"Survival Friendly Command Block" is a Minecraft mod that makes the Command Block obtainable in survival mode
-Made for (but not in association with the author of) Cracker's Wither Storm Mod (Not Required)-
When you first load into a world, a mysterious water pillar is coming down from the skies… (x: 0 z: 0) 
If you swim up that water pillar, you will eventually find floating islands, one of these islands contain the most powerful block in the game… THE COMMAND BLOCK 
On that island, you will find the Command Block levitating on an Ancient Command Block Levitator (more on that later). 
If you place it, how do you break it? You need to forge a "Command Block Destroyer™" in a Smithing Table: 
(Press F6 to disable warnings)
The command block can emit a redstone level of 15 if you place it on an Ancient Command Block Levitator. 
Ancient Command Block Levitator Crafting Recipe:
why is this useful? You can take away the command block and then the signal goes away. There is only one Command Block in the game, so if you have it, you're the only one who can activate an Ancient Command Block Levitator.
Survival Friendly Command Block is an add-on to Cracker's Wither Storm Mod, although it is not required. 
+Feature Removes all the Rundown Houses and replaces them with the Floating Ruins.
