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[16-21]

Hi all,

Currently have a Module with 2 250ml piston tanks operational in an Akula
Wondering if the same module would work in Traf hull and if current engel tanks have a large enough volume??

any idea's suggestions???

regards
adam

[Subculture]

They're little tanks- self made?

I don't think you'll get a scale waterline with 500ml of volume- these boats have a high freeboard. Ramesh(Mankster) built a really nice Trafalgar with his own module based on twin Engel tanks. Can't rememeber the exact volume, but I'm sure was a litre or more. His was an earlier Eden models moulding, with a fairly chunky sail. Chris made a lighter upper hull on later Sheerline boats, this helped improve the stability of the boat, but should also reduce ballast tank volume.

[Subculture]

Whoops- just realised you put OTW Trafalgar, which is a smaller boat. I think you'll be okay with 500ml in an OTW Trafalgar. OTW lay-ups aren't too heavy, so that minimises displacement.

[16-21]

Thanks Andy,

The plan was to use the 2 250ml engel tanks that where bought age's ago..
If memory serves Ramesh's Tireless has 2 600ml engel tanks.

Plans have changed anyways mate, As i started talking to Bob i decided to just go for the S class instead.... So perhaps i'll need to order more tanks from engel lol...

regards
adam

[Subculture]

were these custom tanks from Engel, because the smallest they do is 500ml as standard.

[16-21]

Hi Andy,

The tanks where from engel. 2 250ml with 380 motors.

I had the idea when looking at ramesh's build of his scaleship akula, He mentioned using 500ml tank, I figured it would be better fitting 2 smaller tanks giving same volume...

Now looking at 2 of there 825ml tanks with unipro's for the S class build, assuming of course that 1650ml will be enough to dive her.

[Subculture]

I think 1.5 litres might be adequate- have a word with Mr Dimmack. If so you can use 750ml tanks, and Ron Perrott had a pair of these for sale a while back. They're new and unusued, and he was looking for about £150 for the pair.

250ml Engel tanks would be very short. Having seen a few piston tank boats in operation, I have to say for smaller boats twin tanks don't seem to offer much advantage over a single tank. The shifting c.g issue is negligible, and the boats appear to operate in a very scale like manner.

[16-21]

I received a pm from jeff larue
Regarding the viic otw module. Total length was 32" 11" for ballast tank. Jeff thought about 2.65 litres in total for the tank.

After speaking with Bob
He tells me that the b,tank was enlarged to 12"
I can only assume this was done for the S.
Now both 7 and S share the same module.

[Subculture]

Wow, sounds a lot to be honest, but Bob and Jeff would be in the best position to give a definitive answer. The Engel Type VII which is about the same size but with a thick GRP deck has twin 825ml tanks.

Another option for you- use the mini Engel tanks you have, fit them either end of a larger main ballast tank, and use a water pump or air system for the main ballast, with the engel tanks for the final trim. Nice inexpensive option for you, and the tanks you have don't go to waste.

[16-21]

Confirmed 2.65 cubic litres, However thats the total volume for the ballast tank, since it vents into the other parts of module i would assume 50-70% is used.

Andy, I did consider a hybrid system, possibly vented tank/ decks awash and the 250ml tanks for conning tower it is a big old beast judging by the size's etc.

Draft is 360mm some 70mm more than VIIc,
Otw new module for the VIIc and S class is 32" 10" fore and aft compartments and 12" ballast tank, at 110mm od

Will see what happens might just go for larger engel tanks, Norbert bruggen.

[Subculture]

I'm pretty sure the OTW system uses 80-90% of the tank volume before the water level hits the probes, although I suspect you don't need to fill it to that level to get the boat under- a bit left in reserve to go negative as many skippers prefer, and to allow for different water densities.

The only really sure way to do this, is get the boat, put it together and do a tank test, you'll soon find out what you can or can't get away with.

[16-21]

Very true, perhaps i'll see what tom does on his???