A dropwire secures the tire to the main wire.
Guillotine trap door trigger.
Lower left 4 triggers front side l shows eyebolt and back side r shows hinge.
Lower right tripwire secured to trigger and to the far end of the trap near gate.
Rooter lifting gates require that a hog use its nose.
Guillotine or sliding drop gates use a trip wire to trigger the door to fall.
Therefore it is extremely important that the trap be strategically baited to insure that most if not all of the pigs in a sounder have entered the trap.
Rooter lifting head gate on box trap.
Right outside of gate door.
Note handle at bottom to raise the gate.
Photo courtesy of texas agrilife extension.
I personally prefer the guillotine door as it generally has a bigger opening and it is positively closed with an active latch to prevent pigs from rooting.
Guillotine or drop style doors are called single catch doors because once the trap has sprung that is the door has closed no more animals can enter the trap until it is manually reset.