Sea-Gull ST3621
Description
The chinese caliber Sea-Gull ST3621, a modern 16 1/2 ligne windup movement, is really spectacular, not only aesthetically. It is an enhanced clone of the ETA 6498 (ex Unitas 6498), a savonette caliber with crown at position 3 o’clock.
It instantly impresses by its nice decortations, the sun-ray- and the wave-decoration on the gear train bridge, the perleage on the base plate, the ornaments on the balance cock and the ultra long regulator arm.
base plate
Looking on the base plate shows its technically good design and execution, so all important bearings contain rubies, even for the minute wheel bearing.
Less impressive is the fact, that the perleage decoration was only made on the visible parts. Those parts of the base plate under the balance wheel cock or the gear train bridge are not decorated, as well, as the parts, which are covered by gears.
On the other hand, all parts fit perfectly together, I’ve hardly seen that anywhere before in this perfection!
gear train
The gears seem to be stamped only, but technically this is not a disadvantage, as the excellent timegrapher performance shows.
The construction is classical and consists of mainspring barrel, center minute wheel, third wheel, seconds wheel and escape wheel. Into the latter, a swiss pallet lever engages.
side view of the gear train
The golden-toned screw balance, probably made from Glucydur, is very beautiful. It is rather small and beats already with 21600 A/h.
The beat rate can be adjusted with an extra long regulator arm and a scale on the gear train bridge. What a pity, that the engravings of the scale and of the ornament on the balance cock are to terribly ugly made, maybe just with a black pen. Normally, this must have been made golden-toned!
poor finish of the escapement bridge
There are two additional aesthetic drawbacks: The escapement bridge below the balance wheel has got a very poor and crude finish, and the three screws on the ratchet wheel are fake!
Sea-Gull ST3621: Dial side
On the dial side, we have a perleage decoration everywhere. Very beautiful, again!
In the lab
Timegrapher result
In all positions, this movement runs within the chronometer specs, this is simply perfect!| horizontal positions | |||
|---|---|---|---|
| dial up | +5 s/d | 293° | 0.4ms |
| dial down | +6 s/d | 291° | 0.4ms |
| vertical positions | |||
| crown right (12 up) | +3 s/d | 274° | 0.4ms |
| crown up (3 up) | +-0 s/d | 261° | 0.0ms |
| crown left (6 up) | -1 s/d | 271° | 0.5ms |
| crown down (9 up) | +-0 s/d | 269° | 0.6ms |
Technical data
| Manufacturer: | Sea-Gull |
| Caliber: | ST3621 |
| Size: | 16 1/2''' (measured: 36,6mm) |
| A/h: | 21600 |
| lift angle: | 44° |
| Number of jewels: | 17 |
| Escapement: | Pallet lever |
| Balance types: |
Glucydur screw balance (two legs) |
| Shock protection(s): |
Incabloc |
| Balance bearing / direction hairspring: | Clockwise |
| Moveable stud: | yes |
| Adjust mechanism: | Long regulator arm |
| Construction: |
|
| Construction type: | solid construction |
| Winding mechanism: | yoke winding system |
| Setting lever spring: | 3 hole(s) |
| Attachment of setting lever: | screwed |
| Features: |
|
| Inventory number: | 23060 |