Range Cut

A range cut is a single instantaneous observational estimate of range to a target as reported by a Rangetaker (or his associated team) from a Rangefinder. The English term probably derives from the Royal Navy's predominate use of coincidence range finders, whose action of obtaining a range optically bisects the object being ranged upon. German "R.F.s" used other principles of operation, but the term spans the topic in English.

Nature

Range cuts are one of the atomic staples of fire control computation. They are necessarily prone to several forms of error, no matter their means of perception, collection or transmission, and it is incumbent upon the fire control organisation consuming them to take this fact into consideration. In the capital ships of the Grand Fleet (and many others), the range cuts were often relayed to teams in transmitting stations or directly into an averaging device by means of an automated or semi-automated data relay system.

In a well-developed ship-wide system, range cuts would be reported as simply as working a trigger button on a transmitter connected directly to the rangefinder's mechanisms. In other cases, navyphones or voicepipes or more ad hoc means would signal the data to other interested parties.

See Also

• Rangefinder

Bibliography

• Moss, Michael; Russell, Iain (1988). Range and Vision: The First Hundred years of Barr & Stroud. Edinburgh: Mainstream Publishing. ISBN 1851581286.
• Admiralty, Gunnery Branch (1909). Information Regarding Fire Control, Range-finding and Plotting, 1909. C.B. 1127. Copy 137 at Admiralty Library, Portsmouth, United Kingdom.
• Admiralty, Gunnery Branch (1916). Handbook for Barr and Stroud Naval Range-Finders and Mountings. C.B. 269. The National Archives: ADM 186/205.