▁new ▁dep ot ▁at ▁Ald en ham ▁had ▁already ▁been ▁built ▁and ▁was ▁used ▁to ▁build ▁Hal if ax ▁bom bers . ▁Work ▁on ▁the ▁other ▁elements ▁of ▁the ▁plan ▁was ▁susp ended ▁late ▁in ▁ 1 9 3 9 . ▁ ▁Work ▁on ▁the ▁extension ▁from ▁Ed g ware ▁to ▁Bus he y ▁He ath ▁including ▁work ▁on ▁a ▁vi ad uct ▁and ▁a ▁tunnel ▁started ▁in ▁June ▁ 1 9 3 9 , ▁but ▁was ▁stopped ▁after ▁war ▁broke ▁out . ▁After ▁the ▁war , ▁the ▁area ▁beyond ▁Ed g ware ▁was ▁made ▁part ▁of ▁the ▁Metropolitan ▁Green ▁B elt , ▁largely ▁prevent ing ▁the ▁anticip ated ▁resident ial ▁development ▁in ▁the ▁area , ▁and ▁the ▁potential ▁demand ▁for ▁services ▁from ▁Bus he y ▁He ath ▁thus ▁van ished . ▁Pass enger ▁numbers ▁also ▁dropped ▁on ▁the ▁then - BR ' s ▁Mill ▁Hill ▁and ▁Alex andra ▁Palace ▁branches , ▁so ▁it ▁was ▁useless ▁to ▁elect r ify ▁them . ▁Av ailable ▁funds ▁were ▁directed ▁towards ▁comple ting ▁the ▁eastern ▁extension ▁of ▁the ▁Central ▁line ▁instead , ▁and ▁the ▁Northern ▁He ights ▁plan ▁was ▁dropped ▁on ▁ 9 ▁February ▁ 1 9 5 4 . ▁Ald en ham ▁dep ot ▁was ▁converted ▁into ▁an ▁over ha ul ▁facility ▁for ▁bus es . ▁ ▁The ▁implemented ▁service ▁from ▁High ▁Bar net ▁branch ▁gave ▁good ▁access ▁both ▁to ▁the ▁West ▁End ▁and ▁the ▁City . ▁This ▁appears ▁to ▁have ▁und erm ined ▁traffic ▁on ▁the ▁Alex andra ▁Palace ▁branch , ▁still ▁run ▁with