Survival Whistle

A whistle is considered to be one of survival kits and should be in your EDC (EveryDay Carry) list. Most common international whistle codes are :

• Three blasts : "Help Me!"
• Two blasts : "Come here."
• One blast : "Where are you?"

Each whistle blast should last 3 seconds. Another important code is morse code of "SOS" which is three short blasts (3 seconds each), three long blasts (6 seconds each), and then another three short blasts (3 seconds each). So when you are separated from your group, you can use these codes to get back to them if you are not too far away.

A pocket knife and a hollow branch or stick around 3 to 5 inches with a quarter inch of inner hollow diameter. Good if you can find bamboo trees. If not, the bark of willow trees can be used, but you need to remove the wood from its bark.

In this project I used bamboo about my finger size. Pick a yellow one, it will certainly has hollow core, or grab one that is turning yellow (brownish). The green ones are sometimes still solid inside.

This is the basic design of a whistle. It is very simple.

1. A hollow tube with one sealed end.
2. Cut 45 degree at the open end. (called mouthpiece).
3. Cut an opening at the top which is one straight cut and one diagonal cut (called the blade).
4. Plug some wood at mouthpiece leaving only a little gap for air inflow at the top.

That's it. It is that simple, but the wood at mouthpiece need proper adjustment, because we don't have any glue out there unless you are lucky to get the sticky latex of a tree.

The second picture is curved to get a better and comfortable mouthpiece. A curvy blade is believe to get a different tone on your whistle, but I have not done a focus experiments on it

1. Clean the branches at one node of your bamboo.
2. Straight cut at near the clean node. That is our sealed end of tube.
3. Cut a 45 degrees just before the next node of bamboo. That is our opening end of tube, also the mouthpiece.

1. Make a straight cut about half an inch from the mouthpiece, until you can see your knife from the hollow core.
2. Cut a slope about a quarter inch from the previous straight cut until you meet its end at the hollow core.

Get any branch with the size of the bamboo's hollow core.

1. Shave one side (that will be top side) of the wood.
2. Plug into the mouthpiece until you see the wood is flat with the straight cut of the blade's hole. Then cut the excessive wood at mouthpiece.

Now you can see a little gap at the mouthpiece. That is where the air goes in and it will then splitted by the blade. Some goes out of the tube and some goes into the chamber and rolls back and out from the blade's hole. That produces the sound.

On next experiment, I try two shapes of wood inside the mouthpiece. The slopped down below the blade produces lower tone. More bass. The straight cut below the blade produces higher tone, which is suitable for survival outdoors. If your whistle still mute, check and realign the wood inside the mouthpiece. Make sure it sticks well on the surrounding and leaving a little gap on top for air inflow. And also make sure it is not getting in too far passing the blade's straight cut.

At this point, if your whistle is blasting good, you are 50-50 to survive the zombie apocalypse. you need to analyze your environment. Blasting your whistle in the dark, you may call the other survivors. Or you may as well tell the zombies about your position. Blasting your whistle in daylight you may also activate the sound-sensitive drones from the outside world and telling them your exact coordinates.

Now can you tell me if whistle is really a survival tools? We will get the answer ... if I see you the day after tomorrow ...