COAST ARTILLERY, JOURNAL - Air Defense Artillery

514 THE COAST ARTILLERY JOURNAL
29. a. That the fire control equipment of each fixed mortar battery be
con:pleted to include the following:
(1) A plotting board.
(2) A prediction device.
(3) A Pratt Range Board, Model 1905, with charts of percentage
curves and with a correction scale and index therefor.
(4) A wind component indicator.
(5) A range percentage corrector.
(6) A deflection board.
(7) Two pairs of proportional dividers of suitable span.
(8) An impact board.
(9) A spotting device.
(10) The sending elements of a mechanical display board for each
pit.
Concerning this recommendation, in many batteries a plotting board, prediction
device, deflection board, and the sending elements of mechanical
display boards are available. The additional materiel, for which some funds
may be required, are the wind component indicators and Pratt Range
Boards with correction scale and index; in the case of these items some
materiel may be available from abandoned Coast Artillery posts. As a
temporary measure, the range percentage corrector, impact board, and spotting
device can be improvised locally at little or no expense in accordance
with instructions and plans which can be furnished by the Coast Artillery
Board.
b. That the equipment in each pit include:
(I) A mechanical display hoard.
(2) A special display hoard.
(3) A check-back hoard.
Concerning this recommendation, many batteries are provided now with a
meooanical display hoard connected to the plotting room. Where these
hoards do not exist, and it is practicable to install on~, it should be c~nstructed
by local personnel. The cost of the materials necessary for such a
device is not great. The special display boards can be made locally from
salvaged lumber in accordance with plans which can be furnished by the
Coast Artillery Board. A check-back hoard can be improvised locally at
little or no expense.
c. That the procedure covered in the above discussion be authorized for
all fixed mortar batteries. It is the intent of this recommendation that, if
approved by the Chief of Coast Artillery, the service at large be informed
as to the exact nature of this development and then authorized to install and
use same.
d. That authority for local changes in communication routes and changes
in time interval signals which will conform to Par. 23 0 and n he given
coincidentally with approval of the ahove recommendations.
23. The proposed fire control system was next tested in the Coast
Defenses of Balboa in April, 1925. The report of this test was sent
to the Coast Artillery Board for remark and recommendation. Extracts