Closing the Gap

A track inspector effects an on-the-spot repair of a pull-apart at Blue Island Junction, certainly among the busiest and most critical rail traffic nodes in Chicago. During cold weather, it’s not uncommon for steel rail, which contracts when chilled, to pull apart from an adjoining rail at a joint. As long as the gap between the rails is just a few inches, trains may still pass over at slow speed; however, it won’t take too long for the breach to grow, posing risk of a major derailment. Fortunately, eagle-eyed inspectors examine every inch of mainline track at least twice each week (and aways immediately following a sudden cold snap), looking for broken or defective rail and paying careful attention to rail joints and switches, the most vulnerable components of track.

To fix this particular pull-apart, the inspector merely has to heat the rail up (so it expands enough to close the gap) and secure it with fresh joint bars and bolts. To do this, he starts a controlled fire along the inside of about a hundred feet of rail—fifty feet on either side of the break. In his track inspection vehicle, he keeps a bucket (the blue bucket in the foreground of the photo) filled with a mixture of finely-shredded cellulose insulation soaked in diesel fuel. The inspector (wearing protective gloves) slaps a generous handful of this flammable concoction, which has the consistency of thick oatmeal, onto the rail above every wooden cross tie—about every eighteen inches. Before setting the whole deal ablaze, he makes a quick phone call to the local fire department to let them know not to be alarmed by the sudden clouds of black smoke coming from the railroad tracks. Then, he lights a fusee (a roadside flare) and walks along the track, touching the bright red jet of flame to each little pile of incendiary goo. Soon, it looks like a hundred campfires strung out along the section of railroad. Acrid black smoke billows into the grey winter sky. Now he waits.

Training and experience have taught the inspector that as soon as the little fires begin to die out, their fuel consumed, the steel will have warmed and expanded enough to bring the estranged sections of rail back together. Sledge hammer in hand, he walks the line amidst smoldering fires, gently tapping the rail, coaxing it to inch back into place. Once the rail ends are reunited, he quickly applies two new steel joint bars, one to the inside and one to the outside of the rail. The joint bars, about eighteen inches long, fit snuggly against the rail and span the joint. On each side of the joint, there are bolt holes through the rail, which align with holes in the joint bars. A few new bolts, a few tightening tugs with a very large wrench, and the track is as good as new, ready to handle a quarter of a million tons of freight every day. The whole repair, from discovery to remedy, only takes about 20 minutes. Time is money for the railroad.