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[Tug Captain]

Hi,
am building a 1:100 scale bulk carrier based on builders drawings. The hull will be some 180 cm long and approx 30 cm wide. The original is a geared vessel with grabs and so has 5 hatches.


Instead of having to load/unload lead weights I would like to fix something along the following lines.


The hull will contain one (or several) tanks that can be filled /emptied by means of  water pumps controlled by the Rx. The tanks will have several internal walls to prevent the water ballast from slushing back and forth, causing instability.


Initial calculations indicate I would need to load some 45 -50 liters to get down to the waterline. It would be perfect to find a pump that has a capacity to fill the tanks in 5 -10 minutes. I guess I will need one pump for filling, one for discharging the tanks.


Has anyone tried this and what is your experience?  As I have some 100 meters pretty rough terrain beween the parking lot and the edge of the water it wuold be nice to be able to get the model and radio down to the water in one trip.


Yr comments/suggestions most welcome.
Claes

[Martin (Admin)]

How about using 'free flood ' tanks?

[Shipmate60]

Why not just use 3 or 5 Ltr plastic bottles.
Fill from lake fit into model.
Remove from model and empty back into lake.
No backbreaking and when empty store inside hull.


Bob

[Tug Captain]

Bob,
that coukd be an altyernative
Claes

[John W E]

Hi ya there

I know that this isn't exactly the same vessel as this topic - but - its the semi-submersible heavy lift vessel which Ian built.  He used some good pumps and if you read through the subject and possibly contact him he will be able to give you some really good pointers - here is a link to the excellent built in Masterclass on this forum

http://www.modelboatmayhem.co.uk/forum/index.php/topic,9014.0.html

John

[cos918]

Hi,
am building a 1:100 scale bulk carrier based on builders drawings. The hull will be some 180 cm long and approx 30 cm wide. The original is a geared vessel with grabs and so has 5 hatches.


Instead of having to load/unload lead weights I would like to fix something along the following lines.


The hull will contain one (or several) tanks that can be filled /emptied by means of  water pumps controlled by the Rx. The tanks will have several internal walls to prevent the water ballast from slushing back and forth, causing instability.


Initial calculations indicate I would need to load some 45 -50 liters to get down to the waterline. It would be perfect to find a pump that has a capacity to fill the tanks in 5 -10 minutes. I guess I will need one pump for filling, one for discharging the tanks.


Has anyone tried this and what is your experience?  As I have some 100 meters pretty rough terrain beween the parking lot and the edge of the water it wuold be nice to be able to get the model and radio down to the water in one trip.


Yr comments/suggestions most welcome.
Claes

Hello
Are you sure 40 to 50 liters . I have a ferry a bit smaller at 165 cm by 25 cm and she ant even 1/2 that weight . 50KG of ballast is a very heavy weight .


John

[Brian60]

John that could be because a ferry has a relatively high (above waterline) hull. A bulk carrier as described by the OP had possibly 3/4 to 4/5ths of its hull below the water, so more ballast would be needed to get it deeper in the water. Of course it could be modelled as if it wasn't loaded meaning it would be showing plenty of red oxide paintwork like the real things do. But then you will always get somebody asking why it isn't on the waterline.

[Umi_Ryuzuki]

The Seattle club does that for some of their barges, and a large 600lbs(270k) Liberty ship.

And the Vancouver BC club has a very large freigher that uses pumps to get water in and out.
https://www.rcgroups.com/forums/showthread.php?1152361-Very-Large-Freighter


Both ships have claimed the bollards off tugs, and the Liberty ship has sunken tugs when
handled improperly. It has tug sillouettes at the side of the bridge.

[tugmad]

I have built a 16 ft tanker for our club, although it is in sections which clip together they are 600 x 600 square with only the engine room and focsle sections with bottoms and made watertight , the other hull sections have no bottoms at all and float on a 4" thick foam block fitted under the deck, the sides are 9"" deep so she has 5"" under water and a freeboard of 4"" the batteries and motor are in the watertight engine room section aft.so no ballast is needed at all.

[unbuiltnautilus]

I have built a 16 ft tanker for our club, although it is in sections which clip together they are 600 x 600 square with only the engine room and focsle sections with bottoms and made watertight , the other hull sections have no bottoms at all and float on a 4" thick foam block fitted under the deck, the sides are 9"" deep so she has 5"" under water and a freeboard of 4"" the batteries and motor are in the watertight engine room section aft.so no ballast is needed at all.

Now that is a clever idea ( Wish I had thought of that when I started building SS Ohio! ). It would be easy enough to modify a 1.8m model early in the build, not so sure though, if the build has progressed some way though.

[Stavros]

if you want a good reliable pump to fill and then empty the tanks then I would go for a pair of bilge pumps they are designed to do this and are not all expensive to buy...around £25 on ebay....Rule or Jabasco are the better ones




Dave

[CGAux26]

I have a 48 x 12" propane barge that started out with the 2 "propane tanks" being filled with water via a pump.  It would take 10 minutes to fully ballast, then the same time to pump out.  Bunch of valves to switch from "Fill" to "Drain."  An awful lot of work and tubing went into the system, but it was never very reliable.


I have modified it to the open bottom with foam internal flotation arrangement.  Now it can be dropped in the water and it fills down to the load waterline in seconds.  Pick it up slowly at the end of the day and you are done.  No pump, no battery to charge.

[Big Ada]

http://i1373.photobucket.com/albums/ag383/rokbottom1/The%20start%20of%20something%20Big/100_1577_zpsrlevxus5.jpg
This is my Big Boat, I have added a section to bring its length to 20+ foot long, Tug Mad gave me the Plans of the Hull and I did my own thing with the Superstructure, no Ballast required, seemple.
ps, It has a motor and also a Bow thruster.
Len.

[Tug Captain]

Seems my "large" model is a minor compared with some examples shown here
Claes

[RAAArtyGunner]

Seems my "large" model is a minor compared with some examples shown here
Claes

Not too worry, will get bigger when it grows up and becomes a major 

Seriously some very good simple solutions