The Dorsetshire & Wiltshire Fortress Royal Engineers was a part-time unit of Britain's Royal Engineers formed in 1908. It helped to defend the naval base of Portland Harbour during World War I and provided a detachment to serve with the British Expeditionary Force on the Western Front. Between the World Wars the unit took on the additional role of anti-aircraft searchlight defence and during World War II it was expanded into a full searchlight regiment that served during the Plymouth Blitz.
Origin When the Territorial Force (TF) was created from the former Volunteer Force by the Haldane Reforms in 1908,Dunlop, Chapter 14.Spiers, Chapter 10. it was organised with one or more Fortress Companies of the Royal Engineers (RE) in each of the coast defence commands. Where there were no pre-existing Volunteer RE units in the area new ones were raised. Thus the Dorsetshire & Wiltshire Fortress Royal Engineers were formed in Southern Coast Defences, primarily to operate the defences of Portland Harbour. Although formally separate units administered by different county Territorial Associations and with their own positions in the RE's Order of Precedence, the Dorset company at Weymouth (precedence 18) and the Wiltshire company at Swindon (precedence 11) were linked administratively and commanded by a single officer with the rank of Major.Monthly Army List August 1914.Watson & Rinaldi, pp. 12–3, 83–4.
The Dorsetshire unit was an Electric Lights (EL) Company based at the Sidney Groves Memorial Hall on North Quay, Weymouth, but is also recorded as having used the Old Drill Hall at Easton, in Easton Lane on the Isle of Portland (now the Portland Sculpture & Quarry Trust), which it shared with No 3 Company of the Dorsetshire Royal Garrison Artillery.Weymouth at Drill Hall ProjectOld Drill Hall, Easton, at WWI Great War Centenary Drill Hall list.Dorsetshire Fortress RE at Army Service Numbers blogspot.Portland Sculpture & Quarry Trust. The EL Company operated two coastal defence (CD) searchlights (S/Ls) at Nothe Fort outside Weymouth and maintained and operated the generators, electric lighting and telephone systems of the fortress.'Royal Engineers and Searchlight Displays on Weymouth's Nothe Fort: Military History in Weymouth'. The Dorsetshire Company was one of the few TF units (and the only Fortress Engineer unit) to be shown in the Army List to have volunteered for 'Imperial Service' prior to World War I.Watson & Rinaldi, p. 83.
The Wiltshire unit was a Works Company based at the Drill Hall, Church Road, Swindon, which it shared with a TF company of the Wiltshire Regiment and the 1st South Western Mounted Brigade Field Ambulance of the Royal Army Medical Corps (TF).Watson & Rinaldi, p. 84.Swindon at Drill Hall Project It was almost entirely recruited from the Great Western Railway's Swindon Works.Gittins, p. 137.1st Wilts Fortress Co at IWM Lives of the First World War.RE TF units at Great War Forum.
World War I Mobilisation On the outbreak of war in August 1914, the fortress engineers moved to their war stations in the coastal defences. The Wiltshire Company was undergoing its annual training at Fort Purbrook, Portsmouth, and went straight from there to Weymouth, where along with the Dorset company and work details from infantry battalions, it worked on completing the Portland defences.
Shortly after the outbreak of war, the men of the TF were invited to volunteer for Overseas Service and WO instructions were issued to form those men who had only signed up for Home Service into reserve or 2nd Line units. The titles of these 2nd Line units were the same as the original, but distinguished by a '2/' prefix. They absorbed and trained most of the recruits that flooded in, and supplied drafts to the units on active service.Becke, Pt 2b, p. 6. Some of the extra recruits for the Wiltshire companies came from the Weymouth area, most of the others from the GWR works.
Dorsetshire Company Although the Dorsetshire company had volunteered for 'imperial' service before the war, there is no record of it going overseas as a formed body.Embarkation dates, The National Archives (TNA), Kew, file WO 162/7. Electric Light companies were in great demand at home to man the CD and later anti-aircraft (AA) S/Ls in the South Coast defences,See, for example, Short et al, Chapter IV. but the Dorset company also trained and seconded officers to RE companies in the field.For example, T/Capt E.C. Graves, London Gazette, 18 November 1916.
Wiltshire Companies However, the 1/1st Wiltshire Company did go overseas. The Portland defence works were completed by November 1914, and the men underwent a month of strenuous training, including heavy bridge building and constructing trenches at night. It then embarked aboard the SS Blackwell and arrived at Le Havre on 20 January 1915 to join the British Expeditionary Force (BEF) on the Western Front.Fortress Companies RE at Long, Long Trail.
Ypres The company first worked on a large defensive scheme for Saint-Omer in the rear area, then in April moved up to St Eloi in the Ypres Salient, where it constructed a trench along the Comines Canal and bored tunnels to serve as a covered way across the canal. This was done in hip-deep water and under constant rifle and machine-gun fire, and the company suffered its first casualties. Next the 1/1st Wilts was camped at Brielen, building huts along the Yser Canal to accommodate newly arriving divisions, but these huts came under German artillery fire and were destroyed. The company also repaired bridges over the canal, suffering casualties from the artillery fire. Eventually, having suffered 50 per cent casualties, the company was sent for rest to Danoutre, near Kemmel. Here part of the company spent June worked on defences while the railway machinists operated a sawmill and engineering works at Bailleul.Gittins, p. 139.
565th (Wiltshire) Army Troops Company In September 1915, the RE companies of the TF were renumbered:RE Museum list of WWI unit war diaries.Discussion of RE TF units at Great War Forum. 565th (Wiltshire) Army Troops Co originally 1/1st Wiltshire (Works) Co 566th (Wiltshire) Works Co originally 2/1st Wiltshire (Works) Co 566th Company does not appear to have served overseas, but will have supplied drafts to front line units.Watson & Rinaldi, p. 63. The Wiltshire Fortress Engineers was not only a source of RE officers, but some of its men were commissioned as infantry officers in the Wiltshire RegimentLondon Gazette 23 July 1915.
Somme Reinforced, 565th (Wilts) Company spent the autumn and winter of 1915–16 building a new mill at Steenwerck and a hospital nearby at Trois Ambres, as well as working on roads, light railways and water supplies. The Battle of the Somme opened on 1 July 1916 and shortly afterwards 565th (Wilts) Co was moved into the area to camp at Bronfay Farm and work on water supplies in the Carnoy Valley. This work continued throughout the Somme offensive, and the company built a pumping station on the River Somme with a water pipeline to Trônes Wood after its capture. In the spring of 1917 the company was engaged in building a Corps HQ camp at Foucaucourt, then a new HQ camp for Fourth Army at Villers-Carbonnel near Peronne. This was in the devastated area beyond the old German front line after the German retreat to the Hindenburg Line (Operation Alberich). It then worked on five heavy steel bridges over the Somme at La Chapelette near Peronne.Gittins, p. 140.Becke, Pt 4, pp. 101, 104.
Dunkirk The Third Ypres Offensive was about to begin, and Fourth Army HQ was switched to Dunkirk to command a thrust up the coast to meet the expected breakthrough in Flanders. 565th (Wilts) Company was sent to fit out the Terminus Hotel at Leffrinckoucke, where some shelling was experienced. Detachments installed water tanks and pumps at Dunkirk docks, and constructed a musketry school near Abbeville.
Cambrai In November 1917, the company was sent by lorry to Third Army's front, where the Hindenburg Line had been breached in the Battle of Cambrai. The company was put to work filling mine craters where the Hindenburg defences crossed the Bapaume–Cambrai road between the Canal du Nord and Graincourt. This was done under sporadic machine gun fire. The men next worked on new defences. After the German counter-attack, Company HQ was moved back to Ervillers, where the men worked in the forward areas on water supplies and building camps.Becke, Pt 4, pp. 94–5.
The German spring offensive of 21 March 1918 broke through in the Cambrai sector, followed by the 'Great Retreat', during which 565th (Wilts) Co found itself retreating by day and working on emergency defences with labour battalions by night. When the German offensive ran out of steam, the company was put to building a new defence line between Adinfer Wood and Fonquevillers on the old Somme battlefield. This involved repairing and linking up sections of old British and German trenches. One of the new trenches was named 'Swindon Trench' by the general commanding. During the summer, the company had two companies of the US Army Engineers attached to it for instruction.Gittins, p. 142.
Canal du Nord The Allied counter-offensive (the Hundred Days Offensive) began in August 1918, and 565th (Wilts) Co followed the advance, opening up new water points, including an important one at Douchy. On 12 September, the company reached Ruyaulcourt where it was given the task of constructing a ramp down the face of a retaining wall into the dry Canal du Nord suitable for traffic up to 6-inch guns. This work had to be done under observation from a German Kite balloon, which called down shellfire on the construction site. The balloon was shot down, but at 16.00 on 18 September the Germans put in a counter-attack, preceded by a severe barrage. The company lost one officer and seven sappers killed, 22 wounded (two mortally).
After these severe casualties, the company went for a week's rest at Boyelles. It was back at the Canal du Nord on 27 September with VI Corps Troops RE,Watson & Rinaldi, pp. 22 & 63. where it was joined by the New Zealand Tunnelling Company. Together (14 officers and 310 men in total) they built a Hopkins steel bridge across the canal between Hermies and Havrincourt. This was the largest heavy steel bridge erected on the Western Front during the war, with a span of above a deep gap; in total the bridge was long, launched by rollers. It took 80 three-ton lorry loads to bring up the material, and the total time to unload and erect the bridge was 104 hours. It was opened for traffic on 2 October.
As the Allied advance continued, the company was sent to Raches, where it worked on repairing heavy bridges in the Douai area, as part of First Army Troops RE,Watson & Rinaldi, pp. 19 & 63. though a lack of materials made progress slow. On 10 November, a six-man detachment was working on the Douai railway bridge when a delayed-action German mine exploded, wounding the whole detachment. The company remained working in the area after the Armistice with Germany. It moved to Andenne on the Meuse on 8 January 1919, then to Troisdorf in Germany at the end of January. The company remained with the occupying troops of the British Army of the Rhine until it was disbanded on 19 November 1919.Gittins, p. 143.
Interwar When the TF was reorganised as the Territorial Army (TA) in 1920, both units were due to be reformedMonthly Army List, January 1921. but the Wiltshire unit did not in fact reappear.Monthly Army List, January 1923. By 1927 the Dorsetshire (Fortress) RE consisted of No 1 (Works) Company and No 2 (Lights) Company.Titles and Designations, 1927. At first it was back at Sidney Hall, but by the 1930s it was based at Bincleaves Barracks, close to Nothe Fort.Army List, various dates.Watson & Rinaldi, p. 104.