a German casemate at Omaha Beach, (Normandy) on Flickr.Via Flickr:
Omaha was divided into ten sectors, codenamed (from west to east): Able, Baker, Charlie, Dog Green, Dog White, Dog Red, Easy Green, Easy Red, Fox Green and Fox Red. The initial assault was to be made by two Regimental Combat Teams (RCT), supported by two tank battalions, with two battalions of Rangers also attached. The infantry regiments were organized into three battalions each of around 1,000 men. Each battalion was organized as three rifle companies each of up to 240 men, and a support company of up to 190 men.[14] Infantry companies A through D belonged to the 1st battalion of a regiment, E through H to the 2nd, I through M to the 3rd; the letter ‘J’ was not used. (Individual companies will be referred to in this article by company and regiment, e.g. Company A of the 116th RCT will be A/116). In addition, each battalion had a headquarters company of up to 180 men. The tank battalions consisted of three companies, A through C, each of 16 tanks, while the Ranger battalions were organized into six companies, A through F, of around 65 men per company.
The 116th RCT of the 29th Infantry Division was to land two battalions in the western four sectors, to be followed 30 minutes later by the third battalion. Their landings were to be supported by the tanks of the 743rd Tank Battalion; two companies swimming ashore in amphibious DD tanks and the remaining company landing directly onto the beach from assault craft. To the left of the 116th RCT the 16th RCT of the 1st Infantry Division was also to land two battalions with the third following 30 minutes after, on Easy Red and Fox Green at the eastern end of Omaha. Their tank support was to be provided by the 741st Tank Battalion, again two companies swimming ashore and the third landed conventionally. Three companies of the 2nd Ranger Battalion were to take a fortified battery at Pointe du Hoc, three miles (5 km) to the west of Omaha. Meanwhile C company 2nd Rangers was to land on the right of the 116th RCT and take the positions at Pointe de la Percée. The remaining companies of 2nd Rangers and the 5th Ranger Battalion were to follow up at Pointe du Hoc if that action proved to be successful, otherwise they were to follow the 116th into Dog Green and proceed to Pointe du Hoc overland.[15]
The landings were scheduled to start at 06:30, “H-Hour”, on a flooding tide, preceded by a 40-minute naval and 30-minute aerial bombardment of the beach defenses, with the DD tanks arriving five minutes before H-Hour. The infantry were organized into specially equipped assault sections, 32 men strong, one section to a landing craft, with each section assigned specific objectives in reducing the beach defenses. Immediately behind the first landings the Special Engineer Task Force was to land with the mission of clearing and marking lanes through the beach obstacles. This would allow the larger ships of the follow-up landings to get through safely at high tide. The landing of artillery support was scheduled to start at H+90 minutes while the main build up of vehicles was to start at H+180 minutes. At H+195 minutes two further Regimental Combat Teams, the 115th RCT of the 29th Infantry Division and the 18th RCT of the 1st Infantry Division were to land, with the 26th RCT of the 1st Infantry Division to be landed on the orders of the V Corps commander.[16]
The objective was for the beach defenses to be cleared by H+2 hours, whereupon the assault sections were to reorganize, continuing the battle in battalion formations. The draws were to be opened to allow traffic to exit the beach by H+3 hours. By the end of the day, the forces at Omaha were to have established a bridgehead five miles (8 km) deep, linked up with the British 50th Division landed at Gold Beach to the east, and be in position to move on Isigny the next day, linking up with the American VII Corps at Utah Beach to the west.[17]
The assault force expected to execute this plan totaled over 34,000 men and 3,300 vehicles, with naval support provided by two battleships, three cruisers, 12 destroyers, and 105 other ships. These were provided predominantly by the US Navy, but also included British and Free French warships.[18] The 16th RCT (swollen by 3,502 men and 295 vehicles attached only for the beach landing) numbered 9,828 troops, 919 vehicles and 48 tanks. To move this force required 2 transport ships, 6 Landing Ships, Tank (LSTs), 53 LCTs, 5 Landing Craft Infantry (Large) (LCI/(L)s), 81 LCVPs, 18 LCAs, 13 other landing craft, and about 64 DUKWs.[19] Assault craft were crewed by the US Navy, US Coast Guard and the British Royal Navy.[20]

a German casemate at Omaha Beach, (Normandy) on Flickr.

Via Flickr:
Omaha was divided into ten sectors, codenamed (from west to east): Able, Baker, Charlie, Dog Green, Dog White, Dog Red, Easy Green, Easy Red, Fox Green and Fox Red. The initial assault was to be made by two Regimental Combat Teams (RCT), supported by two tank battalions, with two battalions of Rangers also attached. The infantry regiments were organized into three battalions each of around 1,000 men. Each battalion was organized as three rifle companies each of up to 240 men, and a support company of up to 190 men.[14] Infantry companies A through D belonged to the 1st battalion of a regiment, E through H to the 2nd, I through M to the 3rd; the letter ‘J’ was not used. (Individual companies will be referred to in this article by company and regiment, e.g. Company A of the 116th RCT will be A/116). In addition, each battalion had a headquarters company of up to 180 men. The tank battalions consisted of three companies, A through C, each of 16 tanks, while the Ranger battalions were organized into six companies, A through F, of around 65 men per company.
The 116th RCT of the 29th Infantry Division was to land two battalions in the western four sectors, to be followed 30 minutes later by the third battalion. Their landings were to be supported by the tanks of the 743rd Tank Battalion; two companies swimming ashore in amphibious DD tanks and the remaining company landing directly onto the beach from assault craft. To the left of the 116th RCT the 16th RCT of the 1st Infantry Division was also to land two battalions with the third following 30 minutes after, on Easy Red and Fox Green at the eastern end of Omaha. Their tank support was to be provided by the 741st Tank Battalion, again two companies swimming ashore and the third landed conventionally. Three companies of the 2nd Ranger Battalion were to take a fortified battery at Pointe du Hoc, three miles (5 km) to the west of Omaha. Meanwhile C company 2nd Rangers was to land on the right of the 116th RCT and take the positions at Pointe de la Percée. The remaining companies of 2nd Rangers and the 5th Ranger Battalion were to follow up at Pointe du Hoc if that action proved to be successful, otherwise they were to follow the 116th into Dog Green and proceed to Pointe du Hoc overland.[15]
The landings were scheduled to start at 06:30, “H-Hour”, on a flooding tide, preceded by a 40-minute naval and 30-minute aerial bombardment of the beach defenses, with the DD tanks arriving five minutes before H-Hour. The infantry were organized into specially equipped assault sections, 32 men strong, one section to a landing craft, with each section assigned specific objectives in reducing the beach defenses. Immediately behind the first landings the Special Engineer Task Force was to land with the mission of clearing and marking lanes through the beach obstacles. This would allow the larger ships of the follow-up landings to get through safely at high tide. The landing of artillery support was scheduled to start at H+90 minutes while the main build up of vehicles was to start at H+180 minutes. At H+195 minutes two further Regimental Combat Teams, the 115th RCT of the 29th Infantry Division and the 18th RCT of the 1st Infantry Division were to land, with the 26th RCT of the 1st Infantry Division to be landed on the orders of the V Corps commander.[16]
The objective was for the beach defenses to be cleared by H+2 hours, whereupon the assault sections were to reorganize, continuing the battle in battalion formations. The draws were to be opened to allow traffic to exit the beach by H+3 hours. By the end of the day, the forces at Omaha were to have established a bridgehead five miles (8 km) deep, linked up with the British 50th Division landed at Gold Beach to the east, and be in position to move on Isigny the next day, linking up with the American VII Corps at Utah Beach to the west.[17]
The assault force expected to execute this plan totaled over 34,000 men and 3,300 vehicles, with naval support provided by two battleships, three cruisers, 12 destroyers, and 105 other ships. These were provided predominantly by the US Navy, but also included British and Free French warships.[18] The 16th RCT (swollen by 3,502 men and 295 vehicles attached only for the beach landing) numbered 9,828 troops, 919 vehicles and 48 tanks. To move this force required 2 transport ships, 6 Landing Ships, Tank (LSTs), 53 LCTs, 5 Landing Craft Infantry (Large) (LCI/(L)s), 81 LCVPs, 18 LCAs, 13 other landing craft, and about 64 DUKWs.[19] Assault craft were crewed by the US Navy, US Coast Guard and the British Royal Navy.[20]