Waltham 18s Model 1883

Waltham 18s Model 1883 | 17jewels.info - The Movement Archive

Waltham 18s Model 1883


For European standards, the american pocket watch caliber Waltham Size 18s Model 1883 is unusual, since it has got an attached and not integrated balance and still uses a key for winding and time setting, although it was made around 1900.

With a diameter of almost 44mm (18s in american size) it is very large and with a height of more than 10mm, it builds very high, too.

Waltham 18s Model 1883: base plate

base plate

There are no bearing rubies on this movement, only the balance wheel is ruby-beared, but not on the pase plate, see below.

Waltham 18s Model 1883: gear train

gear train

There’s the classical gear train with mainspring barrel, center minute wheel, third wheel, decentral seconds wheel at 6 o’clock and the escape wheel.

Waltham 18s Model 1883: side view of the gear train

side view of the gear train

The coarse lever matches neither the much better aesthetics of the whole movement, nor the aesthetics of a swiss pallet lever, but it has got pallets made of synthetic rubies.

Waltham 18s Model 1883: lateral lever

lateral lever

The balance wheel is located within a cylinder, which is attached to the upper gear train plate. Here, the only four rubies are used, two pairs or cap- and bearing of the balance wheel staff.

Waltham 18s Model 1883: inside the gear train plate, without cap jewel for the balance bearing

inside the gear train plate, without cap jewel for the balance bearing

In contrast to the not very filigree execution of the movement is the usage of a Breguet hairspring and the large bimetal screw balance. With that combination, the beating rate of 18000 A/h should be achived easily, especially, since a longn regulator arm is used for the adjustment.

Waltham 18s Model 1883: inside the gear train plate

inside the gear train plate

The balance is located under its own cock, which is attached on top(!) of the gear train plate.

Waltham 18s Model 1883: balance wheel missing

balance wheel missing

When the balance wheel is not mounted, you can see the lateral lever.

Waltham 18s Model 1883: Waltham 18s Model 1883: Dial side

Waltham 18s Model 1883: Dial side

On the dial side, you immideatly recognise the lack of a winding system. The movement is wound on the movement side with a key, and the time is set on the dial side by the same key. For 1900 pretty outdated!

In the lab

This work came gummed into the archive covered and received a simple service. However, after a few hours it can happen that it gets completely stuck; the lever pallets may be out of alignment.

Timegrapher result

Despite the Breguet hairspring, the rate values remained far below expectations, probably a tribute to the age and the somewhat antiquated construction method.
Whether the amplitude values are correct remains to be seen, as the lifting angle is not known, and therefore the standard value 52° was assumed.
The enormous beat error is noticeable, but unfortunately this cannot be easily adjusted.

horizontal positions
dial up +12 s/d 142° 8.9ms
dial down +1 s/d 139° 8.8ms
vertical positions
crown right (12 up) +61 s/d 160° >= 9.9ms
crown up (3 up) -73 s/d 138° >= 9.9ms
crown left (6 up) -93 s/d 171° >= 9.9ms
crown down (9 up) -19 s/d 138° >= 9.9ms

Technical data

Caliber:18s Model 1883
Size:18s''' (measured: 43,9mm)
Number of jewels:7
Escapement:Pallet lever
Balance types: bimetallic screw balance (two legs)
Shock protection(s): none
Balance bearing / direction hairspring:Clockwise
Moveable stud:no
Adjust mechanism:Long regulator arm
  • lever, escape wheel, seconds wheel, third wheel, center minute wheel
  • mainspring barrel
Construction type:pillar construction
Winding mechanism:key winding system
  • s (decentral seconds)
Inventory number:23016

Usage gallery

Waltham 18s Model 1883: Waltham pocket watch (grade sterling, year 1906)

Waltham pocket watch (grade sterling, year 1906)

This movement and pocket watch is a donation from the Ristow family to the movement archive. Thank you very much for your great support!