Difference between revisions of "Dreyer Table Mark I"

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(Some desperate formatting.)
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* Spotting handle to enter corrections
 
* Spotting handle to enter corrections
 
* Straddle correction hand (for corrections from a [[Dreyer Calculator]])
 
* Straddle correction hand (for corrections from a [[Dreyer Calculator]])
* [[Dreyer Fire Control Table#Gun Range Counter|Gun range counter]] (on the table)
+
* [[Gun Range Counter|Gun range counter]] (on the table)
 
* Commutator to relay gun range to control positions and conning tower
 
* Commutator to relay gun range to control positions and conning tower
* A flexible shaft to carry gun range to the deflection drums of the [[Dreyer Fire Control Table#Standard Bearing Plot|standard bearing plot]]
+
* A flexible shaft to carry gun range to the deflection drums of the [[Standard Bearing Plot|standard bearing plot]]
  
A hand-worked [[Dreyer Fire Control Table#Pedalling Clutch|pedalling clutch]] allowed the plotted range to be tuned without altering the gun range.
+
A hand-worked [[Pedalling Clutch|pedalling clutch]] allowed the plotted range to be tuned without altering the gun range.
  
 
===Range Plot===
 
===Range Plot===
The [[Dreyer Fire Control Table#Range Plot|range plot]] ran the entire width of the table in the back, with a [[Range Rate Grid|range rate grid]] positioned over it.  Worm shafts from the spotting corrector carried pencils to record the plotted and gun ranges on the paper.  As first created, the tables probably used a [[Dreyer Fire Control Table#Brownrigg Keyboard|Brownrigg keyboard]], but by 1918 they were being replaced by the [[Dreyer Fire Control Table#9 Key Range Typewriter|range typewriter]]<ref name=Brooks176/>.   
+
The [[Range Plot|range plot]] ran the entire width of the table in the back, with a [[Range Rate Grid|range rate grid]] positioned over it.  Worm shafts from the spotting corrector carried pencils to record the plotted and gun ranges on the paper.  As first created, the tables probably used a [[Brownrigg Keyboard|Brownrigg keyboard]], but by 1918 they were being replaced by the [[9 Key Range Typewriter|9 key range typewriter]]<ref name=Brooks176/>.   
  
  
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===Bearing Plot===
 
===Bearing Plot===
The ''Handbook for Capt F.C. Dreyer's Fire Control Tables, 1918'' indicates flatly that these were at some point provided with [[Dreyer Fire Control Table#Standard Bearing Plot|standard bearing plots]],<ref>''Handbook for Capt F.C. Dreyer's Fire Control Tables, 1918''.  pp. 13-15.</ref> but these units received such scant service before the introduction of [[G.D.T.|G.D.T. gear]] that it is hard to bank that many were actually fitted, not least to the humblest of Dreyer tables and the priority they would be afforded.  Moreover, as the old style bearing plot seen on the [[Original Dreyer Table|original Dreyer table]] was so large, and the [[Dreyer Fire Control Table#Deflection Totaliser|deflection totaliser]] pretty useless without [[Deflection Drums|deflection drums]], it is possible that Mark I Dreyer tables in practical World War I service were range-only.<ref>Brooks.  ''Dreadnought Gunnery and the Battle of Jutland''.  pp. 176-177.</ref>
+
The ''Handbook for Capt F.C. Dreyer's Fire Control Tables, 1918'' indicates flatly that these were at some point provided with [[Standard Bearing Plot|standard bearing plots]],<ref>''Handbook for Capt F.C. Dreyer's Fire Control Tables, 1918''.  pp. 13-15.</ref> but these units received such scant service before the introduction of [[G.D.T.|G.D.T. gear]] that it is hard to bank that many were actually fitted, not least to the humblest of Dreyer tables and the priority they would be afforded.  Moreover, as the old style bearing plot seen on the [[Original Dreyer Table|original Dreyer table]] was so large, and the [[Deflection Totaliser|deflection totaliser]] pretty useless without [[Deflection Drums|deflection drums]], it is possible that Mark I Dreyer tables in practical World War I service were range-only.<ref>Brooks.  ''Dreadnought Gunnery and the Battle of Jutland''.  pp. 176-177.</ref>
  
  
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|-
 
|-
 
| [[H.M.S. Hercules (1910)|''Hercules'']]
 
| [[H.M.S. Hercules (1910)|''Hercules'']]
| ???
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| Replaced the [[Original Dreyer Table]] used in this ship<ref>''Pollen Aim Corrector System, Part I. Technical History and Technical Comparison with Commander F. C. Dreyer's Fire Control System'', p. 12.</ref>
 
|  
 
|  
 
|-
 
|-
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*{{BibBrooksThesis}}
 
*{{BibBrooksThesis}}
 
*{{BibRobertsAnatomyDreadnought}}
 
*{{BibRobertsAnatomyDreadnought}}
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*{{BibUKTechnicalHistoryComparisonArgoAndDreyer}}
 
</small>
 
</small>
  

Revision as of 16:29, 21 August 2009

The Dreyer Fire Control Table Mark I was a downsized version of the earlier Mark III table, and probably first deployed in 1915.[1] With a footprint 23% smaller than the Mark III table's,[2] it could more comfortably fit within the smaller transmitting stations of the early dreadnought battleships and battle cruisers into which it was retro-fitted.

Particulars

The Mark I was entirely hand-worked. Although the Mark III table could fall back to a hand-worked mode[3], with the Mark I (and Mark I* tables, this was the only means of operation.

As no one has been able to locate a handbook for the Mark I tables produced in 1916,[1] most of what follows is from the 1918 Handbook for all Dreyer tables, and almost certainly reflects evolutionary change and refinement from the tables' initial installed state (e.g.: manner of plotting range cuts certainly changed between 1915 and 1917).

Dumaresq and Range Clock

A Dumaresq Mark VI* was fitted, with a manual means of setting own heading rather than the gyro-compass input.

Range Clock

An spring-driven Vickers Range Clock adapted by the addition of a follow-up pointer worked by an external chasing handle and by the removal of its range markings on its dial was provided near the dumaresq and acted solely as a variable speed drive. An external rate handle drove an indicator on the dial plate of the dumaresq which the operator sought to keep aligned with the enemy pointer as it set the rate on the clock. The rate handle also acted to skew the wires on the range plot's range rate grid to the proper angle.

The chasing handle drove the follow-up pointer on the clock face. This F.T.P. action passed changes in range on to the spotting corrector gearbox.

Spotting Corrector

The spotting corrector in the 1918 handbook appears just like any, with:

  • Output worm shaft for the plot range pencil holder
  • Spotting handle to enter corrections
  • Straddle correction hand (for corrections from a Dreyer Calculator)
  • Gun range counter (on the table)
  • Commutator to relay gun range to control positions and conning tower
  • A flexible shaft to carry gun range to the deflection drums of the standard bearing plot

A hand-worked pedalling clutch allowed the plotted range to be tuned without altering the gun range.

Range Plot

The range plot ran the entire width of the table in the back, with a range rate grid positioned over it. Worm shafts from the spotting corrector carried pencils to record the plotted and gun ranges on the paper. As first created, the tables probably used a Brownrigg keyboard, but by 1918 they were being replaced by the 9 key range typewriter[1].


Plotting Ranges 2,000 - 20,000 yards
(a +8,000 yard extended scale added later allowed plotting to 28,000 yards)
Scale 400 yards/inch (45 inches for plotting, plus perhaps 5-in margins)
Paper speed 2 inches / minute

Bearing Plot

The Handbook for Capt F.C. Dreyer's Fire Control Tables, 1918 indicates flatly that these were at some point provided with standard bearing plots,[4] but these units received such scant service before the introduction of G.D.T. gear that it is hard to bank that many were actually fitted, not least to the humblest of Dreyer tables and the priority they would be afforded. Moreover, as the old style bearing plot seen on the original Dreyer table was so large, and the deflection totaliser pretty useless without deflection drums, it is possible that Mark I Dreyer tables in practical World War I service were range-only.[5]


Deployment

In February, 1916 Dreyer was awarded £5,000 by the Ordnance Council for his contributions to fire control. A list was drawn up which indicated the "Ships in which Dreyer's Fire Control is fitted or being fitted." Under the heading "MARK I (Simple Mechanical Table...)" were listed the dreadnoughts Marlborough, Dreadnought, Bellerophon, Vanguard, Superb, St. Vincent, Collingwood, Temeraire, Neptune, Colossus, New Zealand, Australia, Erin and Inflexible.[6]

[TO BE CONTINUED - TONE]

Ship using Mark I table Date equipped Notes
Dreadnought mid 1916, perhaps by May 25[7] installed in fore TS
Colossus N/A
Hercules Replaced the Original Dreyer Table used in this ship[8]
Neptune  ???
Collingwood  ???
St. Vincent  ???
Agincourt  ???
Erin  ???
Bellerophon before Jutland[1]
Marlborough  ???
Superb  ???
Temeraire  ???
Australia  ???
New Zealand after Jutland[Inference][1]
Inflexible  ???
Invincible  ???

See Also

Footnotes

  1. 1.0 1.1 1.2 1.3 1.4 Brooks. Dreadnought Gunnery and the Battle of Jutland. p. 176.
  2. Handbook of Captain F.C. Dreyer's Fire Control Tables, 1918. p. 90.
  3. Handbook of Captain F.C. Dreyer's Fire Control Tables, 1918. p. 13.
  4. Handbook for Capt F.C. Dreyer's Fire Control Tables, 1918. pp. 13-15.
  5. Brooks. Dreadnought Gunnery and the Battle of Jutland. pp. 176-177.
  6. "With 'Extract from Recommendations of the Admiralty Members of the Ordnance Council at a Meeting 10.2.16 concerning Dreyer's award' in DRYR 2/1." Brooks. Dreadnought Gunnery at the Battle of Jutland. pp. 175-176.
  7. Roberts. Anatomy of the Ship: The Battleship Dreadnought. p. 31.
  8. Pollen Aim Corrector System, Part I. Technical History and Technical Comparison with Commander F. C. Dreyer's Fire Control System, p. 12.

Bibliography