historic railroad tunnel engineered construction 1850s tunnel series tunnels cross blue ridge mountains virginia united_states second tunnel cross mountains east easternmost located approximately miles west village virginia construction numerous cave ins landslides occurred fragile weak rock tunnel passed point outbreak cholera forced work stop october tunnel completed cost having lined thick elliptical brick arch hold earth line successor reorganization line ohio railway tunnel continued demolished replaced cut construction interstate 1960s 1970s point original tunnels use history march passed act incorporate railroad construct rail line blue ridge mountains railroad renamed february point near eastern base mountains gap appointed chief engineer developed plan cross mountains series tunnels tunnel east built difficult insecure ridge near tunnel located miles west built small spur blue ridge mountains construction middle second tunnel called begun earth encountered weaker quality rendering digging tunnel extremely dangerous difficult task eastern section ridge composed firm rock majority tunnel passed mixture slate formed steep angle clay exposed air mixture causing large amounts earth fall tunnel bore occasions tunnel construction great care taken provide temporary support major cave ins occurred forming ridge feet tunnel slide occurred outside western portal blocked entrance tunnel prevented workers repairing damage internal cave ins rocks fell men worked creating sounds described resembling distant thunder weakness earth especially western sections necessitated implementation strong arch approximately feet tunnel brick lining described nature work tunnel letter difficult work kind seen record western entrance pressure big actually causes surge case coal mines view sliding tendency immense pressure ground enter invested arch prevent collapse work vastly difficult means easy safe job time tunnel come known small stop inn nearby headquarters located later years dropped tunnel simply referred late summer epidemic cholera broke irish workers tunnel letter states epidemic began eastern end tunnel total workers perished disease disease spread western end workers died work ceased outbreak little work tunnel adding delay difficult work posed work tunnels continued eager connect eastern division line construction developed plans use temporary tracks bypass incomplete blue ridge railroad gap west temporary track approximately miles long proposed chief engineer constructed digging continued setbacks difficulties encountered tunnel completed october months prior hole foot gap remarkably exception cholera outbreak injured dangerous work completing tunnel soon began routing trains tunnel avoiding short temporary track american civil war large crack found tunnel arch locations inches wide examination earth tunnel found section earth slipped resting tunnel walls tunnel danger collapsing plan address tunnel structural issues developed place second arch original new arch started feet rails rose peak necessary clear riding atop railroad car time feet metres feet original arch ongoing war lack funds resources new completed foot segments deemed necessary arch total feet tunnel feet completed cost confederate dollars war tunnel continued reorganized ohio railway continued route trains tunnel tunnel demolition construction interstate 1960s 1970s time tunnel demolition original tunnels operation use foot today interstate passes cut replaced architecture constructed elliptical form design typical tunnel construction 1800s blue ridge november report describes design tunnels shape adopted formed horizontal circle feet diameter center sides vertical arch necessary lower continue shaped round bricks stones iron appear eligible shape leaves ample room cars contracting roof secure feet diameter portions tunnel lined brick added strength originally contracted local poor quality bricks decided use bricks east stronger bore estimated total number bricks required entire tunnel upwards examining offers multiple contracted provide bricks resulting arch feet thickness entire length tunnel formed opening approximately feet high extreme feet wide construction support fragile sections tunnel arched left place arch completed thought hazardous remove earth slip occurred civil war remaining acted cracking structural instability tunnel new arch constructed old removed space new old walls filled brick cement original brick replaced ohio railway concrete series tunnel upgrades line beginning 1920s new longer bore distinctive elliptical design original vertical sides semi circular arch construction costs total cost complete amounted cost foot length feet comparison cost foot foot foot foot costs greatly increased expected insecure earth encountered contrary originally appeared solid rock workers inside outside laborers paid approximately day miners paid day equivalent respectively today
Brookville Tunnel