

Only one of those applies to a RIB but it seems like a good rule of thumb

Jono Garton · 23 February 2007, 10:09

Hi Fred

We stock the 90litre tanks that go under your console now.

Jono

Mouldy · 23 February 2007, 11:07

Quote:

Originally Posted by scousefreddy

I use two 25L removable tanks which just about squeeze into the space under the console but there's no more room in there when the tanks are in.

Can you post a couple of pics showing the available space?

Jono Garton · 23 February 2007, 11:49

pic

Jono Garton · 23 February 2007, 11:51

I work to 1 Litre per mile for 90 - 140 four strokes, i think more like .5 l per mile would be more like it.

Jono

Ian M · 23 February 2007, 12:19

I'm getting 0.7 litres per mile, two up, pushing reasonable hard with my 90 Opti on a 5.5 metre XS. So I think that Jono would be pretty close to the money with 0.5 for your rig. Why don't you go out in local waters and measure your fuel consumption?

scousefreddy · 23 February 2007, 13:02

Quote:

Originally Posted by Jono Garton

Hi Fred

We stock the 90litre tanks that go under your console now.

Jono

Sounds good. How much are they and are they quite easy to fit?

Jono Garton · 23 February 2007, 17:27

Quote:

Originally Posted by scousefreddy

Sounds good. How much are they and are they quite easy to fit?

About £120, the console would have to be uplifted, tank fitted and console re fitted.

I personally would put another 25/30 litre drum in front of the console, or upgrade your boat to a 5.5m Humber Destroyer

Jono