Vickers F.T.P. Fire Control Instruments

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Vickers F.T.P. Instruments, c1914[1]
The range receiver in the upper left is a Mark III.

After initial success supplying dial instruments, Vickers manufactured a variety of Step-by-Step Fire Control Instruments incorporating the "follow-the-pointer" principle. They were first used in Boadicea, around 1909, and regained Vickers the lead it had lost in 1906 to Barr and Stroud in supplying sightsetting instruments.

Mark I

These were electrically similar to the dial instruments Vickers had previously provided. A chopper handle built into the switch at the transmitter lifted the brushes off the rotor when the indication was not being driven.[2] They were only used in Boadicea,[3] although one source[4] indicates they were also used in Bellona.

Mark I Pattern Numbers
for 4-inch guns[5]
Device Pattern No.
Range Transmitter 2643
Range Receiver 2645
Deflection Transmitter 2644
Deflection Receiver 2646

Mark II

These were considerably different from the Mark I, internally, by having a brushless design.[6] The range transmitter did not transmit pulses equating to any given range increment, but one rotation of the handle moved the pointer a quarter degree. In deflection, one revolution yielded 1.5 knots of deflection.[7]

Mark II Pattern Numbers
for given guns[8]
Device 4-in guns 6-in guns
Range Transmitter 2651 2647
Range Receiver 2652 2648
Deflection Transmitter 2653 2649
Deflection Receiver 2654 2650

Mark III

These were similar to the Mark II, electrically, but differed by having the receiver not be part of the sight, rendering it cheaper and simpler in construction. Also, the transmitter did not have a sight dial as a tell-tale — simply a drum transmitter and repeat receiver.[9]

Although the Mark III devices differed by the sights they were fitted to, when delivered on a base plate alone, the Pattern numbers were as follows.

Mark III Pattern Numbers
without sight dial[10]
Device Pattern No.
Range Transmitter 2660
Range Receiver
Range Repeat Receiver		 2662
Deflection Transmitter 2661
Deflection Receiver
Deflection Repeat Receiver		 2679

Mark III*

Vickers Cross-connecting gear[11]

These transmitters (which worked with Mark III receivers) could use Cross-connecting Gear by virtue of their wheel gearing, permitting them to drive two or more transmitters by the action of one man at the mechanical transmitter box.[12]

The range transmitter was Pattern 2690 and the deflection transmitter Pattern 2691.[13]

Mark IV*

These transmitters (which worked with Mark III receivers) were being introduced around 1914 to be first tried in the Queen Elizabeth class and featured an improved cross-connecting gear arrangement for the transmitter.[14]

See Also

Footnotes

  1. ↑ Handbook of Fire Control Instruments, 1914, Plate 15.
  2. ↑ Handbook of Fire Control Instruments, 1914, p. 18.
  3. ↑ Handbook of Fire Control Instruments, 1914, p. 72.
  4. ↑ Handbook of Fire Control Instruments, 1909, p. 57.
  5. ↑ Handbook of Fire Control Instruments, 1914, p. 21.
  6. ↑ Handbook of Fire Control Instruments, 1914, p. 18.
  7. ↑ Handbook of Fire Control Instruments, 1914, p. 19.
  8. ↑ Handbook of Fire Control Instruments, 1914, p. 21.
  9. ↑ Annual Report of the Torpedo School, 1909, p. 148.
  10. ↑ Handbook of Fire Control Instruments, 1914, p. 21.
  11. ↑ Handbook of Fire Control Instruments, 1914, Plate 10.
  12. ↑ Annual Report of the Torpedo School, 1909, p. 148.
  13. ↑ Handbook of Fire Control Instruments, 1914, p. 21.
  14. ↑ Handbook of Fire Control Instruments, 1914, p. 20.

Bibliography

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