 Second Lieutenant Leslie Averill , the intelligence officer for 4th Rifle Battalion , continued to investigate the defences . He was able to locate a route to a section of the ramparts that appeared unmanned and was not under fire from the defenders . He was ordered by Barrowclough to force an approach . With the benefit of covering mortar fire , Averill and a platoon of the battalion reserve company , managed to cross the moat and found themselves at the inner ramparts . With the aid of a 30 @-@ foot ( 9 @.@ 1 m ) ladder supplied by the Divisional Engineers , Averill was able to ascend to the top of the ramparts , closely followed by the platoon commander . With his revolver , Averill fired at two Germans manning a guard post , forcing them to cover , fire and the rest of the platoon joined him . Shortly afterwards , Barrowclough and the rest of the battalion used the ladder and entered the town . At the same time , a party from 2nd Rifle Battalion , seized the gate guarding the road into Le Quesnoy from Valenciennes and began entering the town from the north and the Germans quickly surrendered . 
