, ▁during ▁which ▁the ▁ 4 6 th ▁Division ▁over ran ▁the ▁red ou bt ▁but ▁was ▁forced ▁to ▁ret ire ▁after ▁night fall ▁as ▁the ▁sal ient ▁that ▁had ▁been ▁created ▁was ▁un ten able . ▁The ▁British ▁retre ated ▁to ▁The ▁Ch ord , ▁a ▁tren ch ▁behind ▁the ▁east ▁face ▁of ▁the ▁red ou bt ▁and ▁the ▁west ▁face ▁was ▁fort ified ▁as ▁a ▁reserve ▁line . ▁The ▁attack ▁had ▁been ▁a ▁cost ly ▁failure , ▁in ▁which ▁the ▁ 4 6 th ▁Division ▁lost ▁ ▁most ▁in ▁the ▁first ▁ten ▁minutes ▁of ▁the ▁attack . ▁▁ 1 9 1 6 ▁ ▁After ▁the ▁Battle ▁of ▁the ▁H oh enz oll ern ▁Red ou bt ▁in ▁ 1 9 1 5 , ▁the ▁British ▁had ▁retained ▁the ▁west ▁end ▁of ▁the ▁red ou bt , ▁with ▁The ▁Ch ord ▁as ▁the ▁new ▁front ▁line . ▁Art illery ▁bomb ard ments ▁and ▁t unn elling ▁were ▁conducted ▁by ▁the ▁Germ ans ▁during ▁the ▁winter ▁of ▁ 1 9 1 5 – 1 9 1 6 ; ▁due ▁to ▁the ▁nature ▁of ▁the ▁cl ay ▁covering ▁and ▁ch alk ▁below ▁ground , ▁mine ▁explos ions ▁threw ▁up ▁high ▁lips ▁around ▁mine ▁cr aters , ▁which ▁became ▁good ▁observation ▁points . ▁Observ ation ▁increased ▁the ▁accuracy ▁of ▁German ▁bomb ard ments ▁and ▁The ▁Ch ord ▁was ▁re - capt ured , ▁leaving ▁the ▁British ▁on ▁lower ▁ground ▁in ▁the ▁west ▁side ▁of ▁the ▁red ou bt . ▁The ▁British ▁ 1 7 0