ASL Map Spotlight: Operation Neptune

Operation Neptune Unboxing
Operation Neptune (BFP)

Not to be mistaken with the Normandy version of “Operation Neptune” (the naval component of Operation Overlord), this action details the crossing of the then 200-yard wide Seine River by the British 43rd Wessex Division in August of 1944. The Operation Neptune module (and map) gives insight into the British Army assault on the River Seine at Vernon, France in late August, 1944. This module provides ASL players with the opportunity to see how they would fare in a forced river crossing and clearing operation in both scenario and campaign game form.

Operation Neptune Map

This map and action can be found in Bounding Fire Productions’ Advanced Squad Leader historical module: Operation Neptune: British Crossing of the Seine.

Download the Operation Neptune VASL Map

 Watch the Unboxing Video

ASL Map Spotlight: Operation Neptune
Operation Neptune Map, North is down (Bounding Fire Productions)

August, 1944

ASL Map Spotlight: Operation Neptune
Vernon, France, August 1944, north is down (Imperial War Museum)

From early June with the D-Day invasion, the fighting in the hedgerows of Normandy had been grinding and hard fought. With the launch of Operation Cobra west of St. Lo on 30 July, Allied forces had finally achieved the type of breakthrough that allowed them to make progress deep into France. In response, the Germans counter-attacked around Mortain. Those efforts failed to stem the Allied advance, resulting in significant German forces being surrounded in a pocket created by encircling US and Canadian forces.

ASL Map Spotlight: Operation Neptune
British sappers on the shore of the Seine (Imperial War Museum)

By 22 August, following the destruction of the German forces in the Falaise pocket and the collapse of German resistance in the Norman countryside, Allied forces found themselves in pursuit of rapidly retreating German remnants to the next major barrier, the River Seine. In addition to the Americans, the Second British Army was advancing to the Seine with 30 Corps on the right and 12 Corps on the left. In planning for the rapid advance of 30 Corps through France and into Belgium, Lt. Gen Horracks, 30 Corps Commander intended to use two armored divisions and the 50th Infantry Division to accomplish this task. The 43rd (Wessex) Infantry Division was given the key task of preparing the way by establishing a bridgehead across the River Seine.

ASL Map Spotlight: Operation Neptune
British move toward Vernon bridge (Imperial War Museum)

On the evening of the 22 August 1944, the 43rd Wessex Division would become the first British Division to assault the River Seine when it was instructed to force a crossing over the river at Vernon, some 80 km northwest of Paris, and to form a bridgehead of sufficient depth to allow the remainder of 30 Corps to pass through. For the assault crossing, the 43rd Wessex would utilize the 129 Infantry Brigade, reinforced with the 1st Battalion Worcestershire Regiment of 214 Infantry Brigade. The operation was given the codename “Neptune”.

ASL Map Spotlight: Operation Neptune
Crossing damaged Vernon bridge (Imperial War Museum)

Across the river from Vernon lay the suburb of Vernnonet, behind which a steep 300-foot chalk faced escarpment dominated the river and both banks. Two roads from Vernnonet passed through the escarpment, one northeast toward Tilly, the other southeast toward Bois-Jerome-Saint-Ouen. Behind the escarpment lay the dense Forest of Vernon, which provided excellent cover for any German reinforcements.

ASL Map Spotlight: Operation Neptune
Bailey Bridge under construction (Imperial War Museum)

By mid-afternoon 25 August, the British assault forces were in place and “H” hour for the first wave of the Seine crossing was planned for 1900 hours. At this point the River Seine was approximately 200 yards wide, and this evening the river was calm and grey. The plan was for the 129 Infantry Brigade, with the 1st Worcesters under their command, to attack across the Seine in two waves of two Battalions each. The first wave consisted of the 5th Wiltshires on the right and the 4th Somersets on the left; and the second wave the 1st Worcestershires behind the 5th Wiltshires, and 4th Wiltshires behind the 4th Somersets.

ASL Map Spotlight: Operation Neptune
Surrendering Germans cross the Seine (Imperial War Museum)

At 1900 hours the guns and 4.2-inch mortars of the 8th Middlesex Regiment laid down a smoke screen for the assaulting troops as the 5th Wiltshires and 4th Somersets made their assault across the river in storm boats.


ASL Map Spotlights are meant to be quick history lessons on available historical Advanced Squad Leader actions. These short articles are meant to highlight both a short history of the battle portrayed for players unfamiliar with the setting, as well as show the ASL map on which it plays out.Citation:

© 2022-2024, Neal Ulen. All Rights Reserved. Please read the Copyright & Fair Use Notice. is not affiliated with Hasbro, AH Games, Inc., or MMP, Inc. Advanced Squad Leader is a trademark of AH Games, Inc.


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