In the mid 1950s, the rather high building Durowe 1055, a windup movement with a diameter of 10 1/2 lignes, was released.
There are no other versions known of this movement, so it was most probably only short-lived on the market and replaced quicky by other calibers of the same size.
Like more or less all Durowe movements, the Durowe 1055 too, is very well executed, and of course all im portant bearings contain rubies. The escape wheel bearing is even covered on both sides with a cap jewel.
It has got a direcly driven center minute wheel, which was still state of the art that time.
The rest of the gear train follows the usual standard with the third wheel, large center seconds wheel (directly driven) and finally the filigree steel escape wheel with long axle.
The two leg Glucydur screw balance is unusually filigree executed. She is beared in two three-leg shock protections and beats with 18000 A/h.
The exact frequency is adjusted with a long regulator arm.
As escapement, a swiss pallet lever escapement is used.
The base plate is slanted on the outer rim to save some height. This was neccessiary, since at that time, flat watches were en vogue.
Besides that, you have the ususal execution on the dial side with the yoke winding system and the large, but also filigree setting lever spring.
In the lab
Timegrapher resultNot only the amplitude values are really impressive, also the low deviations, which in median, almost completely neutralize each other.
|dial up||+4 s/d||318°||1.9ms|
|dial down||+10 s/d||325°||1.9ms|
|crown right (12 up)||+4 s/d||305°||1.9ms|
|crown up (3 up)||+4 s/d||295°||2.2ms|
|crown left (6 up)||-14 s/d||284°||2.3ms|
|crown down (9 up)||-3 s/d||285°||2.0ms|
|Size:||10 1/2''' (measured: 23,3mm)|
|Number of jewels:||17|
Glucydur screw balance (two legs)|
3 legs (generic)|
|Balance bearing / direction hairspring:||Clockwise|
|Adjust mechanism:||Long regulator arm|
|Construction type:||solid construction|
|Winding mechanism:||yoke winding system|
|Setting lever spring:||4 hole(s)|
Flume: 1957 34