▁t unn els ▁were ▁retained , ▁but ▁water ▁only ▁passes ▁into ▁the ▁East ▁Fen ▁at ▁low ▁flows , ▁and ▁a ▁sl u ice ▁protect s ▁the ▁up stream ▁entrance ▁to ▁the ▁t unn els . ▁Up grad ing ▁of ▁La de ▁Bank ▁p ump ing ▁station ▁from ▁steam ▁engines ▁to ▁oil ▁was ▁completed ▁in ▁ 1 9 4 0 , ▁with ▁new ▁equipment ▁consisting ▁of ▁three ▁R ust on ▁dies el ▁engines ▁connected ▁to ▁ ▁G w yn nes ▁p umps , ▁installed ▁in ▁a ▁new ▁building . ▁The ▁old ▁building ▁was ▁retained , ▁although ▁the ▁steam ▁engines ▁which ▁if ▁hous ed ▁were ▁scra pped . ▁So on ▁after ▁the ▁Second ▁World ▁War , ▁plans ▁for ▁a ▁p ump ing ▁station ▁at ▁Hob hole ▁sl u ice , ▁to ▁replace ▁the ▁gravity ▁out fall , ▁were ▁approved , ▁and ▁the ▁station ▁was ▁fully ▁commission ed ▁in ▁ 1 9 5 7 . ▁The ▁dis astr ous ▁North ▁Sea ▁flo od ▁of ▁ 1 9 5 3 , ▁which ▁affected ▁so ▁much ▁of ▁the ▁East ▁Coast ▁of ▁England ▁had ▁little ▁effect ▁in ▁the ▁Four th ▁District . ▁ ▁In ▁ 1 9 5 6 , ▁work ▁started ▁on ▁a ▁new ▁out fall ▁for ▁the ▁Hob hole ▁d rain , ▁to ▁the ▁south - east ▁of ▁the ▁old ▁sl u ices . ▁A ▁p ump ing ▁station ▁containing ▁three ▁Allen ▁dies el ▁engines ▁was ▁built , ▁each ▁driving ▁a ▁ ▁p ump . ▁The ▁station ▁could ▁dis charge ▁ 8 0 0 ▁tons ▁per ▁minute