A Gunlayer (or Layer — Pointer in American parlance) is the person who controls the angle of elevation of a gun. Typically, he does this by rotating a hand-wheel or working a hydraulic lever in the case of a larger gun. How he establishes the proper angle of elevation differs when the gun is being locally laid laid by director. The gunlayer also fires the gun in many instances, although sometimes this is done electrically from the director.
It's important to note that in all but the very smallest guns, the layer only controls the elevation of the gun, and not its lateral rotation. A separate man, the trainer or turret director trainer generally performs that task.
Station and Equipment
On pedestal mounted guns, the layer was generally stationed on the left side of the mounting. In a large turret with 2 guns, each gun would have a layer sitting on its left side. In a pedestal mounting, he would have a geared hand-wheel which would drive the mounting through its elevating arc. In a large turret, he would use a hydraulic lever or hand-wheel to elevate the gun. He would have a sighting telescope or periscope and possibly some data receivers.
When a gun is not being laid by a director, the layer looks through a sighting telescope or periscope of some kind and works his elevating controls to place his cross hairs onto an agreed point of aim on the target. When this is done, he has laid the gun. In small geared mountings, he may endeavour to work his controls to continuously negate the pitching and rolling of his ship to keep the cross hairs "on", in a process called continuous aim. Otherwise, he might simply place his cross hairs so the motion of his own ship causes them to sweep through the target periodically and he would press the firing trigger only at the proper moment where the cross hairs were moving through the point of aim, a process called firing on the roll.
Different nations and different gun types handled this in various ways.
British Heavy Turrets
When a director was being used to lay the guns, the gunlayer would not look through a sighting scope but instead work his elevating controls as he watched a data terminal called an elevation receiver or (in late-war British destroyers) a similar mechanism mounted nearby. In such a case, he would endeavour to keep two pointers in agreement, and this would indicate the proper elevation was on the gun. In such cases, the firing impulse would almost certainly arrive from the director and the layer would simply monitor his pointers except perhaps to sneak a peek once in a while to verify things appeared to be working properly, as the cross hairs should still be on the target if all was being set correctly.
British Destroyers and Flotilla Leaders
The layer would stop using his sighting telescope and instead focus his work upon keeping a pair of pointers aliged. One pointer was attached to his telescope carrier arm, and pointed backward against an index on an arc fixed to the trainable portion of the gun mounting. The effect of this action was to keep the scopes parallel to or at a fixed angle to the reference plane of the ship's deck. The action of the sightsetter to keep the proper range on the sight therefore meant that the gun was properly elevated when it rolled past a pure vertical. The director was outfitted with Henderson Firing Equipment and would automatically fire the gun at this moment.
The German Navy's director system was a training-only affair. The layer of any German gun under director control would continue to lay his gun locally and to fire when he heard a firing gong sound when firing in salvo firing, or as often as he could when firing in independent firing.
When laying his own gun locally, the layer would also generally fire the gun by pulling a trigger on a pistol grip (often, even small guns had two electrical firing triggers for redundancy, and possibly a percussion-firing lanyard to be worked by someone else should both of these fail). When a director was laying the guns, the layer would usually rely on the director to electrically fire the gun.
- Admiralty, Gunnery Branch (1913). Gunnery Drill Book for His Majesty's Fleet. (Book I.) (Instructions for Power-Worked Mountings). London: Eyre and Spottiswoode, Ltd..
- Admiralty, Gunnery Branch (1917). The Director Firing Handbook. O.U. 6125 (late C.B. 1259). Copy No. 322 at The National Archives. ADM 186/227.
- Admiralty, Gunnery Branch (1918). Director Firing For Flotilla Leaders and Destroyers. Pub. No. B.R. 934 (late O.U. 6127 and C.B. 1461 and 1461(A). The National Archives. ADM 186/234.