On 3 Sep 1939, the strength of the RE was 13,025 Regulars and 76,276 Territorial Army and Supplementary Reserve personnel, for a Corps total of 89,301. This increased substantially during the war, to a peak of 280,632. RE strength reduced somewhat during the war, but on 1 Jan 1945 the total was still 257,900.
Of these, 62% were in field, line of communications, or works roles; 33% in transportation; 1 ½% in survey units; 2 ½% in Movement Control, and 1% in postal duties.
The Corps was smaller than during the First World War. However, the variety of units raised far surpassed that of any earlier period.
The varied roles performed by RE squadrons and companies can be seen in the following list:
• Armoured Engineer Squadron
• Armoured Corps Field Survey Squadron
• Army Troops Company
• Artizan Works Company
• Armoured Engineer Squadron (ex Assault Squadron)
• Armoured Engineer Park Squadron
• Bomb Disposal Company
• Construction Company
• Dredging Company
• Electrical and Mechanical Company
• Field Camouflage Company
• Field Company
• Field Squadron
• Field Company (Airborne)
• Field Park Company
• Field Park Company (Airborne)
• Field Park Squadron
• Forestry Company
• Fortress Company
• Inland Waterways Transport Heavy Workshop Company
• Inland Waterways Transport Light Aid Workshop Company
• Inland Waterways Operating Company
• Map Supply Company
• Mechanical Equipment Company
• Mechanical Equipment (Transportation) Company
• Mechanical Equipment Park Company
• Movement Control Company
• Parachute Squadron
• Port Artizan Company
• Port Construction and Repair Company
• Port Maintenance Company
• Port Operating Company
• Quarrying Company
• Railway Bridging Company
• Railway Construction Company
• Railway Operating Company
• Railway Survey Company
• Railway Workshop Company
• Road Construction Company
• Survey Company
• Tunnelling Company
• Transportation Stores Company
• Workshop and Park Company
The sheer number and variety of units is staggering, and companies and squadrons could be renumbered or converted to other roles as well. @1
The variety of units is repeated in the variety of headquarters that can be found during the war. A completely new type of headquarters, the army group, RE (AGRE) appeared about 1943. This had no fixed organization, but could command a variety of other engineer units and headquarters. Unlike the First War, army troops RE (ATRE) was normally a fixed formation (three field companies and a field park company), and the numbers could but did not necessarily reflect the army to which they might be assigned. GHQ troops RE (GHQTRE) was a similar type of organization.
Corps troops RE (CTRE) numbers, as in the prior war, did reflect the corps to which they were assigned, although some CTRE were formed with designations other than a corps number. And there were many other types of headquarters as well. The Second, more so than the First, was truly a world war, and engineer support came from sources other than the Royal Engineers. A few examples may suffice. The many Indian divisions, of course, received their companies from the Indian Engineers. In addition, virtually all of the engineer units in the Far East were IE, as were almost all of those in Persia and Iraq. @2 Other IE units supported the campaign in Italy.
The South African Engineer Corps had GHQ units in East and North Africa, and provided a corps troops engineers for Italy. The Royal Canadian Engineers supported their divisions, and also provided army troops and corps troops engineers and other GHQ units for the UK, Italy, and NW Europe. Australia and New Zealand both provided engineers for North Africa and the Middle East in the early years of the war.
Given the complexity of unit types, the numbering was less clear-cut than had been the case in the First World War. Field squadrons were originally in one series, from 1 to 21. However, in 1943 and 1944 one squadron in each division added 600 to its number, giving them what had been vacant numbers in the series for companies. Field park squadrons were mostly numbered 141 to 149, again taking numbers from the company series. When assault (later armoured) engineer squadrons were formed, they simply kept whatever number they had (whether originally a field squadron or field company).
The units formed in Italy in 1944 and 1945 were given lettered designations. Parachute squadrons were originally numbered in their own series, but the last squadron formed kept its former number as a field company. The airborne field and field park companies kept their old numbers. In 1945 these became airborne and airborne park squadrons, with whatever number they had. With regard to the numbering of field companies, numbers 1-59 were Regular companies with a variety of roles (and a number of gaps). Numbers in the range 100-110 and 150-157 were Supplementary Reserve companies; those within the 200-299 range were TA companies.
The number range 300-469 was allocated to AA companies.3 Other number ranges contained a variety of types of unit. From 60 to 99 there was a mixture of war-formed chemical warfare and field companies. With several exclusions and exceptions, companies in the 111-140 and 158-199 range were mainly war-formed construction units. In the ranges 500-599 and 600-699 there was a mixture of second line TA units and war-formed companies of many types. In general the higher numbered ranges were : 700-899 war-formed construction, 900-999 port and inland waterway companies, 1000-1099 docks companies. There were also a few numbers higher than that.
@ 1 All identified units and available information on their assignments and changes during the war is given here. In some cases, information on the activation of war formed units is sketchy, and the dates when units were disbanded or placed in suspended animation is even more limited. In this section, disbanded “Sep 1945+” indicates a date of Sep 1945 or later (given the limited information, “disbanded” in this section can include units actually placed in suspended animation). Again, the authors wish to thank David A. Ryan for his assistance in providing additional information and corrections to a draft of this section, filling in a number of gaps.
@ 2 A list of engineer units in the Middle East from WO169, circa 1942, shows exactly two RE companies and 85 IE companies/squadrons.