September 1940 · Real-time strategy · Either side

Invade Britain in 1940, or stop it.

The German invasion planned for September 1940 never sailed. Here it can. Command the Wehrmacht and get nine divisions across the Channel in towed river barges, or command Britain and sink them before they reach the beach. One number keeps the score: the tonnage that gets ashore.

Play free in your browser Desktop, tablet and phone. No install, no account.
  • 80 days, 13 Aug to 31 Oct
  • 2,400 barges in the plan
  • 5 landing beaches
  • 2 sides, both playable
The Channel, September 1940 A period-style chart of the Strait of Dover and the eastern Channel. Dashed routes run from the invasion ports at Le Havre, Boulogne, Calais, Dunkirk and Ostend to the planned landing beaches B to E between Folkestone and Eastbourne, with barge trains on them and minefield barriers on both flanks. 1°W 0°E 1°E 2°E 3°E 4°E 49°30′N 50°00′N 50°30′N 51°00′N 51°30′N 52°00′N B C D E London Dover Folkestone Hastings Eastbourne Calais Boulogne Dunkirk Ostend Le Havre Antwerp Canterbury THE CHANNEL STRAIT OF DOVER NORTH SEA BAIE DE LA SEINE N UNTERNEHMEN SEELÖWELanding beaches B–E · Sept. 1940
The planned crossings: transport fleets from Le Havre, Boulogne, Calais, Dunkirk and Ostend to beaches B to E, between minefield barriers.
The scoreboard

Tonnage landed against need.

A division ashore eats about 300 tonnes a day sitting still and two or three times that in a fight. Every barge, tug, port, minefield and storm shows up in one figure: tonnes landed each day against what the beachhead needs.

The Germans need it high. The British need it low. A gale that swamps one night's barge trains can matter more than a won battle.

An example of the scoreboard: tonnage landed each day for ten days after S-day, against the beachhead's need. A gale on day 4 cuts the landings to 600 tonnes. 12345678910 Days after S-day · bars: tonnes landed · red line: need 68%3-day average gale
Two sides

Play the Wehrmacht or Britain.

The simulation runs both sides in full. Whichever one you don't pick is played by an AI that gives the same orders you can.

As Germany

  • Win the air over the Channel with Luftflotten 2 and 3, or the Royal Navy owns it.
  • Gather the barges, tugs and steamers in the invasion ports while Bomber Command burns them.
  • Choose S-day: calm sea, a rising tide at dawn, a moon for the night passage, ten days' notice.
  • Keep the beachhead supplied until Britain breaks, or take a port and hold it to 31 October.

As Britain

  • Keep Fighter Command alive: radar, sector stations and above all the pilots.
  • Watch the ports on photo-reconnaissance and bomb the barge basins at night.
  • Call CROMWELL at the right moment. Too early costs production; too late costs the beaches.
  • Sink the barge trains in the Channel and throw the landings back before the autumn gales end the season.
Air, sea and land

One problem in three parts.

The Luftwaffe has to hold the air or the Royal Navy owns the Channel. The navy has to be kept out or the barges sink. The barges have to keep coming or the army ashore runs dry. The big moments can be fought yourself in real time, or left to resolve on the map.

The air battle

Spitfire and Hurricane squadrons against Bf 109, Bf 110, Ju 87, Ju 88, He 111 and Do 17 Gruppen. Chain Home warns, sector stations control, and every one bombed blunts the defence. Fly the big raids yourself: Stukas diving on a radar station, or Blenheims over the barge basins at Boulogne under flares.

Night actions in the Channel

A destroyer flotilla out of Dover finds a barge train mid-Channel. Starshell, searchlights, 4.7-inch salvos, torpedoes, ramming. Or take the German side: torpedo boats and E-boats screening, smoke, scatter orders, and the Stukas you'll want at first light.

3D battles on real terrain

Kent and Sussex built from real elevation data. Barges grounding at Hythe under pillbox fire. Fallschirmjäger landing around Lympne and Hawkinge. Matildas and Home Guard counter-attacking the beachhead, and the GHQ Line's ditches and pillboxes in front of London.

Weather, tides and moon

The real windows were few.

Rhine barges swamp above sea state 2. The crossing wants a calm night, a moon to keep station by and a rising tide at dawn on the beaches. After about mid-October the weather mostly shuts the Channel. Picking S-day, or guessing it from the other side, is the biggest decision in the game.

A schematic of a crossing window in September 1940: the moon waning from full on the 16th, the state of the tide at dawn, and the days when wind, tide and moon all allow a crossing, shaded. 15161718192021222324252627282930 tide at dawn
The radio net

1940 voices, through a valve set.

Sector controllers, squadron leaders, destroyer captains and the operations rooms on your side of the net, with the German R/T's own brevity words on the other. Recorded with neural voices and played through a narrow, crackling valve-radio circuit.

Sector controlHello Gannic leader, Sapper calling. Scramble. Vector one-two-zero, angels one-five, buster.

Ops roomHostile raid, seventy plus, approaching Dungeness.

SquadronTally-ho! Many, many bandits. Going in. Line astern.

LuftwaffeAchtung, Spitfire! Pauke, Pauke! … Horrido!

DestroyerEnemy in sight, bearing one-four-zero. Starshell, spread! Open fire!

Home ForcesCromwell. Cromwell. Invasion imminent. All units to immediate readiness.

The German stations speak English with the real German words for attacking, a kill, enemy fighters and height. The voice models have no German voice, so we didn't fake one.

Daily S-day

The same invasion for everyone, every day.

Thirty days from a seeded S-day: a date in September or October 1940, its weather and tides, the air situation, the barges gathered and Britain's readiness. Everyone gets the same one on the same UTC date. Each side has its own leaderboard, ranked by days held, then tonnage (the Germans want it high, the British low), then losses inflicted.

Real, with care

Real names, and no swastikas.

Real forces

Real divisions, squadrons, ships, aircraft and places, as planned for Sea Lion and as they stood in 1940. Churchill, Dowding, Park, Brooke, Raeder, Halder, Göring and the rest appear on decision cards. The cards paraphrase. Nobody is given lines they didn't say.

Insignia

German units carry the Balkenkreuz and British ones the RAF roundel and the White Ensign. No swastikas anywhere, tail fins and flags included, and no party symbols or slogans. Waffen-SS formations are left out of the order of battle.

Gas

Mustard gas is in, because both sides planned for it. Brooke meant to spray it on the beaches. Using it is powerful and costly: opinion abroad, splits at home, civilian casualties and retaliation in kind. Casualties are reported as numbers, never shown.

What it costs

Free. The whole campaign, either side.

The full campaign as Germany or Britain and the Daily S-day cost nothing, with no ads. Later, optional packs will add variety, not power:

None of them exists yet, so the store is closed. Sign in with an Earth Ablaze account if you want a campaign to follow you between devices; you don't need one to play.

What it isn't

Honest limits.

Take command