Research for Better Timber Railroad Bridges

2009 ◽  
pp. 49-49-14
Keyword(s):  
Railroad Bridges

Closure to “Stress Cycles for Fatigue Design of Railroad Bridges”

1977 ◽  
Vol 103 (5) ◽  
pp. 1179-1181
Author(s):  
Roman Wolchuk ◽  
Ronald M. Mayrbaurl
Keyword(s):  
Railroad Bridges ◽  
Fatigue Design ◽  
Stress Cycles

Reference-free dynamic displacements of railroad bridges using low-cost sensors

2017 ◽  
Vol 30 (9) ◽  
pp. 1291-1305 ◽  
Author(s):  
Jose A Gomez ◽  
Ali I Ozdagli ◽  
Fernando Moreu
Keyword(s):  
Low Cost ◽  
Field Measurements ◽  
Dynamic Data ◽  
Train Derailment ◽  
Railroad Bridges ◽  
Cost System ◽  
Railroad Bridge ◽  
Bridge Crossing ◽  
Bridge Responses ◽  
Free Dynamic

Displacements of railroad bridges under service loads are important parameters in assessing bridge conditions and risk of train derailment, according to railroad bridge managers. Measuring bridge responses in the field is often expensive and challenging due to the high costs of sensing equipment. Consequently, railroad bridge managers typically rent or subcontract field measurements to others or choose not to collect dynamic data in the field and make visual inspections. This article studies the use of a low-cost data acquisition platform to measure reference-free dynamic displacements of railroad bridges by combining low-cost microcontrollers and accelerometers. Researchers used off-the-shelf systems to measure accelerations and reconstructed reference-free displacements from several railroad bridge crossing events by running trains with different levels of serviceability in the laboratory. The results obtained from the proposed low-cost sensors were compared with those of commercial sensing equipment. The results show that low-cost sensors and commercial sensing systems have comparable accuracy. The results of this study show that the proposed platform estimates reference-free displacements with a peak error between 20% and 30% and a root mean square error between 10% and 20%, which is similar to commercial structural health monitoring systems. The proposed low-cost system is approximately 300 times less expensive than the commercial sensing equipment. The ultimate goal of this research is to increase the intelligent assessment of bridges by training owners and inspectors to collect dynamic data of their interest with their own resources.

Discussion on American Railroad Bridges

1889 ◽  
Vol 21 (2) ◽  
pp. 566-607
Author(s):  
H. D. Bush ◽  
J. H. Cunningham ◽  
John Sterling Deans ◽  
William E. Hoyt ◽  
O. E. Michaelis ◽  
...  
Keyword(s):  
Railroad Bridges

Securing Niagara (1852–55)

2020 ◽  
pp. 344-395
Author(s):  
Richard Haw
Keyword(s):  
United States ◽  
Suspension Bridge ◽  
The United States ◽  
Railroad Bridges ◽  
Long Span ◽  
Runaway Slaves ◽  
The Impact ◽  
Egyptian Architecture

The Niagara contract was a fitting judgment on John’s career to date, and the bridge itself was a triumph, eliciting praise and admiration from all over the globe, for both its handsome Egyptian architecture and the soundness of its design. It took four years to build and was the world’s first railroad suspension bridge, or at least the first successful one, fully demonstrating the strength and effectiveness of the suspension plan for heavy-going freight. It also compared very favorably with Robert Stephenson’s recently completed Britannia Tubular Bridge, the British engineer’s rival solution to the problem of long-span railroad bridges. A lifelong, committed abolitionist who wrote extensively about the evils of slavery, John also appreciated the impact his bridge had (somewhat incidentally) on the institution of slavery. Harriet Tubman (among others) used John’s bridge numerous times in the late 1850s to lead runaway slaves out of the United States and into British Canada.

Safety and Security Analysis for Movable Railroad Bridges

2019 ◽  
Author(s):  
Yongxin Wang ◽  
Matthew Jablonski ◽  
Chaitanya Yavvari ◽  
Zezhou Wang ◽  
Xiang Liu ◽  
...  
Keyword(s):  
Weight Bearing ◽  
Security Analysis ◽  
Primary Objective ◽  
Hydraulic Systems ◽  
Signaling Systems ◽  
Railroad Bridges ◽  
Gate Arrays ◽  
Custom Made ◽  
Field Programmable ◽  
Programmable Gate Arrays

Movable railroad bridges, consisting of lift, bascule, or swing bridges have been used by American rail tracks that cross usable waterways for over a century. Although custom made, movable bridges share many common components and designs. Most of them use weight bearing towers for the movable span using electric or electro-hydraulic systems lift and/or rotate these movable spans. Automated locks hold the bridge in place as soon as the movement stops. The bridge operation, train and ship signaling systems work in synchrony for trains and waterway traffic to be granted safe passage with minimal delay. This synchrony is maintained by using custom-made control systems using Programmable Logic Controllers (PLCs) or Field Programmable Gate Arrays (FPGAs). Controllers located on the movable and the static parts of the bridge communicate using radio and/or wired underwater links sometimes involving marine cables. The primary objective of this paper is to develop a framework to analyze the safety and security of the bridge operating systems and their synchronous operations with railway and waterway systems. We do so by modeling the movable physical components and their control system with the interconnected network system and determine the faults and attacks that may affect their operations. Given the prevalence of attacks against PLCs, FPGAs and controllers, we show a generic way to determine the effect of what if scenarios that may arise due to attacks combined with failures using a case study of a swing bridge.

Sign in / Sign up

Export Citation Format

Share Document