Spotting Rules, 1916
November 30, 1916
This short document formalizes Royal Navy strategy for how to spot shellfire and bring it onto the target by correction. My copy is comprised through photographs of a black-and-white xerox copy located at the Admiralty Library (though it is worth noting, as I did above, that a copy of at least the 14 original pages exists at TNA).
To summarize this, the Royal Navy apparently decided that excessive innovation was being employed across the various ships of the fleet and that a systematized approach would better serve the fleet as a whole. While the RN was often criticized in the past for an excess of formality and dogma, this does not (to me) appear to be a citable example. Most of the rules are meant not to catalog a profusion of different cases to be considered, but to reduce a spotting officer's license to out-think himself. In effect, the rules boil down to a process of simple choices that reduce the possible complexity. I would think that the methods outlined would be particularly helpful in cases where the occasional salvo might not be spotted at all.
One aspect of this simplfication is that adjustments to range and to range rate were combined once straddling had been achieved. In practice, if a straddle (or succession of them) were followed by an over or a short, the spotting correction for range would be paired with a companion correction in rate of half its value. For instance, "Up 200, open 100" or "down 400, close 200". This synthesis was intended to reflect that a succession of straddles followed by an over or a short salvo must perforce result from a change in rate or from a slightly incorrect rate that has finally demonstrated itself.
Other rules formalize the process of obtaining an initial straddle in the fastest possible time -- a goal made more attractive by the perception that the Germans did this far better at Jutland earlier in the year. This process is also a simple one: first the deflection must be found so the salvoes fall in line with the target, and then an innovation of firing double salvoes was employed to create a "ladder" to bracket the target in range.