▁London ) ▁Brigade ) ▁and ▁ 2 / 1 st ▁Lond ons ▁( 5 8 th ▁( 2 / 1 st ▁London ) ▁Division ), ▁en abling ▁the ▁batt alion ▁to ▁re organ ise ▁with ▁three ▁pl ato ons ▁per ▁company . ▁ ▁O ppy ▁Wood ▁ ▁The ▁German ▁Spring ▁Off ensive ▁opened ▁on ▁ 2 1 ▁March ▁ 1 9 1 8 ▁some ▁miles ▁south ▁of ▁ 5 6 th ▁Division ' s ▁positions ▁outside ▁Ar ras . ▁The ▁ 1 / 4 th ▁B n ▁prepared ▁a ▁def ensive ▁fl ank ▁facing ▁south ▁in ▁case ▁the ▁line ▁was ▁turned , ▁but ▁no ▁attack ▁developed ▁until ▁ 0 3 . 0 0 ▁on ▁ 2 8 ▁March ▁( Operation ▁Mars ) ▁when ▁the ▁batt alion ' s ▁out posts ▁in ▁O ppy ▁Wood ▁came ▁under ▁heavy ▁bomb ard ment . ▁The ▁two ▁forward ▁companies ▁were ▁over run ▁by ▁ 0 9 . 0 0 , ▁despite ▁causing ▁heavy ▁cas ual ties ▁with ▁their ▁Lewis ▁guns . ▁The ▁other ▁two ▁companies ▁in ▁the ▁support ▁tren ch ▁( the ▁Mar quis ▁line ) ▁then ▁held ▁the ▁attack ers ▁while ▁the ▁def ensive ▁fl ank ▁( O use ▁Al ley ) ▁was ▁man ned ▁by ▁details ▁from ▁Advanced ▁Battalion ▁H Q , ▁and ▁art illery ▁fire ▁was ▁brought ▁down ▁on ▁the ▁captured ▁out posts . ▁By ▁ 1 1 . 3 0 ▁the ▁pressure ▁on ▁both ▁fl anks ▁was ▁too ▁great , ▁and ▁the ▁def enders ▁with d rew ▁to ▁the ▁Red ▁Line ▁( h