R/C Naval Combat

What is the best angle for the sloping sides of a water channel?  My two battleships, SMS Prinz Eugen and SMS Tegetthoff, keep demonstrating an unpleasant habit of rolling over when sunk.  While this looks pretty on film, I would prefer that they not do this.  The current water channel in each of them is around 5 degrees slope.  I am wondering if this is enough, or if I need more.

Ya know, Nick, that's a good question. My water channel (recently upgraded to a 5-degree slope) worked great most of the time. It wasn't until my ship got mossed and drifted into the middle of the pond that I encountered problems, and it was especially odd because my ship was listing into the wind, rather than away from it. Indeed it was a very strange sinking, for although my pumps can keep me afloat with ten 1/4" holes in the red at full speed, I didn't have 10 holes total on my hull and both pumps were going at full speed.  it was acting as though I had a lot more damage than I actually did. I'm going to do some bathtub tests to see if I can track down the source of the problem. Perhaps it is time I built and installed an active listing device, to help counteract the problem.

Posted By jadfer on 14 Jun 2010 06:32 PM
Water channel is irrelevant once the water level rises above it. It only servers to direct water when its below the height of the water channel. It it rolls when it sinks it sounds top heavy and you need to put more weight in the bottom of the hull. I changed mine and moved the batteries closer to the bottom and it helped a great deal.

I think this is the problem and the solution.

Rob

Posted By Kotori87 on 14 Jun 2010 06:52 PM

Ya know, Nick, that's a good question. My water channel (recently upgraded to a 5-degree slope) worked great most of the time. It wasn't until my ship got mossed and drifted into the middle of the pond that I encountered problems, and it was especially odd because my ship was listing into the wind, rather than away from it. Indeed it was a very strange sinking, for although my pumps can keep me afloat with ten 1/4" holes in the red at full speed, I didn't have 10 holes total on my hull and both pumps were going at full speed.  it was acting as though I had a lot more damage than I actually did. I'm going to do some bathtub tests to see if I can track down the source of the problem. Perhaps it is time I built and installed an active listing device, to help counteract the problem.

The listing actually makes sense when you think about it.  If a perfectly intact hull is evenly buoyant with balanced weight distribution, it will float upright at rest.  If you punch a bunch of holes in one side at waterline or below, that side is now less buoyant and will be less able to lift its share of the vessel.  In a stationary position, the boat would in that situation list to the damaged side.  When you have propulsion this is less of an issue, and throwing your rudder to turn away from your list can roll you to a more upright position.

On topic of your question on water channel angle, consider this: once you list 5degrees, which is really not all that much, the channel slope on the listing side is now parallel to the water surface- you are now now longer channeling water from the damaged side into your center channel.  Go another 5 degrees and it now has the interesting effect of forming a second water chanel, this one against your hull where water will collect and begin to further roll your ship under.  With no speed you cant drive that water back to the pump(s), with no flow over the rudder you can't induce a counter-list to put the water where it belongs.