This is basically a knock off of NN4ZZ's plate, but on steroids
to handle the MonstIR. I have added a latch built using hardware
store parts. It should be fairly obvious how it works from the
photos. The only slightly clever thing I did was to add a toggle
spring that holds the latch either open or closed. Before the tower
is tilted up, a rope is passed through the eye allowing the latch
to be closed after the tower is up. The rope can then be pulled
free. To lower the tower, a 20 ft pole is used to push up the latch
and open it. You might see a previous attempt at a latch in the some
of the pictures using a gate latch. This approach was abandoned.

MONSTILT MonstIR Tilt Plate view with HDX5106 tower
complete view untilted
full tilt with boom and mast (1)
full tilt with boom and mast (2)
latch before installation
latch installed plate tilted
unlatched with plate in operating position
latch in latched position
latch closeup
overhead view latched
overhead view unlatched
partially complete 2
raw parts, unassembled