August 12, 2018, 19:34Steve Rodbro
4992B “Robustness” ... if that’s a word
I have been reading my way through the posts on this site, and admire all I am learning about these watches. I have seen several comments along the line of these watches being very robust, so many of them are suspected to gave survived since WWII.
I know that many of them were mounted in shock absorbing mounts and boxes, but was wondering about the watch itself ... did they have any special construction that differentiated them from the 992B that would increase their “robustness “? Like, maybe a heavier balance staff?
I weighed five of my 992B’s, and their average weight is 97 grams. My 4992B is 111 grams, a whole 14% higher than the average. I imagine most of this is in the case, with a bit also in the extra, sweep second wheel. I am wondering if anyone knows of specific differences that could contribute to making these watches tougher.
August 13, 2018, 03:57Donald Trumble
All the 992B derivatives have a well earned reputation for durability.
If memory serves the balance staff carries the same part number, begin by looking it up along with other interchangeable parts in the 1961 Hamilton Parts Manual here:http://library.ihc185.com/cata.../ham1961/ham1961.pdf
When that opens scroll down and be sure to bookmark it for easy reference or print your own copy! The copy stores can spiral bind it while you wait.
Lindell recently told me he would soon be selling a Military 992B with Military Markings right here on IHC, that is something you might consider for your collection, Lindell is easy to contact.
August 15, 2018, 15:23Jim Hester
I am not an expert on the details of the construction of these, but in general when the Department of Defense bought timepieces they started by issuing specifications that contractors had to follow in order for their timepieces to be accepted. This included requirements that the timepieces were able to survive shocks and extreme temperatures, that they keep time to a certain degree of accuracy, that they be able to provide the Department of Defense with repair manuals and spare parts for military watchmakers to keep them in good running condition, that they be able to resist rusting - especially Naval aircraft timepieces that were subject to getting salt water spray kicked up around them, etc. etc. Manufacturers then designed their timepieces that they were going to try to sell to the military under military contracts that would meet such requirements and not be so delicate as to break under war conditions, especially since they wanted to keep on selling their timepieces to the military and getting a reputation for fragile timepieces would mean the other makers would get to increase their sales to the military who were buying enormous numbers of timepieces.