18. Operation Neptune

Lieutenant General Sir Frederick Morgan
Chief of Staff to the Supreme Allied Commander
Overture to Overlord

A SECOND FRONT IN WESTERN EUROPE BECAME AN URGENT PRIORITY OF THE GRAND ALLIANCE EARLY in 1942, by which time the Nazi German juggernaut had overrun western Russia, Ukraine, and was well on its way toward the oil-rich Caucasus.¹ Operation Overlord, which took shape over the next 2 years, planned to land in Normandy, battle across France and Belgium, destroy enemy armed forces west of the Rhine, then "clean out the remainder of Germany."² This case study concentrates on Operation Neptune, the cross-channel assault.³

Geographic factors influenced plans and operations from selection of the lodgment area through the D-Day landings to the breakout from consolidated beachheads on July 25, 1944 (D+50). Time, distance, light data, coastal topography, tides, drainage patterns, weather, climate, land use, settlements, and transportation networks all affected courses of action on both sides. Enemy fortifications caused additional Allied concerns.

Campaigns in North Africa (September 1940-May 1943) and thereafter in Italy simulated Second Fronts,⁴ but neither of those "sideshows" satisfied Stalin who needed massive help of a more direct nature, nor would much-debated Anglo-American operations in the Balkans threaten Hitler's primary sources of military power.⁵ The key question therefore became, "Where should Allied armed forces enter Western Europe on their way to the Third Reich?"

British Lieutenant General Sir Frederick Morgan, as Chief of Staff to the Supreme Allied Commander (COSSAC), began to search for a satisfactory lodgment area well before General Dwight D. Eisenhower arrived on scene (map 57). He quickly discarded Norway because "to debouch therefrom southward in battle array would be quite something." Denmark's narrow Jutland Peninsula was likewise unappealing. Prevailing winds off the North Sea whipped beaches in Belgium and Holland, which lacked convenient outlets through waterlogged lands that not only were criss-crossed with canals but, being below sea level, were subject to widespread inundation. Portugal and Spain south of the Pyrennes Mountains were far from objectives inside Germany.⁶

The focus on northern France sharpened swiftly. COSSAC's staff believed that beaches at Dunkirk and in Brittany were much too small to support amphibious assaults followed by rapid buildups on envisaged scales. Field Marshal Gerd von Runstedt, who then was German Supreme Commander in the West, later acknowledged that Allied landings near the thinly held Loire valley would have been ideal in most respects--Major General Günter Blumentritt, his Chief of Staff, confided that a company commander on that coast had to cycle all day to inspect his sector--but both breathed easily because they knew that the Loire Valley was well beyond the reach of "short-legged" fighter bombers based in England. Serious considerations, according to COSSAC, thus "whittled themselves down to two: direction Pas de Calais or direction western Normandy."⁷

Calais at first seemed attractive, because the 22-mile (35-kilometer) cross-channel trip was short enough to maximize loiter times for fighter-bombers, minimize shipping requirements, and limit losses due to anticipated enemy U-boat attacks. Straight-line routes to the German border moreover measured barely 150 miles (240 kilometers). Debits, however, outweighed credits. COSSAC wryly noted that defenders who could read maps as well as he had made Calais the pivot point of Atlantic Wall fortifications. Nearby beaches were small, widely spaced, and exposed to storms, seaports along that stretch of coast were hopelessly inadequate even in perfect condition, and actions to seize Antwerp or Le Havre would necessarily parallel German dispositions for the full distance and thus be subject to flank attacks.⁸

The Baie de la Seine between Caen and the Cotentin Peninsula in contrast was much better sheltered than littorals east or west, beach capacities coupled with port facilities at Cherbourg seemed adequate to satisfy initial needs, COSSAC planners found no serious fault with distances from England, and air power could delay German reinforcements by blowing bridges over the Seine and Loire Rivers, which respectively bounded prospective objective areas on the north and south. Northwestern Normandy thus seemed to be the best possible compromise.⁹

The lodgment area that COSSAC selected in Normandy occupied the Departments of Manche and Calvados (the equivalent of U.S. counties), both bounded on the north by the Baie de la Seine and on the south by rough, wooded terrain that the locals call "bocage." Geographical data bases in support of Operation Neptune addressed relevant factors in four distinctive regions, along with overlapping phenomena.¹⁰

Land forms and land use on Manche's Cotentin Peninsula, in western Calvados, eastern Calvados, and in the hilly hinterland are dissimilar in many important respects, but cross-compartments are common, wide open spaces are conspicuously absent, and most terrestrial corridors that connect northwestern Normandy with the rest of France parallel the coast. All four regions encourage close combat rather than fluid warfare (map 58).

The Cotentin Peninsula. The Cotentin Peninsula, which comprises the northernmost part of Manche, projects into the English Channel like a stubby finger. Topography at the tip, which is devoid of hospitable beaches, features bare granite rocks that stone cutters quarry on the back slopes of a semi-circular escarpment around Cherbourg. Thin, infertile soils are the rule in that rough terrain, which slopes gently toward the south and east where forests give way to orchards, then to checkerboards of thick, high hedges that enclose small fields. Marshy meadowlands and mud flats called "Prairies Marécageuses" follow river valleys in the extreme southeast and thrust long fingers into hills farther west (map 59). Dikes, drainage ditches, and locks along inland waterways plus scattered farmsteads are the only manmade structures in that desolate land. A few narrow causeways cross swamps that separate flat beaches from the first firm ground about a half mile inland (somewhat less than one kilometer).

Western and Eastern Calvados. Bluffs incised by shallow draws back discontinuous beaches that nestle between limestone cliffs where western Calvados meets the Cotentin Peninsula. Tablelands beyond the crest gradually rise southward for about 2,000 yards (1,825 meters) until they overlook the lower Aure River, which is more than 60 feet wide and 12 feet deep (18 by 3.6 meters) at Isigny-sur-Mer. Landscapes in Eastern Calvados, which are less formidable, consist primarily of a low, undulating plain that fronts on sandy beaches. Cultivated fields that begin to displace hedgerows beyond Bayeux become increasingly widespread southeast of Caen. The Orne River valley and the canal that connects Caen with its outport at Ouistreham are among the most prominent terrain features.¹¹

Basically Bocage. Thick blackthorn hedgerows and stone walls, many of them buttressed by large trees and high earthen embankments that follow no consistent alignment, serve as fences in parts of the Cotentin Peninsula and coastal Calvados, but bocage is most prevalent in hilly country farther south, where some fertile valleys and lower slopes sport 300-400 oddly shaped fields per square mile. Easy access from one enclosure to another normally is available only at corners where two or more join. Heath or oak, beach, chestnut, and hornbeam forests, plus stands of planted pines, cover heights that are unsuitable for orchards

or pasture. High-speed corridors that cut clear through the bocage from north to south are widely-spaced.¹²

Successful amphibious assaults against the seacoasts of northwestern Normandy initially depended on intimate knowledge of treacherous currents and tides in the English Channel as well as geographic information about the Baie de la Seine, a comparatively shallow, trough-like depression. Intelligence collectors therefore turned attention to water depths, the location of reefs, rocky ledges, other obstructions, beach gradients, shoreline characteristics, and avenues inland. Operation Neptune planners soon narrowed the search to a stretch between Quineville on the southeastern Cotentin coast and the mouth of the Orne River in eastern Calvados (map 60).¹³

Utah Beach. The most favorable Cotentin site, destined to become Utah Beach, centered on Les Dunes de Varville just north of the Vire Estuary where 4 miles of level, firm sand 700 yards wide (640 meters) terminate against low dunes and a masonry sea wall. Gradients above low water average 1:130 for the first 500 yards, then steepen somewhat, but approaches are clear, surf normally is negligible, landings are feasible at any stage of the tide, and a sheltered anchorage for transport ships lies 2.5 miles (3.6 kilometers) offshore. Motor vehicle exits unfortunately are confined to a few tracks that lead through marshy meadows to a coastal road. The best of them in June 1944 was an unsurfaced causeway, scarcely 12 feet wide (4 meters) and barely above the muck during dry weather.

Omaha Beach. The outlook in western Calvados was less attractive. Swamps and rocky outcroppings offshore, succeeded by sheer walls that sometimes exceed 100 feet (30 meters), characterize the coast for more than three miles east of the Vire River until a crescent-shaped strand appears beneath steep bluffs below Vierville-sur-Mer and Colleville-sur-Mer. That site, which Neptune's planners designated Omaha Beach, occupies the next 7,000 yards or so before palisades reemerge.

Waters off Omaha Beach, unlike those at Utah, not only experience tricky rip tides, eddies, and moderately strong offshore currents, but are open to northerly and easterly winds. Vehicles and waders find traction uncertain in the shallows, even though low tides expose about 300 yards of gently sloping (1:188), well-compacted sand, because submerged bars and runnels run at right angles to the beach. Gradients increase sharply to 1:47 during the final 250 yards below high water, then to 1:8 before tidal flats terminate in a low, wave-cut embankment that large, loose shingle stones and a solidly-constructed wall supplement in some places. A level, marshy shelf thereafter connects beaches to bluffs that before D-Day were broken by five wooded draws just wide enough to accommodate one narrow road, cart track, or trail apiece. No other exits were available for vehicular traffic.

Gold, Juno, and Sword Beaches. More than 15 miles (24 kilometers) of chalky cliffs and rocky flats separated U.S. Omaha Beach from British Gold Beach, which is narrowest near Arromanches-les-Bains and widens toward the east. Low tide uncovers 800 yards of solid sand and the so-called "Plateau de Calvados" reaches seaward another three-quarters of a mile (1 kilometer) at depths no greater than 2 or 3 feet, after which the bottom drops off rapidly enough to allow good anchorages. Gold Beach above the high water mark is almost level, but a massive stone sea wall bridged only by two ramps inhibits vehicular access to heavily traveled roads that link Courseulles with Bayeux and Caen.

Nearly contiguous Juno Beach, reserved for Canadian troops during Operation Neptune, straddles rocky approaches that mar tidal flats for almost a mile (1.7 kilometers). Juno ashore is similar to Gold, except for a line of low, unconsolidated dunes along the waterfront. Seaside resorts, which are almost absent behind Utah and Omaha Beaches, dot the coast all the way from Arromanches past the mouth of the Orne River. Ramps and stairways on Juno Beach help personnel and motor vehicles cross a promenade that otherwise comprises a formidable barrier, village streets thereafter accommodate two-way traffic, and two macadamized roads lead to Caen.

British amphibious forces that landed at Lion-sur-Mer on the westernmost part of Sword Beach found about half a mile of solid sand between high and low water, whereas flats on the eastern flank at Ouistreham are well over twice that wide and gradual gradients approximate 1:300. Views from the water see soft sand and loose dunes ashore, plus a formidable wall with few ramps or stairs, but the going is easier on hard-surfaced roads beyond those barriers.

Northwestern Normandy, adjacent to the English Channel, enjoys moderating climatic influences in every season (the Cotentin Peninsula is almost insular). Mild winters, cool summers, humid conditions, and brisk breezes predominate (table 26).¹⁴

The Department of Manche is the rainiest in all of northern France, with Calvados a bit farther east and Brittany a bit farther west as close contenders. Maximum precipitation, mainly in the form of drizzle or showers, falls most frequently in October, although some weather stations along the littoral show a secondary peak in June or July and downpours occasionally deliver more than two inches (60 millimeters) in a single day. Persistent rains adversely effect the trafficability of poorly-drained soils like those behind Utah Beach and along lower reaches of the Taute, Vire, Aure, Seulles, and Orne Rivers where water tables habitually are close to the surface.

Fog and low clouds are most evident in winter, but poor visibility coupled with ceilings below 2,000 feet (610 meters) often limit air operations during early morning hours in summertime. May, June, and July offer the best chances for 5 or more consecutive days of fine flying weather. The phenomenon of very long days and very short nights at 50 degrees North Latitude during those months not only maximized daylight available to Allied aviators, but allowed German ground forces minimum time to move troops and supplies under cover of darkness.

	Cherbourg	St Lô	Caen
May June July August	Inches Millimeters 2.0 51 1.8 45 1.8 46 3.0 75	Inches Millimeters 2.9 72 2.3 57 2.5 62 2.3 58	Inches Millimeters 2.2 56 2.0 49 2.3 58 2.5 62

Cherbourg

St. Lô

Caen

May

June

July

August

Rural residents of northwestern Normandy were widely dispersed among hundreds of hamlets and isolated farmsteads, although territories within 5 to 15 miles of the coast (8 to 24 kilometers) generally were "off limits" to all but professional fishermen in 1944.The last pre-war census statistics for cities, towns, and villages, compiled in 1936, indicate that regional centers such as Cherbourg, St. Lô, and Caen were relatively small (table 27), but even those figures were inflated, because German occupation forces moved about 100,000 French civilians inland well before D-Day.¹⁵

Roads within Neptune's lodgment area never were designed for sustained heavy traffic. Even the arterial Cherbourg-to-Paris highway carried more tourist trade than commerce, while most other routes served strictly local needs. The lattice in Manche and Western Calvados lacked first-rate north-south roads. The Prairies Marécageuses moreover restricted vehicular traffic near the base of the narrow Cotentin Peninsula to a pair of vulnerable avenues on relatively high ground, both of which, like routes from Omaha Beach inland, thereafter threaded through an untold number of defiles and bridged many streams. Attractive exits to the south and east consequently emanated mainly from Caen on Neptune's left flank.¹⁶

First COSSAC, then General Eisenhower and subordinates in every American, British, and Canadian service on all levels, assessed mountains of information concerning the lodgment area to ascertain the influence of geographic factors on plans and programs for Operation Neptune. Appraisals below emphasize "big pictures."¹⁷

Three urban centers within the lodgment area constituted core areas of great political, economic, and military significance:¹⁶

Key terrain viewed by Allied strategists and tacticians stretched from just beyond the water's edge to targets deep in enemy territory:

COSSAC and his staff concluded, and General Eisenhower later concurred, "It was out of the question to make the whole assault north of the Vire estuary." The beaches were inadequate, exits inland crossed an easily flooded morass, and enemy armed forces might seal off the Cotentin Peninsula at its base and thereby bottle up the entire Allied expedition indefinitely. Divisions put ashore exclusively along the Calvados coast conversely would be hard pressed to seize essential port facilities at Cherbourg in anything like acceptable time. Beaches on both sides of the Vire therefore were required to establish a strong presence ashore and build strength rapidly.²⁰

Allied armed forces followed cross-channel avenues from marshaling areas in England to drop zones, glider landing zones, and beaches in Normandy. Amphibious assault and successive waves took a second set of approaches from ships to shore, whereafter all fanned out along land lines that led through, then out of, Neptune's initial lodgments.

Cross-Channel Avenues. Men and equipment destined to implement Operation Neptune reported to sausage-shaped staging areas from Cornwall to East Sussex beginning the second week in May 1944, where they were quarantined pending cross-channel trips that look deceptively simple as plotted on map 61, but in fact were incredibly complex. U.S. and Royal Navy planners would have faced formidable problems if one naval task force had been sufficient, but in fact there were five filled with military ships and craft of every description, all scheduled to arrive at designated spots in the Baie de la Seine at about the same time. Plans called for all five to rendezvous near the Isle of Wight, which minimized air cover and minesweeping requirements, then begin the run south through treacherous waters where flood tides athwart the north-south course from England to France flow from west to east while ebb tides reverse direction. Each avenue at the half way point divided into fast and slow lanes so lumbering amphibious ships could steer clear of battleships, cruisers, other surface combatants, and troop transports.

Task Force U, which numbered 865 convoy escorts,²¹ fire-support ships, troop carriers, landing ships tank (LSTs), smaller craft, and auxiliaries, loaded 12 separate convoys at nine widely separated locations. Minesweepers cleared lanes through Cardonnet Bank, after which flotillas set sail for the transport area 22,500 yards (20,575 meters) off Utah Beach, where ship captains dropped anchor shortly before 0300 on D-Day. Task Forces O and B en route to Omaha Beach followed similar procedures, as did British and Canadian contingents on their way to Gold, Juno, and Sword. Airborne divisions dog-legged from distant departure airfields.²¹

Ship-to-Shore Approaches. Low tide landings would have simplified tasks for underwater demolition specialists whose job was to blow gaps between obstacles that were concealed only at high tide, but heavily-laden assault forces wading through shallow water for half a mile or more would have taken terrible casualties long before they reached shore. Neptune's planners therefore scheduled landings to start three hours before rising tides reached their peak, so amphibious craft that beached early could later float off (a one-foot tidal rise, for example, inundates nearly 200 feet of flat sand off Omaha Beach, where gradients generally average 1:188). Ideal conditions, however, were not simultaneously obtainable at all five beaches, because high water reaches Cotentin coasts about 40 minutes earlier than it does in Eastern Calvados and the sites selected were neither equally level nor equally obstructed. H-Hour on D-Day consequently occurred at 0630 on Utah Beach, 15 minutes later at Omaha Beach, and 0745 on Gold.

Causeways over marshlands between Utah Beach and the nearest coastal road were crucially important, but five draws that climbed the bluffs behind Omaha Beach were more so, because that steep terrain otherwise blocked tracked as well as wheeled vehicles (figure 39). A rough trail at Exit F-1 on the left flank scrambled up a narrow valley where slopes exceeded 10 percent; an eight-foot-wide cart track at neighboring E-3 led to Colleville, 2,000 yards inland; Exit E-1, which tilted 100 feet in 500 yards, and the D-3 Exit at les Moulins both headed for St.Laurent-sur-Mer as soon as they cleared the crest. Grades were less demanding at Exit D-3 on the right flank and the road was graveled past Vierville until it met macadam. Assault troops that reached the top were much better off than on the beach, because German defenses-in-depth were nearly nonexistent.

Land Avenues Inland. Avenues inland from Neptune's drop zones and beaches were geographically inviting only to the east and southeast, because the Aure River valley and bocage-covered hills separated landing sites in coastal Calvados from tank country due south. Narrow necks of dry ground that form the watershed between the Vire and Taute Rivers channelized movement from the Cotentin Peninsula and Carentan toward St. Lô, severely limited maneuverability in lower Manche even for foot soldiers, and confined vehicular traffic to roads. Pre-invasion phase lines that anticipated fairly rapid headway despite adverse terrain accordingly proved optimistic, whereas progress after Allied forces broke into the open was faster than predicted.²³

Natural and manmade obstacles astride the avenues just described blocked all beaches to some degree and impeded progress inland, then helped German defenders pen Allied armed forces inside the lodgment area from June 6, 1944, until late July. Formations able to bypass one set of obstructions often ran head-on into others as bad or worse.

Beach Fortifications. The objective of German Field Marshal Erwin Rommel obviously was to stop invaders before they reached the water's edge, then annihilate them with interlocking, overlapping cones of fire,²⁴ but beach defenses on D-Day varied considerably because preparations were incomplete. Only two artillery positions along Juno Beach, for example, were under concrete, while the rest occupied roofless bunkers or bare earthen pits.²⁵ The aggregate nonetheless could best be described as awesome.

Defensive bands studded tidal flats with twisted steel girders called "hedgehogs," pilings driven deeply into firm sand at angles calculated to gut incoming landing craft, other diabolical devices, and millions of water-proofed mines. Tetrahedral antitank barriers, caltrops, ditches, concrete blocks, more mines, and concertina wire littered beach shelves and coastal dunes, while immobile roadblocks and "Belgian Gates" mounted on rollers guarded every exit. Fortified beach-front villas, promenades, and sea walls were especially prominent in eastern Calvados--the highest bastion, at Arromanches-les-Bains, measured 15 vertical feet (almost 5 meters). Automatic weapons and artillery housed in cleverly-concealed, well-camouflaged concrete pillboxes and casements were well-sited to cover Allied approaches from maximum to point-blank ranges.²⁵

Obstacles Inland. Fears about floods along the lower Aure Valley and behind Utah Beach were well founded. Amphibious forces slogged their way inland without excessive difficulty, but many heavily loaded paratroopers drowned when 12 air transports overshot designated drop zones and dumped them in swamps astride the Merderet River. Defenders who sought to discourage parachute assaults and glider landings also seeded the few open spaces with several hundred thousand sturdy stakes known as "Rommel's asparagus," mined the tops, and interlaced the lot with tripwires.²⁷

Sturdily constructed villages and farmsteads, often ringed with stone walls, became impromptu German strongpoints across Manche and Calvados, especially those located on dominant ground or at bitterly contested road junctions. Fort du Roule atop a steep granite promentory above Cherbourg fell on June 25th after fierce fighting, but some hardened sites nearby held out for another week.²⁸

"The Normandy Campaign" above all became almost synonymous with "The Battle of the Hedgerows" in summer 1944. Fields of fire for flat trajectory weapons were exceedingly short in the bocage, where poor observation severely limited the effectiveness of mortars, artillery, and close air support. Land combat consequently was risky business. Front-line infantrymen in broad daylight often lost contact with friends a few yards away and could hear but seldom saw enemies except for bodies left behind during hasty withdrawals. Allied tanks went belly up against shoulder-high embankments topped by vegetative ramparts several feet thick until innovative Master Sergeant Curtis E. Culin converted German hedgehogs and tetrahedons into hedgerow cutters that let tanks plow through without losing speed appreciably.²⁹

Four additional geographic effects on Allied courses of action merit brief explanations, because they determined the day and hour that Operation Neptune commenced and strongly influenced staying power. Coastal hydrography and weather conditions were primarily important.

Light data and tides determined H-Hour, the time the first wave of landing craft was scheduled to drop ramps and discharge assault troops ashore. Darkness was undesirable, because control would be difficult in the absence of night vision devices which had not yet been invented. Neptune planners, who preferred a time soon after dawn, picked the Beginning of Morning Nautical Twilight (BMNT) plus 40 minutes, which they deemed ample time for Allied aircraft and fire-support ships with aerial spotters to "soften" targets ashore before battles began on the beaches, while enemy observers still in relative darkness on the ground would lack clear lines-of-sight seaward. Unloadings moreover had to commence not earlier than 3 hours before high tide and terminate not later than three hours thereafter or assault troops would be stranded far from shore. Similar tidal conditions in late afternoon allowed follow-on echelons to land before dark.

Airborne assaults behind Utah Beach and near Caen were timed for 0200 on D-Day, well before H-Hour, to take full advantage of a late-rising moon that would allow transport pilots to approach in darkness but easily discern drop and landing zones (bad weather made that impossible). Captain Frank L. Lillyman, whose 101^st Airborne Division pathfinder team leaped at 0015 local time (12:15 A.M.), was first to set foot on French soil.³⁰

Ideal conditions for amphibious operations in northwestern Normandy combined spring tides with a full moon, a coincidence that normally occurs three days each month. June 5, 1944, the first day that satisfied those specifications during the most favorable month, thus became top choice. Prognoses, however, were poor when the final conference to approve or reject that date convened at 0400 on June 4th, because the worst June storm in 20 years had begun to punish the English Channel with low clouds, high winds, and white-capped water. Air support would be impossible, naval gunfire ineffective, and small boats subject to capsize, according to authorities at the table. General Eisenhower reluctantly ordered a 24-hour weather delay, even though so doing disrupted time-sensitive schedules. Convoys already at sea turned back to refuel while ships fully loaded with seasick soldiers fretted in port. Meteorologists the following day fortunately foresaw a small "hole" in the weather though which Neptune's naval task forces might pass before a second storm stuck. Further postponement would create monumental logistical muddles, troop morale would plummet, and secrecy would be hard to ensure. The Supreme Allied Commander mulled a moment, then said, "I don't like it, but we'll go." Signals flashed to the fleets and forces on shore: PROCEED WITH OPERATION NEPTUNE.³¹

Neptune's planners from the onset knew that Cherbourg port never could satisfy all early needs even with assistance from logistical operations over open beaches.³² They therefore issued prescriptions for two artificial harbors code-named Mulberry A and Mulberry B, each with throughput capacities about equal to that of Dover. Preliminary construction, which began in 1943 at scattered locations in Britain, produced 10 miles of piers, 23 pierheads, 93 floating breakwaters called "Bombardons," and more than 100 gigantic concrete caissons that looked like six-story buildings lying on their sides. A motley fleet of seagoing tugboats towed that cantankerous armada to Normandy beginning just before D-Day, accompanied by 80-some aging blockships loaded with sand ballast and enough high explosives to tear their bottoms out when properly positioned off Omaha and Gold Beaches (see expedient port operations on page 235 for additional details).

Performance exceeded expectations until D+13, June 19, 1944, which dawned cold and gray with gale force winds by mid-afternoon. Meteorologists even so predicted good weather and anxious beachmasters found further reassurance in their "Bible," the Channel Pilot, because the column that counted the average number of stormy June days in the Baie de la Seine contained a great round "O". Long- and short-range forecasts unfortunately were both wrong. Wild winds and surf pounded Mulberry A so severely that little was left except salvage parts with which to rebuild Mulberry B at Arromanches-les-Bains. Good news nonetheless was mixed with bad: Allied forces in midchannel would have been unable to reinforce or resupply assault forces ashore if General Eisenhower had postponed D-Day from the original June 5th to June 19th, the earliest acceptable alternative date.³³

The first emergency landing strip in Normandy appeared at Pouppeville near the southern edge of Utah Beach on D-Day, followed by second one at St. Laurent-sur-Mer on D+2, but Allied fighter-bombers based in Britain urgently required forward facilities that allowed faster turn-around times and used less fuel. Responsive engineers in the U.S. sector hastily constructed 20 fully serviceable expeditionary airfields suitable for daylight operations (seven of them by D+20), despite enemy action and geographic conditions that confined all installations to islands of solid ground where bocage was least obtrusive (map 62 and table 28). Runways, taxistrips, and "hardstands" were surfaced with huge rolls of tar paper or "chicken wire" mesh firmly pegged down after bulldozers and scrapers cleared proper spots.

Those primitive airfields were designed to last 2 or 3 months under "normal" conditions, which did not pertain because deep ruts appeared as soon as the wheels of bomb-laden aircraft crushed pliable tar paper into soggy earth and billowing clouds of powdery dust trailed pilots down wire mesh runways on dry days. Air base engineer battalions struggled manfully around the clock, but many strips were fast becoming unserviceable by early August and were abandoned as soon as more favorable sites became available outside Neptune's lodgment area.

Geographical information concerning northwestern Normandy was incomplete and often inaccurate on D-Day, even though that region had been prominent in European history for more than 1,000 years. Obsolete charts of coastal waters, misleading climatic mean statistics, and belated appreciation of the bocage are just a few among many problems that plagued U.S., British, and Canadian forces during the June 1944 landings and buildup.

Operation Neptune nonetheless was an astounding success. Allied assault forces "entered the continent of Europe" despite perverse weather and terrain, consolidated footholds, and linked all five beachheads during the first week. Allied expeditionary forces by July 2nd had deposited ashore 1,000,000 men, 24 divisions (13 U.S.,11 British, 1 Canadian), 566,000 tons of supplies, and 171,000 vehicles at a cost of 60,770 casualties, of whom 8,975 were killed.³⁴ The sacrifices of those valiants initiated the long-awaited Second Front and, in accordance with General Eisenhower's orders, began "operations aimed at the heart of Germany and the destruction of her Armed Forces."

Percentage	May	June	July	August
<3/10 >8/10	16 59	21 53	19 53	16 57

	Urban	Rural	Total	Density (per square mile)
Manche Calvados	114,380 149,540	324,160 255,360	438,540 404,900	177.1 184.2