Extracts from US II Corps After Action Reports from May 1940
.... The principle weakness of the German artillery we faced was a lack of corps or army level regiments of heavy & medium artillery. During the initial clash with the enemy XIX corps on 16 & 17 May we detected no evidence of supporting corps artillery. The enemy armored divisions attacking those two days each had a 12 piece medium battalion of 150mm howitzers, similar to our divisions. On the 18th & 19th some medium artillery other than the battalion in each infantry division was detected. This was both 105mm & 150mm longer range guns. Initially those were used against the bridges in Rethel. Later on the 18th and after up to three longer ranged 'corps' artillery battalions were identified facing II Corps. In contrast II Corps had eight battalions of howitzers and long range guns reinforcing the division artillery.
A second weakness was in the volume of ammunition used in each attack. 'Counting shell holes' suggests the German artillery fired about a third of the ammunition in a attack as the II Corps artillery. This may have reflected difficulties in bringing up ammunition from the depots in Germany. Such intel that we had indicated the roads back to the Rhineland were named with traffic. While II Corps had its difficulties in bringing up artillery ammunition it was seldom the reserve for each battalion fell below a full unit of fire.
....The enemy infantry was aggressive in executing infiltration. Rather than directly attacking the flanks of a position their infiltration parties went deeper & sought the rear of the position or interdiction of support. Steady troops were able to ignore the infiltration parties until counter attack or combat patrols dealt with them. There was some success in placing ambush parties along likely infiltration routes. Infantry battalion reserves are critical for dealing with infiltration parties. Rapid deployment of groups from the reserve to attack & destroy infiltrators is essential. While good intelligence is necessary rapid action is necessary as soon as any enemy infantry are identified. While immediate destruction of the infiltrating group is desirable it is not necessary in all cases. Often it is enough to pin the enemy group with small arms or light mortar fire.. If driven to ground they become vulnerable to increased mortar fires, a artillery strike, or a well organized assault. Where armored cars or tanks were available (of the 12th Cav) combined arms attacks on pinned infiltration groups were extremely successful.
....Tank support for the infantry is highly desirable. The new doctrine of concentration of the tanks into a single division that operates on its own is leaving the rifleman without a valuable supporting weapon. (Note, this was not US Army doctrine. Independent tank regiments were authorized for assignment to the corps, however the lack of tanks led to the concentration of the few available in the AEFs armored division.) The French army assigned their tanks on the basis of one battalion for each division & it seems worthwhile to follow their success. Twice we were supported by the tankettes of the cavalry, making the attacks by the infantry companies far easier.
....Location of the artillery observation posts has been critical. Good view for the OP cannot be emphasized enough. Static OPs are useful however the artillery observer needs more mobility. The SRC is too heavy and bulky for mobile foot operations. The Forward observation party can't keep up with the infantry maneuver. Often it proved easier to unspool wire behind the FO party as the telephone kit weighed only a few kilograms. The telephone could also be put into action faster than the SRC. Dedication of light trucks to the FO party will be helpful, but too vulnerable in small arms range. The French SAU artillery tank shows some promise. Its radios can remain in continual operation. Those and its sophisticated optical equipment are protected by the armor. This type of vehicle provides a protected & mobile OP for the artillery. If the SAU40 cannot be obtained some other protected vehicle must be provided.
.... The principle weakness of the German artillery we faced was a lack of corps or army level regiments of heavy & medium artillery. During the initial clash with the enemy XIX corps on 16 & 17 May we detected no evidence of supporting corps artillery. The enemy armored divisions attacking those two days each had a 12 piece medium battalion of 150mm howitzers, similar to our divisions. On the 18th & 19th some medium artillery other than the battalion in each infantry division was detected. This was both 105mm & 150mm longer range guns. Initially those were used against the bridges in Rethel. Later on the 18th and after up to three longer ranged 'corps' artillery battalions were identified facing II Corps. In contrast II Corps had eight battalions of howitzers and long range guns reinforcing the division artillery.
A second weakness was in the volume of ammunition used in each attack. 'Counting shell holes' suggests the German artillery fired about a third of the ammunition in a attack as the II Corps artillery. This may have reflected difficulties in bringing up ammunition from the depots in Germany. Such intel that we had indicated the roads back to the Rhineland were named with traffic. While II Corps had its difficulties in bringing up artillery ammunition it was seldom the reserve for each battalion fell below a full unit of fire.
....The enemy infantry was aggressive in executing infiltration. Rather than directly attacking the flanks of a position their infiltration parties went deeper & sought the rear of the position or interdiction of support. Steady troops were able to ignore the infiltration parties until counter attack or combat patrols dealt with them. There was some success in placing ambush parties along likely infiltration routes. Infantry battalion reserves are critical for dealing with infiltration parties. Rapid deployment of groups from the reserve to attack & destroy infiltrators is essential. While good intelligence is necessary rapid action is necessary as soon as any enemy infantry are identified. While immediate destruction of the infiltrating group is desirable it is not necessary in all cases. Often it is enough to pin the enemy group with small arms or light mortar fire.. If driven to ground they become vulnerable to increased mortar fires, a artillery strike, or a well organized assault. Where armored cars or tanks were available (of the 12th Cav) combined arms attacks on pinned infiltration groups were extremely successful.
....Tank support for the infantry is highly desirable. The new doctrine of concentration of the tanks into a single division that operates on its own is leaving the rifleman without a valuable supporting weapon. (Note, this was not US Army doctrine. Independent tank regiments were authorized for assignment to the corps, however the lack of tanks led to the concentration of the few available in the AEFs armored division.) The French army assigned their tanks on the basis of one battalion for each division & it seems worthwhile to follow their success. Twice we were supported by the tankettes of the cavalry, making the attacks by the infantry companies far easier.
....Location of the artillery observation posts has been critical. Good view for the OP cannot be emphasized enough. Static OPs are useful however the artillery observer needs more mobility. The SRC is too heavy and bulky for mobile foot operations. The Forward observation party can't keep up with the infantry maneuver. Often it proved easier to unspool wire behind the FO party as the telephone kit weighed only a few kilograms. The telephone could also be put into action faster than the SRC. Dedication of light trucks to the FO party will be helpful, but too vulnerable in small arms range. The French SAU artillery tank shows some promise. Its radios can remain in continual operation. Those and its sophisticated optical equipment are protected by the armor. This type of vehicle provides a protected & mobile OP for the artillery. If the SAU40 cannot be obtained some other protected vehicle must be provided.