Dreyer Table Mark II

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The Mark II Dreyer Table was a variation of the Mark III Dreyer Table to evaluate the Argo Clock Mark IV by integrating it with the Dreyer range and bearing rate-plots. Little is known of the particulars of the table. Not even the outer dimensions are specified in the Handbook of Captain F.C. Dreyer's Fire Control Tables, 1918.[1] Confusingly, in 1914, these tables were referred to as "Mark III*" tables,[2] a designation later given to a different type of table.

Development

Little detailed information is known of these tables, as they are glossed over in the 1918 Handbook[3] to such a degree that it is difficult indeed to feel this wasn't a petulant effort to avoid highlighting the competitor's gear.[4]

Argo Clock

The Argo clock was connected so its clock range output caused a commutator to drive an electric motor which then interacted with the Dreyer table in the same manner as did the output shaft of the Dreyer-Elphinstone Range Clock in the Mark III table.[5]

Spotting Corrector

This was probably the same as any Mark III table of the same period.

Range Plot

This aspect of the table was probably much like that in the Mark III table, and evolved through its service life on the same path.

Bearing Plot

I think there was none at all. The 1918 Handbook explicitly says that a standard bearing plot was used, but this should be regarded as being suspect for reason of this device's short-lived tenure before the G.D.T. replaced it. A post-war Technical History volume says that the ships that had an Argo Clock had no time-and-bearing "table" at all... just a time-and-range one.[6]

Deployment

The Dreyer Handbook of 1918 lists some ships with Mark II tables, with those no longer in active service crossed out by hand at some later date, and those lost before promulgation not listed at all. Those appearing in that document are footnoted below[7]. Note that this source would not be expected to show Queen Mary or Audacious, as they were lost well before it was prepared. Excepting Orion, the shipboard installations appear to have existed by March 1914.[8]

This source is at slight variance with a schedule of ships listed as those to which Argo Clocks Mark IV would be shipped.[9] it is worth noting that this list was for bare Argo clocks and was a forecast of equipage.


Ship using Mark II table Date equipped Notes
Queen Mary[9] prior to 27 March, 1914[8]
Conqueror[7][9] prior to 27 March, 1914[8]
Orion[7]  ???
Ajax[7][9] prior to 27 March, 1914[8]
Audacious[9] prior to 27 March, 1914[8]
Centurion[7][9] prior to 27 March, 1914[8]

See Also

Footnotes

  1. Handbook of Captain F. C. Dreyer's Fire Control Tables, 1918. p. 90.
  2. Admiralty Weekly Order No. 972 of 27 Mar, 1914.
  3. Handbook of Captain F. C. Dreyer's Fire Control Tables, 1918. p. 15.
  4. The Mark II table receives two sentences in its description and no images whatsoever.
  5. Handbook of Captain F. C. Dreyer's Fire Control Tables, 1918. p. 15.
  6. Pollen Aim Correction System, Part I. p. 12.
  7. 7.0 7.1 7.2 7.3 7.4 Handbook of Captain F.C. Dreyer's Fire Control Tables, 1918. p. 3.
  8. 8.0 8.1 8.2 8.3 8.4 8.5 order NS14083/14, 27 March 1914, ADM 182/5, thanks to Mark Harris
  9. 9.0 9.1 9.2 9.3 9.4 9.5 Dreyer & Usborne. Pollen Aim Corrector System, Part I. Technical History and Technical Comparison with Commander F. C. Dreyer's Fire Control System, 1913. p. 3.

Bibliography

  • 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).
  • Brooks, John (2001). Fire Control for British Dreadnoughts: Choices of Technology and Supply. Unpublished PhD Thesis. London: Department of War Studies. King's College, London.
  • 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.
  • 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.