Monday, March 27, 2006

TTCI Is Changing the Railroad Engineering Paradigm

Gradually, but it is changing! The recently held 11th Annual Research Review demonstrated that once again. So, what's going on?

For years, make that for generations now, Railroad Engineering has consisted of making various track and rolling stock components bigger. Yes, you can point out exceptions that really were innovative, but for the most part, the Railroad Engineer's answer was to "beef it up".

Think about rail sections. In the late 19th Century, ASCE Engineers designed rail sections in five pound increments from fifty-five pounds per yard to ninety pounds per yard. Each rail carried the designation "ASCE", and some of those rails rolled over 125 years ago are still in service! But the interesting thing is that the Civil Engineers designed a theoretical 100ASCE Section; it was called theoretical because no one at the time could comprehend the need of such a large rail section!

100ASCE Rail was, indeed, rolled, and has long ago been updated with heavier and heavier rails, designed and supplied as engineers "beefed up" rail sections. Today we have a recently designed 141AB or 141RE section that is fast becoming a standard. Larger sections prove the paradigm that, "If our rail sections are causing problems, we'll make them bigger". In great measure, the same thing is true with wheels, axles, side frames, bolsters, and even ties. Once, ties were typically eight feet long. One day, they became, 8'-3", then 8'-6", and now it is not uncommon to hear of 9'-0" long ties in standard trackage.

Enter the TTCI: Their charter, as described at the Research Review, is to use "Automation and detection of dynamics that lead to the identification of high loadings and derailments, and then reducing or eliminating them." In other words, rather than simply increase the size of components, we can do things to actually REDUCE the loading! The concept is catching on, for several reasons.

Railroads are finding themselves at capacity on many mainlines. This means that track maintenance time is at a premium. Not only that, but the bean counters now assign a cost to train and maintenance delays. Add the cost of derailments, and these dollars begin to demand attention! So, if better track construction and maintenance procedures can be utilized to reduce impact loads, less maintenance time is required, and the chance of a derailment becomes much lower, too.

What kind of procedures?

Here are just a few: Looking at the wheel-rail interface, that is, what grinding or even profile design can do. More reliable non-destructive testing of wheels and rail. Identifying and reducing the forces of truck hunting. Reducing track stiffness, quantified as the Track Modulus, and making it more uniform at problem areas such as bridge approaches and bridge decks. Strengthening insulated joints. Creating new designs for rail crossings.

Not only does TTCI have quantities to back up their thoughts, but at least two sites, one on the Norfolk Southern and another on the Union Pacific, will be identified as "Mega Sites" to further demonstrate the viability of reducing dynamic loads on the track structure.

Good stuff! Thank you, TTCI, for encouraging us all to look at Railroad Engineering problems in a new way!


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