Difference between revisions of "Renouf Torpedo Tactical Instrument"

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The '''Renouf Torpedo Tactical Instrument''' was a family of [[Torpedo Control]] instruments designed by Lt. Cdr. [[Edward de Faye Renouf]] of [[H.M.S. Conqueror (1911)]] described in the ''Annual Report of the Torpedo School, 1917''.<ref>''Annual Report of the Torpedo School, 1917'', pp. 201-206, also Plates thereat.</ref>
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The '''Renouf Torpedo Tactical Instrument''' was a family of [[Torpedo Control]] instruments designed by Lt. Cdr. [[Edward de Faye Renouf]] of [[H.M.S. Conqueror (1911)]] described in the ''Annual Report of the Torpedo School, 1917''.{{ARTS1917|pp. 201-206, also Plates thereat}}
  
 
It was proposed in 1917 and was to be delivered in 3 types of increasing complexity and function:   
 
It was proposed in 1917 and was to be delivered in 3 types of increasing complexity and function:   
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==Geometric Theory==
 
==Geometric Theory==
 
<gallery>
 
<gallery>
File:ARTS1918Page181Fig1.jpg| Figure I<ref>''Annual Report of the Torpedo School, 1918'', Page 181, Fig I.</ref>
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File:ARTS1918Page181Fig1.jpg| Figure I{{ARTS1918|p. 181, Fig I.}}
File:ARTS1918Page182Fig2.jpg| Figure II<ref>''Annual Report of the Torpedo School, 1918'', Page 182, Fig II.</ref>
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File:ARTS1918Page182Fig2.jpg| Figure II{{ARTS1918|p. 182, Fig II}}
File:ARTS1918Page182Fig3.jpg| Figure III<ref>''Annual Report of the Torpedo School, 1918'', Page 182, Fig III.</ref>
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File:ARTS1918Page182Fig3.jpg| Figure III{{ARTS1918|p. 182, Fig III}}
 
</gallery>
 
</gallery>
 
In Figure I, if your target, located at S, is not moving, a torpedo fired from position O will hit him if it is within a circle drawn about S whose radius (OS) equals the maximum range of a torpedo at the given speed setting.
 
In Figure I, if your target, located at S, is not moving, a torpedo fired from position O will hit him if it is within a circle drawn about S whose radius (OS) equals the maximum range of a torpedo at the given speed setting.
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==Mechanical Design==
 
==Mechanical Design==
[[File:ARTS1918Plate122.jpg|thumb|500px|'''Base Plate Schematic'''<ref>''Annual Report of the Torpedo School, 1918'', Plate 22.</ref>]]
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[[File:ARTS1918Plate122.jpg|thumb|500px|'''Base Plate Schematic'''{{ARTS1918|Plate 22}}]]
  
 
To save time and space, Renouf instruments typically portrayed three torpedo settings at once by having three colour-coded torpedo circles.  The scale chosen was 4,000 yards to an inch.  The primary structure was formed by a flat base plate with a speed scale for the target ship, adjustable by a knob.  The instrument always depicted the target ship steaming left to right across the bottom as indicated by an arrow.
 
To save time and space, Renouf instruments typically portrayed three torpedo settings at once by having three colour-coded torpedo circles.  The scale chosen was 4,000 yards to an inch.  The primary structure was formed by a flat base plate with a speed scale for the target ship, adjustable by a knob.  The instrument always depicted the target ship steaming left to right across the bottom as indicated by an arrow.
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===The Position Bar===
 
===The Position Bar===
[[File:ARTS1918Plate123.jpg|thumb|500px|'''Type A'''<ref>''Annual Report of the Torpedo School, 1918'', Plate 123.</ref><br> Set to show an attacker making 26 knots, intent on firing from 11,000 yards and 45 degrees off the bow of a target at a present range of 20,000 yards and making 17 knots with circles for torpedoes reaching:
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[[File:ARTS1918Plate123.jpg|thumb|500px|'''Type A'''{{ARTS1918|Plate 123}}<br> Set to show an attacker making 26 knots, intent on firing from 11,000 yards and 45 degrees off the bow of a target at a present range of 20,000 yards and making 17 knots with circles for torpedoes reaching:
 
* 18,000 yards at 21 knots
 
* 18,000 yards at 21 knots
 
* 15,000 yards at 25 knots
 
* 15,000 yards at 25 knots
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<small>[[Renouf Torpedo Tactical Instrument Type A|main article]]</small>
 
<small>[[Renouf Torpedo Tactical Instrument Type A|main article]]</small>
  
This type, illustrated above, was the simplest.  It was intended for use in cruisers, light cruisers, flotilla leaders, and destroyers.  Its emphasis was delivering a torpedo attack.<ref>''Annual Report of the Torpedo School, 1918'', p. 180.</ref>
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This type, illustrated above, was the simplest.  It was intended for use in cruisers, light cruisers, flotilla leaders, and destroyers.  Its emphasis was delivering a torpedo attack.{{ARTS1918|p. 180}}
  
It could determine:<ref>''Annual Report of the Torpedo School, 1918'', p. 181.</ref>
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It could determine:{{ARTS1918|p. 181}}
 
* whether torpedo fire was possible from the present position
 
* whether torpedo fire was possible from the present position
 
* when fire was possible, which torpedo setting would be most advantageous
 
* when fire was possible, which torpedo setting would be most advantageous
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=="Type B" for Battleships==
 
=="Type B" for Battleships==
 
<small>[[Renouf Torpedo Tactical Instrument Type B|main article]]</small>
 
<small>[[Renouf Torpedo Tactical Instrument Type B|main article]]</small>
[[File:ARTS1918Plate125.jpg|thumb|500px|'''Renouf Type B'''<ref>''Annual Report of the Torpedo School, 1918'', Plate 125.</ref><br>  
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[[File:ARTS1918Plate125.jpg|thumb|500px|'''Renouf Type B'''{{ARTS1918|Plate 125}}<br>  
 
]]  
 
]]  
  
This type was intended for use aboard battleships and battlecruisers that were not flagships.  The emphasis here was primarily defensive, but could also be used for attack calculations if torpedo circles of one's own torpedoes were substituted for those of the enemy. <ref>''Annual Report of the Torpedo School, 1918'', p. 181.</ref>
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This type was intended for use aboard battleships and battlecruisers that were not flagships.  The emphasis here was primarily defensive, but could also be used for attack calculations if torpedo circles of one's own torpedoes were substituted for those of the enemy. {{ARTS1918|p. 181}}
  
The Type B was nearly identical to the Type A, adding just one more bar called the "Avoiding Bar".<ref>''Annual Report of the Torpedo School, 1918'', p. 185.</ref>
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The Type B was nearly identical to the Type A, adding just one more bar called the "Avoiding Bar".{{ARTS1918|p. 185}}
  
The "B" augmented the functionality of the "A" by permitting these defensive problems to be illustrated:<ref>''Annual Report of the Torpedo School, 1918'', p. 181.</ref>
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The "B" augmented the functionality of the "A" by permitting these defensive problems to be illustrated:{{ARTS1918|p. 181}}
 
* are we within range of enemy torpedoes?
 
* are we within range of enemy torpedoes?
 
* if so, what course change is sufficient to cause them to fall short?
 
* if so, what course change is sufficient to cause them to fall short?
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<small>[[Renouf Torpedo Tactical Instrument Type F|main article]]</small>
 
<small>[[Renouf Torpedo Tactical Instrument Type F|main article]]</small>
  
[[File:ARTS1918Plate127.jpg|thumb|500px|'''Renouf Type F'''<ref>''Annual Report of the Torpedo School, 1918'', Plate 127.</ref><br>Shown the "Course to Steer" fittings in place.  
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[[File:ARTS1918Plate127.jpg|thumb|500px|'''Renouf Type F'''{{ARTS1918|Plate 127}}<br>Shown the "Course to Steer" fittings in place.  
 
]]  
 
]]  
 
This was for use in flagships, and was the most complex model, as it was oriented toward torpedo attack and defence not at the ship level, but the level of a division, a squadron, or even three squadrons.  It could also help identify, from the perspective of the fleet being considered, safe and unsafe arcs for one's own torpedo fire.
 
This was for use in flagships, and was the most complex model, as it was oriented toward torpedo attack and defence not at the ship level, but the level of a division, a squadron, or even three squadrons.  It could also help identify, from the perspective of the fleet being considered, safe and unsafe arcs for one's own torpedo fire.
  
It was twice as large as Types A and B and required 3 sets of fittings to meet its diverse functions:<ref>''Annual Report of the Torpedo School, 1918'', p. 181.</ref>
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It was twice as large as Types A and B and required 3 sets of fittings to meet its diverse functions:{{ARTS1918|p. 181}}
  
 
* its '''"Course to Steer" fittings''' enabled the device to perform the functions of the Type B, and also to calculate when how long before an attacker could fire his torpedoes.
 
* its '''"Course to Steer" fittings''' enabled the device to perform the functions of the Type B, and also to calculate when how long before an attacker could fire his torpedoes.
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==History and Deployment==
 
==History and Deployment==
At the very least, it seems that the Royal Navy was intent upon using the devices, as tables for them to be worked upon are depicted in the [[Admiral_Class_Battlecruiser_(1918)#Torpedo Control|torpedo control arrangements drawn out for ''Hood'']] in the ''Annual Report of the Torpedo School, 1918''.<ref>''The Annual Report of the Torpedo School, 1918'', Plate 132.</ref>
+
At the very least, it seems that the Royal Navy was intent upon using the devices, as tables for them to be worked upon are depicted in the [[Admiral_Class_Battlecruiser_(1918)#Torpedo Control|torpedo control arrangements drawn out for ''Hood'']] in the ''Annual Report of the Torpedo School, 1918''.{{ARTS1918|Plate 132}}
  
 
==See Also==
 
==See Also==
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==Bibliography==
 
==Bibliography==
 
{{refbegin}}
 
{{refbegin}}
*{{BibUKARTS1917}}
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*{{ARTS1917}}
*{{BibUKARTS1918}}
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*{{ARTS1918}}
 
{{refend}}
 
{{refend}}
  
 
[[Category:Torpedo Control]]
 
[[Category:Torpedo Control]]
 
[[Category:Shipboard Equipment]]
 
[[Category:Shipboard Equipment]]

Revision as of 14:01, 24 July 2012

The Renouf Torpedo Tactical Instrument was a family of Torpedo Control instruments designed by Lt. Cdr. Edward de Faye Renouf of H.M.S. Conqueror (1911) described in the Annual Report of the Torpedo School, 1917.[1]

It was proposed in 1917 and was to be delivered in 3 types of increasing complexity and function:

  • Type A (for Attack)
  • Type B (for Battleships)
  • Type F (for Flagships)

The three types shared a common geometric basis that will be discussed here.

Geometric Theory

In Figure I, if your target, located at S, is not moving, a torpedo fired from position O will hit him if it is within a circle drawn about S whose radius (OS) equals the maximum range of a torpedo at the given speed setting.

In Figure II, if your target, located at S at the moment of firing, is steaming along line AB, a torpedo fired from position O can reach him if it is anywhere within a circle drawn about the impact point, E with a radius equal to the endurance of the torpedo. The limiting range circle, then, will always be centered on the impact point, and distance SE and OE are going to be proportional to the speed of the enemy and the speed of the torpedo, respectively. The centre of the torpedo circle must move in the direction the enemy is steaming by a distance SE, which is equal to the SpeedOfEnemy * MaximumTimeOfFlightOfTorpedo, as both torpedo and target will travel for the same duration between firing and impact.

The geometry of the case described above is independent of scale, owing to the similarity of triangles. In Figure III, consider if we move point O well within the extreme range circle and observe that director angle SOT has the same angles as does SXE (the director angle pertaining to the extreme range case). The enemy inclination would be the same in both cases, as would the director angle required to produce the hit.

Mechanical Design

Base Plate Schematic[5]

To save time and space, Renouf instruments typically portrayed three torpedo settings at once by having three colour-coded torpedo circles. The scale chosen was 4,000 yards to an inch. The primary structure was formed by a flat base plate with a speed scale for the target ship, adjustable by a knob. The instrument always depicted the target ship steaming left to right across the bottom as indicated by an arrow.

The Base Plate

The red, fixed circle drawn at 10,000 yards from S is meant to suggest the effective range of secondary armament that the attacker might fear. The radial lines drawn every 10 degrees can be read from either of two scales to treat them as:

  • enemy inclinations in attacking problems, or those where the enemy is the ship depicted at S
  • relative bearings to the enemy for defensive calculations where we consider our own ship to be at S.

This somewhat schematic diagram shows how each of 3 link gears (suggested in gold here) might advance its respective torpedo range circle a different distance along AB according to the different times of flight for the different torpedo speeds as enemy speed is dialed in. Thus, in this implementation, point S is always in the middle of the lower edge of the instrument, and the circles are advanced different distances, displacing their centers (the impact points) rightward toward B. The torpedo rings are painted in white at portions where firing would be unwise owing to:

  • low striking angle of torpedo against hull
  • low relative speed (when firing from astern)
  • ease of evasion, as the enemy is nearly combing the wake already
  • deleterious effect of enemy course estimation errors[Citation needed][6]

This is similar to how the Renouf instruments effected this, but even the simplest Mark added no fewer than 4 bars to depict various tactical considerations.

The Position Bar

Type A[7]
Set to show an attacker making 26 knots, intent on firing from 11,000 yards and 45 degrees off the bow of a target at a present range of 20,000 yards and making 17 knots with circles for torpedoes reaching: * 18,000 yards at 21 knots * 15,000 yards at 25 knots * 11,000 yards at 29 knots

The Position Bar (shown in orange) was pivoted at point S and scaled along its length in thousands of yards. It would be swung to the proper angle to indicate the target's inclination (in attack mode) or the threat's relative bearing (in defence mode). A slider along the scale would be positioned to estimated range, and this bore a pivot point (referenced below). A disc about the hub at S would be referenced later, with the Course to Steer bar, and a small switch (shown in green) would indicate whether the attack from coming from port or starboard (as the instrument always depicts an attack from port).

The Desired Track Bar

The Desired Track Bar (shown in pink and pivoted from the position pointer on the position bar) depicted the proposed movement of the attacker to reach his preferred firing position. It pivoted from the position pointer and was graduated in "DISTANT TO RUN IN THOUSANDS OF YARDS" from the position pointer. A sliding Desired Position Pointer on this bar could be slid to a position to indicate the position the attacker would like to attain. The orientation of this bar and the placement of its pointer, then, would indicate a proposed firing position on the base plate relative to S.

The "Course to Steer" Bar

The "Course to Steer" Bar' (depicted in blue) pivoted around S and was graduated in knots on the same scale used on the target speed scale. A pointer near its hub indicated on the graduated disc at the base of the position bar. This would indicate the relative bearing the attacker would have to place the target to achieve the desired attack position indicated by the desired position pointer.

The Resultant Track Bar

The 'Resultant Track Bar (depicted in pink on the left) was on a pivot that was free to slide along the target's speed scale. It was graduated in "time in minutes to run 1,000 yards along the desired track bar."

"Type A" for Attack

main article

This type, illustrated above, was the simplest. It was intended for use in cruisers, light cruisers, flotilla leaders, and destroyers. Its emphasis was delivering a torpedo attack.[8]

It could determine:[9]

  • whether torpedo fire was possible from the present position
  • when fire was possible, which torpedo setting would be most advantageous
  • how to steer to attain a specific desired firing position
  • how long it would take to attain that firing position
  • the deflection setting for the torpedo deflection sight

"Type B" for Battleships

main article

Renouf Type B[10]

This type was intended for use aboard battleships and battlecruisers that were not flagships. The emphasis here was primarily defensive, but could also be used for attack calculations if torpedo circles of one's own torpedoes were substituted for those of the enemy. [11]

The Type B was nearly identical to the Type A, adding just one more bar called the "Avoiding Bar".[12]

The "B" augmented the functionality of the "A" by permitting these defensive problems to be illustrated:[13]

  • are we within range of enemy torpedoes?
  • if so, what course change is sufficient to cause them to fall short?
  • what is the track angle of the enemy's torpedo, in case I want to comb the wakes?
  • how long until his torpedo crosses my track?

"Type F" for Flagships

main article

Renouf Type F[14]
Shown the "Course to Steer" fittings in place.

This was for use in flagships, and was the most complex model, as it was oriented toward torpedo attack and defence not at the ship level, but the level of a division, a squadron, or even three squadrons. It could also help identify, from the perspective of the fleet being considered, safe and unsafe arcs for one's own torpedo fire.

It was twice as large as Types A and B and required 3 sets of fittings to meet its diverse functions:[15]

  • its "Course to Steer" fittings enabled the device to perform the functions of the Type B, and also to calculate when how long before an attacker could fire his torpedoes.
  • its "Squadron" fittings were helpful when the attacker or target were not a single ship but a division, squadron, or 3 squadrons
  • its "Own Torpedo" fittings allowed it to deal with hazards posed by friendly torpedoes

History and Deployment

At the very least, it seems that the Royal Navy was intent upon using the devices, as tables for them to be worked upon are depicted in the torpedo control arrangements drawn out for Hood in the Annual Report of the Torpedo School, 1918.[16]

See Also

Footnotes

  1. Annual Report of the Torpedo School, 1917. pp. 201-206, also Plates thereat.
  2. Annual Report of the Torpedo School, 1918. p. 181, Fig I..
  3. Annual Report of the Torpedo School, 1918. p. 182, Fig II.
  4. Annual Report of the Torpedo School, 1918. p. 182, Fig III.
  5. Annual Report of the Torpedo School, 1918. Plate 22.
  6. Link to material from Torpedo Control Handbook
  7. Annual Report of the Torpedo School, 1918. Plate 123.
  8. Annual Report of the Torpedo School, 1918. p. 180.
  9. Annual Report of the Torpedo School, 1918. p. 181.
  10. Annual Report of the Torpedo School, 1918. Plate 125.
  11. Annual Report of the Torpedo School, 1918. p. 181.
  12. Annual Report of the Torpedo School, 1918. p. 185.
  13. Annual Report of the Torpedo School, 1918. p. 181.
  14. Annual Report of the Torpedo School, 1918. Plate 127.
  15. Annual Report of the Torpedo School, 1918. p. 181.
  16. Annual Report of the Torpedo School, 1918. Plate 132.

Bibliography

  • H.M.S. Vernon. Annual Report of the Torpedo School, 1917. Originally C.B. 1474. Copy 7 at The National Archives. ADM 189/37.
  • H.M.S. Vernon. Annual Report of the Torpedo School, 1918. C.B. 1527. Copy 143 at The National Archives. ADM 189/38.