In a recent post, Dr Nick Lloyd described 1915 as the ‘forgotten year‘ of the First World War. To correct this, in occasional posts throughout 2015 members of the First World War Research Group based in the Defence Studies Department will examine unknown or forgotten aspects of the war during 1915.

by Dr IAN GOODERSON

‘Considerable experience has now been gained in the methods of carrying out bombing attacks’ noted a report produced by Headquarters, Royal Flying Corps (RFC), in December 1915, but it also acknowledged that the experience was ‘insufficient to lay down any hard and fast rules as to the system to be adopted, and probably it is undesirable to do so.’ The purpose of the report was twofold; to disseminate the experience of bombing so far gained, but also to obtain from the wings and squadrons ‘suggestions which may be of assistance in shaping future policy.’ The report is significant in its indication of how the year 1915 had been one of development in the form and method of air attack upon ground targets, with the RFC transitioning from amateur to something approaching professionalism in its approach to bombing from the air. Much had been learned, and the report is particularly interesting in indicating how closely the bombing experience and methods of the French had been studied, but much still remained to be learned.

The year had begun with spasmodic attempts by the pilots or observers of individual aircraft, who were not on ground attack missions, to throw overboard bombs in the hope of doing some damage to the enemy below; bombs were few and rudimentary, aircraft had no bomb racks, there were no effective bomb sights. During the course of 1915 this began to change. By the end of the year the RFC report could state definitely that such ‘go-as-you-please’ methods, as it termed them, had been abandoned by both the RFC and the French. Instead, it had become an ‘accepted principle’ that bombing attacks on ‘all important objectives’ be carried out by as many aircraft as possible, with ‘all the aeroplanes flying together and reaching the objective together.’ Here was an acknowledgement of an increasing sophistication in the understanding of what targets were important to bomb, the report mentions enemy aerodromes and communications targets such as railways, and that to be effective bombing needed to be concentrated. It also observed that the method of aircraft flying together and reaching the target together ‘is calculated to give A.A. guns the least possible chance of effect, and to render attack by hostile aircraft most difficult.’ For air defence too, 1915 had been a year of transition, the increasing rate and scale of bombing attack driving more and better defences both in the air and in anti-aircraft firepower from the ground. By the end of the year, as the RFC report indicates, air defence had become sufficiently effective, at least in potential, to determine bombing methods: ‘All machines flying in line ahead at the same height is a formation above all to be avoided’, it noted, ‘as being the most vulnerable against attack by A.A. guns.’ The French, it was pointed out, bombed from varying heights of 6,000 feet and over to increase the difficulties of A.A. gunners, with the risk of one aeroplane bombing another being ‘so small as to be negligible.’

The organising and command and control of bombing attacks had also become more systematic by the end of 1915, with sufficient experience to indicate alternative methods, though not enough to be dogmatic as to which was best. Concentrated bombing attacks required methods whereby the squadrons taking part could be sure to arrive over the target simultaneously. One method, favoured by the French, was for all the aircraft of the squadrons to rendezvous over a preselected spot at a given time before proceeding to the target. Another method was for the aircraft of each squadron to have a separate rendezvous equidistant from the target with orders to start at a given time. By the end of the year the III Wing of the RFC had tried both methods but found, when attempting the second for an attack on the German airfield at Hervilly on 14 December 1915, that the aircraft arrived in rapid succession over the target rather than ‘absolutely together’ as intended; it was a method demanding ‘careful planning and synchronization of watches.’ Whatever method, it was pointed out that the rendezvous ‘must invariably be selected well behind the lines, out of view from the enemy’.

In describing the methods of leading bombing missions, and in the tactics of bombing, the RFC report emphasised the importance of visual recognition and drew mainly on the French experience. ‘The Group Commander is the first to leave the ground’, it noted, ‘and he leads throughout the raid. His aeroplane is distinguished by the tricolour rosette on the sides and front of the nacelle and by metal pennants on the rear centre struts.’ Escadrille commanders usually followed the Group Commander who, once all aircraft had rendezvoused, fired a succession of Very lights and led off towards the target, the rest of the aircraft closing in and maintaining as close a formation as possible throughout the raid and the return, ‘They must not disperse.’

The French made their bombing attacks down wind, it being ‘probably considered that any errors in estimating the direction of the wind have less effect when an aeroplane is flying down wind than when running into it.’ By the time of the report, the RFC’s III Wing had tried only one down- wind bombing attack, the one against Hervilly on 14 December, but most bombs had fallen short, attributed to a change in the wind during the two hour interval between the setting of sights and the carrying out of the attack. The provision of sights and their pre-setting reflected the increasing efforts seen during 1915 to develop the skills of bombing, and the RFC report advocated both constant practice and frequent use of the ‘camera obscura’. Bomb loads were as yet small, the alternatives being for an aircraft to carry two 112lb bombs or one 112lb bomb with six or eight 20lb bombs, though as the report noted, ‘Against every description of target the former appears to be the most effective’ indicating that by the end of 1915 the imperative for an increasing weight of bomb tonnage was already underway.

As bombing increased in significance during 1915 it became apparent that to carry it out required a discipline, and courage, of its own. It also began to influence the evolving pattern of air warfare. ‘The bombing machines must be adequately protected’ noted the RFC report, also pointing out how the knowledge that friendly fighter aircraft were patrolling between the bombing aircraft and known enemy airfields gave confidence to their pilots. With sufficient friendly fighters patrolling near the front line it was felt that bombing aircraft could attack targets up to 30 miles beyond without escort, but for more distant raids ‘two out of every ten aeroplanes should carry no bombs and be entrusted with escort duties only.’ The French, it noted, sent their fighters out to meet returning bombers, and to protect possible stragglers that had fallen out of formation and were particularly vulnerable to German fighter attack.

The year 1915 was surely not the most significant of the First World War in demonstrating the effectiveness and potential of aerial bombing, but it may be seen as the year in which bombing, and the gathering and interpretation of its experience, started to become systematic. Yet, bombing was not, it seems, universally popular among pilots whose experience thus far had mainly been reconnaissance or fighting in the air. ‘The growing importance of bombing operations cannot be too fully impressed upon pilots’ noted the RFC report, ‘There are still pilots who belittle the importance and utility of these operations. The results, both material and moral, of recent raids should be sufficient to convince all that well-conceived and thoroughly carried out bomb attacks may have far-reaching effects.’ Skepticism was already being overborne by an article of faith.

Image: A Royal Aircraft Factory R.E.7, which were used in 1915 by the Royal Flying Corps on bombing missions. Licensed under CC BY-SA 3.0 via Wikimedia Commons.