The Kent Fortress Royal Engineers (KFRE) was a volunteer Territorial unit of the British Army that saw service in both World Wars. They are notable for their successful actions in May 1940, when they destroyed substantial oil stocks and installations just ahead of the German advance, and in August 1944, during the assault crossing of the River Seine.

Origin When the Territorial Force was created in 1908, the 1st Sussex Royal Engineers (Volunteers) were split up to provide the Kent and Sussex Fortress Engineers, as well as the field companies of the Home Counties Division. The Kent Fortress Royal Engineers was formed on the basis of K Company of the 1st Sussex at Tonbridge.Morling, pp. 41–3; 'The Family Tree' (front endpapers).Westlake, p. 13.London Gazette, 20 March 1908.

By the outbreak of World War I, the Kent unit had the following organisation:Watson & Rinaldi, p. 13.Kent Fortress RE at Kent Fallen.Monthly Army List.

HQ at Drill Hall, Chatham No 1 Works Company at Tonbridge No 2 Works Company at Drill Hall, Ashford No 3 Works Company at Southborough No 4 Electric Light Company at Submarine Mining School, Gillingham No 5 Electric Light Company at Gravesend No 6 Works Company at Southborough No 7 Works Company at Southborough

The Honorary Colonel was Sir David Salomons, 2nd Baronet

World War I Mobilisation Shortly after the outbreak of war on 4 August 1914, TF units were invited to volunteer for overseas service. Meanwhile, the formation of a reserve or 2nd Line unit was authorised for each 1st Line unit where 60 per cent or more of the men had volunteered for Overseas Service. The titles of these 2nd Line units would be the same as the original, but distinguished by a '2/' prefix.Becke, Pt 2b, p. 6. All the KFRE units were initially employed on the Thames Estuary defences, but, in June 1915, 1/1st–1/3rd Works Companies left and were converted to Field Companies for service overseas; 1/6th and 1/7th Companies also formed field companies that served in home defence. 4th and 5th EL Companies appear to have remained in the Thames defences throughout the war.Watson & Rinaldi, p. 70.

1st Kent Fortress Field Company In June 1915, this company left, embarking for the Gallipoli on 23 September.'Embarkation Dates', The National Archives (TNA), Kew file WO 162/7. On arrival at Suvla Bay, on 7 October, it was attached to the 2nd Mounted Division. The division was evacuated to Egypt in December and broken up in January 1916.Watson & Rinaldi, p. 26.Becke, Pt 2a, pp. 9–17. The field company was then attached to 54th (East Anglian) Division in the Suez Canal defences on 1 July.Becke, Pt 2a, pp. 125–31.Watson & Rinaldi, p. 36. The company was redesignated 495th (1st Kent) Field Company on 1 February 1917.Watson & Rinaldi, p. 61. In March, it advanced with 54th Division into Palestine and fought in the First and Second Battle of Gaza. It joined 75th Division on 7 August 1917 and served with it during the Third Battle of Gaza but returned to the 54th in May 1918 when the 75th was partly Indianised. 495th Company remained with 54th Division for the final advance in Palestine (the Battle of Megiddo). 495th Company was demobilised during 1919.Watson & Rinaldi, p. 39.Becke, Pt 2b, pp. 123–30.

2nd Kent Fortress Field Company 1/2nd Field company also embarked on 23 September and joined 2nd Mounted Division at Suvla. After evacuation to Egypt, it was posted to the Suez Canal defences, took part in the Senussi campaign, and was redesignated 496th (2nd Kent) Field Company on 1 February 1917. It joined the newly formed 74th (Yeomanry) Division on 24 March 1917.Becke, Pt 2b, pp. 117–22.Watson & Rinaldi, p. 38. On 25 May, the company was transferred to 53rd (Welsh) Division and then transferred again on 4 July to 75th Division. Unlike 495 Company, it remained with 75th Division until the end of the war, operating alongside two companies of Queen Victoria's Own Madras Sappers & Miners of the Indian Army. 496th Company began demobilisation in February 1919.

3rd Kent Fortress Field Company The 1/3rd Field Company was largely recruited from Tonbridge and the surrounding villages.

HMS Hythe disaster On 13 October 1915, the company left its depot at Gillingham and proceeded to Devonport, where it boarded the troopship Scotian bound for Gallipoli via Mudros. On arrival at Mudros, on 27 October, the troops were transferred to the auxiliary minesweeper HMS Hythe to be landed at Suvla Bay the following morning. In the early hours of 28 October, the Hythe was involved in a collision with the much larger troopship Sarnia. The Hythe sank within minutes, taking down most of its crew and passengers. The company lost its Officer Commanding, Capt D.R. Salomons (only son and heir of the honorary colonel), and 128 other ranks, almost all recruited from the Tonbridge area. The survivors (4 officers and 78 other ranks) were picked up by the Sarnia and returned to Mudros.Becke, Pt 2a, p. 111.

On 20 November, the company (now reduced to 4 officers and 78 other ranks) re-embarked and landed the same day at Cape Helles, where it was attached to 52nd (Lowland) Division.

Western Front On the night of 7/8 January 1916, 52nd Division was evacuated from Helles and withdrawn to Egypt. Here the 3rd Kent Field Company transferred to the 29th Division, which proceeded to the Western Front in March.Watson & Rinaldi, p. 32.Becke, Pt 1, pp. 117–24. On the first day of the Battle of the Somme the company was attached to one of the attacking brigades, but continuing work on communications and water supply meant that only a small portion of the company went into action.Edmonds, pp. 428–9. The company participated in the Battles of Arras and 3rd Ypres in 1917. On the morning of 30 November 1917, when the Germans counterattacked after the Battle of Cambrai, the company was sleeping in a tunnel at the brewery at Les Rue Vertes after a hard night's work. The company was taken by surprise and captured.Miles, 1917, Vol III, p. 207. The reformed company served at the Battle of the Lys (1918), and finally the Hundred Days Offensive. It became 497th (3rd Kent) Field Company on 1 February 1917, and had been disbanded by mid-March 1919.

1/6th and 1/7th Kent Fortress Companies With the further expansion of the army, the Kent Fortress RE organised the 1/6th and 1/7th Kent Fortress Companies to which the Cinque Ports Fortress Royal Engineers also contributed personnel. In late 1916, the 1/6th and 1/7th were converted to field companies and had joined 73rd Division by 22 November. 73rd Division was a newly organised Home Service formation concentrating at Blackpool. Once organised, the division moved in January 1917 into Essex and Hertfordshire to form part of Southern Army (Home Forces); the engineers were stationed at Witham and Chelmsford. The two field companies were numbered 546th (1/6th Kent) and 547th (1/7th Kent) in February 1917.Watson & Rinaldi, p. 62.Becke, Pt2b, pp. 111–6.

73rd Division's main role was to train and physically condition men for drafting as reinforcements for units serving overseas. By the end of 1917, the division's infantry battalions had largely completed their task and been replaced by training units, whereupon the division was broken up as a Home Defence formation. 546th and 547th Field Companies were redesignated Army Troops Companies and embarked for the Western Front on 22 June 1918,TNA file WO 162/7. landing at Le Havre the following day, and working in the Third Army and Fourth Army areas respectively from 7 July.

The two companies were engaged in engineering works associated with the rapid advance of the British Expeditionary Force in the final months of the war. 546 Company had transferred to Fourth Army by the time of the Armistice, while 547 Company moved to VI Corps in September and to Third Army by November 1918.Watson & Rinaldi, pp. 20–2.

546th and 547th Army Field Companies were disbanded in France on 4 June 1919 and 1 May 1919 respectively.

Second and Third Lines The 2/1st, 2/2nd, 2/3rd, 3/1st, 3/2nd and 3/3rd Kent Fortress Companies later formed a holding and training company, which was numbered 499th (Home Counties) Field Company (alternatively referred to as 499th (Kent) Reserve Company).

2/6th Company later became 579th (Kent) Works Company, while 2/7th Company became an HQ and Deport company for the KFRE, and was later numbered as 580th (Thames & Medway) Fortress Company.Watson & Rinaldi, p. 64.RE Museum list of WWI unit war diaries.

2/4th Company became 598th (Kent) Works Company, later 598th (Thames & Medway) Works Company, and after the remaining TF personnel had been demobilised in 1919 was used to reform the Regular Army 39th Fortress Company, RE, at Sheerness. The Kent Fortress Royal Engineers may also have been the parent for 599th (Thames & Medway) Fortress Company.Watson & Rinaldi, pp. 43, 64.

Interwar The Kent Fortress RE was not reformed in the Territorial Army immediately after the war, but was recreated in 1932 by Major (later Brigadier) Clifford Brazier, the works manager of Bevans Cement Works (later Blue Circle Cement Company) at Northfleet, and largely recruited from his employees.George Letchford at BBC WW2 People's War.

The new unit consisted of Nos 1, 2 and 3 Electric Light and Works Companies.Watson & Rinaldi, p. 104. Personnel from the KFRE appear to have provided the basis for 347 (Kent) Anti-Aircraft Searchlight Company, RE, formed at Sidcup in 29th (Kent) Anti-Aircraft Battalion, RE, in October 1937.Watson & Rinaldi, pp. 108, 113. In April 1939, 347 Company became part of (and gave its name to) a new 73rd (Kent Fortress) AA Battalion.

World War II

Mobilisation On the outbreak of war in 1939, one of the war stations of the Northfleet Section was to man the 120 cm searchlights at Coalhouse Fort at East Tilbury on the north bank of the Thames Estuary. These new remote-controlled 'fighting lights' installed on the north Caponier of the fort were powered by Hornsby engines and enabled the fort's 6-inch coast defence guns to fire at night. Anti-aircraft searchlights were also installed at the fort.Smith, p. 26.

XD operations Germany started the War with her access to oil critical to her plans. Her annual supply was 44 million barrels and over 90% was imported, 60% from outside Europe. Her peak stocks, immediately before the invasion of Russia only reached 56 million barrels.Keller p 5,6 Thus, at the outbreak of war, British strategic planning saw the importance of denying to the Germans the 20 million barrels (two and a half million tons) of oil sitting in refineries in France and the Low Countries. The task was allocated to the divisional engineers of 12th Division(TA) as early as September 1939.Packenham-Walsh, Volume VIII, p76 That unit was sent to France, however, with its division so the role was belatedly transferred to the KFRE, in April 1940,Packenham-Walshe, p76 requiring a field company to carry out tasks for which regimental strength had been planned.

Three small parties of the KFRE were kept at two hour notice to cover the principal installations in Amsterdam, Rotterdam and Flushing.Brazier, p15 Each detachment was to operate under naval command, with tasks to KFRE, unusually, coming direct from the Army's Director of Military Operations.Brazier, p80 The whole programme was named the "XD Operations".