The assembled barrel is fitted onto the main plate.

UK watchmaker showing service of Omega Speedmaster - barrel fitted to plate

The ratchet wheel is mounted on the square end of the barrel arbor.  When this wheel is turned, the arbor turns and draws the mainspring into the middle of the barrel, thus charging the watch.

UK watchmaker showing service of Omega Speedmaster - ratchet wheel fitted to barrel arbor

This is the second wheel and is typical of all train wheels in that it has a steel centre gear fitted to a brass outer gear so that the two parts will turn together.  The steel gear meshes with the barrel teeth and this gear will turn once per hour. Condition is fine.

UK watchmaker showing service of Omega Speedmaster - second wheel review

And here a review of the bearing surfaces, again all good.

UK watchmaker showing service of Omega Speedmaster - second wheel review

When looking for pivot wear, the microscope is used and, although it’s not easy to capture the images, it is very easy to see wear such as this (from another watch) in the green circle where the pivot area is not parallel and may be seen to be worn.

UK watchmaker showing service of Omega Speedmaster -a worn pivot

The second wheel is fitted to the movement in the centre and extends through to the lower (dial) side.

UK watchmaker showing service of Omega Speedmaster - second wheel fitted

The following wheels are used to increase the rotational speed such that the escapement is rotating much faster than the barrel.  This is the third wheel and the steel gear is on the other side so, hidden.

UK watchmaker showing service of Omega Speedmaster - third wheel review

Pivots are fine as well.

UK watchmaker showing service of Omega Speedmaster - third wheel review

And fitted to the movement – its steel gear meshes with the brass gear of the second wheel and this turns approximately once every seven minutes.

UK watchmaker showing service of Omega Speedmaster - third wheel fitted

Then the fourth wheel.

UK watchmaker showing service of Omega Speedmaster - fourth wheel review

And, again the pivots are fine.  This has a very long pivot on the left which passes through the dial and the continuous second hand will be mounted here as it turns once per minute.  There is also an extended pivot on the right which will be used later for the driving gear of the chronograph.

UK watchmaker showing service of Omega Speedmaster - fourth wheel review

And fitted.

UK watchmaker showing service of Omega Speedmaster - fourth wheel fitted

There is one bridge that is fitted over all of these wheels but there is a little to add to that bridge first and it continues here.