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Handbook for 4" Marks VII and VIII breech-loading guns

Handbook for 4" Marks VII and VIII Breech-loading Guns

1916

Repository
Document ID
Pages
Dimensions
Plates
ADM 186/207
58

15cm x 24.5cm
59

 

My copy of this document is a black and white photocopy of an original at TNA.  Most of the plates were in color, but I do not have the benefit of seeing it.  My copy lacks a title page and starts right at the table of contents.  Perhaps I misfiled it but I seem to recall them saying that it was missing in the original. Also, I seem to have missed getting images of plates 40 through 46 (noted in red below).

 

CONTENTS

 
Page
List of Plates
3
  
Description of the Guns
5
  
Description of the Breech Mechanism
6
  
Description of the Firing Gear, Electric and Percussion Locks
7
  
Notes on the Firing and the Night Sight Circuits
10
  
Description of the P. II. Mounting
12
  
Description of the P. II.* Mounting
16
  
Description of the P. III. Mounting
20
  
Description of the P. III.* Mounting
25
  
Description of the P. IV. Mounting
27
  
Description of the P. IV.* Mounting
31
  
Description of the P. IV.** Mounting
34
  
Description of the P. V. Mounting
38
  
Description of the P. VI. Mounting
42
  
Description of the P. VII. Mounting
47
  
Description of the P. VIII. Mounting
51
  
Description of the Field Carriage for the Mark VII. B.L. Gun
53
  
Description of the Percussion Firing Gears
56
  

LIST OF PLATES

I do not have copies of those shown in red

I.
Ordnance B.L. Mark VII.
II.
Ordnance B.L. Mark VIII.
III.
 General arrangement of Breech Mechanism
IV.
 Arrangement of Percussion and Electric Locks
V.
 P. II. Mounting. General arrangement.
VI.
"
 Sectional Elevation of Carriage.
VII.
"

Diagram of Firing and Night Sight Circuits.

P. II. and II.* Mtgs. 1-166.

VII.a
 P. II.* Mounting . Diagram of Firing and Night Sight Circuits as fitted to 4" Guns H.M.S. "Vanguard" and "Collingwood."
VIII.
"
 General arrangement.
IX.
"
 Section through Pedestal.
X.
"
 Arrangement of Training Clamp.
XI.
"
 Arrangement of Elevating Gear.
XII.
"
 Arrangement of Training Gear.
XIII.
"

Diagram of Firing and Night Sight Circuits.

P. II.* Mtgs. 167-204.

XIV.
 P. III. Mounting. General arrangement.
XV.
"
 Section through Pedestal and Carriage.
XVI.
"
 Section of Run-out and Recoil arrangements.
XVII.
"
 Arrangement of Elevating Gear.
XVIII.
"

Diagram of Firing and Night Sight Circuits.

P. III. and III.* Mtgs.

XIX.
 P. III.* Mounting. General arrangement.
XX.
"
 Arrangement of Pedestal and Elevating Gear.
XXI.
"
 Arrangement of Variable Depression Stop.
XXII.
"
 Arrangement of Training Gear.
XXIII.
 P. IV. Mounting. General arrangement.
XXIV.
"
 Section of Pedestal and Carriage.
XXV.
"

Diagram of Firing and Night Sight Circuits.

P. IV. and IV.* Mtgs.

XXVI.
 P. IV.* Mounting. General arrangement.
XXVII.
"
 Section through Recoil Cylinder and Spring Case.
XXVIII.
"
 Arrangement of Training Gear.
XXIX.
"
 Details of Training Gear Ball Bearings.
XXX.
 P. IV.** Mounting. General arrangement.
XXXI.
"
 Section through Pedestal and Training Clamp.
XXXII.
"
 Double-handed Two-speed Training Gear and Firing Contacts.
XXXIII.
"
 Training Gear.
XXXIV.
"

Diagram of Firing and Night Sight Circuits.
XXXV.
 P. V. Mounting. General arrangement.
XXXVI.
"
 Section through Pedestal.
XXXVII.
"
 Arrangement of Recoil and Run-out Gear.
XXXVIII.
"
 Arrangement of Training Gear.
XXXIX.
"

Diagram of Firing and Night Sight Circuits.
XL.
 P. VI. Mounting. General arrangement.
XLI.
"

Arrangement of Carriage and Pedestal.
XLII.
"
 Arrangement of Recoil and Run-out Gear.
XLIII.
"
 Arrangement of Elevating Gear.
XLIV.
"
 Arrangement of Training Gear.
XLV.
"

Diagram of Firing and Night Sight Circuits.

P. VII. and VIII.
XLVI.
 P. VII. Mounting. General arrangement.
XLVII.
"
 Section through Recoil Cylinder and Spring Case.
XLVIII.
"
 Elevating Gear.
IL.
"
 Section through Training Gear.
L.
"
 Training Gear.
LI.
"
 Training, Housing and Depression Stops.
LII.
"
 Diagram of Firing and Night Sight Circuits.
LIII.
 P. VIII. Mounting. General arrangement.
LIV.
"
 Elevating Gear.
LV.
  
LVI.
 Percussion Firing Gear Type I.
LVII.
"
 Type II.
LVIII.
"
 Type III.
LIX.
"
 Arrangement for .303" Aiming Rifle.

Notes

One important background note on naval weapons, and in particular the Royal Navy's weapons of this period, is that small guns like this are often discussed as systems comprised of a gun (which is simply the barrel and breech mechanisms) and a mounting upon which it sits.  The RN nomenclature system details guns by the diameter of their bore and a "Mark" designation of a roman numeral.  Small changes in a design sometimes do not merit a new Mark number, but are instead denoted by appending stars (asterisks) , e.g.: Mark VII**.  Mountings are usually denoted by a roman numeral after a "P.", which may stand for "pedestal", for such is what these man-worked weapon mounts were called.  Mountings may also have stars in their designation.

For instance, on the "I" class destroyers, the 4" guns were accurately identified as 4" B.L. Mark VIII guns on P. V mountings.  The B.L. is short for breech-loading, and is itself a loaded term if you'll excuse that phrasing.  All guns of this period were loaded at the breech, but a distinction was made between those guns which had a self-contained projectile which combined its powder load with the projectile itself and those which separated the projectile and the powder.  B.L. guns were the latter type, and the powder was rammed into the gun breech after the projectile in silk bags.  Q.F., or quick-fire guns were the ones with "bullet-type" ammunition, with an integral brass case containing the propellant.