Original Dreyer Bearing Plot

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Throughout most of the war, the Dreyer Fire Control Tables had a distinctively clumsy plotting system for plotting bearings versus time. It first appeared in the Original Dreyer Table and was replicated with only minor improvements in successive Marks. This design never had a name, but for the sake of discussion on this site, we dub it the Original Dreyer Bearing Plot.

General Characteristics

These early bearing plots were wide (16 inches in Royal Oak's Mark IV* Dreyer Table)[Citation needed] and offered an excessively long length of paper. A fairly simple Bearing Rate Grid positioned over the plot could be angled to judge the bearing rate, and after the original Dreyer table, this grid's action was combined with one or two deflection drums which related the bearing rate to a dumaresq deflection and/or a gun deflection at the present range. As initially provided, however, the common characteristics seem to have been that the plot was overly large in both width and length and featured little to no integration with the other components on the table. More vitally, it is not clear that there existed in these early installations of this plot any means of adding in spotting corrections or transmitting the total gun deflection in any mechanical manner at all.

War-time Refinements

It is possible that the bearing rate grids may have been improved to the model depicted in the Standard Bearing Plots of the 1918 Dreyer Table Handbook and perhaps that pattern's Deflection Totaliser was also retrofitted.


Successive Patterns

The bearing plot was clearly seen as one of the weakest aspects of the Dreyer tables.[Citation needed] After Jutland, complaints had reached a crescendo and a replacement devised in the form of the Standard Bearing Plot. This new plot boasted several improvements, primarily offering a smaller plot and new devices to add in spotting corrections and mechanise deflection output from the table. However, before the standard bearing plot had lived up to the name by being widely deployed, in 1918[Citation needed] Gyro Director Training Gear was tested in prototype, and offered compelling advantages centred on an even better optimisation of plotting real estate and integration to both Dreyer table and the director. The original Dreyer bearing plot was belatedly replaced by G.D.T. gear which would serve into World War II.[Citation needed]

See Also



  • Brooks, John (2005). Dreadnought Gunnery and the Battle of Jutland: The Question of Fire Control. Oxon: Routledge. ISBN 0714657026. (on Amazon.com and Amazon.co.uk).
  • Admiralty, Gunnery Branch (1918). Handbook of Captain F. C. Dreyer's Fire Control Tables, 1918. C.B. 1456. Copy No. 10 at Admiralty Library, Portsmouth, United Kingdom.
  • Dreyer, Frederic; Usborne, Cecil through Gunnery Branch, Admiralty. (1913). Pollen Aim Corrector System, Part I. Technical History and Technical Comparison with Commander F. C. Dreyer's Fire Control System. P. 1024. in Admiralty Library, Portsmouth.
  • Elliott Brothers, London (1916). Captain F. C. Dreyer's Fire Control Apparatus, Mark IV. Copy 19 "as fitted in H.M.S. Royal Oak" at H.M.S. Excellent Library, Portsmouth, United Kingdom.