Show DANGER OF FROST HELD MENACE TO PROPOSED MOUNTAIN DELL WORK 1 Contractors Favored Resurfacing a ing Early Du During ing Summer Summet Question as to whether or not the concrete work In connection with the waterproofing of the old section sec see tion of the Mountain Dell dam can safely be done this late in the season season season sea sea- son because of weather and temperature temperature tem tern conditions has been raised and it is le learned that some members members members mem mem- bers of the city commission are not notI I fully convinced that the work should be started now I It is pointed out that the high al altitude a- a at the dam causes much cold colder cold rl er weather there now than in in the city and the frost action Is la said to tobe tobe tobe be severe severt I In this connection It Is pointed out that the work now being advocated advocated advocated was recommended to the city commission by the city engineers engineer's office by Fred A. A consulting engineer and by a special commit tee of be mountain intern branch of the Associated Contractors of America some months ago At the time a a question aro arose e as to whether the process of ot water-proofing water the upstream surface or the bitu bitu- minous-concrete minous film fUm process should be used Discussion of at the relative merits of ot the two processes occupied occur i pled pied the attention of the city t commission commission com com- mission the engineering department the water department and others f for r several weeks and no action was taken FILM RECOMMENDED Early arly in the summer a special committee e of the contractors' contractors association asso asso- elation composed of H. H W. W Baum Eric and V. V P. P Strange inspected in in- in the dam and In a a. report to the association recommended that thata a bituminous film be spread over the tie lower section of the dam and that this he covered with a concrete facing twelve inches thick at the Bottom lot tom and tapering to tu a ou tout Inches at the top On April 23 the committee report was forwarded to the city s son sion on for consideration The report in part reads The city Is proceeding to refill these holes hoes and depressions with but In view of the differing coefficients dents of ot ex expansion between the Portland cement mortar used In and ordinary concrete we we doubt If the patches will long survive sur sur- vivo vive the action of the elements It further tates s-tates that In the opinion of the committee these conditions con con- at the dam darn merit the Serious seri ous consideration on the part of the She he city of or some som plan for tor reinforcing the old dam such as imposing another another another an an- other layer of concrete of not less than twelve Inch thickness on tha tho upstream face of the present dam NOT ACKNOWLEDGED Members of the contractors contractors' as assocIation association as- as advise ie that the city commission commission com com- mission never acknowledged receipt of the report This is the same plan of waterproofing waterproofing waterproofing water water- proofing submitted to the commission commission commis commis- sion in executive session executive session Thursday by the mayor following a renewed recommendation from Mr Ir Noe and following a trip to California by the mayor and the dent of waterworks in which this plan of water-proofing water dams was inspected fw Reports on the cost of ot operations on the Mountain Dell dam show that has now been appropriated appropriated appropriated for the addition and work In connection with it The sum ot of has been spent in gun- gun and nd chipping and repairing the old section of the dam which It Is now proposed to todo do over with a Q water-proof water coating of bitumen and concrete at an estimated cost of about The spent on and repairs is now to be covered up with the new work |