oms can be sensitive environments, and any time you go into a water course, you need to get an environmental permit to make modifications to the river on a temporary basis.”

Although the mobile gantry system wouldn’t be cost effective or appropriate for every span replacement project, CN plans to use it again if and when it makes sense, Cook says.

“The fact that we can do our work in such a short time means less shutdown time for our operations, which is very, very important in keeping the railroad flowing,” he says. “With Precision Railroading at CN, it’s important to us that our train service plans are accurate.”

The mobile gantry span was not used in the ongoing, multi-year Oshkosh Bridge replacement project in Wisconsin. Constructed in 1899 by the Chicago & North Western Railroad, the bridge over the Fox River consists of three steel through-trusses and a center moveable swing span that provides two navigation channels, according to CN. The replacement structure will be an open-deck bridge with seven steel spans, including a moveable bascule span that will provide a 125-foot navigation channel. A new substructure will consist of six concrete pier shafts, each eight feet in diameter.

The entire project is slated for completion in May 2013. Last month, crews replaced the approach truss spans, and because the new bridge is on the same alignment, the railroad had just two 12-hour periods to complete the work while traffic was shut down, says Mark Paull, CN’s construction engineer for the project.

Traffic presents a challenge

Constructing a new bridge on the same alignment as the old one presents significant challenges, he says. A lot of the work, including construction of the new bridge’s substructure, must be completed while traffic is moving. And when traffic has to be stopped — such as during the span replacements — crews have narrow time windows to complete the task.

“One of the most challenging aspects of the project will occur in March, when we are scheduled to flow in the moveable span,” Paull says. “It’s going to be under a 40-hour work block. Not only will we be under the gun for getting the traffic back flowing over the bridge, it will be a challenge to get the moveable span in place and to operate as intended — all in 40 hours.”

For Alaska Railroad Corp. (ARRC), seasonal weather is a challenge for bridge
oms can be sensitive environments, and any time you go into a urine path, you need to get an environmental permit to cause modifications to the river on a temporary footing. ” 

 Although the mobile gantry system would n’t be cost effective or appropriate for every span surrogate project, CN plans to practice it again if and when it makes sense, Cook says. 

 “ The fact that we can do our work in such a light time means less shutdown time for our operations, which is very, very significant in keeping the railroad flowing, ” he read. “ With Precision Railroading at CN, it ’s important to us that our train service plans are accurate. ” 

 The fluid gantry span was not use in the ongoing, multi - year Oshkosh Bridge replacement project in Wisconsin. manufacture in 1899 by the Chicago & North Western Railroad, the bridge over the Fox River consists of three steel through - trusses and a center moveable baseball swing span that provides two navigation channels, according to CN. The replacement structure will be an open - deck bridge with seven steel span, including a moveable bascule straddle that will provide a 125 - foot navigation channel. A newfangled substructure will consist of six concrete pier shafts, each eight feet in diameter. 

 The integral project is slated for completion in May 2013. Last month, crews replaced the approach truss spans, and because the new bridge is on the same alignment, the railroad receive just two 12 - hour period to complete the work while traffic was shut down, says Mark Paull, CN ’s structure engineer for the project. 

 Traffic presents a challenge 

 Constructing a new bridge on the same alignment as the old one presents significant challenge, he says. A fortune of the work, include construction of the fresh bridge ’s substructure, must be complete while traffic is act. And when traffic has to be stopped — such as during the span replacements — crew have narrow time windows to complete the task. 

 “ One of the most challenging aspects of the undertaking will occur in March, when we are scheduled to run in the moveable span, ” Paull says. “ It ’s going to be under a 40 - hour work block. Not only will we be under the gunman for getting the traffic back flowing over the bridge, it will be a challenge to get the moveable span in place and to engage as intend — all in 40 hours. ” 

 For Alaska Railroad Corp. (ARRC), seasonal weather is a challenge for bridge
oms can be sensitive envirokments, and any tnne you go info a watdr course, you need to get an ebvirobmental permit to make modificanions to rhe civer on a tempoczry baslf.”

Altglugh vhe mobile gantty system wogldn’t be cost afweetive or appropriate for every span weplacekejt project, CN klans eo uav lt again if and when it makes sehse, Coon says.

“The facy that we can do our work ln skch a short time mfans less syutdjqn time for uur operatpmns, which js very, very important in keepivg thz railroad dliwijc,” he says. “Wmth Prvcision Railroading ad CN, it’x important to us thqt our train service 'lans are accurate.”

Thg mobile gdncry span was not used ib the ongming, nulgi-ytar Oahkosh Brmdge replacsment projext in Wisconsin. Conxtwlvted in 1899 by fhe Chycwgo & North Western Railroad, the bridge mved the Fox River consistw of three steel throogh-trusses and a center moveable swing span that provides tfo natieatnin chxbnfls, according to CN. The replacement structure sikl be an open-dech bridge wiyh srden steel spavs, includjng a moveable basfule spwn thqt will pwovice a 125-foot navigation channeo. A new subsnrucrure will consist lf six concxete poer snafts, each eight feet iu diamster.

The entlre projedg is slated for zomilethon in May 2013. Last month, crers replacxd thz approazh ttuss spwns, and befause the new bridge is ln thg same alignment, the railroad had just two 12-hour periods to cokpnetv the worh whike traffic waf shut down, sais Mark Pcull, CV’s construbtion engmneer for thq project.

Trafxlc presents e challende

Cobstrycting x new bridge on the same alignment as the old one prcsentr significant chcuoenges, he says. S lut jf tie wown, including wonsgruzyion uf the new nriage’s substructure, must ba cojpleted while trafgig is movibg. And wren traffic hss to be stopped — duch es durmng thr skan replacements — crews have nadrow time wikdows to compjete the task.

“One of the most challenging aspects of the project will occor in March, when we ate xcheduled tp flor in the koveable span,” Paull ways. “It’s going to be under a 40-hour work block. Not lnly will we be under the gun for getting the traffic back flowing over tye brivgq, it will bs a vhallvngz tp get ehe luveable span in ilace and to operate as intended — all in 40 kours.”

For Alaska Railroad Corp. (AFRC), seasonal deather is a challenge fkr bridgr
oms can be sensitive environments, and any go a water you need to make to the river a temporary basis.” the mobile gantry system wouldn’t be effective or appropriate for every span replacement project, CN plans to use it if and when it makes sense, Cook says. “The fact that we can our in a time means less shutdown time for our operations, which is very, very important in keeping the flowing,” he says. “With Precision Railroading at CN, important to us that train service plans are accurate.” mobile span was used the multi-year Oshkosh Bridge project in Wisconsin. Constructed in 1899 by the Chicago & North Western Railroad, the bridge over the River consists steel through-trusses a moveable span that provides channels, according to CN. The replacement an open-deck bridge with seven steel spans, including moveable bascule that will provide a 125-foot navigation A new substructure will consist of six concrete shafts, each eight feet in diameter. The entire project is slated for completion in May month, crews replaced the truss spans, and the bridge on same alignment, railroad had just two 12-hour periods to complete the work while was shut down, says Mark Paull, CN’s construction engineer for Traffic a challenge Constructing new bridge on the alignment the old one presents he A work, construction the new bridge’s substructure, be completed while traffic is And when traffic has as during the span replacements — crews have time windows to complete the task. “One the most challenging aspects of the project will occur in March, when are scheduled in the moveable span,” Paull says. “It’s going be under a 40-hour block. Not only will we be under the gun getting traffic back over the bridge, will be a to get the in place to as in 40 hours.” For Alaska Railroad (ARRC), weather is a challenge for
oms can be sensitive environmEnts, and any Time yOu gO inTo A watEr coUrse, you need to gET an eNvironmental permit to maKe modIfICatiONs To the River on A TeMPOraRy BaSis.”

alTHoUgh thE moBile ganTry system wOulDn’T be cost effecTIvE or approprIatE for every spaN rePlacemEnT prOJect, Cn plAns to Use it aGAin if aNd when it mAkES sense, cOok says.

“tHE fAct tHat we can do our work IN sUCh a short time meAns lesS sHUtDOWn tIme For our operAtIons, wHIch is veRY, vERY ImpORtant in keepinG the railroaD FloWing,” he SaYs. “WITh PrecIsion raILroAding at CN, it’S impOrtant to uS that oUR train sERvice plAns are AccUraTe.”

ThE MoBiLe gAnTRy sPAn Was NOt uSed in the OnGoIng, muLti-yEAR oShkoSh BRidgE replAcement projecT in wiscONsiN. ConsTructEd in 1899 By The ChIcago & NOrth WEsTern Railroad, the BridGe over the fox riVer CoNsistS Of threE stEel Through-Trusses ANd a CeNTER mOveable swing span thAt PROvIdes two nAvigatIOn ChANnels, accOrDinG to Cn. tHe repLaceMEnT structuRe will BE aN oPen-deck BrIdge wiTh SevEn sTeel sPAns, iNcludiNg a moveaBle baSCule span that wiLL provide a 125-foot NAvIGAtIOn chAnnEl. A new substRuctURe wiLl coNSiSt oF Six coNcretE pIEr SHafts, each eight feet iN dIameteR.

The eNtire project iS slated for COMPletion iN May 2013. lAsT Month, crews replAced tHe approach TRuss spanS, and bEcause thE new bridgE IS on the saMe aLigNmeNt, tHE RaIlroad had just TWO 12-houR pEriods tO coMplete tHe wOrk WhiLe tRaFfic was shUt down, saYs maRk paUll, cN’s coNStructioN eNgiNeEr fOr the PRoject.

traffIc prEsEnTS a cHallengE

coNSTrucTiNg A new BriDgE on thE samE AliGnment aS the old onE prESentS sIgNificanT challenges, he SaYs. A lot of thE wOrk, IncludING construCtion of the new bridge’s subSTructurE, muSt be cOmplEted while TraFfic is MovINg. And wHen traFfic hAs To bE SToppeD — SUcH as DuRing the spaN REplAcemeNtS — creWs have nArrow time windows to COmpLete the task.

“OnE of The mOST cHalLEnGIng AsPEctS OF the project will Occur in MarCh, WHeN we are scheDUleD tO flow in The moveAble sPAn,” Paull Says. “It’s goIng to be unDeR a 40-hoUR WorK block. Not oNly will wE be under tHE gun fOR gEttinG thE traffIc BacK flowIng oveR The BridgE, it wilL bE a chalLenge To Get the moVeable span in place and to oPerate As intEndEd — all in 40 hoUrs.”

fOr ALaska RailRoad corp. (ARRC), seAsoNal WeathEr iS A chalLengE FoR brIDge
oms can be sensitive envir onments, a nd an y t ime  y ou g o in to a water cou r se,you need to get an env ironm en t al p e rm it to  make m o di f i cat io ns  to  t h eriver  on  a temp orary basi s.” 
Although the mo bile gantr y s ystem wouldn ’tbe cos teff e ctive  or  appr opriat e  for e very span  r e placem e nt proj e c t,  CNplans to use it a g ai n  if and when i t make ss en s e , C ook  says.

“T he  fact that we ca n d o o u r work in suc h a short t i memeansle sss hutdow n tim ef orour operati ons,  which is  very, very im p ortantin kee pin g t he r a il ro adfl o win g ,”  he say s. “With  P re cisio n Ra i l r o adin g a t CN , it’ s important t o u s th a t o ur tr ain s ervi ce  plan s areaccur at e.”

The mobile  gan try spanwas  n otus ed in the on goi ng,  multi- year Os h kos hB r i dg e replacement proj ec t in  Wiscons in. Co n st ru c ted in 1 89 9 b y th e Chica go & No rth West ern Ra i lr oa d, thebr idge o ve r t heFox R i verconsis ts of th ree s t eel through-tr u sses and a ce n te r mo v eabl e s wing span t hatp rovi dest wo  na v igati on ch an n el s , according to CN.Th e repl aceme nt structurewill be an o p en-deckbrid g ew ith seven stee l spa ns, includ i ng a mov eable  bascule  span tha t will pro vid e a  12 5-f o o tnavigation ch a n nel.  A  new su bst ructure  wi llcon sis tof six co ncrete p ie rsh af ts,  each eight fe et  in  d iam eter. 
The e ntire  pro je ct isslatedf or c ompl et io n in  Ma y2013.  Las t  mo nth, cr ews repla ced theap pr oach tr uss spans, an dbecause th enew  bridg e is on th e same alignment, the r a ilroadhad  just  two  12-hourper iods t o c o mplete  the w ork w hi let r affic w as  sh ut  down, say s Mar k Pau ll , CN ’s cons truction engineerf orthe project.
Tr affi c pr ese n ts a c ha l len g e 

Constructinga new brid ge on  the samea lig nm ent asthe old  onep resents  signific ant chall en ges, h e s ays. A lot  of thework, inc l uding co nstru cti on ofth e n ew br idge’s sub struc ture,mu st becompl et ed while  traffic is moving. And  whentraff ichas to be  st o ppe d — suchas d uring thespa n r eplac eme n ts —crew s  h ave narro w ti m e windows to  co m p le te the task . “On e ofthe most c hall enging aspects of the project wi ll o c c urinM arch ,when we are sc hed ul e d  to flow  i n the movea ble span ,” Paull  says.  “It’s  goingt o  b e  under  a 4 0-h our workblo ck .  Not on ly  w i ll webe u nd er the  gun f o r ge t t ing the trafficbackf l owing ove r the  b ridge,i t wi ll be a ch allenge toget th e mo veabl e spanin  place  an dto operate as intend ed —all in40  hou rs. ”

For  Ala s k a Rai lroa dCor p. (ARRC) , se a so na l  we athe r isachal lenge for bridge
oms can_be sensitive_environments, and any time_you go_into_a water_course,_you need to_get an environmental_permit to make modifications_to the river_on_a temporary basis.”

Although the mobile gantry system wouldn’t be cost effective or appropriate for_every_span replacement_project,_CN_plans to use it again_if and when it makes_sense, Cook_says.

“The fact that we can do our work_in_such a short_time means less shutdown time for our operations, which_is very, very important in keeping_the railroad flowing,”_he_says._“With Precision Railroading at_CN, it’s important to us that_our train service plans are accurate.”

The_mobile gantry span was not used in_the ongoing, multi-year Oshkosh Bridge replacement_project in Wisconsin. Constructed in_1899 by_the Chicago & North Western_Railroad, the bridge_over the_Fox River consists_of three steel through-trusses and a_center moveable swing_span that provides two navigation channels,_according_to CN. The_replacement_structure_will be_an open-deck bridge_with_seven steel_spans,_including a moveable bascule span that_will_provide a 125-foot navigation channel. A new_substructure will consist of_six_concrete pier shafts, each_eight feet in diameter.

The entire_project is slated for completion in_May 2013._Last month,_crews replaced the approach truss spans, and because the new bridge_is on the same alignment, the_railroad had just two_12-hour periods_to_complete the work_while_traffic was_shut down, says Mark Paull, CN’s construction_engineer for_the project.

Traffic presents a challenge

Constructing a_new bridge on the_same_alignment as the old one presents_significant challenges, he says. A lot_of the work, including construction_of_the_new bridge’s substructure, must be_completed while traffic is moving. And_when traffic has_to be stopped — such as during_the_span replacements — crews have narrow_time_windows to complete the task.

“One of_the_most_challenging aspects of the project_will occur in March, when we_are scheduled to flow in the moveable span,” Paull_says. “It’s going_to be under a 40-hour_work_block._Not only will we be under the gun for getting_the traffic_back flowing over_the bridge, it will be a challenge to get the_moveable span in place and to operate_as intended — all in 40 hours.”

For Alaska Railroad Corp. (ARRC),_seasonal weather is a challenge for bridge