Continuity mistake: When we see Ryan walking at the very start, he walks past a group of 3 people walking in the other direction. Camera cuts to show the front of Ryan and behind him and the people have miraculously disappeared. There is no way the could have walked out of sight, and there is no way they couldn't have arrived in sight either. (00:01:10)
Continuity mistake: At the start we see a close up of Ryan's face and in the background is a couple walking away. The bloke has a blue baseball cap on and dark shirt while the woman has got a light blue top and what appears to be a cream coloured skirt on. The camera then shows Ryan back as he is walking and now this couple are in front of Ryan about to walk past him. (00:01:15)
Continuity mistake: In the opening scene, when old James Ryan's family is behind him in the wider shot, one of the three blonde girls at the back has her hair over her ear and her right hand down by her side. In the following closeup of her, her hair is now behind her ear and her hand is up by her bag strap. (00:01:30)
Factual error: After the soldiers' initial disembarkment they are shown crouching in groups near the shore and later running towards the bunkers. Unlike the movie shows, anything even as simple as crouching behind the tank traps, let alone actually standing up and running, was impossible at Dog Green Sector and indeed for anyone when pinned down by a machine gun from a high far-away position. In the real-life landing at Dog Green within 7-10 minutes all the officers of the landing company were dead and the survivors inert. They could do nothing except throw away all their equipment and slowly crawl up the beach, shielded from bullets by the incoming tide and dead bodies. 1 hour 40 minutes after landing twelve (known) survivors made it to the base of the cliffs. Only 2 had enough strength left to go on and fight with another group. (The second wave, apart from one boat which was almost entirely killed, opted to land elsewhere when they saw the fate of the first wave.) In this way the movie rather poorly represents what it meant to make a properly opposed landing on D-Day - although whether this is justified or not is another matter. (00:07:00 - 00:07:40)
Revealing mistake: In the opening sequence Cpt Miller is wading through the sea with another man. You can see an odd looking square-shaped object clearly through his wet uniform. It may come as no surprise that a second later he is shot dead centre of the pocket. The object was obviously a charge. (00:07:45)
Continuity mistake: When Miller first hits the sand at Omaha a mortar round blows up behind him. He kneels in the sand, his face covered with bloody water. Seconds later a young soldier shouts at him and suddenly Miller is chest deep in the water with a clean face. Also his helmet liner strap changes position across the visor of his helmet. (00:08:35 - 00:09:50)
Factual error: The "tank traps" (actually designed to flip landing craft, when submerged) on Omaha are back-to-front. The bottom of the pole that that rests on the other two should be nearest the sea and not as shown in the movie. Documentary footage of the actual landings will confirm this. (00:09:15)
Continuity mistake: When Miller is shocked, we see him in a close up with his hair slicked into a point on his forehead. Camera shows a few people taking shelter under a tank trap and back to Miller. In this shot, his hair is arranged completely differently. He didn't touch it himself, as he is supporting himself on a tank trap with one hand and holding his helmet in his second hand. (00:09:15)
Continuity mistake: During the beach scene, Miller is kneeling at the rear of a Belgian fence talking about the beach being pre-sighted. There is a soldier in front of the fence who gets shot three or four times. If you look the first scene, he gets shot in the upper leg area, then when Miller moves out from behind the obstacle, the bullet wound has magically disappeared. (00:11:15)
Audio problem: On the beach, a soldier with a B.A.R. puts his arm around Captain Miller's neck and says they don't have a chance. His line carries over to the next shot of Miller unwrapping his Thompson, but we can see that soldier behind Miller, and he's not talking. (00:16:00)
Revealing mistake: In the Omaha Beach fight when the soldiers are ordered to gather more weapons and ammo, there is a massive explosion shortly after - if you look closely you can see the wires used to pull the unfortunate victims into the air. (00:16:25)
Continuity mistake: At the start of the movie on Omaha Beach, just before Tom Hanks and the others clear the fence with the Bangalore torpedoes, a man is shot and it ricochets off his helmet, but in the previous scene he can be seen looking at Tom Hanks, in the following shot he is looking away towards the bunkers. (00:16:50)
Continuity mistake: In the beach scene, a GI takes a shot in the helmet, removes his helmet while he collects his sense, and is promptly shot in the head. As he falls back, his head lolls back, yet when the camera angle changes, his chin is tucked down in his chest. (00:17:40)
Continuity mistake: During the Omaha beach scene, when Miller, Horvath and a few other soldiers are at the front of one of the bunkers trying to get past the firing squad, he puts down his knife with the mirror attached and grabs his gun, holding it underneath, but in the following shot he is holding it at the top. (00:19:35)
Continuity mistake: At the beginning of the film when we see Tom Hanks below the big bunker, and he tells Jackson to get in an impact crater, Jackson kisses his cross with his right hand, but in the following shot, he is suddenly holding his rifle. (00:20:20)
Continuity mistake: During the Omaha Beach scene where Captain Miller is at the front of the concrete bunker and calls upon Jackson to get into one of the impact craters, Miller moves behind Jackson. When Miller makes the move for the diversion he puts his hand on Jackson's right shoulder but in the following shot Miller is at least 2 to 3 feet away from Jackson. (00:20:20)
Audio problem: After the Rangers break through the German lines at Normandy, Captain Miller delivers a message on the hand radio. After he turns his back to the camera and stops talking, he continues to move his mouth. (00:24:30)
Factual error: The typing pool scene, in which we first learn about Private Ryan, features vintage typewriters of various makes and models being used to notify families of soldiers killed in action. One of the first typewriters we see is a Swiss-made Hermes Ambassador from the mid-1950's. (00:28:40)
Continuity mistake: At the start of the film in the telegraph scene, a Captain goes into the Colonel's office to tell him about the Ryan brothers. He is holding a folder which he puts on the Colonel's desk, but we don't see him pick it back up in all the following shots, yet it suddenly appears back in his hands. (00:29:15)
Continuity mistake: When discovering that 3 of the 4 brothers were killed, it's stated that they were all in the same company until they were split after the Juneau was sunk. We also see a few shots later when the Army car is pulling up to the mother's house that there is a picture of all 4 of them together in uniform. When Miller and Ryan are talking about Ryan's memory of his brother towards the end of the movie, he states that the last time the 4 of them were together was the night of the barn accident before Dan went to basic. (00:29:30)
Answer: These were barrage balloons, commonly used during the war. They are used to stop low level bombing and low level fly bys by enemy fighter planes. The cables attached to the balloons are designed to cut through the wings of the aircraft and to bring them down, so any pilot would have to fly above them, and the balloons would also restrict the view from above.