Help..and this is a weird one!

[ch5120]

Ladies and Gents,
Im in the Army but have a few mates who were in and are now doing a civvy version of my job in places that you dont go on holiday to! They get paid probably 3 times my wage but they still come back to us still serving paupers to bail them out.
This is their latest problem...they have a floating fuel tank, holding 22,000ltrs of fuel. This is a rubber floating fuel tank (see link)
http://www.trelleborg.com/en/Dunlop-...Oil-spilliage/
http://www-g.eng.cam.ac.uk/125/1950-...awthorne3.html
Now we use 100,000ltr versions in the mil and use a CSB (see link)
http://www.lornecampbelldesign.com/b...litary-CSB.htm
So would a rib be able to tow short distance (inland water-think large lakes and rivers) etc?
I was thinking 8m+ with 150BHP+???
Help would be appreciated.

[Anchorhandler]

It depends on a lot of factors but the two main ones will be the pitch of prop you have and whether or not there is any tidal flow or water movement to try and overcome.
You might find that the prop starts cavitating pretty quick due to poor flow over it.

I take it the tank would be full?

To give you an idea, in my line of work, we use small launch for very light towing work. It is about 8meters long and has a 2.3tonne bollard pull yet it is only powered by a Mermain 140hp turbo diesel. That Mermaid does however drive a 30" prop and its only spinning at 2300rpm at peak power.

I would guess that, as long as there is no other resistance to overcome, the rib will probably do it but your going to have to coax the outboard up through the revs very gently until its starts moving.


Simon

[jimn]

I would have thought it would work as a one off but you would be at displacement speeds so it would not be ideal.

[m chappelow]

Steering the thing will be a pain in the arse too i reckon ,
even with a sliding bridle or a central fitted samson post ,maybe ok once you get it moving forwards or just doing very slight steering course changes but as the other posts say the small props will cavitate a great deal and i wouldent like to think about stopping the thing in an emergency .

[Slaphead]

I take it this is a sausage shaped vessel weighing 22 tonnes when full....if 1 litre is to weigh 1 kg? I say this because I once towed my mates yacht weighing about 4 tonnes with my Pacific 22 weighing about 1.7 tonnes and it was not easy. The tow was me in front with about 20 metres of line and even with him steering the yacht, if his boat veered off course it pulled my stern all over the place making it impossible for me to keep straight. We eventually settled for a side tow with the yacht acting as rudder and me acting as propulsion. I think weight of the towing vessel was the deciding factor

I take it there is no means of steerage on the barge.

[ch5120]

No, there is no steerage. On the larger ones we use i have been on a CSB when they have been towed and its not easy, plan ahead and make the turn big! The fact that CSB's have Dowty jets on them make it a bit easier to tow.
I have emailed my mate with the info above and we will see what happens.
cheers for help