Due to the numbers of vehicles and troops to be loaded (35,000 personnel and 5,560 vehicles at Tilbury and 10,700 personnel and 1,910 vehicles at Felixstowe), it was planned to start loading at D-7. Concentration of forces was to commence on May 10th and be complete by May 14th. This did not prove to be achievable and concentration continued up to May 29th. The main reason for the delay was caused by confusion arising from troops detailed to concentrate in R and S areas which were temporality placed under the command of 1 or 30 Corps, both whose HQ was outside Eastern Command’s area. Confusion also arose between the Corps HQ, Eastern Command HQ and 21 Army Group HQ. Concentration was at times chaotic with some units arriving with a surplus of equipment, some with deficiencies, and some not moving on the appointed day then arriving unannounced on another day. Some units were not fully mobilised on the day they were ordered to move. For example on one occasion in S Area, preparations to receive 600 men and 200 vehicles were made but only three men in a jeep turned up! On another occasion, a unit arriving in R Area thought it was just another exercise, turning up in a number of decrepit vehicles, determined not to be caught in “another ruddy exercise” and had left their best vehicles behind “for the real thing”. A few quick phone calls were required to bring up the real vehicles!
Eastern Command was responsible for the co-ordination of all road traffic except within the Marshalling Areas, where the various HQ’s were responsible. Two Military Police (Traffic Control) companies (29th and 76th) Coy’s were allotted to Eastern Command by GHQ Home Forces and 21 Army Group provided another two companies (25th and 26th Coy’s).
76th TC Company was allotted to R area and 25th in Q area. 29th TC was allocated to S area and 26th to the back areas, especially for S area. These Companies were responsible for the erection and maintenance of signage as well as providing static pointsmen. In addition they provided personnel for the actual marshalling of vehicles and also Dispatch Riders to act as guides between Traffic Control Points and camps / embarkation areas.
The Civil Authorities were concerned about the effect of heavy military traffic on roads on civilian life and especially road closures. In the end, broad agreement was made between the Military with the Regional Commissioner and Regional Transport Commissioner. In reality the only road closures were those roads to be used as Marshalling parks. All roads scheduled for closure were closed on May 24th until further notice. In accordance with the cover plan, roads in R area were closed after the Marshalling areas had ceased to operate for a period of two days on two occasions.
To cut down on confusion and to canalise traffic, 15 standard routes were selected. There was insufficient Traffic Control troops to cover all these routes so it was decided to patrol and sign post the routes within an arc of 25 to 50 miles from Tilbury only. Signs were black on white, enamelled and made of heavy gauge metal and were of large dimensions – “only an idiot could have lost his way”. Diversions for the civil population were carried out by the police, using standard AA signs.
Preliminary discussions with the railway companies, LMS and LNE, began in December 1943 regarding the use of rail facilities. A meeting in January 1944 estimated that the rail resources required would be:
36 Armoured Fighting Vehicle trains to Purfleet .
22 trains for carriers and personnel to Brentwood area
12 trains for carriers and personnel to Southend area
12 trains for carriers and personnel to Ipswich area
17 trains (in one day) from Brentwood to Tilbury
7 trains from Southend to Tilbury
9 to 10 trains per day into S Marshalling Area
These figures caused concern to the railway companies. Every effort was made to acquire additional resources to move by road. A change of plans for Force L resulted in almost all the AFV’s being handled at Felixstowe and as the formation concerned was located in Eastern Command this move took place by road. In the end, the need to use rail was nowhere near on the scale envisaged and many movements could take place on normal services with only a small number of special services required.
R area - a force of 10,700 personnel and 1,910 vehicles was to be loaded into 20 LST and 40 LCT.
S area - In all the following forces were concentrated and moved through S area:
Force L – 11,900 personnel and 1,740 vehicles for loading into 26 LSTs, 3 LSTs(I) and 16 LCIs(L)
First British Build-up (known as the “WARLEY” build-up) – 23,500 personnel and 3,820 vehicles for loading into 25 MT ships and 4 LSPs.
It was recognised that it would be impossible to conceal the concentrations from the enemy. Thus the general principle was concealing the details of the operation rather than the concentration of forces to mount it, in particular to conceal the objectives and date of the invasion.
It was considered the enemy may try and disrupt operations by:
Enemy agents landed by parachute, submarine or E-boat who would collect and transmit details of the operation or try to disrupt it by sabotage.
Airborne raids by not more than 200 troops
Air attack perhaps a concentrated first attack by 250 bombers and then a curtailed scale of attack by 50 sorties per night for to or three nights a week. Germany was thought to only have sufficient fighter-bombers to mount 50 sorties by day and 25 by night.
The use of rockets and fly-bombs was considered but the use of gas, of which measures had to be taken to guard against, as considered unlikely.
The main defensive arrangements fell on the Home Guard to avoid calling upon the resources of 21st Army Group. It was decided on national considerations not to muster the Home Guard for operational duties, so the Home Guard resource had to be found from the compulsory part-time duty of the Home Guard i.e. a maximum of 48 hours duty in four weeks. Home Guard members could of course volunteer for additional duties and there was no shortage of these volunteers but many employers were unwilling to release them from work. The military was disappointed with the civil ministries refusal to treat the requests for additional Home Guard service as generously as possible for employees of formations and establishments under their control.
The duties of the Home Guard included guard duties along the part of the coast considered vulnerable to raids, provision of mobile patrols and inlaying pickets for the protection of the main transport routes and marshalling areas, guards for vulnerable points connected with Overlord and a readiness to undertake decontamination duties. In addition, some Coastal batteries were to be manned at short notice and of those manned by the Home Guard, 12 men were on duty every night.
In all, there was at least 5,000 Home Guard employed on operational duties every night throughout Eastern Command for seven weeks. This often included men undertaking duties beyond what was expected of Home Guard duties. For example men from inland areas often volunteered to undertake coast watching duties for seven days at a time. Even in West Norfolk, which was not within the area affected by Overlord, some Home Guard undertook nightly patrols.
Some regular troops were available as a mobile reserve; Belgian troops stationed at Lowestoft, the Royal Netherlands Brigade at Harwich, a company of the Royal Scots for Tilbury and 1 Royal Gloucestershire Hussars as a District Reserve.
AA Command provided a total of 26 HAA and 152 LAA guns for the protection of Embarkation points and Marshalling areas. The balloon barrage was extended and smoke screens were provided for Tilbury, Yarmouth and Ipswich. These smoke screens were designed to operate by night during alerts and were ready by 26th April.
The construction of camps and infrastructure connected with Overlord was a formidable task. Construction of hards was started under the direction of CRE Special Services in November 1942 and was completed before camp construction began. In all nine major camps were constructed to accommodate 40,000 troops, two existing camps and barracks enlarged and buildings requisitioned and made ready for military occupation. This work was carried out by two Field Coys, two Artizan Works Coys and eight Pioneer Coys. In addition, the Americans constructed a large camp at Fritton Warren (Q Area).
Provision had to be made for AA Command, with accommodation often improvised from poles and corrugated iron.
The Ministry of War Transport, under District Royal Engineers, undertook considerable road improvements and hard core was dumped at certain points to facilitate rapid road repairs and bomb damage. Nearly 20,000 enamelled signs were provided.
A hospital was nominated in each Marshalling area to act as a Casualty Clearing Station. Arrangements had also to be made to receive the return flow of wounded from the beach heads in medically equipped LSTs and hospital ships.