Dials on masts

[Guest R Pope]

This may be later than WW1, but here goes; Jane's 1924 shows American battleships with large dials on the cage masts, forward and aft. Some have them, some don't. Are they part of the fire control system? They have a single hand, and the face is numbered 1-10. They disappeared when the cage masts were deleted before WWII.

[Horace Bachelor]

They're range clocks, used to show the rate of change of range and deflection.

Not quite sure for who's use they were intended.

Here's a link about US Naval gunnery which may help.

http://www.gwpda.org/naval/usnfirec.htm

Cheers

Rich.

[Guest R Pope]

They must have been for relaying info to other ships in the line. Nobody in the turrets would have been able to see them! Their use was limited to a few years, so they must have been replaced by something better.

Thanks for the link!

[Guest richpics5174]

There's a photo of the French destroyer BOURASSQUE (or is it SIROCCO, there are different captions that I've seen as they are sister ships) sunk off Dunkirk and there's a large clock like object mounted at her bridge. This would be a range-clock as well right?

Cheers,

Richard

[dmilford]

The clock dials were to pass range information between consecutive ships in the line for co-ordinated firing on the same target. Deflection marks were also commonly painted on gun turrets to show deflection for the same reason.

Radio and lamp signals were also tried but found to be too slow whereas the dials proved quick and simple.