Come with me and help me make a repair of this short section of track. The track alignment and cross level is way out of whack (high tech railroadin term there...LOL), with track twist and track warp present. We will be correcting those anomalies today in this video, and your going to sit in the cab of my Jackson 6700 tamper and help me do it!
I don't normally let track get in this bad of shape. My tamper has been broke down and we've been waiting on parts, which had gotten back ordered then shipped to Columbus, Ohio, then to South Carolina where they got lost before they finally arrived here. And they were shipped from Erie Pa. about 4 hours north of us. So if we had known all that delay was going to happen I just would have drove the 4 hours to Erie a month ago and picked the parts up, but go figure.
Every dot on the computer screen as I'm plotting is called a station. 1 station = 5 linear feet of track. The meter in the center of the meter board you will be watching measures the amount of alignment deviation from what would be normal alignment. That center meter is the liner gauge. When the needle goes to the left of the center on the gauge, that means the track has to be shifted to the right.
We are working today in grade rail right reference and line rail left reference. That means our light carriage out front, the middle mask and the rear mask follower are all held against the left rail, by a spring on the light carriage and air cylinders on the masks.
The jackbeam (also sometimes called a clamp frame) picks the track up and also shifts the track right or left whatever is required. When the needles go to green, that means the voltages that are being measured have now equaled zero voltage, that zero voltage tells the machine to stop jacking or lining track. It's quite complicated to explain by typing exactly what all goes on to make this happen. Someday I'll make a video and get more detailed on how it all works.
The meter on the left of the center one shows me the left rail in reference to the right rail and vise versa for the right meter. When the left meter needle is low as you will see in the vid, that means the jackbeam will pick the left rail up to cross level it with the right rail, and when the voltages from the transducers equal zero, the jackbeam quits it's jacking function. Also remember we are on tangent track today so no super elevation will be added like if we were in a curve.
All the signals from the transducers and light receivers are processed through the tamper's logic system (you can see that logic system on the vid I made on calibrating a servo valve, link below). Then when the voltages register zero the servo valves stop sending hydraulic fluid to the jack beam's hydraulic cylinders which stops the jacking and lining process.
Jackson 6700 Tamper How to Calibrate a Jacking Servo Valve here: https://youtu.be/33pBsI5ymPk