Surfaces and Gaps:
Surfaces are enemy strengths, also referred to as hard spots. Gaps are enemy weaknesses, also referred to as soft spots.
The commander strives to match the combined arms strength against the enemy’s weakness. Because of the fluid nature of war, gaps are rarely be permanent and will usually be fleeting. To exploit them requires flexibility and speed. The British method of Central inflexible planning in WW1 was unable to exploit these gaps as it was too slow to respond. They were gone by the time a plan had been drawn up and anyway the troops were unable to execute such plans quick enough due to the lack of mission type planning.
Once gaps are located, exploitation by fast-moving, mobile forces is critical. Exploitation usually occurs at a gap and extends the destruction of the enemy by maintaining continuous offensive pressure. Exploitation destroys the enemy’s cohesion. In a classic demonstration of maneuver warfare, the commander aims to render the enemy incapable of effectively resisting by shattering his moral, mental, and physical cohesion and his ability to fight as an effective, coordinated whole.
Simply put in Blitzkrieg the objective is to advance rapidly by avoiding enemy strengths and focusing efforts against the enemy’s weaknesses.
In the Battle at the Canal du Nord the Canadians demonstrated graphically the concept of Surfaces and Gaps.
The objective of getting past the Canal, a critical defensive barrier in the Hindenburg line was given to the Canadians. This was a flooded canal, 30 metres in width with a dry section to the south. The British General Haig wrote the battle orders for the Canadians directing them to attack the enemy in their position of greatest strength, across a canal and into a fortified German trench. Curry flatly rejected the orders.
With the support of General Byng, Currie had bridges quickly assembled and crossed the dry section of the canal at night, surprising the Germans with an attack in the morning. A classic gap exploitation. The effectiveness of Canadian engineers, for whom Haig had no use was also demonstrated. Innovative combined arms thinking with mission planning won the battle.
After crossing the canal the Canadians exploited the german gap further by splitting their forces; attacking behind the German positions to the left and taking Bourlon Wood to the right of the crossing. Classic blitzkrieg encircling.
By October 1, the Germans had thrown 6 divisions into the fight.
Hardly the bled white force you and others mention Pogo. The tactics won the battle, the victory was not due to the lack of troops on the German side.
Another Blitzkrieg tenet was demonstrated with is a part of the Surface and Gap theory. As enemy cohesion breaks down, the exploitation may develop into a pursuit. The pursuit seeks to annihilate the enemy force once resistance has completely broken down. The condition of the enemy may determine whether an exploitation becomes a pursuit. The opportunity to conduct a pursuit is often fleeting and must be seized quickly by the commander. An encircling force must have continuous fire support and greater mobility than the enemy.
On October 9 the Canadians attacked Cambrai and by October 11 had secured the entire district with their 37 kilometer advance into enemy territory. This action had resulted in the liberation of 54 towns and villages. A classic pursuit style fight exploiting the gap created by the breakdown of the German cohesion.
