Factual error: The naval captain in this episode has a military mustache as prescribed by army regulations. The Royal Navy regulations, however, prohibited separate mustaches and beards - if facial hair was worn, a "full set" of beard and mustache with the beard joined to the mustache was mandatory, and that to be grown to the commanding officer's satisfaction within six weeks.
Factual error: Foyle is subordinate to an Assistant Commissioner of the Metropolitan Police, but Hastings had its own force (merged with other Sussex forces 1943-47) and the Met had no jurisdiction outside London.
Factual error: When Sam reads the newspaper, one article claims that 254 people were killed in a Paris air raid. This episode takes place in February 1941, when Paris was already occupied by the Germans, and England did not bomb Paris. Oddly enough, this same article appears in a previous episode.
Factual error: The American flag shown has 50 stars, not the 48 stars that were on the flag at that time.
Factual error: While this episode is set in 1946, early in the London street scenes a red Routemaster bus is prominently featured. The first of these buses was not delivered to London Transport until 1956.
Enemy Fire - S3-E2
Factual error: While repairing Mary Wrenn's lights Gordon Drake says "Someone fused the ring main with a 3 amp fuse." It was February 1941 but ring mains were not introduced until 1947. (00:14:50)
Factual error: A sign says "REMEMBER THE ENEMY IS LISTENING" in Chicago typeface, but this font wasn't invented until 1984. (01:15:50)
Fifty Ships - S2-E1
Factual error: In the scene when Foyle meets the Home Guard colonel, Letwin, the colonel, has his Sam Browne belt slung over his left shoulder which is totally wrong, especially for an officer risen to field rank. Apart from being intended to provide support for the officer's sword (even if not worn and even if his service revolver is likely to induce sagging), the belt slung over the left shoulder will obscure medal ribbons. Horror of horrors.
Factual error: The episode takes place in 1946. Numerous scenes are shown in which the public buildings are clean. In 1946 they were soot streaked and grimy black and white from generations of coal fires and pollution. In addition one street scene has a street sign on a pole with a modern graphical notice on it rather than a worded notice of the time. Also, in the same scene the street name plate has a rather updated type face.
Factual error: Foyle's son is assigned to be a target for radar tracking, and he is assigned a Spitfire. However, the aircraft depicted is a four-bladed model, which didn't exist in 1940.
Factual error: Sergeant Brooks calls Det Sgt Milner "Sir" but they are of equal rank.
Factual error: The episode is in May 1940. The ship in the photo that causes the arrest of Thomas Kramer is a King George V class battleship. The lead ship of the class was commissioned 11 Dec 1940.
Factual error: A number of the cars have number plates in which the numbers precede the letters, whereas at the time the letters came first.
Factual error: In this episode - in 1942 - streptomycin is used to cure anthrax infection. But streptomycin was first isolated in 1943, and first used successfully - on Sen. Bob Dole - in 1946.
Factual error: SS officers did not carry a unit identification tattoo on the forearm, as implied in this episode. Most (but not all) carried a small, black, blood group tattoo under the armpit.
Factual error: Foyle is a Chief Superintendent. But the series is set during the Second World War and the rank was not introduced until 1949.
Factual error: In the sequence where Michael runs over the innkeeper Judd, the car which comes up behind Judd has very bright headlights with the characteristic three spokes towards the centre. At that time, all cars had to have masked headlights as could be seen elsewhere, including on the earlier shots of the green SS Jaguar outside the pub in daylight. Also, when the car lights are first switched on, it looks as if the later Hartley (louvered) masks were used rather than the early hooded type.
Factual error: Fort Benning is stated to be in Virginia. It actually spans the Georgia - Alabama state line.
Factual error: Eternity Ring is set in 1946. Samantha was accused of spying because she was seen with a man outside The Old Vic. She admits seeing a play there but not the play alleged (Henry V instead of The Cherry Orchard). The Old Vic was bombed in the Blitz and was closed from 1941 to 1950.
Factual error: Foyle is disembarking from a trans-Atlantic voyage from a ship which, in long shot, is painted in Union-Castle line colours. This line served African ports, not the USA. Their ships had lavender-coloured hulls from the mid-50s.
Answer: They are using the accepted names of the bombs. During World War 2 the Germans used the metric system and produced bombs ranging from 50kg to 2500kg. Referring to the weight of the bombs in pounds (or fractions of tons) risked confusing the situation and would require someone to understand how to convert from imperial measures to metric, not an easy thing to do when under stress.