1972 Day 'N Date ST-5501

A lot of Hamilton collectors draw a line in the sands of time at 1969.  This is the year Hamilton ceased manufacturing US-made movements in Lancaster PA.  Production was moved to Switzerland but models for the US continued to be produced.  However, all of the models in the 1970s featured Swiss-made calibers.  Considering a large proportion of the 1960's models featured Swiss-made movements, was the 1970's really that much different?  

Probably.

One of the big reasons the 1970's was so different was the design aesthetic changed dramatically - as did, I suppose, fashion in general.  It's not my favorite decade, to be honest, at least in men's fashion.

Watches in the 1970s can often be big and chunky... not to the scale of some of the tuna fish cans you find nowadays but the styling was much larger than the sleek designs of the 1960s.

Innovation continued though, and the 1970s introduced the first Electronic and Quartz models - not that I'm a huge fan of those either.

Hamilton introduced their first calendar models in the early 1950s but the first models to feature the day of the week were introduced in the1970s.  You could get Day and Date models with automatic (self winding), stem wound, and electronic movements.  One of the stem wound models was the Day 'N Date ST-5501.

 

The  Day 'N Date ST-5501 was first introduced in the 1972 catalog and it was presented in a stainless steel case with a quick change II movement.  Prior to the quick change movements, you had to advance the time to midnight in order to set the date.  It was tedious.  The quick change movements enabled you to pull the stem out partially and set the date or day by turning the crown.  The catalog indicates the watch as a red dial but the image doesn't do the dial justice.   The catalog image doesn't show a second hand, which is interesting - but it definitely does have one.  The model was also offered in 1973.

My Day 'N Date ST-5501 project watch arrived without it's original bracelet.  It looks like it's definitely had it's fair share of use and abuse.  I can't say I've seen too many other Hamilton watches with a red dial - this is a first for me.

The back of the case has the model number 800002-3 so the Day N' Date ST5501 could also be known by that number as well.   Although sometimes cases were shared between models so that's not a hard and fast rule.

This crystal has had the snot polished out of it.  It actually is dished inward like a shallow bowl, it's been that polished. 

With the back removed you can see the caliber 800 tucked inside.  This movement is based on an ETA 2769 caliber - helpful to know if you need to find a part.  The movement appears to tick but it's got some tension in the barrel and it's not running.  I don't see any watchmaker's marks inside the case to indicate it's been serviced before but I can see the train bridge is missing a screw... it's not inside so that's a little odd.  Where did it go?

The perimeter has a bit of rust thanks to water getting inside.  Some of it might come off in the ultrasonic but this is a good reminder to keep vintage watches far away from water - even if you think they're "waterproof".  If you see moisture inside the crystal, you need to open the watch and let it dry out immediately.

I need to pry out the levers that hold the dial feet in place.  You can see the two small tabs sticking out of opposing sides of the movement.  Now I can lift the hands and dial off.

Once the dial is out of the way you can see the business-end of the day and date complications.  The center day wheel will lift straight up and off the front of the movement.

 

The main plate gets a little more complicated now.  All of the bits on the left side of the movement drive the outer date wheel and the inner day wheel in opposing directions.  The date wheel rotates clockwise and the day wheel moves counterclockwise.   The bits on the right side of the main plate help to index the day wheel and includes the parts needed for the quick change setting.

Screw by screw, piece by piece, the various parts are removed so they can be thoroughly cleaned.

Great care has to be taken with the u-shaped spring that indexes the date wheel.  This part is always under tension and likes to disappear when you try to remove or install it.  Looking for this spring when it vanishes can double the length of time it takes to service this movement as you'll spend countless minutes on your hands and knees looking for it.

Once all the parts are removed from the front of the movement I can do the same to the back. This process is much easier and very familiar.   Pretty much every ETA sweep second movement has the same layout.  You can clearly see the ETA 2769 stamped on the main plate.

Everything is now cleaned and ready to be reassembled.  There are a lot more parts to this model than most vintage Hamiltons.  With care and patience they will all go back in place.

First I need to reassemble the basic movement.  This particular example has a very strange quirk.  With two screws in the train bridge, the wheels will lock up.  However, with only one screw, the wheels spin freely.  I could try to add a shim under the other screw but since it came missing a screw, perhaps that's the way it has always been?  Somehow I doubt it, but it is what it is unless I want to get a donor movement.

It's running very nicely and I should be able to reduce the beat error to near zero.  Notice the beat rate is 21,600 beats per hour - that's faster than the typical 18,000 BPH that most vintage watches have.  18,000 is five beats per second, just like One Mississippi, Two Mississippi, etc.  21,600 is six beats per second - a little more precise than 5.  High precision mechanical watches can beat as fast as 36,000 BPH - or 10 beats per second.  However for really high precision you'd need a quartz watch.

There... I'll leave it running a smidgeon fast.  Watches tend to settle down a little after they run for a while.

The dial goes back in place and now I can set the time forward until the day and date change.  They don't flip at the same time so I will set the hands at midnight once the day changes.

The reassembled movement goes back into the case.  It's much shinier now and runs great.

A new crystal completes the restoration.  I think the red dial is very interesting.  Probably more of a casual watch than a dress watch but it's definitely very cool.