Today the going train mechanism stopped at 10:10am! Some of us woke up to a message on the team communication at 10:20am that the faces were still showing 10:10… Panic! By 10:35am, we had reached our first person to the top of the tower. The time was corrected and the clockworks set in motion again. What followed was the task of finding out what stopped it in the first place. This wasn’t a peaceful process as our grand old clock decided to have some fun at our expense and stop a few more times during this. Check it out in the video below.
Whenever we started the clock again it used to work fine for five to fifteen minutes and then the tick-tock sound of escapement began diminishing and finally it gets stuck.
Probable causes
We almost spent the whole day trying to figure out what might the problem be. Some of the changes made are-
- Increased the driving weight.
- Oiled gears of the going train as well as the gears at the dials.
- Tightening the bolts of the connecting rod between the escapement and pendulum.
- Adjusting the escapement arbor to change the distance between lantern pinion and the corresponding gear.
- Examining gear tooth profiles for signs of damage.
Solution
Bheem recognized that the clock was always getting stuck when the minute hand was at around 10 minutes mark. Aman found that the rod connecting the going train and chiming train was stuck. The clock stopped because the 4 petal cam wasn’t able to push the rod up. This happened at around 10 minutes only as the cam had enough height. Connecting rod got stuck because of this part as shown in the pic.
This part is on the shaft connecting to the air brakes of the chiming train. It has pegs at the end which might act as the stopping mechanism to prevent the rod lifting up too much. As Anish and Harshit were working on the carillon assembly they might have it placed it vertical and somehow it got stuck. The simplest way to avoid this is to make its position horizontal like in this pic.
