Although I don't own a trailer mounted pit, I have installed security on racing (car/motorcycle) trailers and some governmental vehicles with specialized applications.
There are several options you can put into place, some work well and others are easily defeated.
The simplest is the hitch lock, this basically keeps an honest person honest. These can be defeated by cutting the lock, or on some lighter weight trailers the latch or tongue can be unbolted from the trailer and the crook can just bolt a new one on, or just securely chain to their truck just to get it out of sight. Any chain, lock, or cable can be easily cut no matter where you place it. You have to remember that the majority of these thieves are not amateurs because this is a specialized market or they cut it into scrap and they have probably done this many times before. Statistics show very few are ever recovered, so your best defense to to realize someone will attempt to steal it at some point.
Anther option is if the trailer is parked at a building with a security system, the use of a magna-pull can be incorporated into the security system. A magnetic receptacle is mounted on the trailer on the closest point to the building. If it is not parked near a building you can trench to a post and mount the pigtail in a waterproof box. Once the trailer is parked in place, the armored pigtail is inserted into the magnetic receptacle and the alarm can be activated. If the unit is moved the armored pig tail pulls loose and triggers the alarm, if the pigtail is cut the alarm also triggers. This works extremely well with alarms that allow partitioning of the security system, that way the rig can remain armed even when the building is disarmed.
Another option is that if the rig has it's own 12vdc power source you can install a simple security system with shock and leveling sensors. If the unit is tilted or is hit hard (like dropping on a ball or Pintle hook) the alarm will sound.
Most importantly, a good high resolution camera system in the building can lead to prosecution and quick recovery. But use great caution in not buying a cheap system here, there are many poor units out there.
Another option is the GPS Tracking alarm. There are many out there, Uplink, Find it Now USA, ect.... Again the unit would have to have it's own 12vdc power source to work. When the unit is tilted or moved it will send a text message that motion has been sensed. Using a computer or calling the company can give you the exact location of your unit. These can even be programed to send a message once a day, and included with the message is the location of the unit. Annual subscription costs are about $60.00 - $70.00 per year complete.
Incorporating several of these into your unit make an even greater level of security. Think of security as an onion, there are many layers of security to employ.
Magna-Pull Contact
Video security day mode as seen through a remote computer or cell phone.
Video security night mode as seen through a remote computer or cell phone.
Good luck and keep us posted.
