I picked up this interesting piece earlier today. It was made for the Italian Air Force by Universal Geneve and retailed by A. Cairelli Roma. The timer features a modified high beat (36.600) Valjoux 067 movement. The following is a description of how the timer was used (from Christie’s auction website): The luminous numerals indicate the distance travelled by a dropped bomb in hm (hectometer: 100 meters). The operator, knowing the launch altitude, would set the arrow at the corresponding distance. Then, he would use the crown to start the timer, and press the button once the hand reached the desired distance to stop it. When the bomb is dropped, one more push on the crown would set the hand in motion counterclockwise, thus starting the countdown to the moment the bomb would reach the ground. At this point, another push on the button would stop the timer, and a last activation of the crown would reset the hand.
Just came across this, found it in a rabbit hole I went down (thx to @VetPsychWars for the bomb timer tip) https://www.horobox.com/en/news-det...omb-timer-chronograph-pusher-mechanism---copy
Very cool piece of history, what is the case diameter? I imagine this has massive wrist presence, especially considering the extra width added by the crown trigger device.
Doesn't go on the wrist but next to the timing and aiming devices it was held in with a cradle. Some of the lesser models like the Zenith or Lip could pass under the Panerai radar regarding the case size but barely. The dial on the smallest of them is 42mm in diameter and if you were to buy a "strap" for the watch you'd be looking at a size between 28 and 32mm depending on the case design and maker... The general idea is same for all of them Start Stop Rewind Reset... What is curious is that these fetch crazy prices yet most of them ( unlike the UG) have bare and very simple mechanisms, first one i bought i thought it was missing pieces compared to a stopwatch i owned. Marvelous bits of WW2 tech.