Prison Architect: How to Prevent Tunnel escapes

Hi fellow Guild Guiders, This is my first Prison Architect strategy/guide and i have been playing P.A since like Alpha 13. Tunnel, not so new on the news, it happens when a prisoner dig through the toilet (i have no idea how they fit in there) with a tool, could be a spoon or a fork. Of course now you have the Failure Conditions which if you're prison have too many riot, and escape you get Sacked! How do you prevent Prisoner from Tunneling?

• Do Shakedown every now and then (mostly on Sleep schedule), i do mine on 12AM every 2 days, The Shakedown may disturb prisoners so not too frequent, Do it frequently until you stop finding tunnels then after that do it Periodically. 

• Place your cell block in the middle of the prison far away from fences. 

• Place double fence, where you confine your prison with fence then after a few blocks from the fence place another fence, that way you have a gap between the fences (fill it with concrete floor or asphalt to make it slower for them to dig), Fences are free so dont worry about going to negative money. 

• Perimeter walls, Expensive! I advise you to not use Perimeter fence when your money is low because its 200$/square, If you have a big and profitable prison the Perimeter fence can slow down tunneling to an extra day or even two.
• Monitoring Behavioral, Monitor a random prisoner every night see if they have a schedule of their own, If the prisoner relaxes a few hours before midnight then they sleep exactly at a time you should try to search them. In the morning if you are unsure about the prisoner being tunneling this is the perfect time, when they wake up hover over them to see the status of their Sleep need, if its maxed out then theres a chance that he didnt sleep that night but digging a tunnel

• Big Water Pipe are dangerous, prisoner can dig to a Big Water Pipe, it helps them from digging through dirt. they just crawl through the Big Water Pipe near the fence, from there they continue digging through dirt.
• Group Tunnels[UNCONFIRMED] is when 2 prisoner joins together(preferably the cell next to them) to tunnel together, that makes the tunneling faster.

So, helpful? Great. Get back to monitoring your prisoner.

   TIPS:

1. If a prisoner is frequent to digging a tunnel keep an eye on him, most likely he will dig again.
2. Frequent shakedown may lead to riot.
3. Place metal detector at every entrance of cell block, that way you can detect wether the prisoner has stole a spoon or fork.
4. Dog Patrols are helpful, they sometimes dig tunnel
5. When the prisoner escaped, catching him will he tricky, especially when you have a small map where the fence is a the border of the map.
6. Expand your land so your prisoner will have a long run after he escape