Opencast and Underground Mine Surveying
I own two working Wild GAK-1 gyros and have a third for spare parts.
The first unit is mated to an old-style T-2 that reads in grads and includes a B3 compass that reads in grads, a Wild illuminated target set and documentation. If memory serves me, the T-2 has an inverted image.
The second unit is mated with an old-style T-16 with an endless horizontal tangent screw, solar reticle and tubular compass and comes with a Wild target set and documentation. The gyro release screw sticks a little, but it is functional.
I have a spare T-16 with the gyro mount and a spare GAK-1 that does not work. All come in their original bullet cases and one unit has the original wooden shipping cases. I haven't fired them up in a couple of years so will need to run both of them up and check the instrument constants. The two converter boxes have the cabling to connect to an external battery. The T-16 unit has an instructor's "eyepiece" that allows two people to view the gyro marks during observations. I used the T-16 unit to map a corkscrewing stope in a Colorado silver mine.
I will post photos and detailed descriptions next week in the "For Sale" category and time permitting, I'll power them up and check the instrument constants.
Mr Gene Kooper, the old T16 type is more interesting to me but if push comes to shove the T2 which reads grades will do....both machines determine True North. The instructor's eyepiece is also desirable for me because I train junior surveyors too.