An Cosantóir

An Cosantóir March 2015 www.dfmagazine.ie 18 | by LT CDR CAOIMHIN MAC UNFRAIDH, FLEET WARFARE OFFICER, FLEET OPERATIONAL READINESS, STANDARDS AND TRAINING SECTION PhOtOS A/S DAVID JONES T he Naval Service's anti-surface gunnery mission is the focus of all routine gunnery training but it is also developing a limited fire-support capability in conjunction with the Ar- tillery Corps and the Air Corps, in support of joint Defence Forces objectives. The NS has consistently made the case that 76mm is the minimum calibre naval armament consistent with the proper execution of its mission, as it enables the engagement of targets from close-in to stand-off ranges and is of sufficient calibre to penetrate and disable a steel hull, giving the NS a stopping power that it lacks with its secondary armaments. The complex, modern fire-control systems required to make full use of these weapons demand a significant effort from techni- cians and impose a training burden on officers and gunners. However, these challenges must be met in order to ensure that the NS maintains a fighting capacity and deterrent, and that it can properly defend, protect and support Ireland's interests at sea. The OTO Melara 76mm is the primary armament on five ships of the current NS fleet, including the latest addition, LE Samuel Beckett. In June 2013 the Flag Officer Commanding Naval Service (FOCNS) directed the Standing Naval Warfare Group (SNWG) to design a surface gunnery trial for the gun and fire-control system on P61 (LÉ Samuel Beckett), which was then under construction, in order to 'confirm that the new fire unit is functioning satisfac- torily and meets the fleet standard for accuracy and consistency'. Accordingly, a planning cell was formed and set to work. This was an opportunity to deliver a financial saving, as otherwise a trial would have to have been contracted from a private company at significant expense. It was also a chance for the gunnery specialists within the NS to deliver a practical return on their training. The SNWG conducted a joint advanced naval gunnery exercise (JANGE) in August 2013 as a precursor to the acceptance trial. Using P42 (LÉ Ciara) as the firing ship, the JANGE developed the techniques necessary for fall-of-shot observation and over-the- horizon targeting by helicopter to ranges up to 16km. (As a point of interest, it is believed to have been the longest range shoot in Defence Forces' history, as the Glen of Imaal does not allow for the full capabilities of the artillery's 105mm guns to be exercised.) The trial was to be conducted over three days and in accordance with statistical principles. The trials data - with factory/harbour acceptance trials that had already been completed - would allow certain conclusions to be drawn about aspects of performance that could not be fully tested within the given time frame. A tentative plan was briefed by the trials team to the Director of Ordnance who assigned a senior officer to oversee the project. Planning meetings were then held between the Air Corps, the Artillery Corps and the NS trials team. The trial at this point was given, perhaps inevitably, the title Operation Godot and warning orders were issued. The plan may be summarised as an anti-surface warfare trial, biased to the medium - and long-range characteristics of the fire-unit, with a live-firing element, in three phases: bedding-in, statistical trial and an operational shoot, with fall-of-shot to be recorded for analysis. The trial also had to stand up to the scrutiny of the contractors who had tendered and fitted the gun and the FCS (OTO Melara and General Electric respectively), each of whom would have representatives present throughout. LÉ Samuel Beckett proceeded to Danger Area D-13 off the South Coast and layed three Danbuoys 5,800m, 11,000m and 15,100m from a gunline: 35%, 75% and 95% of the system's maximum range. (Danbuoys are moored metal buoys whose original pur- pose was to mark a swept channel through a minefield. In fact, the Danbuoys used on this occasion originally belonged to LÉ Grainne, a coastal minesweeper commissioned in 1971.) The Danbuoys served as references for the aerial observers, vis- ible targets for the electro-optical fire-control system and as con- spicuous marks for the radar operators. Laying multiple Danbuoys at the precise locations called for by the plan was a precision navigation and seamanship evolution and it was pleasing to see this old skill displayed by the new ship's team. Ten rounds (LÉ Samuel Beckett's first) were fired at various bear- ings and elevations, maximizing vertical and horizontal stresses to induce the latent deflection that might remain in the installation (eg deformation of the gun deck). These deflections were then measured by a delicate tilt-and-alignment check and factored into the fire-control computer prior to the trial. Such adjustments are normal in a new-build but they must

• Cover