Lost at sea =(

[topgun]

Came back from college for the weekend and I took my alfa out today on it's 5th voyage at a local lake. I dive at too high of an angle and blow the tanks in panic. The bubbles uselessly goto the surface and the sub is still heading straight for the bottom. I assume it got stuck in the weeds(i tried to give it full power and up elevator, no effect)? The lake is estimated to be around 20 ft deep at that area. It has been 6 hours since it sank. I plan on getting a diver asap.

Does anyone know how long can the WTC keep the water out at depths like this? Are we talking days possibly?

Awww borsche!
Tom Kudla

[raalst]

Sorry to hear it....

as

Sorry to hear it....

as the air in the WTC cools, leakage becomes more likely,
but only up to the point where inside and outside
pressure match again.

at 21 feet, pressure is 1.7 bar,
that would mean that 1/1.7th = 58%
of the wtc will still be air.

off course there are other factors, such as where the
leaks are, whether there are multiple, etc.

Electronics often still work when dried thoroughly
afterwards.

Hope you soon catch your "fish"

[anonymous]

You must be upset about

You must be upset about the lost sub. On the brighter side you should get it back and, as Ronald has said, you should be able to recover most things (electronics etc in freshwater) - so it is worth recovering.

The key thing if you are using a diver (I was one) is to help to locate the sub - underwater search is difficult particularly in poor visiibility.

Mark the possible location with a buoy and weight, look for air bubbles. If you still have power look for propwash or borrow a hydrophone to listen for prop noise.

Longer term,when youv'e got her back - it sounds like you use a pressurised tank system and you may consider fitting baffles in the tank to reduce the chances of losing your air. (I had a similar sinking last year - got it back!) You may also consider using a hydrophone and onboard Pinger system. (See below)

My Webpage

[Guest]

For a pressurised tank, I'd

For a pressurised tank, I'd consider fitting a good air tight valve.

It does do away with the 'leaky valve' failsafe, but at least you won't get the problem experienced by David.

Cheers

Andy



Edited By Sub culture on 1098808000

[topgun]

After 70 hours underwater, the

After 70 hours underwater, the diver found my sub in 12 feet of murky cold water. The prop was wrapped in fishing line(complete with sinkers) and she sat on the bottom at about a 20 degree up angle.

If I would of just pulled the elevator up one second sooner it would have cleared the cobwebs of line on the bottom before the prop hit.

There was no visible damage, and there was only a teaspoon of water in the WTC... quite surprising considering the water temperature was around 45 F at a depth of 12 ft for 70 hours.

As for the air tight valve, how did you construct yours?

Thanks,
Tom Kudla

[Guest]

Have you got access to

Have you got access to a workshop?

You will need soldering equipment, a bench drill and lathe to make the valve I have built.

Failing that, if you just want to seal air, a schraeder valve (tyre valve) is all that is required. Bit restrictive for water though I would think.

Andy

[anonymous]

Dear Tom & Andy,
I am

[color=#000000]Dear Tom & Andy,
I am very pleased that you got your sub back - I thought you would!
On the cause of the sinking and ASSUMING you are using a pressure tank system (ie water pump) What happens is]

[Guest]

I understand what you are

I understand what you are driving at now. I thought this was caused involuntarily.

I would consider that placing the inlet to the tank nearer the middle of the tank would also help prevent the exposed water surface being breached by excess angle of dive.

[anonymous]

That's it!

The inlet/outlet in the

That's it!

The inlet/outlet in the middle of the tank helps, but you can still get an air/water surface as a result of "sloshing" hence the baffles. The air can be lost in under a second.

I must admit I was sceptical at first when I read an article by Gareth Smith of the AMS (UK) on baffles. But I have seen benefits in my R Class.

Half fill a plastic bottle with water and try to balance it in the middle on a ruler. Water sloshes from end to end even in a small bottle.

[slats]

Tom,
glad to here you got

Tom,
glad to here you got your Alfa back. I have one and would go nuts if it was down.
Just a small tip that Skip Assay passed on to me. If ever in the future your boats going down in an uncontrolled fashion (too steep etc), instead of driving ahead with planes up, just try all back full. I don't know why but this manourve of going full astern seems to suck the sub very quickly back to the surface particularly if your bow down.
All the best
John.