The Battle of Britain Five Months That Changed History, May—October 1940 by James Holland (z-lib.org).epub

It was no good blubbing, however. All three bridgeheads across the
Meuse needed to be expanded quickly, yet the situation at Dinant,
Monthermé and Sedan was still very precarious for the Germans –
especially at Sedan. Despite the mass panic by the French of the previous
evening, it had principally been the rear echelon and artillery who had
flooded back; much of the 55th Division’s infantry still stood firm.
Moreover, the reserve units of the French X Corps, including an armoured
battalion, were ready and waiting to move forward, while a further cavalry
division was also only a short distance away and could easily have been
hurried forward to help at Sedan.
In contrast, the German infantry involved in the crossing were
absolutely exhausted, having had no sleep to speak of since 10 May and
having been involved in heavy fighting the previous day. Furthermore, it
was not until around 7.20 a.m. that the first German panzers crossed the
Meuse. The French armour was ordered up at around 4 p.m. on the 13th, to
make a stand at a blocking position along a ridge that ran either side of the
village of Bulson a few miles to the south of Sedan. The idea was that as the
German panzers appeared, the French armour would be waiting for them. It
would then open fire, and knock out the panzers, and then the French tanks
and infantry would counter-attack, forcing the Germans back across the
Meuse.
This was quite a realistic prognosis, but unfortunately, although the
French tanks had only about twelve miles to travel, they did not reach the
Bulson ridge until 8.45 a.m. on the 14th – some seventeen hours later – by
which time the panzers were already there. Rather than the French lying in
wait for the Germans, the opposite occurred – and the French were routed.
By the time the French could have brought any more reinforcements
forward, Guderian’s bridgehead had been massively expanded. At 12.30
p.m., the general received news that the bridge across the Ardennes Canal
had been safely captured. This was a huge coup, because the canal, to the
west of Sedan, ran southwards, potentially blocking Guderian’s intended
westward thrust. With the bridge taken intact, there was nothing to stop him
– nothing, that is, except for his superior officers, and even Hitler himself.
And it was at this moment that Guderian faced one of the biggest
gambles of his life.