Straps for vintage fixed wire lug trench or officer's wristwatches.
The earliest use of the term "trench watch" that I have seen is an advert in The Sketch" magazine dated 15 Dec 1915 by J W Benson of Ludgate Hill and Old Bond Street London. The advert illustrates only ladies bracelet watches but also mentions "Trench Watches in Silver Cases with leather strap from £2 . 2s."
From Thresher and Glenny advert 1916
The eminent military historian Dr. Spencer Jones told me that The phrase "a proper wristwatch" (to denote a smart looking officer) had certainly emerged by summer 1916. A smart looking officer, such as the one shown in the extract here from an advert by the leading London gentleman's outfitters Thresher and Glenny from 1916, would want to make sure that he had all the latest military kit; after all, his life might depend on that kit. So what would a wristwatch that an officer, or an NCO or "other ranks", was wearing in the summer of 1916 look like, and how did it differ from pre-war or civilian wristwatches?
It is of course impossible to know whether a wristwatch was actually used in the trenches purely from its appearance, but as the Great War progressed through 1915 and 1916 a number of features became increasingly important to the men at the front. Features that were of little importance to the civilian population, but became vital in the cramped, wet, muddy trenches, where operations were often conducted in darkness, and lights could not be shown for fear of attracting enemy fire.
Wristwatches were made before the Great War in small numbers, and watches from the pre-war period will certainly have been taken or pressed into service when the war broke out, either existing wristwatches or converted fob watches. There is a popular story that ladies had their fob watches converted into wristwatches to give to their man when he went off to war and that these are called "sweetheart watches", but I am not sure how much truth there is in this charming story. But these pre-war watches, whether they were converted fob watches or purpose made wristwatches, were not specifically designed to be used in the trenches.
The easiest way for watch manufacturers to satisfy the sudden increase in demand for wristwatches that arose during the Great War was to add small loops of wire, called "fixed wire lugs", to an existing design of small pocket watch so that it could be attached to a wrist strap. But the principal idea of a wristwatch was to enable the time to be easily read without using both hands, so wristwatches were made with "open face" cases. This presented a problem in that existing Lépine or open face watches had their crown at the 12 o'clock position and so were not ideal for for a wristwatch. When wristwatches are seen with the 12 o'clock at some unusual angle, this is often a sign that the watch was not actually manufactured as a wristwatch but was converted some time later, usually by a local jeweller.
Pocket watches called "savonnette" or "hunter", with a hinged metal cover that protects the crystal, had the dial arranged so that with the winding stem at 3 o'clock the seconds dial was at 6 o'clock. It was a simple matter for a manufacturer to take a savonnette movement and put it into a Lépine or open face case that had loops of wire attached to take a leather wrist strap. Note that this is not a "conversion" of a pocket watch, it is putting together parts that were already being made in a way that they normally wouldn't be assembled. The case was specifically made to be a wristwatch case, without a pendant at all or with a shorter one than for a pocket watch, and with fixed wire lugs for the wrist strap. These were the first true, purpose designed, wristwatches
1914 Borgel wristwatch