Hello everyone!
The Weymouth-class - HMS Weymouth, HMS Dartmouth, HMS Yarmouth and HMS Falmouth - were the second group of the British Town-class light cruisers. They were the last British light cruisers without vertical armour and differed from the preceding Bristol-class by having a single-caliber armament of eight 152mm guns. The guns were a 50-caliber high velocity design that had disadvantages in terms of long-range accuracy compared with 45-caliber guns, so their use was discontinued after this class; otherwise, these ships were considered highly satisfactory. Although the four ships were built by four different private yards, there were virtually no discernible external differences above the waterline as built; this however might have something to do with photographic source material of poor quality and arbitrary labelling. Weymouth, Falmouth and Dartmouth had four shafts...
... only Yarmouth had twin-screw machinery. By 1914, the emergency conning station, which was open in the original design, had received a shelter.
In 1915, all four had their main topmasts removed, and by that time, they also had received rangefinders for their main guns fore and aft and a single 76mm HA gun between funnels No.2 and 3. HMS Dartmouth spent most of her service in the first world war in the Mediterranean...
... Falmouth and Yarmouth were with the Home Fleet most of the time. In 1916, all four received additional superstructure around the funnels and - if I read the period photographs correctly - an additional pair of searchlights. Falmouth was lost to a submarine torpedo in 1916, the only of her class to perish in the war.
HMS Weymouth was in the Mediterranean in 1915/6, but later that year joined the home fleet. She differed from her sisters by the greater extent to which her aft superstructure was modified; during her time in the Mediterranean, she was camouflaged somewhat like below (the only photograph I found of her in camo was only 150x250px, so more than a rough approximation was not possible)
In 1917, the three surviving units received director control for their main artillery, which necessitated stepping tripod legs to the foremast and restepping the fore topmast. The aft searchlights were relocated along the centreline.
In 1918, Weymouth and Dartmouth had a second 76mm HA gun mounted dead aft. Dartmouth had her CT removed as a weight-saving measure (that's what Conway says anyway; Friedman mentions all three retaining their CTs. I have not found a photograph of Dartmouth in 1918, so I just can't say; I tossed the dice and erased the CT).
Weymouth and Yarmouth were fitted with flying-off platforms forward in 1918. Weymouth apparently had her aft superstructure modified to the same shape as the other two in 1917 or 1918. According to period photographs, at least Weymouth got her main topmast back while she had her flying-off platform; for the others, I can't say, as Friedman claims all three did not get her main topmasts back before 1920, when the flying-off platforms were already gone again.
After the war, all three had their bridges rebuilt and extended; the flying-off platforms were removed, probably (but not certainly) before the main topmasts were re-installed on Yarmouth and Dartmouth.
Their main topmasts were re-installed between 1920 and 1924 at the latest, maybe earlier (see above); in this guise they served throughout the 1920s before they were scrapped towards the end of the decade. One of them received a prominent lattice tower while acting as a signals TS, but I have not found any reference as to how that looked; if anyone has a photograph, I draw it, but in the meantime, that's not really possible.
Any suggestions and additional sources are welcome!
Greetings
GD