Omega 105.003 original shock tests…

[M'Bob]

I read that the Ed White tested by NASA survived a 40G shock test from six different directions. The ISO standard for watches to be deemed shock resistant calls for it to maintain timekeeping accuracy after a meter drop on to a horizontal wooden surface.

Two questions: what would be a reall-world example of a 40G shock? And, which of these two tests is more severe? Thanks.

 

[Geme81]

the 2 can be equivalent, all depends on the stopping distance, in other words the time it decelerates so the material on wich it impacts it is relevant.( 1 g = 9.81 m/s^2)
Imagine to drop a watch from 1 m and it decelerate in 2,5 cm it generate 40 g. If it decelerates in 1cm it will be 100 g...
CASIO G-SHOCK watches are famous to resist 10m drop and even higher depending on the model. (the name was defined according to ghis capability)
I hope to have answered
Geme

 

[Eve]

i would be also interested, what is the period of time (NASA tests), in which high-Gs effect the watch, and how it may vary with different period of time.

A human being can withstand pretty high G-forces if they are applied just for a short period of time, but withstanding even 7 G for longer period can lead to a black out or other problems. i understand that this probably donsnt directly apply to mechanical items, as there is no blood stream, what so ever. but i still wonder if this has an effect?

Edited: Jan 22, 2024

 

[Dash1]

M'Bob

after a meter drop on to a horizontal wooden surface.

Geme81

depends on the stopping distance, in other words the time it decelerates so the material on wich it impacts it is relevant.( 1 g = 9.81 m/s^2)
Imagine to drop a watch from 1 m and it decelerate in 2,5 cm it generate 40 g. If it decelerates in 1cm it will be 100 g

So the Speedmaster dropped from one metre onto a wooden surface would decelerate in well under 1cm and therefore the g force is much higher than the quoted 40g, right?

 

[Geme81]

Dash1

So the Speedmaster dropped from one metre onto a wooden surface would decelerate in well under 1cm and therefore the g force is much higher than the quoted 40g, right?

I don't have the deceleration profile to tell you the right answer but Yes, in general the shock due to a drop can be larger than the 40 g. As you mentioned perhaps the choice of selecting the wood as floor material was to mitigate a potemtial incredibly high g-load and to prevent the damage of the watch parts that directly impact. I would be interested if ther is a NASA official document used to define such tests.
Usually NASA do not leave any missed info or detail in defining such tests, it is common for them to document and justify by numbers all they do.
Do yo uhave perhaps a reference paper or document from NASA watches test campaign?

 

[M'Bob]

Dash1

So the Speedmaster dropped from one metre onto a wooden surface would decelerate in well under 1cm and therefore the g force is much higher than the quoted 40g, right?

Interesting. I don’t know when the ISO standard was implemented, but the ref. 105.003 was fitted with the Incabloc shock resistance. If you’re correct, this could mean that the NASA test for shock was less demanding than the standard test in the industry at the time. So either it wasn’t in place yet, or it was, and the engineers either didn’t access it, or thought it wasn’t specific enough for their needs?

 

[murph]

Dropped about a meter onto oak. I don’t wind it but the shatter pattern is clear. Thank god my floor is o.k.

 

[M'Bob]

murph

Dropped about a meter onto oak. I don’t wind it but the shatter pattern is clear. Thank god my floor is o.k.

The very sought after “light snowfall Ed White.”

 

[Caselock]

Ah, someone likes Hesalite-haze like I do....

 

[Olhenry56]

Geme81

the 2 can be equivalent, all depends on the stopping distance, in other words the time it decelerates so the material on wich it impacts it is relevant.( 1 g = 9.81 m/s^2)
Imagine to drop a watch from 1 m and it decelerate in 2,5 cm it generate 40 g. If it decelerates in 1cm it will be 100 g...
CASIO G-SHOCK watches are famous to resist 10m drop and even higher depending on the model. (the name was defined according to ghis capability)
I hope to have answered
Geme

I almost replied with a contradictory answer, until I caught my mistake (I carelessly conflated a 1m fall with a 1s fall). Had to brush off some of the cobwebs!