Difference between revisions of "Iron Duke Class Battleship (1912)"

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{| class="wikitable collapsible" border=2 cellpadding=2 cellspacing=0 style="margin: 0 0 1em 0.5em; background: #f9f9f9; border: 1px #aaa solid; border-collapse: collapse;" align=center;
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|-
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! colspan=6 align=left|Overview of 4 vessels
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|-
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| colspan=6 align=left|<small>Citations for this data available on individual ship pages</small>
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|-
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! align=center | Name
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! align=center | Builder
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! align=center | Laid Down
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! align=center | Launched
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! align=center | Completed
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! align=center | Fate
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|- align=left
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| {{Template:UK-Benbow}}
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|[[William Beardmore & Company]]
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|30 May, 1912
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|12 Nov, 1913
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|7 Oct, 1914
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|Sold Mar, 1931
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|- align=left
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| {{Template:UK-EmperorOfIndia}}
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|[[Vickers]]
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|31 May, 1912
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|27 Nov, 1913
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|10 Nov, 1914
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|Sunk 1931
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|- align=left
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| {{Template:UK-IronDuke}}
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|[[Portsmouth Royal Dockyard]]
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|12 Jan, 1912
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|12 Oct, 1912
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|10 Mar, 1914
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|Sold 2 Mar, 1946
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|- align=left
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| {{Template:UK-Marlborough}}
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|[[Devonport Royal Dockyard]]
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|25 Jan, 1912
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|24 Oct, 1912
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|2 Jun, 1914
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|Sold 27 Jun, 1932
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|}
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</div name=fredbot:ships>
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==Sea-keeping==
 +
Admiral [[John Rushworth Jellicoe, First Earl Jellicoe|Sir John R. Jellicoe]], who hoisted his flag in ''Iron Duke'' as Commander-in-Chief of the [[Grand Fleet]] in August, 1914, wrote to the [[Director of Naval Construction (Royal Navy)|Director of Naval Construction]], [[Eustace Henry William Tennyson d'Eyncourt, First Baronet|Eustace H. W. T. d'Eyncourt]] on 9 September:
 +
 +
<blockquote>I don't know if it is intended in the design but she is 18 inches by the head when complete with coal & the fore part of the thick belt is then 1 ft under water and it <u>very rarely sits above water</u>.  Surely there is something wrong about this.  There seems no way of curing it now, but future ships should not be the same.  She draws over 33 ft forward at this moment although I have got rid of 600 tons of oil.  She is very wet indeed.<br>The <u>next</u> point is the 6" gun ports.  They can't be used at sea because you can't open or shut them from inboard.  Consequently the main deck is absolutely underwater & there is no way of keeping it out.  Moreover the water finds its way down to the lower deck & it is quite a serious matter.  We are raising all main deck coamings, but it is a big job & meanwhile there is 6 inches of water or more constantly on the main deck.  The ship being down by the head & the scuppers all at the <u>after</u> end of compartments, the water won't run away.<br>We can't use the 2 after 6" guns at all, as the ship would get far too much water in.  The ports are now permanently closed.<ref>Jellicoe to d'Eyncourt.  Letter of 9 September, 1914.  D'Eyncourt Papers.  National Maritime Museum.  DEY/16.</ref></blockquote>
 +
 
==Radio==
 
==Radio==
According to the ambitions of 1909, these ships had [[Service Gear Mark II]] wireless upon completion.<ref>ARTS 1908 Wireless Appendix, p. 13.</ref>
+
According to the ambitions of 1909, these ships had [[Service Gear Mark II]] wireless upon completion.{{ARTS1908|Wireless Appendix, p. 13}}
 +
 
 +
==Searchlights==
 +
The ships were fitted with Crompton's 24-in twin projectors. In 1914, some or all of these were to be modified to permit 90 degree elevation for use in anti-aircraft work.{{ARTS1914|p. 52}}
  
 
==Armament==
 
==Armament==
  
 
===Main Battery===
 
===Main Battery===
This section is sourced from ''The Sight Manual, 1916'' except as otherwise noted.<ref>''The Sight Manual, 1916'', pp. 4, 23-26, 106, 108-109.</ref>
+
This section is sourced from ''The Sight Manual, 1916'' except as otherwise noted.{{TheSightM|pp. 4, 23-26, 106, 108-109}}
  
In April 1915, the 13.5-in Mark V(H) guns were in Mark II* mountings except in ''Benbow'', which had Mark III* mountings (though it is possible that later these were updated and all mountings acquired a second star).    The mounts were able to elevate 20 degrees and depress 5 degrees.  ''Benbow'' and ''Empress of India'' had 100 rounds per gun and ''Iron Duke'' and ''Marlborough'' 80 rounds plus 6 shrapnel.  Each gun had a 6-pdr sub-calibre gun for practice.<ref>All mount designations, ammunition allotments and sub-calibre gun data taken from ''List of H.M. Ships Showing Their Armaments, April 1915'' (ADM 186/164), pp. 2, 3.  [http://navweaps.com/Weapons/WNBR_135-45_mk5.htm Navweaps.com] differs on number of stars.</ref>
+
In April 1915, the 13.5-in Mark V(H) guns were in Mark II* mountings except in {{UK-Benbow}}, which had Mark III* mountings (though it is possible that later these were updated and all mountings acquired a second star).    The mounts were able to elevate 20 degrees and depress 5 degrees.  {{UK-Benbow}} and {{UK-EmpressOfIndia}} had 100 rounds per gun and {{UK-IronDuke}} and {{UK-Marlborough}} 80 rounds plus 6 shrapnel.  Each gun had a 6-pdr sub-calibre gun for practice.<ref>All mount designations, ammunition allotments and sub-calibre gun data taken from ''List of H.M. Ships Showing Their Armaments, April 1915'' (ADM 186/164), pp. 2, 3.  [http://navweaps.com/Weapons/WNBR_135-45_mk5.htm Navweaps.com] differs on number of stars.</ref>
  
The sighting arrangements were similar to those in ''Tiger'' and the ''King George V'' class.
+
The sighting arrangements were similar to those in {{UK-Tiger}} and the ''King George V'' class.
  
 
The sights were cam-worked and limited to 15 degrees elevation, but the central sights had "20 degree super-elevation strips".  Additionally, 6 degree super-elevation prisms would have been provided by 1916.  The deflection gearing constant was 61.3, with 1 knot equalling 2.51 arc minutes, calculated as 2500 fps at 5000 yards.
 
The sights were cam-worked and limited to 15 degrees elevation, but the central sights had "20 degree super-elevation strips".  Additionally, 6 degree super-elevation prisms would have been provided by 1916.  The deflection gearing constant was 61.3, with 1 knot equalling 2.51 arc minutes, calculated as 2500 fps at 5000 yards.
Line 19: Line 70:
 
The side sighting scopes were 43.25 inches above and 39 inches abreast the bore.  The central scopes were offset 56.25 inches above and 42 inches abreast.
 
The side sighting scopes were 43.25 inches above and 39 inches abreast the bore.  The central scopes were offset 56.25 inches above and 42 inches abreast.
  
OOQ open director sights capable of 20 degrees elevation were to be fitted sometime following 1916.
+
O.O.Q. [[Open Director Sight]]s capable of 20 degrees elevation were to be fitted sometime following 1916.
  
The guns were capable of continual aim in all but heavy weather.  Gunlayer and turret trainer each used a single hand wheel.  Elevation was at 5 degrees per second was achieved by just a single revolution of the hand wheel &mdash; a final increase in sprightliness over ''King George V'' and ''Lion'' classes. <ref>Brooks.  ''Dreadnought Gunnery and the Battle of Jutland'', pp. 45-46.</ref>
+
The guns were capable of continual aim in all but heavy weather.  Gunlayer and turret trainer each used a single hand wheel.  Elevation was at 5 degrees per second was achieved by just a single revolution of the hand wheel &mdash; a final increase in sprightliness over ''King George V'' and ''Lion'' classes.{{BrooksDGBJ|pp. 45-46}}
  
 
===6-in Battery===
 
===6-in Battery===
The ships mounted twelve 6-in Mark VII guns in P VIII mountings, two on the main deck and ten on the upper deck.<ref>''List of H.M. Ships Showing Their Armaments, April 1915'' (ADM 186/164), p. 2.</ref>
+
The ships mounted twelve 6-in Mark VII guns in P. VIII mountings, two on the main deck and ten on the upper deck.<ref>''List of H.M. Ships Showing Their Armaments, April 1915'' ({{TNA|ADM 186/164}}), p. 2.</ref>
 +
 
 +
After the [[Battle of Jutland]], when alterations to increase protection forced weight-savings to compensate, the ammunition allotment for these guns was to be reduced to 140 rounds per gun and 6 shrapnel rounds.{{GFGTO|No. 167, part 5}}
  
 
===Other Guns===
 
===Other Guns===
* Four 3-pdr Hotchkiss guns on Mark I* mountings on the flying deck.<ref>''List of H.M. Ships Showing Their Armaments, April 1915'' (ADM 186/164), p. 2.</ref>
+
* Four 3-pdr Hotchkiss guns on Mark I* mountings on the flying deck.<ref>''List of H.M. Ships Showing Their Armaments, April 1915'' ({{TNA|ADM 186/164}}), p. 2.</ref>
* One 3-in Mark I gun on a Mark II H.A. mounting on the shelter deck.<ref>''List of H.M. Ships Showing Their Armaments, April 1915'' (ADM 186/164), p. 2.</ref>
+
* One 3-in Mark I gun on a Mark II H.A. mounting on the shelter deck.<ref>''List of H.M. Ships Showing Their Armaments, April 1915'' ({{TNA|ADM 186/164}}), p. 2.</ref>
 +
 
 +
Immediately before the start of war, the 3-pdr Mark I* mountings on {{UK-IronDuke}} and {{UK-Marlborough}} (at least) were be given spring eyepieces.{{AWO1914|179 of 24 July, 1914}}
  
 
===Torpedoes===
 
===Torpedoes===
Line 36: Line 91:
  
 
===Range Dials===
 
===Range Dials===
As of 1920, all four ships were equipped with a [[Range Dial Type B]] and a [[Range Dial Type C|Type C]].<ref>''Manual of Gunnery of H.M. Fleet, Volume III, 1920'', p. 44.</ref>
+
As of 1920, all four ships were equipped with a [[Range Dial Type B]] and a [[Range Dial Type C|Type C]].{{UKManGun1920III|p. 44}}
 +
 
 +
===Phones and Voicepipes===
 +
In early 1914, the {{UK-IronDuke}} (at least) had a voicepipe between {{TS}} and {{GCT}}.{{AWO1914|1012 of 9 Apr, 1914}}
 +
 
 +
By mid-1918, it was approved to fit [[Pattern 333X Navyphones|Pattern 3331 Navyphones]] with loud-sounding bells in the auxiliary machinery compartments of [[Lion Class Battlecruiser (1910)|''Lion'']] and [[Orion Class Battleship (1910)|''Orion'']] classes and later where existing navyphones have proven ineffective.{{ARTS1917|p. 233}}
  
===Phones===
 
 
====Main Battery====
 
====Main Battery====
  
 
====Secondary Battery====
 
====Secondary Battery====
[[File:ARTS1913Plate55.jpg|thumb|300px|'''Navyphones for 6-in Fire Control'''<br>As shown in ''Annual Report of the Torpedo School, 1913''. ]]
+
[[File:ARTS1913Plate55.jpg|thumb|300px|'''Navyphones for 6-in Fire Control'''{{ARTS1913|Plate 55}}]]
 
Each of the six 2-gun groups was on its own navyphone circuit, feeding a [[Pattern 2464 Navyphone]] for the group officer as well as a pair of [[Telaupad]]s for each gun.  These led to six 2-way C.O.S.es in the 6-in TS which would dictate whether the given 6-in group's phones were tied to either
 
Each of the six 2-gun groups was on its own navyphone circuit, feeding a [[Pattern 2464 Navyphone]] for the group officer as well as a pair of [[Telaupad]]s for each gun.  These led to six 2-way C.O.S.es in the 6-in TS which would dictate whether the given 6-in group's phones were tied to either
 
# the [[Pattern 2463 Navyphone]] and its associated [[Pattern 2465 Navyphone|Pattern 2465 transmitter]]
 
# the [[Pattern 2463 Navyphone]] and its associated [[Pattern 2465 Navyphone|Pattern 2465 transmitter]]
Line 49: Line 108:
  
 
===Rangefinders===
 
===Rangefinders===
A drawing of the ship in Burt's ''British Battleships'' seems to imply that initially, each turret carried a 9-ft rangefinder in its roof.<ref>Burt. ''British Battleships'', pp. 194-195.</ref>
+
A drawing of the ship in Burt's ''British Battleships'' seems to imply that initially, each turret carried a 9-ft rangefinder in its roof.{{Burt1986|pp. 194-195}}
  
The {{TCT}} rangefinder, initially a 9-foot instrument of unknown model, sat on an M.Q. 8 mounting.<ref>Annual Report of the Torpedo School, 1918'', p. 175.</ref>
+
The {{TCT}} rangefinder, initially a 9-foot instrument of unknown model, sat on an [[M.Q. 8]] mounting.{{ARTS1918|p. 175}}
  
In 1916-1917, a "medium-base" length rangefinder was added over the conning tower.<ref>Burt. ''British Battleships'', p. 197.</ref>
+
In 1916-1917, a "medium-base" length rangefinder was added over the conning tower.{{Burt1986|p. 197}}
  
 
Sometime, likely not before 1918, these were to be upgraded to 15-foot instruments, with new armoured hoods and racers and training driving the hood directly rather than through the rangefinder mounting.  These rangefinders lacked hand-following gear to facilitate in transmission of range cuts, and when it was considered as an addition around 1917, space concerns were causing issues.{{ARTS1917|p. 198. (C.I.O. 481/17)}}
 
Sometime, likely not before 1918, these were to be upgraded to 15-foot instruments, with new armoured hoods and racers and training driving the hood directly rather than through the rangefinder mounting.  These rangefinders lacked hand-following gear to facilitate in transmission of range cuts, and when it was considered as an addition around 1917, space concerns were causing issues.{{ARTS1917|p. 198. (C.I.O. 481/17)}}
  
By 1918, two additional 9-foot instruments were also to be provided for torpedo control, abreast the captain's sea cabin, except on ''Iron Duke'', where they were placed on either side of the lower chart house platform, displacing a pair of 23-in signalling searchlights to the compass platform.{{ARTS1918|p. 177}}
+
By 1918, two additional 9-foot instruments were also to be provided for torpedo control, abreast the captain's sea cabin, except on {{UK-IronDuke}}, where they were placed on either side of the lower chart house platform, displacing a pair of 23-in signalling searchlights to the compass platform.{{ARTS1918|p. 177}}
  
By 1918, the ships had:<ref>Burt. ''British Battleships'', p. 193.</ref>
+
By 1918, the ships had:{{Burt1986|p. 193}}
 
* two 25-ft in turrets (presumably in "B" and "X")
 
* two 25-ft in turrets (presumably in "B" and "X")
 
* one 18-ft in a turret (presumably in "A" or "Y")
 
* one 18-ft in a turret (presumably in "A" or "Y")
Line 65: Line 124:
 
* one 9-ft in a turret (presumably in "Q")
 
* one 9-ft in a turret (presumably in "Q")
 
* one 9-ft (in forward superstructure, likely the one adding 1916-1917)
 
* one 9-ft (in forward superstructure, likely the one adding 1916-1917)
* one 15-ft in TCT
+
* one 15-ft in {{TCT}}
 
* two 9-ft in fore bridge (likely the torpedo control ones alluded to above)
 
* two 9-ft in fore bridge (likely the torpedo control ones alluded to above)
* two 2m F.T. 29<ref>length and type inferred from reported 6-ft 6-in base length and knowledge of B&S RFs.</ref> high-angle RFs
+
* two 2m [[F.T. 29]]<ref>length and type inferred from reported 6-ft 6-in base length and knowledge of B&S R.F.s.</ref> high-angle RFs
  
In 1920-1, a 12-ft rangefinder was added over the {{TCT}} in the aft superstructure, and a "long-base" rangefinder added to the rear of "X" turret.  Between May 1928 and May 1929, ''Iron Duke'' had a "small" rangefinder added on a high platform on aft superstructure, possibly to make up for the wholesale removal of the T.C.T. from her and ''Marlborough'' in 1927.<ref>Burt. ''British Battleships'', p. 198.</ref>
+
In 1920-1, a 12-ft rangefinder was added over the {{TCT}} in the aft superstructure, and a "long-base" rangefinder added to the rear of "X" turret.  Between May 1928 and May 1929, {{UK-IronDuke}} had a "small" rangefinder added on a high platform on aft superstructure, possibly to make up for the wholesale removal of the T.C.T. from her and {{UK-Marlborough}} in 1927.{{Burt1986|p. 198}}
 +
 
 +
By 1921, the ships were equipped as follows:{{HRFs1921|p. 172}}
 +
* "A" turret: 25ft [[F.X. 2]] on [[M.G. 15]] mounting
 +
* "B" and "Q" turrets: 9ft [[F.T. 8]] on [[M.G. 3]]
 +
* "X" turret: 25ft [[F.X. 2]] on [[M.G. 17]] or [[M.G. 18]]
 +
* "Y" turret: 18ft [[F.T. 24]] or [[F.T. 25]] on [[M.G. 8]]
 +
* Fore bridge: two 9ft [[F.Q. 2]]s on [[M.P. 2]]s
 +
* Top of chart house platform: 9ft [[F.Q. 2]] on [[M.P. 2]]
 +
* Gun control tower: 9ft [[F.T. 8]] on [[M.G. 8]] inside, 15ft [[F.T. 24]] on [[M.G. 8]] on top/rear
 +
* Torpedo control tower: 15ft [[F.T. 24]] on [[M.Q. 8]]
 +
* After superstructure: 2m [[F.T. 29]] on [[M.T. 6]]
  
 
===Evershed Bearing Indicators===
 
===Evershed Bearing Indicators===
 
All four units were likely fitted with this equipment before late 1914.{{INF}}<ref>They are not mentioned in the pertinent section of ''Handbook for Fire Control Instruments, 1914''</ref>   
 
All four units were likely fitted with this equipment before late 1914.{{INF}}<ref>They are not mentioned in the pertinent section of ''Handbook for Fire Control Instruments, 1914''</ref>   
  
However, it is clear that all 6-in guns had a bearing indicator fitted.{{ARTS1913|p. 102}}  This strongly implies that a rich installation supported the main battery at least.
+
However, it is clear that all 6-in guns had a bearing indicator fitted.{{ARTS1913|p. 102}}  This strongly implies that a rich installation supported the main battery at least. However, at Jutland, {{UK-IronDuke}} experienced confusion in her 6-in battery as to which enemy destroyer was being targeted.{{UKJutlandOD|p. 63}}
  
 
Otherwise, one might reasonably assume the particulars resembled those of the [[King George V Class Battleship (1911)|''King George V'' class]].{{INF}}
 
Otherwise, one might reasonably assume the particulars resembled those of the [[King George V Class Battleship (1911)|''King George V'' class]].{{INF}}
 +
 +
In 1917, it was approved that capital ships of [[H.M.S. Dreadnought (1906)‎|''Dreadnought'' class]] and later should have Evershed equipment added to their {{CT}}, able to communicate with either the fore top or the G.C.T..  If there were not enough room in the C.T., a bearing plate with open sights and 6-power binoculars would be added to the C.T..{{ARTS1917|p. 230}}
 +
 +
Also in 1917, it was decided that all directors were to be fitted with receivers and, "as far as possible", ships were to have fore top, {{GCT}} and controlling turrets fitted to transmit as well as receive, though this was noted as being impossible in some earlier ships.  While it would have been nice to have the {{CT}} able to transmit bearings to the 6-in guns, it was decided not to do this for reasons of space.{{ARTS1917|p. 230}}
  
 
===Mechanical Aid-to-Spotter===
 
===Mechanical Aid-to-Spotter===
Line 82: Line 156:
 
* one on each side of the foretop, driven by flexible shafting from the Evershed rack on the director
 
* one on each side of the foretop, driven by flexible shafting from the Evershed rack on the director
 
* one on each side of the [[Gun Control Tower]] employing an electrical [[F.T.P.]] system.
 
* one on each side of the [[Gun Control Tower]] employing an electrical [[F.T.P.]] system.
As the need for such gear was apparently first identified in early 1916, it seems likely that these installations were effected well after Jutland.<ref>''The Technical History and Index: Fire Control in HM Ships, 1919'', pp. 25-6.</ref>
+
As the need for such gear was apparently first identified in early 1916, it seems likely that these installations were effected well after Jutland.{{FCHMShips|pp. 25-6}}
 +
 
 +
In 1917, it was decided that these should probably all have mechanical links from the director and pointers indicating the aloft Evershed's bearing.{{ARTS1917|p. 230}}
  
 
===Gunnery Control===
 
===Gunnery Control===
The control arrangements were as follows.<ref>''Handbook for Fire Control Instruments, 1914'', p. 7.</ref>
+
 
 +
[[File:HFCI1914Plate69.jpg|thumb|500px|'''Main Battery Turret Control'''{{HFCI1914|Plate 69}}]]
 +
 
 +
[File:HandbookFCInstruments1914Plate63.jpeg|thumb|500px|'''Turret Indicating Lamp & Gong Circuits'''{{HFCI1914|Plate 63}}]]
 +
 
 +
The control arrangements were as follows.{{HFCI1914|p. 7}}
  
 
====Control Positions====
 
====Control Positions====
Line 97: Line 178:
 
* Alternative positions aft (Groups 1 & 2 from one, group 3 from a second one)
 
* Alternative positions aft (Groups 1 & 2 from one, group 3 from a second one)
  
Some ships had {{COS}}es within the control positions so they could be connected to either {{TS}}.<ref>''Handbook for Fire Control Instruments, 1914'', p. 7.</ref>
+
Some ships had {{COS}}es within the control positions so they could be connected to either {{TS}}.{{HFCI1914|p. 7}}
  
 
====Control Groups====
 
====Control Groups====
Line 120: Line 201:
 
[[File:HandbookFCInstruments1914Plate97.jpg|thumb|300px|'''Firing Circuits'''<ref>As shown in ''Handbook for Fire Control Instruments, 1914'', Plate 97. </ref>]]
 
[[File:HandbookFCInstruments1914Plate97.jpg|thumb|300px|'''Firing Circuits'''<ref>As shown in ''Handbook for Fire Control Instruments, 1914'', Plate 97. </ref>]]
  
The ships were fitted with a cam-type tripod-type director in a light aloft tower on the foremast along with a directing gun in 'X' turret.<ref>''The Director Firing Handbook, 1917''.  pp. 88, 142.</ref>{{ARTS1913|Plate 56}}
+
The ships were fitted with a cam-type tripod-type director in a light aloft tower on the foremast along with a directing gun in 'X' turret.{{DirectorH|pp. 88, 142}}{{ARTS1913|Plate 56}}
  
The main battery could be divided into forward ("A", "B" and "Q") and aft ("X" and "Y") groups for split director control.<ref>''The Director Firing Handbook, 1917'', p. 88.</ref>
+
The main battery could be divided into forward ("A", "B" and "Q") and aft ("X" and "Y") groups for split director control.{{DirectorH|p. 88}}
  
A {{COS}} in the {{TS}} afforded these options:<ref>''The Director Firing Handbook, 1917''.  p. 88.</ref>
+
A {{COS}} in the {{TS}} afforded these options:{{DirectorH|p. 88}}
 
# All turrets on aloft tower
 
# All turrets on aloft tower
 
# All turrets on directing gun
 
# All turrets on directing gun
 
# Forward group on aloft tower, aft group on directing gun
 
# Forward group on aloft tower, aft group on directing gun
 +
 +
The turret [[Elevation Receiver]]s were pattern number H. 1, capable of matching the 20 degree elevation limit of the mountings.  The [[Training Receiver]]s were the [[Single Dial Turret Training Receiver|single dial type]], pattern number 6 in {{UK-Benbow}} and pattern number 5 in the others.{{DirectorH|pp. 144, 145}}
  
 
====Secondary Battery====
 
====Secondary Battery====
The ships had a pair of directors fitted to port and starboard on the forward superstructure to direct the 6-in broadside guns.  [[H.M.S. Marlborough (1912)|''Marlborough'']]'s were pedestal-mounted, and the others tripod-mounted.<ref>''The Director Firing Handbook, 1917''pp. 143.</ref>
+
The ships had a pair of directors fitted to port and starboard on the forward superstructure to direct the 6-in broadside guns.  [[H.M.S. Marlborough (1912)|''Marlborough'']]'s were pedestal-mounted, and the others tripod-mounted.{{DirectorH|pp. 143}}
 +
 
 +
The [[Elevation Receiver]]s on the guns were 6-in P. VIII Type with electrical tilt correctors, Pattern F.C. 1, capable of 14 degrees elevationThe [[Small Type Training Receivers]] were pattern number 18.{{DirectorH|p. 144, 146}}
  
 
===Transmitting Stations===
 
===Transmitting Stations===
Like [[H.M.S. Tiger (1913)|''Tiger'']] and ''possibly'' later ships,{{INF}} these had a TS for the main battery and another for the 6-in secondary battery.<ref>''Handbook for Fire Control Instruments, 1914'', pp. 6-7.</ref> It is not clear to me whether the secondary battery's TS had a Dreyer table.
+
Like {{UK-Tiger}} and ''possibly'' later ships,{{INF}} these had a {{TS}} for the main battery and another for the 6-in secondary battery.{{HFCI1914|pp. 6-7}} It is not clear to me whether the secondary battery's TS had a Dreyer table.
  
 
===Dreyer Table===
 
===Dreyer Table===
In June 1918, ''Marlborough'' had a [[Mark I Dreyer Table]] while the other three units had [[Mark IV Dreyer Table]]s<ref>''Handbook of Capt. F.C. Dreyer's Fire Control Tables'', p. 3.</ref> and all had been provided [[Dreyer Turret Control Table]]s.<ref>absent from list in ''Handbook of Capt. F.C. Dreyer's Fire Control Tables'', p. 3.</ref>  The disparity in Dreyer Marks creates a loose impression that all ships were initially given Mark I tables and for some reason ''Marlborough'' missed her chance for an upgrade, perhaps due to her damage at the [[Battle of Jutland]].
+
In June 1918, ''Marlborough'' had a [[Mark I Dreyer Table]] while the other three units had [[Mark IV Dreyer Table]]s{{DreyerH|p. 3}} and all had been provided [[Dreyer Turret Control Table]]s.<ref>absent from list in ''Handbook of Capt. F.C. Dreyer's Fire Control Tables'', p. 3.</ref>  The disparity in Dreyer Marks creates a loose impression that all ships were initially given Mark I tables and for some reason ''Marlborough'' missed her chance for an upgrade, perhaps due to her damage at the [[Battle of Jutland]].
  
At some point, the ships each received  [[Dreyer Turret Control Table]]s, but it is unclear when and whether each turret received one or simply the two control position turrets.<ref>''Handbook of Capt. F.C. Dreyer's Fire Control Tables'', p. 3.</ref>
+
At some point, the ships each received  [[Dreyer Turret Control Table]]s, but it is unclear when and whether each turret received one or simply the two control position turrets.{{DreyerH|p. 3}}
  
 
===Fire Control Instruments===
 
===Fire Control Instruments===
Continuing the pattern established in the [[Colossus Class Battleship (1910)|''Colossus'' class]], all 4 units used [[Vickers F.T.P. Fire Control Instruments Mark III|Vickers F.T.P. Mark III]] range and deflection instruments to the gun sights (except Mark III* in the 6-in {{TS}} panels) and [[Barr and Stroud]] (probably Mark II* or later{{INF}}) instruments for other purposes.<ref>''Handbook for Fire Control Instruments, 1914'', pp. 72.</ref>
+
[[File:HFCI1914Plate64.jpg|thumb|300px|'''Indicator Lamp and Gong Circuits'''{{HFCI1914|Plate 64}} ]]
 +
 
 +
Continuing the pattern established in the [[Colossus Class Battleship (1910)|''Colossus'' class]], all 4 units used [[Vickers F.T.P. Fire Control Instruments Mark III|Vickers F.T.P. Mark III]] range and deflection instruments to the gun sights (except Mark III* in the 6-in {{TS}} panels) and [[Barr and Stroud]] (probably Mark II* or later{{INF}}) instruments for other purposes.{{HFCI1914|pp. 72}}
  
 
The Mark III F.T.P. range receivers on the 6-in guns were fitted with [[Usborne Accelerating Gear]].  An adapted [[Vickers Range Clock]] similar to that used in the [[Mark I Dreyer Table]] could be employed to relay ranges to the 6-in guns.  An operator on the clock would have to follow-the-pointer to transmit the ranges.  Each 6-in broadside had its own independent Captain's cease fire gong circuit.  Firing keys were Pattern 872, and each gun had a fire gong.{{ARTS1913|p. 102 & Plate 54}}  
 
The Mark III F.T.P. range receivers on the 6-in guns were fitted with [[Usborne Accelerating Gear]].  An adapted [[Vickers Range Clock]] similar to that used in the [[Mark I Dreyer Table]] could be employed to relay ranges to the 6-in guns.  An operator on the clock would have to follow-the-pointer to transmit the ranges.  Each 6-in broadside had its own independent Captain's cease fire gong circuit.  Firing keys were Pattern 872, and each gun had a fire gong.{{ARTS1913|p. 102 & Plate 54}}  
  
The ships also had ''Gun Ready'' signals in the {{TS}} and control positions, but had no ''Target Visible'' signals.<ref>''Handbook for Fire Control Instruments, 1914'', p. 11.</ref>
+
The ships also had ''Gun Ready'' signals in the {{TS}} and control positions, but had no ''Target Visible'' signals.{{HFCI1914|p. 11}}
 
   
 
   
In 1916, it was approved that the ships should have a range rate transmitter/receiver pair between TS and spotting top for the main armament.  Additionally, it was ordered that ''Lion'' and ''King George V'' classes and` later should receive instruments such that the fore top could be interchangeable as a gun control position with the GCT.<ref>''Handbook for Fire Control Instruments, 1916'', p. 145.</ref>
+
In 1916, it was approved that the ships should have a range rate transmitter/receiver pair between TS and spotting top for the main armament.  Additionally, it was ordered that ''Lion'' and ''King George V'' classes and later should receive instruments such that the fore top could be interchangeable as a gun control position with the GCT.{{HFCI1914|p. 145}}
  
The ships were perhaps the first to be provided [[Kilroy Turret Training Indicator]]s.<ref>''Handbook for Fire Control Instruments, 1914'', Plate 87.</ref>{{INF}}
+
The ships were perhaps the first to be provided [[Kilroy Turret Training Indicator]]s.{{HFCI1914|Plate 87}}{{INF}}
  
 
====Secondary Battery====
 
====Secondary Battery====
[[File:ARTS1913Plate54.jpg|thumb|300px|'''Diagram of 6-in Fire Control'''<br>As shown in ''Annual Report of the Torpedo School, 1913''. Pardon the blurry photo. ]]
+
[[File:ARTS1913Plate54.jpg|thumb|300px|'''Diagram of 6-in Fire Control'''{{ARTS1913|Plate 54. Pardon the blurry photo}} ]]
 
A description of the fire control system for the 6-in guns is found in the ''Annual Report of the Torpedo School, 1913''.
 
A description of the fire control system for the 6-in guns is found in the ''Annual Report of the Torpedo School, 1913''.
  
 
==Torpedo Control==
 
==Torpedo Control==
By the end of 1915, all four ships had been equipped with a [[Torpedo Control Plotting Instrument Mark I]] in their TCT.{{ARTS1915|p. 60}}
+
By the end of 1915, all four ships had been equipped with a [[Torpedo Control Plotting Instrument Mark II]] in their {{TCT}}.{{ARTS1915|p. 60}}
  
 
In 1916, a number of further changes were decided upon:{{ARTS1916|p. 145}}
 
In 1916, a number of further changes were decided upon:{{ARTS1916|p. 145}}
* Navyphone communication between CT and aft torpedo flat and T.C.T. and fore torpedo flat
+
* Navyphone communication between {{CT}} and aft torpedo flat and {{TCT}} and fore torpedo flat
 
* removal of secondary director hoods
 
* removal of secondary director hoods
* "transfer of instruments in the secondary positions" to the CT and TCT.  I presume that "secondary positions" means the secondary director hoods.
+
* "transfer of instruments in the secondary positions" to the {{CT}} and {{TCT}}.  I presume that "secondary positions" means the secondary director hoods.
* it was approved that the ships should have a transmitters in the {{TS}} and receivers in T.C.T. and C.T. so that gunnery data for range, course and speed could be shared with the torpedo control group.   
+
* it was approved that the ships should have a transmitters in the {{TS}} and receivers in {{TCT}} and {{CT}} so that gunnery data for range, course and speed could be shared with the torpedo control group.   
 
* arrangements were to be made that all capital ships with 21-in torpedoes to receive transmitters and receivers so that the T.C.T. could pass the plotted torpedo deflection to the C.T., which could then use a reciprocal set of equipment to send the T.C.T. a deflection to be placed on the sight and range to open fire.
 
* arrangements were to be made that all capital ships with 21-in torpedoes to receive transmitters and receivers so that the T.C.T. could pass the plotted torpedo deflection to the C.T., which could then use a reciprocal set of equipment to send the T.C.T. a deflection to be placed on the sight and range to open fire.
 +
 +
By 1917-1918, a number of common Torpedo Control equipment packages were to be provided to those ships not already sporting them.  Those for the 21-in torpedo ships follow.
 +
 +
[[File:ARTS1917Plate71.jpg|thumb|400px|'''Torpedo Control Data between C.T. and T.C.T..'''{{ARTS1917|Plate 71}} ]]
 +
The data instruments to be wired between C.T. and {{TCT}} to share range, order and deflection data provided a single deflection transmitter in the T.C.T. so that the results of the torpedo plot to be sent to the single deflection receiver in the {{CT}} for the information of the Torpedo Control Officer.  Conversely, a combined range and deflection transmitter forward allowed the T.C.O. to send back the deflection and intended firing range to the secondary T.C.O. in the {{TCT}}.{{ARTS1917|p. 208.  (T.O. 29/17.)}}
 +
 +
[[File:ARTS1917Plate72.jpg|thumb|240px|'''Torpedo Control Evershed'''{{ARTS1917|Plate 72}} ]]
 +
The 21-in torpedo ships were also to be provided with Evershed transmitters in the {{CT}} and a receiver at the torpedo rangefinder in the {{TCT}} in order to ensure that it was obtaining data on the intended target.  Limited "slit space" in the C.T. required that the customary binocular-based transmitters be foregone in favour of placing the transmitter on or below the floorboards and to drive it by a shaft from a [[Torpedo Deflection Sight Mark IV]].  A control key on the transmitter allowed it to indicate when it was controlling the remote rangefinder or not.{{ARTS1917|p. 208. (C.I.O. 4585/17.) }}
 +
 +
Those ships in the {{UK-BS|1}}, as were these, also were to receive bearing and inclination instruments between the C.T. and fore spotting top to allow the Torpedo Control Officer to send the target bearing to the spotting top so that men there could signal back the inclination of the target.{{ARTS1917|p. 208.  (C.I.O. 3343/17.)}}
 +
 +
Finally under the 1917-1918 mandate, sufficient instruments were to be provided to permit the Fore Bridge to communicate with the tubes.{{ARTS1917|p. 208.  (C.I.O. 1644/17, 3706/17.)}}
 +
 +
In mid-1920, it was decided that each ship should receive a [[Renouf Torpedo Tactical Instrument Type B]],{{ARTS1919|p. 119}} and a single [[Torpedo Control Disc Mark III*]] with a pair of mounting brackets to be installed in her primary torpedo control position.{{ARTS1919|p. 113}}
 +
 +
Early in 1923, all Mark II-II**** torpedoes had their low speed performance downgraded to 23 knots to 13,000 yards &ndash; 1,000 yards less than previously.  This required issuance of a new deflection disc for [[Torpedo Control Disc Mark III*]] numbered T. 226A to all ships carrying these weapons, meaning ships of the [[Iron Duke Class Battleship (1912)|''Iron Duke'']] and [[King George V Class Battleship (1911)|''King George V'']] classes, as well as {{UK-Thunderer|f=p}}.{{ARTS1913|p. 126}}
  
 
==See Also==
 
==See Also==
 +
{{refbegin}}
 
{{WP|http://en.wikipedia.org/wiki/Iron_Duke_class_battleship}}
 
{{WP|http://en.wikipedia.org/wiki/Iron_Duke_class_battleship}}
 
*[http://dreadnoughtproject.org/models/ships/HMS_Iron_Duke/ 3D Model] available for licensing
 
*[http://dreadnoughtproject.org/models/ships/HMS_Iron_Duke/ 3D Model] available for licensing
 +
{{refend}}
  
 
==Footnotes==
 
==Footnotes==
Line 174: Line 279:
 
==Bibliography==
 
==Bibliography==
 
{{refbegin}}
 
{{refbegin}}
*{{ARTS1913}}
 
*{{FCHMShips}}
 
 
*{{HFCI1914}}
 
*{{HFCI1914}}
*{{BrooksDreadnoughtGunnery}}
 
 
*{{DirectorH}}
 
*{{DirectorH}}
 
*{{DreyerH}}
 
*{{DreyerH}}
 +
*{{FCHMShips}}
 +
*{{BrooksDGBJ}}
 +
*{{ARTS1913}}
 
{{refend}}
 
{{refend}}
 
  
 
{{Footer Iron Duke Class Battleship (1912)}}
 
{{Footer Iron Duke Class Battleship (1912)}}
Line 200: Line 304:
 
{ship
 
{ship
 
name=Benbow
 
name=Benbow
pend=51 (Apr 1918)<ref>Dittmar; Colledge.  p. 33.</ref>
+
pend=75 (Aug 1914)<br>14 (Jan 1918)<br>51 (Apr 1918){{DittColl|p. 33}}
builder=[[Beardmore, Parkhead]]
+
builder=[[William Beardmore & Company]]{{Conways1906|p. 31}}
order=1911-1912 Programme
+
order=1911 Programme{{Conways1906|p. 31}}
 
laid=30 May, 1912
 
laid=30 May, 1912
launch=12 Nov, 1913
+
launch=12 Nov, 1913{{DittColl|p. 33}}
 
comm=7 Oct, 1914
 
comm=7 Oct, 1914
 
fate=Sold
 
fate=Sold
 
fate2=Scrapped
 
fate2=Scrapped
fatedate=Mar, 1931
+
fatedate=Mar, 1931{{DittColl|p. 33}}
 
}
 
}
  
 
{ship
 
{ship
 
name=Emperor of India
 
name=Emperor of India
pend=16 (April, 1918)<ref>Dittmar; Colledge.  p. 33.</ref>
+
pend=11 (Aug 1914)<br>60 (Jan 1918)<br>16 (Apr 1918){{DittColl|p. 33}}
builder=[[Vickers, Barrow-in-Furness]]
+
builder=[[Vickers]]{{Conways1906|p. 31}}
order=1911-1912 Programme
+
order="
laid=31 May, 1912
+
laid=31 May, 1912{{Conways1906|p. 31}}
launch=27 Nov, 1913
+
launch=27 Nov, 1913{{DittColl|p. 33}}
 
comm=10 Nov, 1914
 
comm=10 Nov, 1914
fate=Sold
+
fate=Sunk
fate2=Scrapped
+
fate2=as target, raised, scrapped{{DittColl|p. 33}}
fatedate=Dec, 1931
+
fatedate=1 7 , 1931{{DittColl|p. 33}}
 
}
 
}
  
 
{ship
 
{ship
 
name=Iron Duke
 
name=Iron Duke
pend=94 (1914)<br>76 (January, 1918)<br>14 (April, 1918)<ref>Dittmar; Colledge.  p. 33.</ref>
+
pend=94 (Aug 1914)<br>76 (Jan 1918)<br>14 (Apr 1918){{DittColl|p. 33}}
builder=[[Portsmouth Royal Dockyard]]
+
builder=[[Portsmouth Royal Dockyard]]{{DittColl|p. 33}}
order=1911-1912 Programme
+
order="
laid=15 Jan, 1912
+
laid=12 Jan, 1912{{Conways1906|p. 31}}
launch=12 Oct, 1912
+
launch=12 Oct, 1912{{DittColl|p. 33}}
 
comm=10 Mar, 1914
 
comm=10 Mar, 1914
 
fate=Sold
 
fate=Sold
 
fate2=Scrapped
 
fate2=Scrapped
fatedate=2 Mar, 1946
+
fatedate=2 Mar, 1946{{DittColl|p. 33}}
 
}
 
}
  
 
{ship
 
{ship
 
name=Marlborough
 
name=Marlborough
pend=66 (April, 1918)<ref>Dittmar; Colledge.  p. 33.</ref>
+
pend=79 (Aug 1914)<br>85 (Jan 1918)<br>66 (Apr 1918){{DittColl|p. 33}}
builder=[[Devonport Royal Dockyard]]
+
builder=[[Devonport Royal Dockyard]]{{DittColl|p. 33}}
order=1911-1912 Programme
+
order="
laid=25 Jan, 1912
+
laid=25 Jan, 1912{{Conways1906|p. 31}}
launch=24 Oct, 1912
+
launch=24 Oct, 1912{{DittColl|p. 33}}
 
comm=2 Jun, 1914
 
comm=2 Jun, 1914
 
fate=Sold
 
fate=Sold
 
fate2=Scrapped
 
fate2=Scrapped
fatedate=27 Jun, 1932
+
fatedate=27 Jun, 1932{{DittColl|p. 33}}
 
}
 
}
  
Line 253: Line 357:
  
 
data -->
 
data -->
 +
 +
[[Category:Featured Ship Classes]]

Revision as of 08:46, 29 March 2020

Overview of 4 vessels
Citations for this data available on individual ship pages
Name Builder Laid Down Launched Completed Fate
Benbow William Beardmore & Company 30 May, 1912 12 Nov, 1913 7 Oct, 1914 Sold Mar, 1931
Emperor of India Vickers 31 May, 1912 27 Nov, 1913 10 Nov, 1914 Sunk 1931
Iron Duke Portsmouth Royal Dockyard 12 Jan, 1912 12 Oct, 1912 10 Mar, 1914 Sold 2 Mar, 1946
Marlborough Devonport Royal Dockyard 25 Jan, 1912 24 Oct, 1912 2 Jun, 1914 Sold 27 Jun, 1932

Sea-keeping

Admiral Sir John R. Jellicoe, who hoisted his flag in Iron Duke as Commander-in-Chief of the Grand Fleet in August, 1914, wrote to the Director of Naval Construction, Eustace H. W. T. d'Eyncourt on 9 September:

I don't know if it is intended in the design but she is 18 inches by the head when complete with coal & the fore part of the thick belt is then 1 ft under water and it very rarely sits above water. Surely there is something wrong about this. There seems no way of curing it now, but future ships should not be the same. She draws over 33 ft forward at this moment although I have got rid of 600 tons of oil. She is very wet indeed.
The next point is the 6" gun ports. They can't be used at sea because you can't open or shut them from inboard. Consequently the main deck is absolutely underwater & there is no way of keeping it out. Moreover the water finds its way down to the lower deck & it is quite a serious matter. We are raising all main deck coamings, but it is a big job & meanwhile there is 6 inches of water or more constantly on the main deck. The ship being down by the head & the scuppers all at the after end of compartments, the water won't run away.
We can't use the 2 after 6" guns at all, as the ship would get far too much water in. The ports are now permanently closed.[1]

Radio

According to the ambitions of 1909, these ships had Service Gear Mark II wireless upon completion.[2]

Searchlights

The ships were fitted with Crompton's 24-in twin projectors. In 1914, some or all of these were to be modified to permit 90 degree elevation for use in anti-aircraft work.[3]

Armament

Main Battery

This section is sourced from The Sight Manual, 1916 except as otherwise noted.[4]

In April 1915, the 13.5-in Mark V(H) guns were in Mark II* mountings except in Benbow, which had Mark III* mountings (though it is possible that later these were updated and all mountings acquired a second star). The mounts were able to elevate 20 degrees and depress 5 degrees. Benbow and Empress of India had 100 rounds per gun and Iron Duke and Marlborough 80 rounds plus 6 shrapnel. Each gun had a 6-pdr sub-calibre gun for practice.[5]

The sighting arrangements were similar to those in Tiger and the King George V class.

The sights were cam-worked and limited to 15 degrees elevation, but the central sights had "20 degree super-elevation strips". Additionally, 6 degree super-elevation prisms would have been provided by 1916. The deflection gearing constant was 61.3, with 1 knot equalling 2.51 arc minutes, calculated as 2500 fps at 5000 yards.

Range drums were provided for full charge at 2450 fps, three-quarter charge at 2000 fps, as well as 6-pdr sub-calibre gun and .303-in aiming rifle. Muzzle velocity was corrected by adjustable scale plate between 2560 and 2260 fps. The adjustable temperature scale plate could vary between 40 to 100 degrees Fahrenheit, and a "C" corrector could alter the ballistic coefficient by +/- 20%.

The periscope holder was inclined 1 degree 37 minutes (which may have effectively been 2.5 degrees for mechanical reasons; it equalled .195 degrees correction at 10,000 yards).

The side sighting scopes were 43.25 inches above and 39 inches abreast the bore. The central scopes were offset 56.25 inches above and 42 inches abreast.

O.O.Q. Open Director Sights capable of 20 degrees elevation were to be fitted sometime following 1916.

The guns were capable of continual aim in all but heavy weather. Gunlayer and turret trainer each used a single hand wheel. Elevation was at 5 degrees per second was achieved by just a single revolution of the hand wheel — a final increase in sprightliness over King George V and Lion classes.[6]

6-in Battery

The ships mounted twelve 6-in Mark VII guns in P. VIII mountings, two on the main deck and ten on the upper deck.[7]

After the Battle of Jutland, when alterations to increase protection forced weight-savings to compensate, the ammunition allotment for these guns was to be reduced to 140 rounds per gun and 6 shrapnel rounds.[8]

Other Guns

  • Four 3-pdr Hotchkiss guns on Mark I* mountings on the flying deck.[9]
  • One 3-in Mark I gun on a Mark II H.A. mounting on the shelter deck.[10]

Immediately before the start of war, the 3-pdr Mark I* mountings on Iron Duke and Marlborough (at least) were be given spring eyepieces.[11]

Torpedoes

Four 21-in broadside tubes, the forward ones bearing 80 degrees and the aft tubes bearing 100 degrees.[12]

Fire Control

Range Dials

As of 1920, all four ships were equipped with a Range Dial Type B and a Type C.[13]

Phones and Voicepipes

In early 1914, the Iron Duke (at least) had a voicepipe between T.S. and G.C.T..[14]

By mid-1918, it was approved to fit Pattern 3331 Navyphones with loud-sounding bells in the auxiliary machinery compartments of Lion and Orion classes and later where existing navyphones have proven ineffective.[15]

Main Battery

Secondary Battery

Navyphones for 6-in Fire Control[16]

Each of the six 2-gun groups was on its own navyphone circuit, feeding a Pattern 2464 Navyphone for the group officer as well as a pair of Telaupads for each gun. These led to six 2-way C.O.S.es in the 6-in TS which would dictate whether the given 6-in group's phones were tied to either

  1. the Pattern 2463 Navyphone and its associated Pattern 2465 transmitter
  2. the single 2464 in the G.C.T. for its broadside.

Additionally, when the C.O.S. was in position one, each group's panel in the T.S. had a grouping switch so that any transmitter could address either or both of the other groups on its broadside. See the notes on the gunnery groups to see how this loosely mimics the fire control instruments.[17]

Rangefinders

A drawing of the ship in Burt's British Battleships seems to imply that initially, each turret carried a 9-ft rangefinder in its roof.[18]

The T.C.T. rangefinder, initially a 9-foot instrument of unknown model, sat on an M.Q. 8 mounting.[19]

In 1916-1917, a "medium-base" length rangefinder was added over the conning tower.[20]

Sometime, likely not before 1918, these were to be upgraded to 15-foot instruments, with new armoured hoods and racers and training driving the hood directly rather than through the rangefinder mounting. These rangefinders lacked hand-following gear to facilitate in transmission of range cuts, and when it was considered as an addition around 1917, space concerns were causing issues.[21]

By 1918, two additional 9-foot instruments were also to be provided for torpedo control, abreast the captain's sea cabin, except on Iron Duke, where they were placed on either side of the lower chart house platform, displacing a pair of 23-in signalling searchlights to the compass platform.[22]

By 1918, the ships had:[23]

  • two 25-ft in turrets (presumably in "B" and "X")
  • one 18-ft in a turret (presumably in "A" or "Y")
  • one 15-ft in a turret (ditto)
  • one 9-ft in a turret (presumably in "Q")
  • one 9-ft (in forward superstructure, likely the one adding 1916-1917)
  • one 15-ft in T.C.T.
  • two 9-ft in fore bridge (likely the torpedo control ones alluded to above)
  • two 2m F.T. 29[24] high-angle RFs

In 1920-1, a 12-ft rangefinder was added over the T.C.T. in the aft superstructure, and a "long-base" rangefinder added to the rear of "X" turret. Between May 1928 and May 1929, Iron Duke had a "small" rangefinder added on a high platform on aft superstructure, possibly to make up for the wholesale removal of the T.C.T. from her and Marlborough in 1927.[25]

By 1921, the ships were equipped as follows:[26]

Evershed Bearing Indicators

All four units were likely fitted with this equipment before late 1914.[Inference][27]

However, it is clear that all 6-in guns had a bearing indicator fitted.[28] This strongly implies that a rich installation supported the main battery at least. However, at Jutland, Iron Duke experienced confusion in her 6-in battery as to which enemy destroyer was being targeted.[29]

Otherwise, one might reasonably assume the particulars resembled those of the King George V class.[Inference]

In 1917, it was approved that capital ships of Dreadnought class and later should have Evershed equipment added to their C.T., able to communicate with either the fore top or the G.C.T.. If there were not enough room in the C.T., a bearing plate with open sights and 6-power binoculars would be added to the C.T..[30]

Also in 1917, it was decided that all directors were to be fitted with receivers and, "as far as possible", ships were to have fore top, G.C.T. and controlling turrets fitted to transmit as well as receive, though this was noted as being impossible in some earlier ships. While it would have been nice to have the C.T. able to transmit bearings to the 6-in guns, it was decided not to do this for reasons of space.[31]

Mechanical Aid-to-Spotter

At some point, all ships in this class were equipped with four Mechanical Aid-to-Spotter Mark IIs:

  • one on each side of the foretop, driven by flexible shafting from the Evershed rack on the director
  • one on each side of the Gun Control Tower employing an electrical F.T.P. system.

As the need for such gear was apparently first identified in early 1916, it seems likely that these installations were effected well after Jutland.[32]

In 1917, it was decided that these should probably all have mechanical links from the director and pointers indicating the aloft Evershed's bearing.[33]

Gunnery Control

Main Battery Turret Control[34]

[File:HandbookFCInstruments1914Plate63.jpeg|thumb|500px|Turret Indicating Lamp & Gong Circuits[35]]]

The control arrangements were as follows.[36]

Control Positions

Main battery:

  • Gun control tower
  • "B" turret
  • "X" turret

Each 6-in broadside:[37]

  • G.C.T. (abreast conning tower)
  • Alternative positions aft (Groups 1 & 2 from one, group 3 from a second one)

Some ships had C.O.S.es within the control positions so they could be connected to either T.S..[38]

Control Groups

The five 13.5-in turrets were each a separate group with a local C.O.S. so that it could be connected to

  • Transmitting Station
  • Local control from officer's position within turret

The 6-in guns were formed into three 2 gun groups on each side[39], and the circuits for each side are led through one of two 3-way C.O.S..es offering the following modes:[40]

  1. each group on that broadside worked by its own transmitters in the TS
  2. the broadside as a whole is connected to the adapted Vickers range clock situated in its 6-in GCT
  3. each group on that broadside is connected to the alternative control position, where (1? 3?) portable range-and-deflection transmitters with tell-tales are used.

See the section below for a diagram.

Directors

Main Battery

Training and Elevation Circuits[41]
Training and Elevation Circuits[42]
Firing Circuits[43]

The ships were fitted with a cam-type tripod-type director in a light aloft tower on the foremast along with a directing gun in 'X' turret.[44][45]

The main battery could be divided into forward ("A", "B" and "Q") and aft ("X" and "Y") groups for split director control.[46]

A C.O.S. in the T.S. afforded these options:[47]

  1. All turrets on aloft tower
  2. All turrets on directing gun
  3. Forward group on aloft tower, aft group on directing gun

The turret Elevation Receivers were pattern number H. 1, capable of matching the 20 degree elevation limit of the mountings. The Training Receivers were the single dial type, pattern number 6 in Benbow and pattern number 5 in the others.[48]

Secondary Battery

The ships had a pair of directors fitted to port and starboard on the forward superstructure to direct the 6-in broadside guns. Marlborough's were pedestal-mounted, and the others tripod-mounted.[49]

The Elevation Receivers on the guns were 6-in P. VIII Type with electrical tilt correctors, Pattern F.C. 1, capable of 14 degrees elevation. The Small Type Training Receivers were pattern number 18.[50]

Transmitting Stations

Like Tiger and possibly later ships,[Inference] these had a T.S. for the main battery and another for the 6-in secondary battery.[51] It is not clear to me whether the secondary battery's TS had a Dreyer table.

Dreyer Table

In June 1918, Marlborough had a Mark I Dreyer Table while the other three units had Mark IV Dreyer Tables[52] and all had been provided Dreyer Turret Control Tables.[53] The disparity in Dreyer Marks creates a loose impression that all ships were initially given Mark I tables and for some reason Marlborough missed her chance for an upgrade, perhaps due to her damage at the Battle of Jutland.

At some point, the ships each received Dreyer Turret Control Tables, but it is unclear when and whether each turret received one or simply the two control position turrets.[54]

Fire Control Instruments

Indicator Lamp and Gong Circuits[55]

Continuing the pattern established in the Colossus class, all 4 units used Vickers F.T.P. Mark III range and deflection instruments to the gun sights (except Mark III* in the 6-in T.S. panels) and Barr and Stroud (probably Mark II* or later[Inference]) instruments for other purposes.[56]

The Mark III F.T.P. range receivers on the 6-in guns were fitted with Usborne Accelerating Gear. An adapted Vickers Range Clock similar to that used in the Mark I Dreyer Table could be employed to relay ranges to the 6-in guns. An operator on the clock would have to follow-the-pointer to transmit the ranges. Each 6-in broadside had its own independent Captain's cease fire gong circuit. Firing keys were Pattern 872, and each gun had a fire gong.[57]

The ships also had Gun Ready signals in the T.S. and control positions, but had no Target Visible signals.[58]

In 1916, it was approved that the ships should have a range rate transmitter/receiver pair between TS and spotting top for the main armament. Additionally, it was ordered that Lion and King George V classes and later should receive instruments such that the fore top could be interchangeable as a gun control position with the GCT.[59]

The ships were perhaps the first to be provided Kilroy Turret Training Indicators.[60][Inference]

Secondary Battery

Diagram of 6-in Fire Control[61]

A description of the fire control system for the 6-in guns is found in the Annual Report of the Torpedo School, 1913.

Torpedo Control

By the end of 1915, all four ships had been equipped with a Torpedo Control Plotting Instrument Mark II in their T.C.T..[62]

In 1916, a number of further changes were decided upon:[63]

  • Navyphone communication between C.T. and aft torpedo flat and T.C.T. and fore torpedo flat
  • removal of secondary director hoods
  • "transfer of instruments in the secondary positions" to the C.T. and T.C.T.. I presume that "secondary positions" means the secondary director hoods.
  • it was approved that the ships should have a transmitters in the T.S. and receivers in T.C.T. and C.T. so that gunnery data for range, course and speed could be shared with the torpedo control group.
  • arrangements were to be made that all capital ships with 21-in torpedoes to receive transmitters and receivers so that the T.C.T. could pass the plotted torpedo deflection to the C.T., which could then use a reciprocal set of equipment to send the T.C.T. a deflection to be placed on the sight and range to open fire.

By 1917-1918, a number of common Torpedo Control equipment packages were to be provided to those ships not already sporting them. Those for the 21-in torpedo ships follow.

Torpedo Control Data between C.T. and T.C.T..[64]

The data instruments to be wired between C.T. and T.C.T. to share range, order and deflection data provided a single deflection transmitter in the T.C.T. so that the results of the torpedo plot to be sent to the single deflection receiver in the C.T. for the information of the Torpedo Control Officer. Conversely, a combined range and deflection transmitter forward allowed the T.C.O. to send back the deflection and intended firing range to the secondary T.C.O. in the T.C.T..[65]

Torpedo Control Evershed[66]

The 21-in torpedo ships were also to be provided with Evershed transmitters in the C.T. and a receiver at the torpedo rangefinder in the T.C.T. in order to ensure that it was obtaining data on the intended target. Limited "slit space" in the C.T. required that the customary binocular-based transmitters be foregone in favour of placing the transmitter on or below the floorboards and to drive it by a shaft from a Torpedo Deflection Sight Mark IV. A control key on the transmitter allowed it to indicate when it was controlling the remote rangefinder or not.[67]

Those ships in the First Battle Squadron, as were these, also were to receive bearing and inclination instruments between the C.T. and fore spotting top to allow the Torpedo Control Officer to send the target bearing to the spotting top so that men there could signal back the inclination of the target.[68]

Finally under the 1917-1918 mandate, sufficient instruments were to be provided to permit the Fore Bridge to communicate with the tubes.[69]

In mid-1920, it was decided that each ship should receive a Renouf Torpedo Tactical Instrument Type B,[70] and a single Torpedo Control Disc Mark III* with a pair of mounting brackets to be installed in her primary torpedo control position.[71]

Early in 1923, all Mark II-II**** torpedoes had their low speed performance downgraded to 23 knots to 13,000 yards – 1,000 yards less than previously. This required issuance of a new deflection disc for Torpedo Control Disc Mark III* numbered T. 226A to all ships carrying these weapons, meaning ships of the Iron Duke and King George V classes, as well as H.M.S. Thunderer.[72]

See Also

Footnotes

  1. Jellicoe to d'Eyncourt. Letter of 9 September, 1914. D'Eyncourt Papers. National Maritime Museum. DEY/16.
  2. Annual Report of the Torpedo School, 1908. Wireless Appendix, p. 13.
  3. Annual Report of the Torpedo School, 1914. p. 52.
  4. The Sight Manual, 1916. pp. 4, 23-26, 106, 108-109.
  5. All mount designations, ammunition allotments and sub-calibre gun data taken from List of H.M. Ships Showing Their Armaments, April 1915 (ADM 186/164), pp. 2, 3. Navweaps.com differs on number of stars.
  6. Brooks. Dreadnought Gunnery. pp. 45-46.
  7. List of H.M. Ships Showing Their Armaments, April 1915 (The National Archives. ADM 186/164), p. 2.
  8. Grand Fleet Gunnery and Torpedo Orders. No. 167, part 5.
  9. List of H.M. Ships Showing Their Armaments, April 1915 (The National Archives. ADM 186/164), p. 2.
  10. List of H.M. Ships Showing Their Armaments, April 1915 (The National Archives. ADM 186/164), p. 2.
  11. Admiralty Weekly Order No. 179 of 24 July, 1914.
  12. Annual Report of the Torpedo School, 1918. p. 51.
  13. Manual of Gunnery (Volume III) for His Majesty's Fleet, 1920. p. 44.
  14. Admiralty Weekly Order No. 1012 of 9 Apr, 1914.
  15. Annual Report of the Torpedo School, 1917. p. 233.
  16. Annual Report of the Torpedo School, 1913. Plate 55.
  17. Annual Report of the Torpedo School, 1913. p. 103 & Plate 55.
  18. Burt. British Battleships of World War One. pp. 194-195.
  19. Annual Report of the Torpedo School, 1918. p. 175.
  20. Burt. British Battleships of World War One. p. 197.
  21. Annual Report of the Torpedo School, 1917. p. 198. (C.I.O. 481/17).
  22. Annual Report of the Torpedo School, 1918. p. 177.
  23. Burt. British Battleships of World War One. p. 193.
  24. length and type inferred from reported 6-ft 6-in base length and knowledge of B&S R.F.s.
  25. Burt. British Battleships of World War One. p. 198.
  26. Handbook for Naval Range-Finders and Mountings, Book I. p. 172.
  27. They are not mentioned in the pertinent section of Handbook for Fire Control Instruments, 1914
  28. Annual Report of the Torpedo School, 1913. p. 102.
  29. Battle of Jutland Official Despatches. p. 63.
  30. Annual Report of the Torpedo School, 1917. p. 230.
  31. Annual Report of the Torpedo School, 1917. p. 230.
  32. The Technical History and Index, Vol. 3, Part 23. pp. 25-6.
  33. Annual Report of the Torpedo School, 1917. p. 230.
  34. Handbook for Fire Control Instruments, 1914. Plate 69.
  35. Handbook for Fire Control Instruments, 1914. Plate 63.
  36. Handbook for Fire Control Instruments, 1914. p. 7.
  37. Annual Report of the Torpedo School, 1913. Plate 54.
  38. Handbook for Fire Control Instruments, 1914. p. 7.
  39. Annual Report of the Torpedo School, 1913. Plate 54.
  40. Annual Report of the Torpedo School, 1913. p. 102.
  41. Annual Report of the Torpedo School, 1913. Plate 56.
  42. As shown in Handbook for Fire Control Instruments, 1914, Plate 96.
  43. As shown in Handbook for Fire Control Instruments, 1914, Plate 97.
  44. The Director Firing Handbook. pp. 88, 142.
  45. Annual Report of the Torpedo School, 1913. Plate 56.
  46. The Director Firing Handbook. p. 88.
  47. The Director Firing Handbook. p. 88.
  48. The Director Firing Handbook. pp. 144, 145.
  49. The Director Firing Handbook. pp. 143.
  50. The Director Firing Handbook. p. 144, 146.
  51. Handbook for Fire Control Instruments, 1914. pp. 6-7.
  52. Handbook of Captain F. C. Dreyer's Fire Control Tables, 1918. p. 3.
  53. absent from list in Handbook of Capt. F.C. Dreyer's Fire Control Tables, p. 3.
  54. Handbook of Captain F. C. Dreyer's Fire Control Tables, 1918. p. 3.
  55. Handbook for Fire Control Instruments, 1914. Plate 64.
  56. Handbook for Fire Control Instruments, 1914. pp. 72.
  57. Annual Report of the Torpedo School, 1913. p. 102 & Plate 54.
  58. Handbook for Fire Control Instruments, 1914. p. 11.
  59. Handbook for Fire Control Instruments, 1914. p. 145.
  60. Handbook for Fire Control Instruments, 1914. Plate 87.
  61. Annual Report of the Torpedo School, 1913. Plate 54. Pardon the blurry photo.
  62. Annual Report of the Torpedo School, 1915. p. 60.
  63. Annual Report of the Torpedo School, 1916. p. 145.
  64. Annual Report of the Torpedo School, 1917. Plate 71.
  65. Annual Report of the Torpedo School, 1917. p. 208. (T.O. 29/17.).
  66. Annual Report of the Torpedo School, 1917. Plate 72.
  67. Annual Report of the Torpedo School, 1917. p. 208. (C.I.O. 4585/17.) .
  68. Annual Report of the Torpedo School, 1917. p. 208. (C.I.O. 3343/17.).
  69. Annual Report of the Torpedo School, 1917. p. 208. (C.I.O. 1644/17, 3706/17.).
  70. Annual Report of the Torpedo School, 1919. p. 119.
  71. Annual Report of the Torpedo School, 1919. p. 113.
  72. Annual Report of the Torpedo School, 1913. p. 126.

Bibliography

  • Admiralty, Gunnery Branch (1914). Handbook for Fire Control Instruments, 1914. G. 01627/14. C.B. 1030. Copy 1235 at The National Archives. ADM 186/191.
  • Admiralty, Gunnery Branch (1917). The Director Firing Handbook. O.U. 6125 (late C.B. 1259). Copy No. 322 at The National Archives. ADM 186/227.
  • 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.
  • Admiralty, Technical History Section (1919). The Technical History and Index: Fire Control in H.M. Ships. Vol. 3, Part 23. C.B. 1515 (23) now O.U. 6171/14. At The National Archives. ADM 275/19.
  • 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).
  • H.M.S. Vernon. (Feb 1914) Annual Report of the Torpedo School, 1913, with Appendix (Wireless Telegraphy). Copy 42 at The National Archives. ADM 189/33.


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