What was the cause of losing your boat? Fail safe questions learned the hard way.

[trout]

It was the SubRegatta in Keystone, 2003. They co-ran with a boat group. The boat people did not care for us sub folk. I was running the Type 23 earlier in the day and it ran well, but started to act up (not emptying its ballast tanks). On the bench I noticed that if I blew or sucked air through the pump it would start working again. I should have not run it again, but testing it several times it seemed to be working. I trimmed this 23 so that very little forward motion would submerge the sub. As it was running, it made a sudden dive. Nothing I could do to stop it (the running theory is one of the boat guys turned his radio on - many still used 75mhz). Well after diving it went below the ability of the positive buoyancy to bring it back up. We had a diver, but he did not find it.

[Monahan Steam Models]

Ken,

Thank you for posting more details about the conditions when your Marlin was lost. I wonder if the weeds in the lake played a roll in the loss?

Casey/Tom,

Both of your boats seemed to have suffered a similar fate from deep diving beyond the point of sufficient buoyancy to recover. This makes me recall a topic that has been brought up a handful of times in past threads which was a drop ballast weight fail safe.

I would like to propose a rough idea for a potential drop ballast fail safe mechanism to be discussed or to be shot down by a firing squad.

The basic idea would be purely mechanical without needing any input from the transmitter or onboard electronic device. I would consider this to be the last ditch fail safe when all other fail safes have failed to surface the boat.

The mechanism would be a small mechanical pressure differential diaphragm that would release the ballast weight when the pressure on the “sea” side of the diaphragm becomes a greater force than the spring on the other side of the diaphragm can offset this allowing a pin to move and drop the weight.

Over the years I have had to design and use a number of mechanical diaphragm regulators for various projects requiring the need for them. They are very simple devices made up of only a few simple parts depending on the job and in the conditions that they need to preform. The surface area of the diaphragm and the spring rate pressure would determine at what depth the ballast weight would be released. So if you don’t normally operate your boat to a depth greater than let’s say 3 feet as just an example, then the ballast wood be dropped just beyond that depth.

Okay you’re free to open fire now for suggesting such a bone headed idea! LOL

Nick

[Das Boot]

If you lose your buoyancy due to end cap failure, gas or power loss, and you wind up under something or stuck in weeds, dropping ballast is a waste of time. Not to mention cumbersome and ruins the scale look. I imagine someone could design a constant on relay connected to a working buoy that jettisons on loss of power, connected to some line and float. But this only works if you’re not under any obstacle. Never seen it done, but who knows.

[Ken_NJ]

British x-craft had droppable explosive charges. That is a type of submarine you can make scale like droppable ballast in place of the explosives. Use a LOSS device to activate.

[Monahan Steam Models]

If you lose your buoyancy due to end cap failure, gas or power loss, and you wind up under something or stuck in weeds, dropping ballast is a waste of time. Not to mention cumbersome and ruins the scale look. I imagine someone could design a constant on relay connected to a working buoy that jettisons on loss of power, connected to some line and float. But this only works if you’re not under any obstacle. Never seen it done, but who knows.

For dropping ballast, I would never consider having it simply attached to the underside of the keel. It would definitely ruin scale appearance. I would instead for example have a slot cut in the underside of the keel for a ballast bar to drop out or in the case of using buckshot as ballast, have a hatch that dropped open to dump it. Or like Ken has mentioned using a feature that dropped away from the boat like the droppable explosive charges.

But yeah, not much that can be done if the boat gets stuck under an obstacle. That’s where maybe a high pitch pinger may come in handy for locating the lost boat.

I suggested the purely mechanical autonomous way the failsafe would be actuated to account for power loss, signal loss and such.

[He Who Shall Not Be Named]

For dropping ballast, I would never consider having it simply attached to the underside of the keel. It would definitely ruin scale appearance. I would instead for example have a slot cut in the underside of the keel for a ballast bar to drop out or in the case of using buckshot as ballast, have a hatch that dropped open to dump it. Or like Ken has mentioned using a feature that dropped away from the boat like the droppable explosive charges.

But yeah, not much that can be done if the boat gets stuck under an obstacle. That’s where maybe a high pitch pinger may come in handy for locating the lost boat.

I suggested the purely mechanical autonomous way the failsafe would be actuated to account for power loss, signal loss and such.

A water soluble retainer. Like a length of spaghetti, Tic-Tac, or cough-drop, or week-old booger.

[CC Clarke]

Water-soluable plug over a small canister of yellow sea dye marker placed inside the hull. That stuff was visible from the air!

Fluorescent Dye Marker (landfallnavigation.com)

As an extra precaution - install a tag with contact info inside the WTC just in case someone else finds it first.

[Bob Gato]

I experimented with this for surface craft and shakedown runs of subs-NOW please read with an open mind-as the post says the active ingredient is very predictable in 65 degree water and will release in about 1 hour in ph neutral water. Its not pretty-that's where I stopped thinking about it...like I said I only used it for shakedown dives...if I were to run for longer then 1 hour, I'd quick change the unit for a fresh one...On surface boats it would hopefully never need changing out and could be hidden in a lazerette box or under a cushion.

https://www.rcgroups.com/forums/show...61&postcount=1

Luckily the Atlantis sub I am building could have a scale operational buoy -BG

[Ken_NJ]

The real Marlin was used for practice by the sonar guys on ASW ships. The Marlin had two very bright lights they would switch on while underwater to show where they were to the surface ships.

On my Marlin, I have a float switch in the sail which activates the nav lights when the boat is surfaced. When the Marlin submerges, the float switch deactivates the nav lights and activates the two very bright LED's on the deck. They point upwards. So should I loose my Marlin again, I should have these LED's to help locate it. In the future I'll also be designing my own underwater audio device to assist in finding a lost sub, should that happen again.

Navigation lights on, bright deck lights off. BTW, that RADAR antennae also works.




Nav lights off. Bright deck lights on. That white stick on the open bridge has a magnet which allows me to test the float switch and lights.

[Monahan Steam Models]

Ken,

Great work on the Marlin. I love the detail! The float switch for the Navigation and bright upward lights is awesome. Even the rotating radar, very cool. Nicely done.

Nick

[Monahan Steam Models]

I experimented with this for surface craft and shakedown runs of subs-NOW please read with an open mind-as the post says the active ingredient is very predictable in 65 degree water and will release in about 1 hour in ph neutral water. Its not pretty-that's where I stopped thinking about it...like I said I only used it for shakedown dives...if I were to run for longer then 1 hour, I'd quick change the unit for a fresh one...On surface boats it would hopefully never need changing out and could be hidden in a lazerette box or under a cushion.

https://www.rcgroups.com/forums/show...61&postcount=1

Luckily the Atlantis sub I am building could have a scale operational buoy -BG

No one can argue with you that the real Atlantis didn’t have a buoy!

[Monahan Steam Models]

A water soluble retainer. Like a length of spaghetti, Tic-Tac, or cough-drop, or week-old booger.

The week-old booger may still be too sticky to release when rehydrated…

[He Who Shall Not Be Named]

The week-old booger may still be too sticky to release when rehydrated…

... thanks for ruining my evening meal, you ****!

[Monahan Steam Models]

... thanks for ruining my evening meal, you ****!

Jeez, all I said was too sticky, not edible… Not judging your meal preferences…

[redboat219]

How about an ejectable untethered marker bouy with a strobe light atop?