Part one: Risks to through-truss bridges - the old saying is; "Do not trust the truss". If these pictures have been previously seen, they are collected here for the convenience of this conversation and for understanding the topic. Old Frisco bridge over the Gasconade River currently has one through truss section remaining. The biggest risk to this bridge is if a serious derailment of a moving train having heavy cars demolishes some or one of the through truss panels. This type of truss is OK for distributed loads but is quite weak from localized high point-live-loads. Also the structural panels have to be vertical or the truss has no real strength. There have been times when only one panel was destroyed that triggered the entire through truss to collapse. That is not a likely problem with plate girder bridges, the train just falls off. Leon Copeland picture posted on Facebook. Pictured here is the old Frisco bridge over the Gasconade River on the current Cuba Subdivision. Nice to see a Safety walkway. Leon Copeland posted on 2/21/2918 to Facebook to Ship It On The Frisco. Robert Jason Dennen 2/21/2019-posted FB These first bridge sections seen are plate girder designs. The farther out section is the only remaining through truss section. The bridge has had many flooding conditions. It appears that the pier footings down into to solid rock have proven themselves. If these pictures have been previously seen, they are collected here for the convenience of this conversation and understanding the topic. Additional photos: - Two sections of the truss bridge had severe damage from a derailment at Jerome - Photocard picture with normal level Gasconade River at Jerome - Frisco truss bridge that collapsed from a derailment at Birds Nest over Meramec River - 1966 Frisco plate girder bridge installed at Birds Nest crossing over Meramec River to replace the prior through truss. - Two sections of the truss bridge that had damages from the derailment at Jerome Under each photo will be a comment about the topic. FriscoGasonadeRiverBridge-derailment.jpg The section through truss on the right side has lost its center panel's vertical column. That through truss section also experienced the most damage. See Part two.
Part two. Short recap from Part one Topic; Risk to through truss bridges - "Do not trust the truss". Old Frisco bridge over the Gasconade River currently has one remaining through truss. If these pictures have been previously seen, they are collected here for the convenience of this conversation and for understanding the topic. Additional photos: - Two sections of the truss bridge had severe damages from a derailment @ Jerome - Photocard picture with normal level Gasconade River @ Jerome - Frisco truss bridge that collapsed from a derailment @ Bird's Nest Crossing over Meramec River - 1966 Frisco plate girder bridge installed at Bird's Nest Crossing to replace the prior through truss. - One sections of the truss bridge had a demolished center column. It also had the most damage. Under each picture will be a comment about the topic. FriscoGasonadeRiverBridge-derailment.jpg or Frisco Gasoade River Bridge-derailment.jpg Both these truss sections were damaged during a serious derailment. They were replaced by plate girder sections. End of Recap of Part one. ~~~~~~~~~~~~~ Beginning of Part two ~~~~~~~~~~~~~ FriscoGasconade_river_JeromeMO_postcard.jpg The normal Gasconade River. How may times when being on a canoe float that one looks up. In those shoreline old sycamore trees, what is seen is large debris up 25' . FRISCO-Birds Nest wreck.jpg Collapsed bridge from a derailment is seen at the Birds Nest Crossing over the Meramec River. The collapse was triggered when the first panel was demolished. Then other panels started bending, breaking and shearing off the joints. Truss pier plates stayed, but truss supports just fell with the bridge. 105153-M.jpg 1966 plate girder bridge was installed at the Birds Nest Crossing over the Meramec River. This plate girder bridge replaced the prior multi sectional through truss. If a serious derailment happens, the likely worst thing that happens is that the train falls off of the bridge unless the locomotive and engineer would not survive. A fire on top of the ties could destroy the wood but the plates of the girder are solid, thick, well vertically reinforced and cross braced; not likely to be deformed from an overhead fire. frisco-gasconade-river-bridge@I44.jpg The only remaining truss section. The panels are still vertical as required. Enough top connecting beams are in good condition to keep the panels vertical. Those connecting beams are likely not loaded. With no other crossing bridges near by, the safety walkway is needed rather than have people being hurt if forced to walk between the rails. FriscoGasonadeRiverBridge-derailment.jpg or Frisco GasonadeRiverBridge-derailment.jpg Both these truss sections had serious damages. The one on the right side had the center panel which lost its centered vertical column. Lucky that the entire panel was not demolished. The centered vertical columns were large enough to allow the bridge to be statically somewhat stronger. Its cross section and both its joints did not withstand the horizontal impact. Bigger and stronger joint plates are likely needed in order to attempt better resist horizontal impacts. Another way to improve the situation is that trains passing through have slower speeds. Too often truss structures are just designed for only static loads and not for horizontal impacts or fires. "Do not trust the truss".
Part 3; If you do not mind Meteor910, Ken, April 24, 2010 you shared some very good pictures of the accident at the Warren through truss bridge over the Gasconade River and you offered for "Comments and observations from any of you are most welcome". "Ken". Part 3, To complete this topic about "Potential for Through-Truss Bridges to Collapse", due to derailment impacts, I would like to copy those photos here since they give a better view of the severe damages and how close the center river through truss came to collapsing. With the panel's centered column gone, the diagonal column was nearly completely severed. That truss panel sections and that entire truss show permanent deformities ( pictures 2, 3 & 6 ). Due to all such, the structural members are unpredictable, particularly when a heavy train would attempt to cross over. Accident, Jan 1961, Gasconade River Bridge MP 123.3 on Frisco's Eastern Division. ( Discussion in 'General' started by meteor910, Apr 24, 2010 ). Diagonal column ruptured 60% with strong bending about to buckle and tear off. Bottom horizontal truss is twisting, about to make things more complicated and unpredictable. OTHER PICTURES: Pictures were taken by the late John Sillick, and are now part of the collection of Jeff Cooney, Shortly thereafter in 1961, the middle and Jerome side (west) truss bridge structures were replaced by two deck girder spans. The truss bridge on the Arlington side remained, and is still in use today. Ken - small crane SLSF 99053 and steam generator car SLSF 52. The extensive damage to the west and center truss bridge structures is evident. ..... The main channel of the Gasconade is to the left, ... Ken A close up of SLSF 99053 and SLSF 52. You can also see the pile driver at work. The crew is driving in piles to help shore up the bridge structure. Ken
