Which turned out to be the Only thing holding the (now) two halves of the bridge together!

The bridge is usually one piece, into which the barrel arbor is inserted from the top, with the barrel then fitted from underneath with the mainspring already lubed and fitted.
The winding hub which has the mainspring hook formed into it, is then located into the mainspring eye, then the arbor is screwed into the hub and the barrel cap fitted, which then holds it all together as an assembly.

Note that the arbor tightens up as the mainspring is wound!

What usually happens, due to wear, the bridge breaks next to the key square where the notch for the click spring is located, and the barrel now running in an oversized hole, then tilts over stopping the watch!

John

Way behind updating this topic now, so some more shots of the debris!

This is a side shot of the bridge showing the 'repaired' click spring!

John

And this was the mainspring barrel.
The middle has been chewed out and a plate soldered in to repair the centre bush!

Looks like the mounting for the Geneva stopwork took a hit at the same time, so got left off.

John

Apologies for the quality of some of the photo's, camera problems!

Next up was what was actually Inside the barrel!

Obviously the mainspring is broken, but take a closer look at the inner hook on the arbor!

John

This was the sorry mess the mainspring was in.
The barrel had actually been soldered with it in place if the blueing all over it was anything to go by!

Even a gorilla winding a spring in by hand wouldn't mess them this bad!

John

And this folks is the consequence of a busted mainspring!
Note the angle of the skew on the pinion teeth!

When the spring let go, the torque reaction whacked the barrel teeth into the pinion teeth so hard, it canted the barrel over in the pivot holes of the 'repaired' bridge, twisting the teeth as it went!

Some force for a tiny spring!

The 'peening over' of the end of the centre post, is a result of knocking the cannon pinion onto the key square too hard, and without a dust cap between the post and square.
As the square is usually not much bigger across the flats than the outer diameter of the post, this damage is typical.

John

The underside of the centre bridge!

Filed away to clear the centre wheel, which must have been flopping around and tilting enough in the worn holes to rub on it!

John

And this was being sported on the dial plate as a 'new' support for the modified mainspring barrel!

Actually the guy that did the repairs was either ahead of the Swiss at this point, or he copied a later movement design.

If the Swiss had done something similar with these movements in the first place, there'd be many fewer cripples knocking around today!

John

Nice imprint of vice (vise?) jaws on the balance cock!

Note the peened over retaining screws on the endstone cap!

John.

And the underside of it!

John

John, all I can say is, wow and thanks for sharing these images of this movement that's been around the block.

Roland.

Thanks Roland, a few more pic's to come yet as soon as I can make the time to edit everything.

I've tried every which way to replace the wreckage with another movement, but everything I've found or Ernie's sent, is either bust bad, or won't fit the case.

The movement is on the road to recovery though, but it'll be a long haul as most of the replacement parts I'm having to make by modifying bits from similar movements.
Thankfully I've plenty of 'bitzers' to draw on!

John