Rattling around the web, researching rescue tools, I came across

New York City Fire Department
FORCIBLE ENTRY REFERENCE GUIDE. December, 2006. TECHNIQUES AND PROCEDURES:

http://www.vententersearch.com/supplemental/fdny_fe.pdf

Why did I post this?:
Some day I may need or want to rescue someone. Or get out myself. And if you're going to rescue a damsel in distress it is best if you show that you know what your doing. No damsel worth rescuing wants a bumbling idiot. She can grow into that opinion after you're married.

It's pretty neat and I'm a curious ape descendant. Some of you are also curious sorts. I always wondered how they did it. Now I have some idea of how they do it.

Knowing how they do it, and knowing which locks they find hardest to get through, helps me select locks and design doors, windows to resist intruders. Just make sure you can get out and the FD can still get in. Good thing most burglars are wimps and most firemen aren't.

Finding out what tools they prefer to use from people who do this sort of thing daily gives me valuable insights and guides my selection of tools. Conclusion -- two strong people with irons, Halligan and flat-head axe, can get through almost anything. Just a matter of time and effort.

Pretty scary if you tend to worry about keeping people out. Let me assure you that knowing these techniques is not IMHO any great help to thieves because:
Using them is hard work, thieves are not known for their willingness to do a lot of hard labor, or they would have a job. Odds are if your house is well secured most burglars will move on to a less fortified home. Most homes that are broken into were left unsecured or had very easy to defeat locks.

Most of the tools used are large, heavy and expensive. Carrying around a 42" Kelly is going to attract attention. Most burglars can't swing that sort of cash and are reluctant to draw that sort of attention to themselves.

Many of the techniques require two people. Often one to hold the bar and another to swing a sledge or axe. Your average junkie looking for a quick score is not a team player.

Fire departments use specialized techniques to limit damage. A determined intruder could simply chainsaw through the wall on any wood frame house, or beat a hole with a sledge hammer through the wall of a masonry home. Wood or masonry backing a truck, preferably a stolen one because it is hard on the chrome, into most any house will pretty much guarantee entry. Locks keep the relatively honest people out.

Besides all that, I know that only the finest people come to this site, and all of you will only use your new found power for good. No doubt.