Vickers range clock: differenze tra le versioni

Versione delle 17:51, 27 feb 2013

Versione delle 17:52, 27 feb 2013

Riga 6:

Il meccanismo consiste in un quadrante circolare con una lancetta singola, similmente ad un orologio.

The dial was engraved with the ranges in yards. The clockwork motor drove the pointer at a constant rate determined by a control on the right hand side of the device. This had a handle and its own dial, on which the rate of change of range (or "range rate") could be selected. This was calculated by other means, often by use of a [[Dumaresq]] or a time-and-range plot. A second rotating handle was fitted to the left of the clock. This was connected by gears to the dial plate, which rather than being fixed as on a clock, could be rotated. One turn of the handle would rotate the scale {{convert|100|yd|m|abbr=on}}100yd relative to the pointer. Thus the clock could be set to the initial range to a ship, or corrections could be made to update the reading without disturbing the mechanism.<ref>Brooks p.25-27</ref>

The range on the dial was the range as passed to gunners for firing, and as such included any corrections necessitated by time of flight, wind, etc., rather than being a true instantaneous record of distance to the enemy. By 1913, a second red pointer had been added to the original black one, attached to it by a friction grip, which could be adjusted relative to the original hand, so that one indicated true range and the other the corrected range for targeting.<ref> Brooks p. 53</ref>

Riga 20:

A small aperture on the dial would reveal a visual tell-tale which indicate that the clock's spring required winding.

==Note==

<references/>

==References==

==Bibliografia==

*{{cite book |title=Dreadnought Gunnery at the Battle of Jutland: The Question of Fire Control |last=Brooks |first=John |year=2005 |publisher=Frank Cass Publishers |___location=London |isbn=0-7146-5702-6 }}

*[http://www.hnsa.org/doc/br1534/ B.R. 1534 Handbook on Minor Fire Control Instruments, 1946] as transcribed at the Historic Naval Ships Association website