Renouf Torpedo Tactical Instrument Type F

The Type F ("F" standing for "Flagship") was the most elaborate version of the the family of Renouf Torpedo Tactical Instruments, intended for use in flagships to help them judge torpedo attack and defence at the divisional level and beyond.

Although it could be used to solve any of the problems the Type B focused on, it was uniquely able to examine torpedo threats when multiple ships were involved on both sides.

Mechanical Design

Renouf Type F
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.

The device had 3 sets of fitting supplied:

• "Course to Steer" fittings to perform all functions of the Type B
• "Squadron" fittings (which included the avoiding bar) for attack and defence of a division, squadron, or 3 squadrons
• "Own Torpedo" fittings to deal with hazards posed by friendly torpedoes

The Type F's torpedo circles were worked independently from one another, not together as in Types A and B. Its base line ran down the centre of the base plate, essentially doubling the size of the instrument and allowing threats from the starboard to be depicted naturally.

"Course to Steer" Fittings

The device could work a new problem (in attack and defence forms) over the Type B when the fleets were on converging courses, namely "how long before attacker is in position to fire?"

The process was as follows:

• Advance torpedo circles to speed of target fleet
• Set attacker range on the position bar
• Set attacker direction by his bearing (on defensive problems) or by the target's inclination (on attack problems) on position bar
• Place desired track bar to course of attacker
• Set resultant track bar pivot to speed of target fleet
• Place "Course to steer" bar parallel to desired track bar
• Turn resultant track bar so its reading edge cuts speed of attacker on the "course to steer" bar
• Read off time to run 1,000 yards on resultant track bar
• Turn desired track bar parallel to resultant track bar and read off range to run on resultant track bar to reach the pertinent torpedo circle
• Multiply time to run 1,000 yards by this range to run to determine how long before attacker is in torpedo range

"Squadron" Fittings

Renouf Type F
Shown with "Squadron" fittings in place.

Fleet Bar

This bar is depicted in magenta in the figure and can slide and rotate through a pivot fitted on the central base line of the instrument. "It is graduated in thousands of yards each way, which divisions represent the space occupied by two ships in line."

Position Bar

This is depicted in orange in the figure, and is graduated in thousands of yards. Rather than pivot on the central base line, its pivot is on the sliding fleet bar. The position pointer is the pivot point on which rides the squadron bar. A second, simpler slider located nearer the hub is called the destroyer position pointer.

Squadron Bar

This is depicted in magenta in the figure and is pivoted on the destroyer position pointer which in turn rides on the position bar. "It carries three small bars on the underside, each of which represents a squadron of eight ships. Each squadron is pivoted at the leading ship..." This arrangement permitted the squadron bar and its underslung 3 squadrons (depicted as white lines in the illustration) to be arranged in any manner relative to the primary pivot on the base line.

History and Deployment

Unknown [TO BE CONTINUED - TONE]

Bibliography

• Template:BibUKARTS1917
• Template:BibUKARTS1918