The different types of mechanical movements and how they work

On an American pocket watch, the layout of the plates tells you more than the brand name on the dial.

A full-plate movement hides most of the train under one large plate. Waltham and Elgin used this layout for decades. It is sturdy. It is also slower to disassemble, because the top plate comes off as one piece and the wheels have to be managed together.

A 3/4-plate movement leaves the balance and often part of the train visible under a smaller plate and a balance cock. Hamilton used this layout on the 992 and 992B. It is easier to inspect without a full strip, and it is the layout most railroad collectors already recognize.

A bridge movement uses separate bridges for the wheels. Many Swiss pocket watches are built this way. The work is the same: clean, peg the jewels, oil the pivots, and set the balance. The order of assembly is not the same as a full-plate American watch.

Hand-wound is the normal type on this bench. A few vintage wristwatches are automatics, and a few are chronographs. Quartz is a battery movement, not a spring movement. I replace batteries and clean those cases, but that is not a mechanical service.

If you can open the back, a photo of the movement is enough to say which of these it is. Send that photo with the enquiry on the Services page.