Show I IDAM LOWER LOER COffER DAM I pro pro-I Wor c On Hoover Project Proceeds Proceeds Pro Pro- According To Engineering Engineer Engineer- ing lag Report I BOULDER CITY Nev Work Work 1 on the lower coffer dam downstream down down- downstream down I stream from Hoover dam site was I under way Wednesday The upstream upstream upstream up up- stream coffer dam that is now now diverting the flow of the river river through the two big diversion tunnels tunnels tunnels tun tun- nels on the Arizona side of the Colorado will be completed within within with with- in three weeks engineers an an- The upper dam is being put in place immediately below a rock barrier About 35 feet of fill out of 95 feet remain to be built The concrete is now being poured The he square yards of surfacing will be poured in two days The upstream coffer dam will protect the excavation work forthe for forthe forthe the Hoover dam now being carried earned car car- ned ried on in the stream bed from flood waters I IThe The lower coffer dam prevents the water from backing up into the excavation site after it is conducted conducted conducted con con- ducted around the site through the tunnels each cach 50 feet In diameter diameter diameter eter through the Arizona Anzona cliffs at Black canyon |